Apparatus for luminal stenting

DESCRIPTION

Luminal stent implantation device

Background

The walls of the vasculature, particularly the arterial walls, can develop areas of pathological dilation called aneurysms. As is well known, aneurysms have thin, weak walls that are prone to rupture. Aneurysms can be the result of the vessel wall being weakened by disease, injury, or a birth defect. Aneurysms can be found in different parts of the body, and the most common are abdominal aortic aneurysms and brain or cerebral aneurysms in the neurovasculature. When the weakened wall of an aneurysm ruptures, it can result in death, especially if it is a cerebral aneurysm that ruptures.

Aneurysms are usually treated by excluding the weakened part of the vessel from the arterial circulation. To treat a brain aneurysm, such reinforcement is done in many ways including: (i) surgical clip implantation, where a metal clip is secured around the base of the aneurysm; (ii) packaging the aneurysm with small, flexible wire coils (microcoils); (iii) use of embolic materials to "fill in" an aneurysm; (iv) use of balloons or removable coils to occlude the main vessel supplying the aneurysm; and (v) implantation of an intravascular stent.

Intravascular stents are well known in the medical arts for the treatment of vascular stenoses or aneurysms. Stents are prostheses that expand radially or otherwise within a vessel or lumen to provide support against folding of the vessel. Methods for dispensing these intravascular stents are also well known.

In conventional methods of introducing a compressed stent into a vessel and placing it within an area of ​​stenosis or an aneurysm, a guiding catheter having a distal tip is percutaneously inserted into the vascular system of a patient. The guiding catheter is advanced into the vessel until its distal tip is close to the stenosis or aneurysm. A guide wire positioned within an inner lumen of a second inner catheter and the inner catheter are advanced through the distal end of the guide catheter. The guide wire is then advanced out of the distal end of the guide catheter into the vessel until the distal portion of the guide wire carrying the compressed stent is positioned at the site of injury within the vessel. Once the compressed stent is positioned in the lesion, the stent can be released and expanded to support the vessel.

US 2011/034987 describes a roller sleeve mechanism for a proximal delivery stent.

Compendium

The present invention is defined in the appended claims.

The following is a non-limiting summary of some of the embodiments and examples described herein.

An example described herein is a method of operating a stent delivery system within a patient's vessel. The method comprises placing a catheter in the vessel, the catheter having a lumen defining an axis extending between a proximal end and a distal end, such that the distal end of the catheter is at a treatment site; placing a core assembly within the catheter lumen, the core assembly having (i) an elongated member comprising a distal end, (ii) an intermediate portion comprising a distal end positioned at the distal end of the member, (iii) a stent having a distal portion and being transported through the middle portion, and (iv) a distal cover attached to the distal end of the limb, the core assembly that is positioned within the lumen such that the distal end of the intermediate portion is positioned axially adjacent to the distal end of the catheter with at least a portion of the distal cover extending into a space within the lumen radially between the end distal of the intermediate portion and the distal end of the catheter; advancing the central assembly distally with respect to the catheter to allow expansion of the distal portion of the stent, the expansion that drives the distal covering away from the intermediate portion; and proximally withdrawing the core assembly on the catheter so that the intermediate portion is positioned axially adjacent the distal end of the catheter with the distal cover positioned out of the space.

Additional optional features of this method will now be described, as follows.

During proximal removal of the core assembly into the catheter, the distal cover can be positioned outside the space to provide a free margin between the middle portion and the catheter.

The method may further comprise releasing the stent at the treatment site within the vessel. The method may further comprise still proximally removing the central assembly from the lumen while keeping the distal end of the catheter in place at the treatment site. The method may further comprise still inserting a

ES 2 744 583 T3 second core set in the lumen, the second core set that is configured to deliver a second stent at the treatment site.

Proximal removal of the central assembly may comprise flipping a first free end of the distal cover from a proximally oriented position to a distally oriented position. The distal cover can be attached to the central assembly at a second end of the distal cover, the first end being positioned distally relative to the second end when the distal cover is flipped over.

Another example described herein is a method of operating a stent delivery system within a blood vessel of a patient. The method comprises placing a catheter in the vessel, the catheter having a lumen extending between a proximal end and a distal end, such that the distal end of the catheter is at a treatment site; advancing a core assembly distally within the catheter, the core assembly having (i) a distal portion, (ii) a distal cover that extends from the distal portion, and (iii) a stent that has a distal portion and is transported by the core assembly, the core assembly that is advanced within the catheter such that the distal cover extends proximally from the distal portion and an annular space between the distal portion and the catheter; advancing the central assembly distally relative to the catheter to allow expansion of the distal portion of the stent, the expansion that drives the distal cover radially away from the central assembly; and proximally withdrawing the core assembly on the catheter so that the distal cover extends distally through the annular space.

Additional optional features of this method will now be described, as follows.

During proximal withdrawal of the core assembly into the catheter, the distal cover may extend distally through the annular space to provide a space between the catheter and an intermediate portion of the core assembly proximal to the distal cover.

Proximal removal of the central assembly may comprise flipping a first free end of the distal cover from a proximally oriented position to a distally oriented position. The distal cover can be attached to the central assembly at a second end of the distal cover, the first end being positioned distally relative to the second end when the distal cover is flipped over.

Another example described herein is a method of operating a stent delivery system within a blood vessel of a patient. The method comprises placing a catheter in the vessel, the catheter having an inner wall and a lumen extending between a proximal end and a distal end, such that the distal end of the catheter is at a treatment site; positioning a core assembly within the lumen, the core assembly comprising a distal cover extending in a proximal direction to at least partially cover a distal part of a stent supported in the core assembly, at least a part of the distal cover being interposed between the distal part of the stent and the internal wall; distally advancing the distal portion of the stent past the distal end of the catheter to allow expansion of the distal portion of the stent; and proximally withdrawing the core assembly into the lumen, the distal cover retracting into the lumen in an overturned configuration and oriented distally from the core assembly.

Additional optional features of this method will now be described, as follows.

The distal cover may comprise an elongated flexible material having a first end and a second end, the material that is coupled to the central assembly at the second end, and proximally removing the central assembly may comprise flipping the distal cover, so as to that the first end moves from a first configuration, in which the first end is located proximally relative to the second end, to a second configuration, wherein the first end is distally relative to the second end.

The distal cover may comprise a plurality of elongated flexible strips having first ends and second ends, the second ends being coupled to the central assembly, and proximally removing the central assembly may comprise flipping the distal cover so that the first ends are drawn together distally towards the second ends.

Proximally removing the core assembly may comprise retracting the distal cover on the catheter so that the distal cover extends distally through an annular space between the core assembly and the inner wall.

The invention described herein is a core assembly. The central assembly comprises a central member having an intermediate region and a distal tip; a stent extending over the intermediate region of the central member and comprising a distal portion; and a distal cover comprising a first end and a second end, the second end being coupled to a distal tip structure, the distal tip structure comprising (a) an internal lumen that receives the central member, or (b) a coil, so that the distal tip structure can slide and / or rotate relative to the central member, the distal cover having a

ES 2 744 583 T3 dispensing orientation in which the first end (i) extends approximately relative to the distal tip and (ii) at least partially surrounds the distal portion of the stent, the distal cover movable from orientation dispensing to a flipped orientation where the first end is positioned distally relative to the second end, and a proximal stop and a distal stop, wherein the distal stop is configured to limit the range of sliding motion of the distal tip structure.

Additional optional aspects of this core assembly will now be described as follows.

The first end of the distal cover may comprise a folded portion. The folded part may comprise an inner layer and an outer layer, the inner layer that is positioned intermediate the stent and the outer layer, the inner layer that can be turned over to facilitate expansion of the stent.

The distal cover may comprise one or more elongated strips of material.

The distal cover may comprise no more than two elongated strips of material.

The distal covering can extend the length of at least one third of the stent.

The distal tip of the central member comprises a tip structure carried by the central member, the distal cover that is coupled to the tip structure. The tip structure may comprise at least one cross member oriented generally transverse to the central member, and the distal cover can be coupled to the tip structure by virtue of forming an enclosure that encloses the at least one cross member. The tip structure may comprise a coil, and the at least one cross member may comprise at least one segment of the coil. The distal cover may form an enclosure that encloses at least one coil segment by virtue of wrapping, at least partially, around the segment.

The distal tip may comprise Teflon.

The central member may comprise a cable.

The distal cover can be configured to rotate around the central member. The second end of the distal cover can be rotatably coupled with respect to the central member. The stent can be configured to rotate about the central member at least in part by virtue of the rotational engagement of the distal cover.

Another example described herein is a core assembly for a stent delivery system. The central assembly comprises a central member extending in a longitudinal direction, the central member having a distal section and a proximal section; a tubular restriction member having an internal lumen and disposed along the central member and having a distal portion (i) spaced from the central member and (ii) defining a capture area in the lumen; a protruding member that extends radially along the central member at least partially distal of the capture area, the protruding member having an outer surface, the protruding member that is disposed between the distal section and the proximal section of the member central; and a stent having (i) a first part disposed within the capture area and (ii) a second part, distal to the first part, that extends through or on the outer surface of the projecting member, such that the protruding member and restriction member cooperate to inhibit expansion of the first part of the stent.

Additional optional features of this core assembly will now be described as follows.

The assembly may further comprise a distal cover coupled to the distal section of the central member, the distal cover at least partially covering a distal portion of the stent, such that when the central assembly is slidably disposed within a catheter, the cover distal is disposed between the distal portion of the stent and an internal wall of the catheter.

The central assembly may be operative to engage the stent in both a dispensing position and a re-sheathing position, and the distal portion of the restriction member may be axially detached from a distal portion of the stent in both the dispensing and re-sheathing position. in the re-holster position.

The restriction member may comprise a sheath having a distal end and an internal lumen. The protruding member may have an external cross-sectional profile that is sized approximately equal to or larger in size than a cross-sectional profile of the lumen of the restriction member.

The distal section of the central member may be a distal tapered section.

The central member may comprise a cable.

The protruding member and the restriction member can secure the stent by inducing a variable diameter in the stent between the first part and the second part.

ES 2 744 583 T3

The protruding member may comprise a generally cylindrical outer surface, and the capture area may be defined between an outer surface of the central member and an inner surface of the tubular restriction member, and the outer surface of the protruding member may be radially displaced from the outer surface of the central member. The outer surface of the protruding member can be radially displaced from the inner surface of the restriction member. The outer surface of the protruding member can be radially spaced between the outer surface of the central member and the inner surface of the restriction member.

The second part of the stent can be supported on the outer surface of the protruding member.

The stent can be engaged between the protruding member and the restriction member in a press fit to inhibit expansion of the first end of the stent.

The stent can be engaged between the protruding member and the restriction member in an interference fit to inhibit expansion of the first end of the stent.

The protruding member can be rotatably mounted on the central member.

The projecting member may comprise an annular ring supported on the central member.

The capture area can be defined between the distal portion of the restriction member and the central member.

The protruding member can be axially detached from the distal portion of the restriction member.

Another example described herein is a method of operation of a stent delivery system. The method comprises moving a central assembly through a catheter to a treatment site, the central assembly comprising (i) a stent having a proximal section and a distal section, (ii) a central member having a distal section, and a proximal section, (iii) a protruding member disposed along the central member between the distal section and the proximal section, and (iv) a restriction member axially spaced from the protruding member and the distal portion of the stent, the restriction member extending over a first part of the proximal section of the stent with the protruding member seated under a second part of the proximal section of the stent, distal to the first part, such that the stent is secured between a distal end of the restriction member and a proximal end of the protruding member in a dispensing position; proximally retracting the catheter relative to the core assembly until the distal end of the restriction member and the first part of the stent are positioned distally beyond the distal end of the catheter while maintaining the first part of the stent in a collapsed state by securing of the stent between the distal end of the restriction member and the proximal end of the protruding member in the dispensing position with the distal section of the central member extends distally relative to the stent; and expanding a distal portion of the stent in juxtaposition with a vessel wall while maintaining the first portion of the stent in the folded state in the dispensing position.

Additional optional features of this method will now be described, as follows.

The method may further comprise proximally removing the core assembly on the catheter to re-sheath the stent within the catheter after the distal portion of the stent has expanded.

Expanding the distal portion of the stent may comprise deploying a distal covering that at least partially covers the distal portion of the stent. The method may further comprise flipping the distal cover so that a free first end of the distal cover moves from a proximally oriented position to a distally oriented position.

Expanding the distal portion of the stent may comprise automatically expanding the distal portion of the stent as the distal portion of the stent exits the catheter.

The method may further comprise releasing the first part of the stent to allow the first part of the stent to expand in juxtaposition with the vessel wall. Releasing the first part of the stent may comprise proximally retracting the restriction member relative to the protruding member to allow the first part of the stent to expand in juxtaposition with the vessel wall. The method may further comprise proximally retracting the catheter core assembly to remove the catheter core assembly. The method may further comprise inserting a second core assembly into the catheter to deliver a second stent to the treatment site.

Another example described herein is a stent delivery system. The system comprises a catheter having a distal end; and a core assembly comprising a tubular restriction member comprising a lumen and a distal portion, a stent having a proximal portion disposed within the lumen and a distal portion disposed outside the lumen, a central member extending within the lumen, and distally beyond the distal portion of the stent, and a radially projecting member coupled to the central member and disposed

ES 2 744 583 T3 distal of the dist part of the restriction member within the distal portion of the stent; wherein the restriction member and the protruding member collectively form a gripping mechanism that engages the proximal portion of the stent in a collapsed state, the gripping mechanism that is operative to (i) exert a distal thrust force on the stent to distally advance the stent relative to the catheter until the proximal portion of the stent is distally beyond the distal end of the catheter and (ii) exert a proximal pulling force on the stent to proximally withdraw the stent into the catheter when the proximal portion of the stent is distally beyond the distal end of the catheter and the stent is at least partially expand in juxtaposition with a vessel wall.

Additional optional features of this system will now be described as follows.

The gripping mechanism can be configured to exert the distal push force and the proximal pull force on its own without the cooperation of other components or structures.

The gripping mechanism can be formed collectively by the distal portion of the restriction member and a proximal portion of the projecting member.

An arcuate tip of the central member may extend distal to the projecting member.

When the assembly is oriented substantially in a straight line, the protruding member may optionally not press the stent against the internal surface of a catheter.

The protruding member may comprise a generally cylindrical outer surface that is radially spaced from the inner surface of a catheter, such that when the assembly is oriented substantially in a straight line, the protruding member does not press the stent against the inner surface of the catheter. .

The protruding member may comprise a generally cylindrical outer surface that is radially spaced from the inner surface of a catheter, such that when the assembly is oriented substantially in a straight line, a radial distance between the outer surface of the protruding member and the lumen The inside of the catheter is dimensioned greater than the thickness of a stent.

Another example described herein is a stent delivery system. The system comprises a microcatheter having a distal end configured to be inserted into a blood vessel; a restriction member that extends into the microcatheter and has a distal portion; a central member that extends into the microcatheter, the central member having a distal segment; at least one sleeve positioned around the distal segment of the central member and rotatably coupled to the central member; and a stent that extends along the distal segment of the central member, a proximal end of the stent that is engaged with the distal portion of the restriction member, and the sleeve to restrict movement of the stent relative to the restriction member and the sleeve. while the central member is rotatable relative to the stent, the restriction element, and the sleeve.

Additional optional features of this system will now be described as follows.

The central member can be rotatable relative to the stent and the microcatheter when a distal end of the stent expands in contact with the vessel.

The microcatheter may comprise a lumen having a central axis, and the distal segment of the central member may comprise an arcuate tip that extends transverse to the axis.

The sleeve can be positioned adjacent the distal portion of the restriction member along the central member in an engaged position. The restriction element may have a capture area configured to receive a first part of the stent, the stent having a second part, distal to the first part, supported on an external surface of the sleeve to restrict movement of the stent relative to the sleeve. and the restraining member. The restriction member and sleeve may cooperate to grip the proximal end of the stent.

The central member can extend into the restriction member.

The system may further comprise a distal cover that extends proximally from the distal segment of the central member and interposes between an external surface of the stent and an internal surface of the microcatheter. The distal tip can be rotatably coupled to the central member. The sleeve and distal cover can allow rotation of the central member relative to the stent.

The system may further comprise an actuator attached to a proximal portion of the central member, the actuator that is configured to impart rotation to the central member.

The central member may comprise a dispensing cable.

ES 2 744 583 T3

Another example described herein is a method of operation of a rotary stent delivery system. The method comprises advancing a distal end of a catheter into a blood vessel; advancing the delivery system within the catheter, the delivery system comprising a stent, a restriction member, a central wire having a central longitudinal axis, and a sleeve rotatably coupled around the central wire, the stent extending over the sleeve and which is restricted from movement relative to the sleeve and the restriction member, the center wire that can rotate relative to the stent, the sleeve and the restriction member; and advancing the center wire distally to guide the delivery system along a vessel path.

Additional optional features of this method will now be described, as follows.

Advancing the stent may comprise moving the stent into juxtaposition with a wall of the blood vessel.

The center wire may comprise a more distal curvilinear tip that bends away from the axis, and the method may further comprise rotating the tip through the center wire relative to the stent, sleeve, and restriction member. The tip can be advanced into a bifurcation of the vessel. Rotating the tip may comprise directing the tip in a direction away from an apex of the bifurcation.

Another example described herein is a stent delivery system. The system comprises a microcatheter having a lumen; a restriction sheath having a distal portion and extending into the lumen of the microcatheter; a central member that extends into the lumen of the microcatheter; at least one sleeve positioned around and rotatably coupled to the central member; and a self-expanding stent having (i) a first part disposed within the lumen of the sheath and (ii) a second part distal to the first part and extending over an external surface of the sleeve, while the central member is rotatable with relationship to the stent, the restriction member, and the sleeve.

Additional optional features of this system will now be described as follows.

The sleeve may have an external cross-sectional profile that is dimensioned larger than an internal cross-sectional profile of the lumen of the restriction sheath.

The central member may extend into a lumen of the restriction sheath.

When in a dispensing position, the first portion of the stent can be restricted from expansion and restricted from longitudinal movement relative to the sleeve and the distal portion of the sheath. The stent may have a first diameter in the first part and a second diameter in the second part, sized larger than the first diameter, so that the stent is secured between the sleeve and the distal part of the sheath.

A collective external profile of the stent and sleeve can be dimensioned larger than the internal profile of the sheath.

The distal part of the restriction sheath (i) may be separate from the central member and (ii) may have a capture area. An outer surface of the sleeve can be radially displaced from the capture area.

The present invention can be used in methods and apparatus for dispensing an occlusion device or devices (eg, stent or stents) into the body. The occlusion device can easily be adapted to the shape of the tortuous vessels of the vasculature. The occlusion device can be used in a variety of applications. For example, the occlusion device can direct blood flow within a vessel away from an aneurysm. Furthermore, such an occlusion device can allow adequate blood flow to be provided to adjacent structures, so that those structures, whether they are branch vessels or oxygen-demanding tissues, are not deprived of necessary blood flow.

Delivery of an intravascular stent to a treatment site within a patient's vessel requires substantial precision. Generally, during the implantation process, a stent is passed through a vessel to a treatment location. The stent can be expanded at the treatment location, often allowing a first end of the stent to expand and thereafter slowly expanding the remainder of the stent until the entire stent has expanded. The process of initially coming into contact with the vessel wall as the first end of the stent expands may be referred to as "landing" of the stent. The final position of the stent within the vessel is generally determined by its initial placement or landing within the vessel. In some situations, the stent may initially "land" in a suboptimal location within the vessel. Using traditional methods and appliances, it can be very difficult for a physician to reposition the stent within the vessel. For example, a physician may be unable to recapture, fold, remove, or re-sheath the stent back into the catheter after the stent has partially expanded within the vessel. Therefore, initial landing is critical for successful stent placement.

ES 2 744 583 T3

In accordance with one aspect of at least some embodiments described herein, is the embodiment of a medical device delivery system that can be configured to advantageously allow a physician to recapture, fold, remove or re-sheath a stent within a delivery system catheter after the stent has expanded and at least partially landed in the vessel in order to allow the physician to improve the placement of the stent within the vessel. Additionally, some embodiments can be configured to allow a physician to recapture, fold, remove, or re-sheath the stent, even if the entire stent has moved out of the catheter lumen and at least partially expanded against the vessel wall. In addition, some embodiments can be provided so that the delivery system can engage and retain any braided stent without requiring special purpose engagement structures on the stent.

In order to allow a physician to recapture, fold, remove, or re-sheath a stent within a delivery system, some embodiments provide a core assembly that is slidably disposed within a catheter and is capable of securing, grasping, or engaging at least a portion of the stent in order to control the movement, deployment, and expansion of the stent. In some embodiments, the core assembly may comprise a restriction member and a core member. The stent may extend over the central member and into a recess formed by the restriction member to engage or secure a portion of the stent.

Optionally, the central assembly may also comprise a protruding part or member disposed along the central member. In such embodiments, the stent can extend over the projecting member and into the recess.

For example, the protruding member and the restriction member may collectively form a gripping mechanism that engages or secures the stent. The grasping mechanism can engage a proximal or first portion of the stent in a folded state. The gripping mechanism can provide a press fit or interference fit between the restriction member and the protruding member to inhibit expansion of the first end of the stent. The grasping mechanism can allow the stent to be withdrawn, recaptured, retracted, or re-sheathing the catheter, even after the stent has been moved out of the catheter lumen (i.e., the catheter has been completely withdrawn from the stent) and the stent has expanded at least partially in juxtaposition with the vessel wall.

The gripping mechanism can allow the central assembly to exert a pushing force and a pulling force on the stent to adjust its axial position relative to the catheter. In some embodiments, the gripping mechanism may be operative to exert a distal thrust force on the stent to advance the stent distally relative to the catheter until the proximal portion of the stent is distally beyond the distal end of the catheter. In addition, the gripping mechanism may also be operative to exert a proximal pulling force on the stent to proximally withdraw the stent from the catheter when the proximal portion of the stent is distally beyond the distal end of the catheter and the stent is expanded at least partially juxtaposed with a vessel wall. The gripping mechanism can be configured to exert the distal push force and the proximal pull force on its own without the cooperation of other components or structures.

In some embodiments, the stent can be secured or hooked between the protruding member and a distal end of the restriction member (which may be a sheath) in order to prevent expansion of a proximal or first portion of the stent. For example, the protruding member and the restriction member can secure the stent by inducing a variable diameter in the stent between the first part and the second part.

In some embodiments, the assembly can be configured such that the central member has a distal section and a proximal section. The distal section of the central member may be a distal tapered section. The central member may comprise a cable. The distal section of the central member comprises a distal tip. The distal tip of the central member may comprise polytetrafluoroethylene (PTFE or TEFLON®).

The restriction member may have an internal lumen that is configured to receive the central member. Furthermore, the restriction member may have a distal portion that can be detached from the central member and may have a capture area in the lumen. The capture area can be defined between the distal portion of the restriction member and the central member. For example, the capture area can be defined radially between an outer surface of the central member and an inner surface of the tubular restriction member.

Furthermore, the protruding member can be disposed along the central member at least partially distal from the capture area. The protruding member can extend radially. Furthermore, the protruding member may have an external surface. In some embodiments, the projecting member can be disposed axially between the distal section and the proximal section of the central member. Furthermore, the stent can have a first part and a second part. The first part can be a proximal part that is arranged within the capture area. The second part can be arranged distal relative to the first part. The second part may extend through or on an external surface of the protruding member, such that the protruding member and the restriction member cooperate to inhibit expansion of the first part of the stent.

ES 2 744 583 T3

In some embodiments, the central member may extend into the lumen of the stent and distally beyond the distal portion of the stent. The protruding member can be coupled to the central member and distal of the distal part of the restriction member can be disposed within the distal part of the stent.

The protruding member may optionally have a generally cylindrical outer surface. For example, the protruding member may comprise an annular ring coupled to or supported on the central member. The outer surface of the protruding member can be radially displaced from the outer surface of the central member. Furthermore, the protruding member can be axially detached from the distal portion of the restriction member. For example, the outer surface of the protruding member can be radially displaced from the inner surface of the restriction member. Furthermore, the outer surface of the protruding member can be radially displaced from the capture area that is defined by the restriction member and the central member. In some embodiments, the outer surface of the protruding member can be radially spaced between the outer surface of the central member and the inner surface of the restriction member. Furthermore, the second part of the stent may extend over or be supported on the outer surface of the protruding member.

The protruding member can be disposed at least partially distal from the distal portion of the restriction member. Furthermore, when the assembly is oriented substantially in a straight line, the protruding member can be configured such that it does not press the stent against the internal surface of the catheter.

The protruding member may also have an outer surface that is radially spaced from the internal surface of the catheter, such that when the assembly is oriented substantially in a straight line, the protruding member does not press the stent against the internal surface of the catheter. For example, the protruding member may have a generally cylindrical outer surface. Furthermore, when the assembly is oriented substantially in a straight line, a radial distance between the outer surface of the protruding member and the inner surface of the catheter can be dimensioned greater than the thickness of the stent.

A catheter may be provided in order to form a stent delivery system. The stent delivery system may comprise the catheter and core assembly. The catheter may have a distal end. As noted above, the core assembly may comprise a tubular restriction member, a stent, a core member, and a radially projecting member.

According to some embodiments, the restriction sheath may include a lumen that has an internal profile in cross-section. The protruding member may have an external cross-sectional profile that is sized approximately equal to or greater than the internal profile of the catheter. The external cross-sectional profile of the protruding member can be dimensioned larger than the internal profile of the catheter. The stent may extend over the protruding member and into the restriction sheath such that the stent has a first diameter at the proximal portion of the stent and a second diameter at the distal portion of the stent, sized larger than the first diameter. In this way, the stent can be secured between the projecting member and the distal end of the sheath. According to some embodiments, the protruding member can be rotatably mounted on the central member, as further discussed herein. Furthermore, the protruding member and the central member can also be formed from a continuous piece of material.

Furthermore, a collective external profile of the stent and proximal member can be dimensioned larger than the internal profile of the sheath. The central member can be configured to be steerable when the stent partially expands within a blood vessel and can be rotated relative to the stent and the restriction sheath. In some embodiments that comprise a projecting member, the central member can also be rotatable relative to the projecting member.

Delivery of a stent into a vessel and subsequent expansion of the stent in juxtaposition with the vessel wall can present some challenges in tortuous vessels. For example, during dispensing to the treatment site, the dispensing system can be configured to comprise one or more rotating components that allow the components of the system to rotate relative to each other while the dispensing system traverses tortuous geometries. Such flexibility can reduce the overall pushing force required and tend to avoid "pounding" of the stent as it is withdrawn and / or expanded in the vessel.

The dispensing system may comprise a rotatable central assembly. The central member can rotate independently of the protruding member (if present) and / or the stent and the restriction member within the catheter to reduce "battering" and also to allow directing of the central member, as further discussed in present memory. Such rotational ability can facilitate movement of the core assembly through a delivery system catheter to reduce the dispensing force required to reach the treatment site.

In addition, the rotatable core assembly can be configured to allow the core member to rotate independently of the stent that is deployed in the vessel. In this way, the protruding end of the central member can be rotated without interrupting contact between the vessel wall and the stent. In this way, the doctor can

Rotate a protruding and distal end of the central member to preferably align the protruding end with the geometry of the adjacent vessel to avoid abrasion or perforation of the vessel wall while advancing the assembly.

For example, after the stent has moved to the treatment site, the central member of the delivery system can often include a distally protruding end that can be displaced distally as the stent expands and releases. The distal movement of the protruding end poses a risk of potential abrasion or perforation of a wall of the vessel into which the stent is being delivered. Furthermore, when the stent is being delivered adjacent to a bifurcation of the vessel or a sharp turn in the vessel, the geometry of the vessel, such as an apex of the bifurcation, can be particularly difficult to avoid.

In some embodiments, a center assembly can be rotatable by providing a protruding member that is rotatably mounted on the center member. In such embodiments, the central member may be rotatably coupled relative to the protruding member thereof in order to allow the central member to rotate relative to the protruding member, the restriction member, and the stent. For example, the protruding member may comprise an annular component that is rotatably mounted on the restraint mechanism.

Thus, a stent or rotatable stent delivery system can be provided. Such a system can comprise a microcatheter, a central member, and a stent. The microcatheter can have a distal end configured to be inserted into a blood vessel. The central member can extend into the microcatheter. Furthermore, the central member may have a distal part and an intermediate part proximal to the distal part. The stent can extend along the middle. Furthermore, the central member can be configured to be steerable as the stent partially expands within the vessel while being rotatable relative to the stent and the microcatheter. Accordingly, the central member can be steerable to prevent detachment of the stent from the vessel wall and abrasion or perforation of the vessel wall.

The system can also comprise a projecting member. The protruding member can be positioned along the central member in the middle and can be rotatably coupled to the central member. The central member may comprise an arcuate tip that extends distal to the projecting member. The distal portion of the central member may comprise the arcuate tip, which may extend transverse to a longitudinal axis of the microcatheter. The arcuate tip can extend transverse to or away from a central axis of the microcatheter lumen. The microcatheter can be either the restriction sheath or the catheter discussed herein.

The distal portion may comprise an assembly that includes the distal cover and the distal tip structure. The tip structure can be rotatably or fixedly coupled relative to the central member. In addition, the distal cover is attached to the tip structure.

The distal tip structure may comprise at least one member or component that can be transported by the central member. The at least one member may be oriented generally transverse or parallel to the central member. For example, the tip structure may comprise a coil or coils, a circumferentially extending band or bands of material, a jaw or jaws, and / or other structures that can smoothly pass into a vessel at the distal portion of the central member. Furthermore, the at least one member may comprise at least one coil segment or other structure.

In a rotatable core assembly, the distal portion of the core member may comprise a distal tip structure and / or a distal cover that can be rotatably coupled to the core member. Thus, a rotatable interconnection between the distal tip structure and / or the distal cover and the central member can allow the central member to rotate freely of the distal tip structure and / or the distal cover, thereby preventing transmission. of any rotational or twisting stress to the stent through the distal cover. For example, the distal cover can be configured to rotate around the central member. Furthermore, the second end of the distal cover can be rotatably coupled with respect to the central member. Furthermore, the stent can be configured to rotate about the central member at least in part by virtue of the rotational engagement of the distal cover.

In operation, once the catheter has been placed in the blood vessel, the stent can partially expand in juxtaposition with a wall of the vessel. The clinician can rotate a more distal curvilinear tip of the central member of the delivery system. The tip can be configured to bend away from a central longitudinal axis of the central member. Thus, when rotated, the curvilinear tip of the central member can rotate relative to the stent and the restriction member. Furthermore, as noted above in some embodiments comprising a projecting member, the central member can be rotatably coupled to the projecting member. In such embodiments, when rotated, the curvilinear tip of the central member can rotate relative to the stent, the protruding member, and the restriction member. Consequently, the clinician can align the curvilinear tip with a vessel path to avoid abrasion or perforation of the vessel wall. Thereafter, the central member can be advanced distally to guide the central member along a

ES 2 744 583 T3 trajectory of the vessel. Such methods and systems can be particularly useful when the geometry of the vessel includes a bifurcation or sharp turn in the vessel, especially to guide the tip of the central member away from an apex of a bifurcation adjacent to the treatment site.

The core assembly can be configured to comprise a distal portion that allows a distal or leading end of the core assembly and the stent to be lubricated through a catheter while also facilitating re-sheathing of the distal portion within catheter, as desired.

The distal cover engages the central member and at least partially surrounds the distal portion of the stent. Thus, when the core assembly is slidably disposed within the catheter, the distal cover can be positioned between, for example, radially between, the distal portion of the stent and the inner wall of the catheter.

The distal cover may comprise a flexible material that can extend anteriorly over at least a portion of the stent in order to provide a lubricating interface between the central assembly and an internal surface of the catheter lumen.

The attachable distal cover is attached to the distal tip frame or center wire using a variety of attachment means. The distal cover can be coupled to the distal tip structure by virtue of forming an enclosure that encloses at least one member of the distal tip structure. For example, the distal cover may form an enclosure that encloses the tip structure, eg, at least one coil segment, by virtue of being at least partially wrapped around the segment.

The distal cover may comprise one or more elongated strips of material. For example, the distal cover may comprise a pair of elongated longitudinally extending strips that at least partially cover or surround the distal portion of the stent. In some embodiments, the distal cover comprises no more than two elongated strips of material. In some embodiments, the distal cover can be cut from a tubular member such that a plurality of elongated strips are formed and interconnected by an annular ring of material.

In addition, the distal cover can be configured to allow the distal end of the stent to expand when the distal end of the stent moves axially past a distal end of the catheter. In some embodiments, the distal cover can be configured to provide little or no restraining force or otherwise inhibit expansion of the distal end of the stent.

The distal cover can be configured to flip, flip, or otherwise move from one position to another. The distal cover comprises a first end and a second end. The first end can be a free first end, and the second end engages the distal tip structure. The distal cover has a first or proximally oriented position, orientation or dispensing configuration, in which the first end extends proximally relative to the distal portion of the central member and at least partially covers or surrounds the distal portion of the stent. The distal cover can be moved from the first dispensing position, orientation or configuration, or proximally oriented, in which the first free end is positioned proximally relative to the second end, to a second re-sheathing position, orientation or configuration, flipped or distally oriented wherein the first end is positioned distally relative to the second end. In this way, the distal cover can allow the core assembly to be easily withdrawn or received in the catheter lumen. In addition, the distal portion of the restriction member may be axially detached from a distal portion of the stent in both the dispensing position or configuration and in the re-sheath position or configuration.

The distal cover may extend anteriorly relative to the point of attachment of the distal cover and / or the distal tip structure while the stent is being delivered to the treatment site. For example, the distal covering can extend the length of at least about one third of the stent. In addition, the distal cover can be turned over to extend distally with respect to the attachment point of the distal cover and / or the distal tip structure after the distal end of the stent has expanded.

Various methods of operating the core assembly and the stent delivery system are also described. Initially, in order to place the stent delivery system within a patient's vessel, a physician may first place a catheter in the vessel. The catheter may have a lumen defining an axis extending between a proximal end and a distal end, such that the distal end of the catheter is at a treatment site. The doctor can place the core assembly into the lumen of the catheter. The physician can also advance the core assembly distally into the catheter. Thereafter, various method implementations can be made using one or more of the core sets described herein.

For example, the operation of a stent delivery system can be accomplished by first moving the core assembly through a catheter to a treatment site. A restriction member of the assembly can be configured to receive a portion of a proximal stent portion such that the stent is secured between a distal end of the restriction member and a proximal end of a protruding member in a dispensing position. The catheter can be retracted proximally relative to the core assembly until the distal end of the

ES 2 744 583 T3 restriction and proximal portion of the stent are positioned distally beyond the distal end of the catheter while maintaining the proximal portion of the stent in the dispensing position or configuration with the distal section of the central member extending distally relative to the stent. In addition, a distal portion of the stent can be expanded in juxtaposition with a vessel wall while maintaining the proximal portion of the stent in the dispensing position.

The core assembly can be withdrawn proximally within the catheter to re-sheath the stent within the catheter after the distal portion of the stent has already expanded. When using a self-expanding stent, a distal portion of the stent can automatically expand when the distal portion of the stent exits the catheter. Furthermore, in order to expand a distal portion of the stent, a distal cover may be deployed, which at least partially surrounds or covers a distal portion of the stent.

Furthermore, the distal cover extends in a proximal direction to at least partially cover a distal portion of a stent supported on the core assembly. At least a part of the distal cover can be interposed between the distal part of the stent and the inner wall. The distal portion of the stent can be advanced distally beyond the distal end of the catheter to allow expansion of the distal portion of the stent. The core assembly can then be withdrawn into the lumen, such that the distal cover retracts into the lumen in a flipped configuration oriented distally from the core assembly.

Furthermore, in some examples, where the core assembly has (i) an elongated member comprising a distal end, (ii) an intermediate portion comprising a distal end positioned at the distal end of the member, (iii) a stent that has a distal and medially carried portion, and (iv) a distal cover attached to the distal end of the limb, the core assembly can be positioned within the lumen so that the distal end of the intermediate portion is positioned axially adjacent to the distal end of the catheter with at least a portion of the distal cover extending into a space within the lumen radially between the end distal of the intermediate portion and the distal end of the catheter. The clinician can then advance the core assembly distally relative to the catheter to allow expansion of the distal portion of the stent. Expansion can push the distal cover away from the middle. Finally, the clinician can proximally remove the core assembly on the catheter so that the middle portion is positioned axially adjacent the distal end of the catheter with the distal cover positioned out of the space. In some examples, during proximal removal of the core assembly into the catheter, the distal cover may be positioned outside the space to provide a free margin between the middle portion and the catheter.

Additionally, in some examples, the core assembly may have (i) a distal portion, (ii) a distal cover that extends from the distal portion, and (iii) a stent that has a distal portion and is carried by the assembly. central. The core assembly can be advanced within the catheter such that the distal cover extends proximally from the distal portion and an annular space between the distal portion and the catheter. The clinician can advance the core assembly distally relative to the catheter to allow expansion of the distal portion of the stent. The expansion can push the distal cover radially away from the central assembly. In addition, the core assembly can be removed proximally on the catheter so that the distal cover extends distally through the annular space. In such examples, during proximal removal of the core assembly on the catheter, the distal cover may extend distally through the annular space to provide a free margin between the catheter and an intermediate portion of the core assembly proximal to the distal cover.

In addition, examples of the methods may further comprise advancing the core assembly distally within the catheter, such that a proximal end of the stent is positioned outside the lumen. The method can be performed to further comprise the step of releasing the stent at the treatment site within the vessel. The method may also comprise proximally removing the central assembly from the lumen while keeping the distal end of the catheter in place at the treatment site. Additionally, a second core assembly can be inserted into the lumen. The second core assembly can be configured to deliver a second stent at the treatment site.

In some examples of the methods, proximally removing the core assembly may comprise turning a first free end of the distal cover from a proximally oriented position to a distally oriented position. Furthermore, the distal cover can be attached to the central assembly at a second end of the distal cover, and the first end can be positioned distally relative to the second end when the distal cover is turned over.

According to yet other examples of the methods, the distal cover may comprise a plurality of elongated flexible strips having first ends and second ends. The second ends can be attached to the central assembly. In such examples, proximally removing the center assembly may comprise flipping the distal cover so that the first ends are drawn together distally to the second ends.

ES 2 744 583 T3

An steerable stent delivery system may comprise a microcatheter, a central member, a protruding member, and a stent. The microcatheter can have a distal end configured to be inserted into a blood vessel. The central member can extend into the microcatheter. The central member may have a distal portion and an intermediate portion proximal to the distal portion. The protruding member can be placed along the central member in the middle. The protruding member can be rotatably coupled to the central member. The stent can extend over the projecting member and along the intermediate portion. Furthermore, the central member can be configured to be steerable as the stent partially expands within the vessel while being rotatable relative to the stent and the microcatheter.

The central member may be steerable to prevent (i) detachment of the stent from the vessel wall and (ii) perforation of the vessel wall. Furthermore, the microcatheter may comprise a lumen having a central axis, and the distal portion of the central member may comprise an arcuate tip that extends transversely to the axis. Furthermore, the system may further comprise a restriction member arranged along the central member and a distal part (i) separated from the central member and (ii) having a capture area. The protruding member can be positioned adjacent a distal end of the restriction member. The stent may have (i) a first part disposed within the capture area and (ii) a second part, distal to the first part, supported on an external surface of the protruding member to secure the stent between the protruding member and the restriction member.

The system may also comprise a distal cover extending proximally from the distal portion of the central member and interposed between an outer surface of the stent and an inner surface of the microcatheter. The system may also comprise a distal tip attached to the central member at the distal portion thereof, and the distal cover may be attached to the distal tip. The distal tip can be rotatably coupled to the central member. The distal tip and central member can be formed from a continuous piece of material.

The system may further comprise an actuator attached to a proximal portion of the central member, and the actuator may be configured to impart rotation to the central member.

Methods of operation of a stent delivery system are exemplified. According to some examples described herein, the delivery system may comprise a tubular restriction member, a central member or cable having a central longitudinal axis, an annular protruding member rotatably coupled to the central cable, and a curvilinear tip. more distal that bends away from the axis. The stent can extend over the protruding member and be secured between the protruding member and the restriction member so that the center wire can be rotated relative to the stent, the protruding member, and the restriction member. According to some examples of methods described herein, a physician can place a distal end of a delivery system catheter into a blood vessel. The physician may partially expand a stent of the delivery system in juxtaposition with a wall of the blood vessel. The physician can then rotate the tip relative to the stent, the protruding member, and the restriction member. For example, the physician can rotate the tip until a desired orientation is achieved relative to the geometry of the blood vessel. Thereafter, the clinician can advance the central wire distally to guide the central wire along a vessel path.

In some examples, when the clinician rotates the tip, the relative movement between the center wire and the stent can prevent dislocation of the stent from the vessel wall. Also, in some examples, the physician may advance the tip toward a bifurcation in the vessel. Furthermore, in some examples, the method may be implemented where rotating the tip comprises directing the tip in a direction away from an apex of the bifurcation.

A stent delivery system may comprise a restriction sheath, a central member, a protruding member, and a stent. The restriction sheath may have a distal end and a lumen having an internal profile in cross section.

The stent may have (i) a proximal portion disposed within the lumen of the sheath and (ii) a distal portion that extends over an external surface of the projecting member. In some examples, the distal portion may be at least partially covered in the distal region of the central member. The stent may have a first diameter in the proximal part and a second diameter in the distal part, sized larger than the first diameter, so that the stent is secured between the projecting member and the distal end of the sheath.

In some examples, the central member may have a distal region and extend into the lumen of the sheath. The protruding member can be rotatably mounted on the central member. For example, the projecting member can be rotatably mounted on the central member proximal to the distal region. The protruding member may have an external cross-sectional profile that is sized approximately equal to or greater than the internal profile of the catheter. In some examples, the protruding member may have an external cross-sectional profile that is dimensioned larger than the internal profile of the catheter.

ES 2 744 583 T3

The stent can be secured between the protruding member and the distal end of the sheath to prevent expansion of the first part of the stent. Furthermore, a collective external profile of the stent and proximal member can be dimensioned larger than the internal profile of the sheath. The central member can be configured to be steerable as the stent partially expands within a blood vessel by being rotatable relative to the stent, the protruding member, and the restriction sheath. The external profile of the projecting member can be generally cylindrical. The protruding member may comprise a tubular structure fitted over the central member. The restriction sheath may comprise a distal portion (i) separate from the central member and (ii) having a capture area. Optionally, an outer surface of the projecting member can be radially displaced from the capture area. The stent can be engaged between the protruding member and the restraining sheath in a press fit to prevent expansion of the first part of the stent. The stent can be engaged between the protruding member and the restraining sheath in an interference fit to prevent expansion of the first part of the stent.

Additional features and advantages of the subject technology will be set forth in the description below, and in part will be apparent from the description, or may be learned by practicing the technology in question. The advantages of the technology in question will be realized and achieved by the structure particularly pointed out in the written description and embodiments herein, as well as in the accompanying drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the technology in question.

Brief description of the drawings

The accompanying drawings, which are included to provide a further understanding of the subject technology and are incorporated in and constitute a part of this specification, illustrate aspects of the description and together with the description serve to explain the principles of the subject technology. .

Figure 1 is a schematic partial cross-sectional view of a stent delivery system, according to one or more described embodiments.

Figure 2 is a schematic side view of a core assembly of the system shown in Figure 1 with a stent mounted thereon, according to some embodiments.

Figure 3A is a schematic side cross-sectional view of a proximal part of the central assembly shown in Figure 2, according to some embodiments.

Figure 3B is a schematic side cross-sectional view of a proximal part of the central assembly shown in Figure 2, according to some embodiments.

Figure 4A is a schematic side cross-sectional view of one embodiment of a core assembly.

Figure 4B is a schematic side cross-sectional view of another embodiment of a core assembly.

Figure 5A is a schematic side cross-sectional view of a distal portion of the central assembly shown in Figure 2, according to some embodiments.

Figure 5B is a schematic side cross-sectional view of another embodiment of a distal portion of the central assembly shown in Figure 2.

Figure 5C is a rear perspective view of yet another embodiment of a distal portion of the core assembly shown in Figure 2.

Figure 6 is a schematic side view of the central assembly of the system of Figure 1 where the stent is not shown, according to some embodiments.

Figure 7A is a schematic partial cross-sectional view of the system of Figure 1, in which a stent has initially expanded against the wall of a vessel and a distal cover is disengaged from the system, in accordance with some embodiments.

Figure 7B is a partial cross-sectional schematic view of the system of Figure 1, in which the distal cover has migrated to a flipped position, according to some embodiments.

Figure 7C is a schematic partial cross-sectional view of the system of Figure 1, in which the distal cover has migrated to another flipped position, according to some embodiments.

ES 2 744 583 T3

Figure 8 is a partial cross-sectional schematic view of the system of Figure 1, in which the stent has partially expanded against the vessel wall and moved out of the lumen of a catheter, in accordance with some embodiments.

Figure 9 is a schematic partial cross-sectional view of the system of Figure 1, in which the stent has been retracted or re-sheathed in the catheter lumen after initial expansion of the stent, according to some embodiments.

Figure 10 is a schematic partial cross-sectional view of the system of Figure 1, in which the stent and a distal tip assembly of the central assembly have been retracted or re-sheathed in the catheter lumen after expansion. initial stent, according to some embodiments.

Figure 11 is a schematic view in partial cross-section of the system of Figure 1, in which the stent has expanded and released from the central assembly in juxtaposition with the wall of the vessel, according to some embodiments.

Figure 12 is a partial cross-sectional schematic view of the system of Figure 1, in which the core assembly has been retracted or received within the catheter lumen after releasing the stent, according to some embodiments.

Figure 13A is a schematic partial cross-sectional view of a stent delivery system positioned at a treatment site adjacent to a bifurcation of the vessel.

Figure 13B is a schematic partial cross-sectional view of the stent delivery system and the treatment site shown in Figure 13A, in which a distal portion of a central member of the stent delivery system has been rotated to avoid abrasion or perforation of the wall of a vessel, according to some embodiments.

Detailed description

In the following detailed description, numerous specific details are set forth to provide a complete understanding of the technology in question. It should be understood that the technology in question can be practiced without some of these specific details. In other cases, well-known structures and techniques have not been shown in detail so as not to obscure the technology in question.

Described herein are various embodiments of stent delivery systems that feature small cross sections that are highly flexible and can provide benefits such as allowing the clinician to recapture, fold, remove or re-sheath and reposition a partially expanded stent. , avoid abrasions or perforations of vessels during placement, place several stents (for example, “telescopic”) without removing the microcatheter, and / or avoid the twisting stress and "pounding" that can occur during stent delivery. Various other features and advantages of the embodiments are discussed and shown herein.

In some embodiments, a stent delivery system is provided that may include a core assembly and an introducer sheath and / or catheter. The core assembly comprises a stent that is extended over, carried or supported by a core member. The central member may comprise a central cable. The core assembly is movable within the sheath and / or introducer catheter in order to deliver the stent to a predetermined treatment site, such as an aneurysm, within the vasculature of a patient. Thus, prior to delivery of the stent, the catheter can be configured to be inserted and advanced through the vasculature of the patient. The catheter can be made of various thermoplastics, for example, polytetrafluoroethylene (PTFE or TEFLON®), fluorinated ethylene propylene (FEP), high-density polyethylene (HDPE), polyether ether ketone (PEEK), etc., which can be optionally coated on the inner surface of the catheter or an adjacent surface with a hydrophilic material such as polyvinylpyrrolidone (PVP) or some other plastic coating. In addition, any of the surfaces can be coated with various combinations of different materials, depending on the desired results.

The stent can take the form of a vascular occlusion device, a revascularization device, and / or an embolization device. In some embodiments, the stent can be an expandable stent made of two or more filaments. The filaments can be formed from known flexible materials including shape memory materials, such as nitinol, platinum, and stainless steel. In some embodiments, the filaments can be round or ovoid wire. In addition, the filaments can be configured so that the stent is self-expanding. In some embodiments, the stent can be fabricated from platinum / 8% tungsten and 35N LT alloy leads (nickel cobalt alloy, which is a low titanium version of the MP35N alloy). In other embodiments, one or more of the filaments may be formed of a biocompatible metallic material or a biocompatible polymer.

The wire strands can be braided into a resulting lattice-like structure. In at least one embodiment, during braiding or winding of the stent, the filaments can be braided using a 1-over-2 pattern.

ES 2 744 583 T3 below 2. In other embodiments, however, other braiding methods may be followed, without departing from the scope of the description. The stent may have porosity configured to reduce hemodynamic flow to and / or induce thrombosis within, for example, an aneurysm, but simultaneously allow perfusion into an adjacent branch vessel whose ostium is traversed by a portion of the stent. As will be appreciated, the porosity of the stent can be adjusted by "packing" the stent during deployment, as is known in the art. The ends of the stent can be cut in length and therefore remain free for radial expansion and contraction. The stent can exhibit a high degree of flexibility due to the materials used, the density (ie, porosity) of the filaments, and the fact that the ends are not secured.

Information regarding examples, features, and other additional details of the occlusion devices or stents, methods of use, and other components that may be optionally used or implemented in the occlusion devices or stents described herein, can be found in the US Patent Applications of applications in process of the Applicants N ° 12/751997, presented on March 31, 2010; 12/426560, filed April 20, 2009; 11/136395, filed May 25, 2005; 11/420025, filed May 24, 2006; 11/420027, filed May 24, 2006; 12/425604, filed April 17, 2009; 12/896707, filed October 1, 2010; 61/483615, filed May 6, 2011; 61/615183, filed March 23, 2012; 61/753533, entitled Methods and Apparatus for Luminal Stenting, filed Jan. 17, 2013; 13/614349, entitled Methods and Apparatus for Luminal Stenting, filed September 13, 2012; and 13/664547, entitled Methods and Apparatus for Luminal Stenting, filed October 31, 2012.

For example, in some embodiments, the stent or occlusion device may be a self-expanding stent made of two or more round or ovoid wire strands. The filaments can be formed of flexible materials including biocompatible metals or alloys, such as nitinol, platinum, platinum-tungsten, stainless steel, cobalt-chromium, or cobalt-nickel. In some embodiments, the stent or occlusion device can be fabricated from a first plurality of platinum / 8% tungsten filaments and a second plurality of 35N LT (nickel cobalt alloy, which is a low titanium version alloy MP35N). In other embodiments, one or more of the filaments may be formed of a biocompatible metallic material or a biocompatible polymer.

The central member may be flexible enough to allow the stent delivery system to bend and adjust to the curvature of the vasculature as necessary for axial movement of the stent within the vasculature. The center member can be made of a conventional guidewire material and have a solid cross section. Alternatively, the central member can be formed from a hypotube. The material used for the central member can be any of the known guidewire materials including superelastic metals or shape memory alloys, for example nitinol. For example, the central member, along its length or at least at its distal end or tip, may comprise polytetrafluoroethylene (PTFE or TEFLON®). Alternatively, the central member can be formed of metals such as stainless steel.

In one or more embodiments, the stent delivery system can exhibit the same degree of flex throughout its entire length. However, in other embodiments, the stent delivery system can have two or more longitudinal sections, each with different degrees of flexion or stiffness. Different degrees of flex for the stent delivery system can be created using different materials and / or thicknesses within different longitudinal sections of the central member. In another embodiment, the flexing of the central member can be controlled by separate cuts (not shown) formed within the central member. These cuts can be separated longitudinally and / or circumferentially from each other.

In some embodiments, the core assembly can secure, grasp, or engage a proximal end of the stent to facilitate recapture, retraction, removal, or re-sheathing of the stent in the catheter lumen. The core assembly may optionally comprise a restraining member or containment sleeve. Furthermore, the central member of the central assembly may optionally comprise at least one projecting member or a variable diameter portion arranged along the length of the central member that can cooperate with the restraining member or the containment sheath to secure, grip or hooking the stent into a snap, friction, or interference fit. Accordingly, in some embodiments, the restriction member and the projecting member may cooperate to form a gripping mechanism that engages a proximal or first portion of the stent. The gripping mechanism can secure or hook the first part of the stent in a folded or expanded state.

For example, the containment sheath can be moved relative to the central member and configured to receive a proximal or first end of the stent. When assembled, the stent may extend over the central member with a proximal portion of the stent extending over a variable diameter portion of the central member and the proximal end of the stent received axially within a distal end of the containment sheath. The distal end of the containment sheath and the variable diameter portion of the central member may be axially spaced or offset from each other. The spacing of the distal end of the containment sheath and the variable diameter portion of the central member can be configured to create a snap, friction, or interference fit with the stent extending therebetween to secure, grip, retain, or hook the proximal part of the stent. For

Consequently, the variable diameter portion or the protruding member of the central member may cooperate with the containment sheath or the restriction member to inhibit expansion of the proximal or first portion of the stent.

In some embodiments, the proximal portion of the stent can be secured, grasped, retained, held, or hooked in a collapsed or unexpanded state. Furthermore, in some embodiments, the proximal portion of the stent may be secured or hooked in a manner that induces a change in diameter in the proximal portion of the stent. For example, the proximal portion of the stent may extend over or be seated in the variable diameter portion of the central member, while a section of the proximal portion of the stent is disposed axially within the distal end of the containment sheath, the section of which it is pushed to a diameter size smaller than the diameter size of the proximal portion that extends over or sits on the variable diameter portion of the central member. Also, in some embodiments, the distal end of the containment sheath may abut a portion of the stent that changes in diameter to thereby create a snap, friction, or interference fit.

In some embodiments, the variable diameter portion of the central member may comprise one or more axially extending steps and / or projections. The variable diameter part can be formed as an integrated structure of the central member (eg, the central member and the variable diameter part can be formed from a single continuous piece of material). However, the variable diameter portion may be a separate structure that is placed on, attached to, and / or attached to the central member. Also, in some embodiments, the variable diameter portion can be fixed relative to the central member. In other embodiments, the variable diameter portion can be rotatably and / or longitudinally movable relative to the central member.

For example, the variable diameter portion may comprise a cylindrical structure or a support member that is configured to rotate around the central member, but may be fixed in a longitudinal position (or have a limited range of longitudinal movement) relative to the member. central. Accordingly, in some embodiments, the variable diameter portion can facilitate stent rotation. Typically, during delivery of the stent to the treatment site, passage through tortuous vessels can induce torque in the delivery system and / or the stent. However, in some embodiments, a rotatable variable diameter portion (preferably cylindrical) can support the stent and allow the stent to rotate around the central member, thereby alleviating torsional stresses during delivery. Such a rotatable variable diameter portion can thereby reduce or eliminate the tendency of the stent to "beat" when released or expanded. "Thumping" is the rapid, rotational unwinding that sometimes occurs when the stent is released, due to the release of twisting forces that have been exerted on the stent during delivery. Furthermore, the rotatable variable diameter portion can also allow the core assembly to exhibit greater flexibility during delivery of the stent to the treatment site.

In addition, securing or engaging the proximal portion of the stent may allow a physician to exert a distal pushing force on the stent to advance the stent distally relative to the catheter, as well as exert a proximal pulling force on the stent to proximally withdraw or retract the stent on the catheter, even after the entire stent has moved distally past a distal end of the catheter and partially expanded into juxtaposition with a vessel wall.

In fact, after navigating the core assembly along the length of the catheter to the treatment site within the patient, the stent can be deployed from the catheter in a variety of ways. In one embodiment, the catheter can be retracted while maintaining the position of the central member to expose the distal end of the central member and the distal end of the stent. While this is being done, the stent can be engaged in a collapsed state at least at the proximal end or in part thereof. In some embodiments, the stent can be attached to both the proximal and distal ends or parts thereof while the catheter is being retracted.

For example, the catheter can be withdrawn proximally relative to the central assembly, thereby exposing a distal tip assembly of the central assembly. The distal portion or core assembly assembly comprises a distal tip structure and a distal cover, which may be flexible.

The distal tip structure may comprise at least one member or component that can be transported by the central member. In some embodiments, the at least one member may be oriented generally transverse or parallel to the central member. For example, the tip structure may comprise a coil or coils, a circumferentially extending band or bands of material, a jaw or jaws, and / or other structures that can smoothly pass into a vessel at the distal portion of the central member. Furthermore, the at least one member may comprise at least one coil segment or other structure.

The distal cover at least partially covers or surrounds a distal end of the stent that extends over an intermediate portion of the core assembly in a first pre-wrapping, dispensing, or expanding position. For example, in this position, the core assembly can be axially positioned within the catheter lumen so that the distal end of the stent is positioned axially adjacent to the distal end of the catheter with at least a portion of the distal cover extending in a space within the catheter lumen radially between the distal end of the

ES 2 744 583 T3 catheter and at least one of the stent or the intermediate part of the central assembly. The distal cover extends proximally from the distal portion or assembly and the space between the distal portion and the catheter. Furthermore, in some embodiments, at least a portion of the distal cover may be positioned outside of a space radially between the distal tip structure of the core assembly and the catheter. Accordingly, in some embodiments, the distal cover may comprise one or more strips of a flexible and / or lubricating material that can be positioned radially between the distal end portions of the stent and the internal surface of the catheter to reduce friction of the stent. sliding between the central assembly and the catheter.

However, as long as the distal end of the stent does not sheathe or move beyond the distal end of the catheter lumen, the distal end of the stent may begin to expand and thereby push the distal cover from the first position or wrapping, dispensing, or expanding configuration prior to a second deployed, expanded, re-sheathed, or flipped configuration or position. As the distal cover is moved to the flipped position or configuration, the distal end of the stent can expand in juxtaposition with the vessel wall. If the stent is "landed" in the correct position within the vessel, the remainder of the stent can be unsheathed, expanded, and released into the target vessel.

However, according to some embodiments, after the stent has partially expanded and even if the stent has been fully removed or moved beyond a distal end of the catheter, the stent delivery system may allow the physician to recapture, fold , remove or re-sheath the stent on the catheter, and later deploy, expand, or de-sheath the stent from the catheter again. As noted above, some embodiments allow the stent to be secured, grasped, or hooked proximally by the core assembly in order to exert both a distal pushing force on the stent and to exert a proximal pulling force on the stent. Thus, even when the stent has been fully unsheathed or moved past a distal end of the catheter, a proximal end of the stent can remain secured, gripped, or engaged with the core assembly to allow the stent to retract or retract. withdraw proximally on the catheter until the entire length of the stent has been re-sheathed on the catheter. According to some embodiments, the distal cover can be retracted or removed on the catheter in its second position or configuration, deployed, expanded, re-sheathed, or flipped over.

For example, while the stent is retracting or withdrawing back into the catheter, the distal cover can be positioned radially out of the space between the catheter and at least one of the stent or the intermediate portion to provide a free margin between them and facilitate re-sheathing for retraction of the stent and the central assembly on the catheter. Also, in some embodiments, the distal cover may be positioned in the space radially between the catheter and the distal tip structure of the core assembly. Thereafter, the catheter and / or core assembly can be repositioned axially within the vasculature at a desired location, and the stent can be unsheathed, expanded, landed, and released in the vasculature if the placement location is correct.

Therefore, according to some embodiments, the distal cover can facilitate re-sheathing of the core assembly. Re-sheathing of the core assembly can be done with or without the stent engaged or secured with the core assembly.

In some embodiments, the distal cover can also facilitate retraction and removal of the core assembly after the stent has been released into the vasculature. As noted, the distal cover can be removed on the catheter in its second position or configuration deployed, expanded, re-sheathed, or flipped over. Whether or not the stent has been released into the vasculature, the entire core assembly can be removed proximally within the catheter and removed proximally from the catheter. Thus, if the stent has been released into the vasculature, the core assembly can be removed from the catheter and a second core assembly can be inserted into the catheter in order to deploy a second stent at the treatment site. Such embodiments can provide significant advantages to a physician, including, for example, that the catheter does not need to be withdrawn and removed from the vasculature in order to deploy a first or subsequent stent at the treatment site. Accordingly, then, the vasculature either does not need to be subjected to additional stress and the operation can be performed with greater speed and efficiency.

The stent delivery system can also optionally include a steerable tip mechanism or a stent tip assembly. The steerable tip mechanism can allow a physician to avoid abrasion or perforation of the vessel wall during the procedure. In some embodiments, the steerable tip mechanism may comprise a steerable lead having a curvilinear distal end. For example, a central member of the central assembly can be configured to be steerable by being rotatable relative to a protruding member (if present) and the stent, catheter, and / or other components of the stent delivery system. The central member may comprise a central cable. In addition, the center wire may comprise a curved or arcuate distal section that can be rotated or reoriented to point the center wire in a desired direction by rotating the center wire. Accordingly, in some embodiments, rotation of the central member relative to the stent may allow the physician to avoid dislodging the stent from the vessel wall after initial expansion of the stent and also prevent abrasion or perforation of the blood vessel.

ES 2 744 583 T3

For example, in some embodiments, the stent can extend over a member projecting from the central member and can be secured between the projecting member and a restriction member. The protruding member can be rotatably coupled to or abutting the central member so that the central member can rotate relative to the stent, the protruding member, and the restriction member. Accordingly, rotation of the central member may allow a physician to adjust the position or orientation of a terminal or distal portion of the central member. Furthermore, in some embodiments, the distal portion of the central member may be formed in an arcuate or curved configuration to allow the central member to conform to tortuous vessel geometries. For example, the distal portion of the central member may comprise a curled, curved, or arcuate tip that extends distally from the central member and is oriented transverse to or bends away from a central axis of the catheter lumen.

Thus, if the treatment site is adjacent to a tortuous vessel location (for example, a sharp turn in the vessel) or a bifurcation, for example, the physician can select or control the direction in which the limb extends. central to avoid abrasions or perforations of the vessel during expansion and delivery of the stent at the treatment site.

For example, before or during removal of the stent at the treatment site, the physician may observe the position of the distal tip assembly of the central member relative to the surrounding vasculature. As the stent expands during the deployment process, it can generally be foreshortened, which may require or cause the core assembly, including the distal tip assembly, to move distally to accommodate shortening of the stent. This distal movement of the tip assembly can present an abrasion or perforation hazard, or the risk that the distal tip may engage the vessel wall in a manner that could create an abrasion or perforation in the vessel. If the clinician can identify an abrasion or perforation hazard, the clinician can assess whether reorienting the tip would allow it to move distally without producing an abrasion or perforation. The clinician can use a proximal actuator of the stent delivery system to rotate the central member, thereby rotating the distal tip of the central member. In some embodiments, the distal tip can have a curvilinear or arcuate configuration. In some embodiments, the arcuate or curved portion of the tip may be radiopaque to allow the clinician to observe through fluoroscopy or other imaging the orientation of the tip relative to the surrounding vasculature, and determine whether the tip should be rotated or reorienting to a position where further distal advancement of the central assembly is less likely to damage the vasculature. Such a position could be one where the tip points toward a less risky path (for example, at a fork, the smoothest rather than the sharpest of the turns provided at the fork, or the larger vessel rather than the smaller one. ). Thus, rotation of the distal tip can reorient the direction of the central member to avoid a bifurcation apex, a sharp turn in the vessel, or other structures of the vasculature that may pose a risk of abrasion or perforation. Thereafter, if the central member is advanced distally axially into the vasculature, a properly oriented distal tip can follow the path of the vasculature without abrading, puncturing, or damaging the vessel wall.

Furthermore, in some embodiments, the core assembly of the stent delivery system may be configured to comprise one or more rotatable protruding members mounted on the core member or core cable. The protruding member can be positioned axially adjacent a distal end of a restriction member that extends over the central member. In some embodiments, the protruding member may have an external cross-sectional profile that is sized approximately equal to or greater than the internal cross-sectional profile of the catheter. For example, the protruding member may have an external cross-sectional profile that is dimensioned larger than the internal profile of the catheter.

Furthermore, in some embodiments, the distal tip assembly or structure, for example, including the distal cover, may be configured to rotate around the central member. For example, one end of the distal cover can be rotatably coupled with respect to the central member. In this way, the stent can be configured to rotate about the central member at least in part by virtue of the rotational engagement of the distal cover.

As similarly noted above in other embodiments, a stent may extend over the protruding member and may be engaged or secured between the protruding member and the restriction member. The stent can have a diameter varying from a first part to a second part thereof as the stent engages in a friction and / or interference fit. The rotatable protruding member can allow the core assembly to exhibit torsional flexibility that can reduce the pushing force required to move the core assembly through the catheter to the treatment site.

Figures 1-6 depict a stent delivery system 100 that can be used to dispense and / or deploy a stent 200 into a hollow anatomical structure such as a blood vessel 102. Stent 200 may comprise a proximal end 202 and an end distal 204. Stent 200 may comprise a braided stent or other form of stent such as a laser cut stent, a coiled stent, and the like. Stent 200 can optionally be configured to act as a "flow diverter" device for the treatment of aneurysms, such as those found in blood vessels, including arteries in the brain or within the skull, or at other locations in the body, such as the peripheral arteries. Stent 200 may optionally be similar to 19

ES 2 744 583 T3 any version or size of the PIPELINE ™ Embolization Device marketed by Covidien of Mansfield, Massachusetts, USA The stent 200 may alternatively further comprise any suitable tubular medical device and / or other features, as described In the present memory.

As shown in Figure 1, the stent delivery system 100 depicted may comprise an elongated tube or catheter 110 that slidably receives a central assembly 140 according to the invention configured to transport stent 200 through catheter 110. Figure 2 illustrates core assembly 140 without depicting catheter 110 for clarity. The depicted catheter 110 (see Figures 1, 5, 7, and 8) has a proximal end 112 and an opposite distal end 114, an internal lumen 116 extending from proximal end 112 to distal end 114, and an internal surface 118 facing lumen 116. At distal end 114, catheter 110 has a distal opening 120 through which center assembly 140 can be advanced past distal end 114 in order to expand stent 200 within blood vessel 102. The proximal end 112 may include a catheter hub 122.

Catheter 110 may optionally comprise a microcatheter. For example, catheter 110 can optionally comprise any of the various lengths of the MARKSMAN ™ catheter available from Covidien of Mansfield, Massachusetts, USA Catheter 110 can optionally comprise a microcatheter having an internal diameter of about 0.030 inches or less, and / or an outside diameter of 3 French or less near the distal end 114. Instead of or in addition to these specifications, catheter 110 may comprise a microcatheter that is configured to percutaneously access the internal carotid artery, or a location within the distal neurovasculature of the internal carotid artery, with its distal opening 120.

Information regarding additional embodiments of catheter 110, and additional details and components that may be optionally used or implemented in the embodiments of the catheter described herein, can be found in U.S. Patent Application Publication US 2011/0238041 A1, published September 29, 2011, entitled Variable Flexibility Catheter.

Central assembly 140 may comprise a central member 160 configured to extend generally longitudinally through lumen 116 of catheter 110. Catheter 110 may define a generally longitudinal axis extending between a proximal end and a distal end thereof. As discussed herein, the distal end of catheter 110 can be positioned at a treatment site within a patient. The central member 160 may comprise an intermediate portion 814 which is the portion of the central member over or above which the stent 200 is placed or extends when the central assembly 140 is in the pre-deployment configuration, as shown in FIGS. Figures 1-5B, 13A and 13B. Stent 200 can be mounted on or extend above the middle portion of core member 160. Core member 160 can comprise a core wire. Central member 160 may have a proximal end or section 162 and a distal end or end 164. In some embodiments, distal end 164 and / or other parts of central member 160 can be tapered so that central member 164 becomes thinner as it extends distally.

Central member 160 can be engaged with, terminated at, or terminated at a distal tip. In some embodiments, the central member 160 may comprise a proximal section and a distal section. The distal section of the central member 160 may be a distal tapered section, as illustrated. The distal tapered section may have a gradual taper that continues to the distal tip of central member 160.

The distal tip of the central member 160 may comprise a distal portion or assembly 180. In some embodiments, the distal tip assembly 180 may comprise a distal tip frame 182 and / or a distal cover 400 or a stent engagement portion. The distal tip structure 182 may comprise at least one member or component that is transportable by the central member 160. In some embodiments, the at least one member may be oriented generally transverse or parallel to central member 160. For example, tip structure 182 may comprise a coil or coils, a circumferentially extending band or bands of material, a jaw or jaws and / or other structures that can pass smoothly into a vessel. Furthermore, the at least one member may comprise at least one segment of a coil or other structure.

In the illustrated embodiment, the center wire can optionally be configured to extend through distal tip assembly 180 and terminate at distal end 164. In some embodiments, center member 160 can be configured to transmit axial / longitudinal force and torque from proximal end 162 of central member 160 to distal end 164, where distal tip assembly 180 is disposed.

The distal end 164 of the central member 160 may be a flattened section of the central member 160. The distal end 164 may be flattened from a conical diameter of the central member 160 to a generally rectangular cross-section having a dimensioned thickness less than the diameter of the adjacent part of the central member. For example, distal end 164 may have a thickness of between about 0.013mm (0.0005 inches) to about 0.76mm (0.003 inches). The distal end 164 can thus be flattened from a distal portion of the central member 160 having a diameter of between about 0.76mm (0.003 inches) to about 0.127mm (0.005 inches). In some embodiments, the end

ES 2 744 583 T3 distal 164 may be a flat portion having a thickness of approximately 0.025 mm (0.001 inches). In addition, the length of the flat portion of the distal end 164 can be between about 8mm and about 15mm. In some embodiments, the length of the flat portion of the distal end 164 may be between about 10mm and about 12mm. Either in the form of the flattened wire described above or a distally extending tip coil, or other configuration, the distal end 164 may optionally be covered with or included radiopaque material, such as a radiopaque polymer. A suitable radiopaque polymer is a thermoplastic polyurethane (eg PELLETHANE ™ 80A or TECOFLEX ™) doped with a radio quencher such as tungsten or barium sulfate.

As illustrated in Figures 1-2, some embodiments of central member 160 can be configured with an arched or curved distal end 164. Distal end 164 extends distally from central member 160 and can be oriented transverse to or bent away from a central axis of catheter lumen 116. Distal end 164 can be curved or bent to form an angle of approximately 45 degrees with the longitudinal axis of central member 160. The distal end 164 can be heat set or otherwise processed to maintain the bowed / curved / angled configuration. As further discussed herein, central member 160 may be twisted or twisted to rotate arcuate or curved distal end 164 thereof to advantageously allow a physician to carefully navigate and direct distal tip assembly 180 and the central member 160 through the tortuous geometry of the vessel, thereby avoiding abrasion or perforation of the wall of a vessel.

The distal tip assembly 180 may be axially coupled adjacent to the distal end 164 of the central member 160. In addition, the central member 160 may extend into and form a core of the distal tip assembly 180, or it may be otherwise connected to the hub assembly. distal tip 180.

In some embodiments, the distal tip assembly 180 may be rotatably coupled to the distal end 164 of the central member 160. As further discussed herein, a rotatable coupling between the distal end 164 of the central member 160 and the hub assembly Distal tip 180 may allow central member 160 to rotate independently relative to distal tip assembly 180 (and possibly other components of central assembly 140). Such relative rotation can advantageously impart greater flexibility to core assembly 140 as it is passed through catheter 110 toward the treatment site. Furthermore, in embodiments where distal end 164 of central member 160 extends distally beyond distal tip assembly 180, such relative rotation may also advantageously allow distal end 164 to be rotated independently of distal tip assembly 180, thereby which can reduce any torque in stent 200, core assembly 140, and / or surrounding vasculature.

However, in other embodiments, the distal tip assembly 180 may be rigidly or fixedly coupled to the distal end 164 of the central member 160 such that the distal tip assembly 180 and the central member 160 rotate as a single unit. For example, central member 160 may be operatively coupled with distal tip assembly 180 such that distal tip assembly 180 is usable to radially direct or orient central member 160 within catheter 110 and / or a blood vessel by twisting or twisting. twisting the central member 160.

The distal tip structure 182 can be configured to comprise an atraumatic distal end face formed by a rounded bead of solder, especially in embodiments where the distal end 164 of the central member 160 does not extend distally beyond the distal tip assembly. 180. In addition, the distal tip structure 182 may have other atraumatic shapes designed to prevent damage to the vessel into which it can be inserted.

Central member 160 may be flexible enough to allow flexing and buckling as it passes through tortuous blood vessels. In some embodiments, the central member 160 may taper along at least part of its length or contain multiple tapered or stepped sections of different diameters or profiles, and become narrower and more flexible as it extends distally.

Core assembly 140 may also optionally include a proximal retention member 220 located proximal of stent 200. Proximal retention member 220 may comprise one or more materials. For example, in some embodiments, proximal retention member 220 may include a marking band 222 attached to central member 160 through a solder bead 224 or other suitable connection. Marker band 222 can be a generally cylindrical structure made of platinum or other radiopaque material. In at least one embodiment, proximal retention member 220 may be arranged in central assembly 140 such that there is a small gap, for example, from about 0.0mm to about 0.5mm, axially between band 222 of retention member 220 and proximal end 202 of stent 200.

In embodiments where the marker band 222 of the proximal retention member 220 is made of platinum or other radiopaque material / substance visible through fluoroscopy, CT scanning, X-ray, MRI, ultrasound technology, or other imaging, a user can be able to determine the location and track the progress of proximal end 202 of stent 200 within catheter 110 or blood vessel 102 by determining the location of proximal retention member 220.

ES 2 744 583 T3

Instead of, or in addition to, the depicted components of proximal retention member 220, retention member 220 may include a marker coil (not shown) or a coil or other sleeve (not shown) having a longitudinally oriented distally open lumen. which at least partially receives and surrounds proximal end 202 and / or other proximal portion of stent 200. In addition, proximal retention member 220 may also comprise a biasing member, such as a coil spring wrapped around central member 160, that can be configured to bias stent 200 in the distal direction.

Referring now to Figure 3A, system 100 may also comprise a stent retention assembly 300 configured to releasably engage a proximal portion 206 of stent 200. Stent retention assembly 300 may allow a clinician to secure, grasp or engaging proximal portion 206 of stent 200 in a manner that allows the stent to be controlled, positioned, and released at a precise and desired position within the vessel. The stent retention assembly 300 can allow a clinician to push the stent distally, pull the stent proximally, remove or move the stent distally past the distal end of the catheter, and / or recapture, fold, remove, or re-sheath the stent. in the catheter after the stent has partially expanded within the vessel.

Furthermore, the stent retention assembly 300 can be configured to achieve such superior control using only the securing, grasping, or engagement between the stent retention assembly 300 and the proximal portion 206 of the stent 200. Thus, a distal portion 210 The stent does not need to be directly subjected to or received by the pushing or pulling forces exerted by the physician. Instead, the distal portion 210 of the stent can be guided by the forces exerted on the proximal portion of the stent and generally expand freely when moved out of the catheter. Thus, the clinician can carefully control the axial position of the distal portion of the stent in order to properly land the stent within the vessel, and whenever the stent needs to be repositioned, the clinician can recapture, fold, remove, or reattach. sheath the stent onto the catheter and attempt to land the stent back into the vessel in the desired position.

The stent retention assembly may comprise one or more components that cooperate to secure, grasp, or engage a portion of the stent 200. In some embodiments, a component attached to, coupled to, carried by, or formed on the central member 160 may cooperate with other structures of the system 100 in order to provide such superior stent control.

For example, as seen in Figures 2-3A, the core assembly 140 may also comprise a restriction member or external grip member 320. The restriction member 320 may have a proximal end 322 and a distal end 324. The member Restriction 320 may comprise an elongated sheath having a central lumen extending between proximal end 322 and distal end 324. The central lumen can be configured to receive the central member 160 therethrough.

In some embodiments, the restriction member can be a simple tube or sheath. For example, the restriction member may have an internal diameter of between about 0.381mm (0.015 inches) and about 0.584mm (0.023 inches). The internal diameter can also be between approximately 0.432 mm (0.017 inches) and approximately 0.533 mm (0.021 inches). In some embodiments, the internal diameter can be about 0.432mm (0.017 inch) or about 0.533mm (0.021 inch). Furthermore, an outer diameter of the restriction member may be between about 0.457mm (0.018 inches) and about 0.711mm (0.028 inches). The outer diameter can also be between approximately 0.508 mm (0.020 inches) and approximately 0.66 mm (0.026 inches). In some embodiments, the outer diameter can be about 0.508 mm (0.020 inches) or about 0.635 mm (0.025 inches). The axial length of the restriction member can also be between about 150 cm and about 200 cm. Furthermore, the restriction member can be formed from a flexible material. For example, the restriction member can be formed from material such as PTFE, polyimide, or other such polymers.

However, the restriction member can also be configured as a structural alternative to a simple tube or sleeve. Such structures may include a distal end portion that is "fully" tubular coupled to a proximal portion that is composed of one or more longitudinal struts or cables, or that comprises a slotted or spiral cut tube. In any of the described restriction members, the distal end portion may comprise a coil (eg, a metal coil) or other form of appropriately sized proximally retractable sleeve for use in the core assembly 140.

In addition, the central assembly 140 comprises proximal and distal stop members. The abutment members may comprise a protrusion or a recess disposed along the central member 160. For example, a abutment member may comprise a protruding member or internal gripping member 340. The protruding or internal gripping member 340 may be a radially extending component. The protruding or internal gripping member 340 may be disposed along the central member 160 between the distal section 164 and the proximal section 162 thereof. For example, the protruding member 340 can be disposed axially between the proximal section 162 and the distal section of the central member 160. The stent retention assembly 300 can be configured

ES 2 744 583 T3 such that restriction member 320 and projecting member 340 cooperate to secure, engage, or grasp proximal end 202 and / or proximal portion 206 of stent 200. In addition, restriction member 320 may be longitudinally movable relative to central member 160 and / or projecting member 340 to release the proximal portion of the stent and allow it to expand within the vessel. Thus, during axial advancement or withdrawal of stent 200 within lumen 116 of catheter 110 or expansion of stent 200 within the vessel, proximal portion 206 of stent 200 can be controlled by stent retention assembly 300.

The stent retention assembly 300 can be configured such that one or more components thereof define a capture area in which at least a portion of the proximal portion of the stent can be secured, hooked, or grasped. The capture area may extend around at least a portion of the circumference of the central member 160. Accordingly, at least a portion of the circumference of the proximal portion of the stent can be secured, hooked, or grasped in the capture area.

As shown in Figure 3A, the depicted embodiment illustrates that the restriction member 320 may comprise a tube or sheath that receives a portion of the central member 160 in a lumen of the restriction member 320. The distal end 324 of the restriction member 320 it can be separated from the central member 160 to define a capture area 350 therebetween. Capture area 350 in the illustrated embodiment may be formed as a generally cylindrical shaped gap configured to receive at least the proximal end 202 of stent 200 therein. Accordingly, the distal end 324 of the restriction member 320 may at least partially circumferentially cover or surround at least the proximal end 202 of the stent 200 when the proximal end 202 is received axially within the capture area 350.

In some embodiments, a distal portion of the restriction member can fit over or extend over the proximal end of the stent. As shown in Figures 1-3A, proximal end 202 of stent 200 can be positioned in the lumen of restriction member 320; preferably, the proximal end portion of stent 200 is radially compressed slightly and is radially adjacent to the inner wall of restriction member 320. The protruding member 340 may retain the proximal portion of the stent 200 in the restriction member 320. When the protruding member 340 is positioned distal of the distal end of the restriction member 320, this can be accomplished in whole or in part by engaging, securing or gripping stent 200 between projecting member 340 and the edge of the distal opening of restriction member 320. In such embodiments, the stent 200 can be hooked, secured, or grasped in a generally axial direction. When the protruding member 340 is partially or fully positioned within the lumen of the restriction member 320, this can be accomplished in whole or in part by grasping the stent 200 between the outer surface of the protruding member 340 and the inner surface of the limb restriction 320. In such embodiments, stent 200 can be hooked, secured, or grasped in a generally radial direction. In addition, some embodiments can be provided in which the stent 200 can be hooked, secured or grasped in a direction transverse to the radial and axial directions.

In certain embodiments, the outer surface of the protruding member 340 may be tapered so that its outer diameter increases in a distal direction, and the inner surface of the restriction member 320 may be tapered to match the taper of the protruding member 340. In those embodiments, stent 200 can be grasped between the outer surface of the protruding member 340 and the inner surface of the restriction member 320, and / or between the protruding member 340 and the edge of the distal opening of the restriction member 320. .

With reference to Figures 1-4B and 7-10, preferably only a relatively small portion (e.g., significantly less than half the length, or less than 25% of the length, or less than 10% of the length) of stent 200 is axially positioned within restriction member 320. In the delivery configuration or within the catheter shown in Figure 1, the balance of the stent 200 extends distally and somewhat radially out of the distal end 324 of the restriction member 320, preferably which is radially adjacent to the internal surface 118 of the catheter 110, except where the distal portion 210 of the stent extends to a distal cover or a distal stent cover 400 (further discussed herein). For example, the axial length of the restriction member extending over the stent can be between about 4mm and 15mm. The axial length of the restriction member extending over the stent can also be between about 6mm and 10mm. Also, in some embodiments, the axial length of the restriction member extending over the stent can be about 8mm.

In addition, in the embodiment of Figure 3A, retention member 220 is shown in dashed lines to illustrate that this component can optionally be included in stent retention assembly 300. Proximal securing, gripping, or latching 206 of stent 200 can be accomplished with or without the use of retention member 220. However, in some embodiments, retention member 220 may provide a proximal limit to stent migration and tend to ensure that stent 200 does not migrate proximally as restriction member 320 moves proximally relative to the protruding member. 340 when stent 200 is being released. Retaining member 220 may be integrally formed with central member 160, such as being formed from a single continuous piece of material. However, the retention member 220 can also be formed separately from and later coupled to the central member 160. In some

In embodiments, the retention member 220 can be fixed relative to the central member 160. However, the retention member 220 may also be free to rotate and / or slide longitudinally along the central member 160.

According to some embodiments, the abutment or protruding member 340 may extend in a radial direction around at least a portion of the circumference of the central member. The protruding member may have an outer surface that extends radially beyond or is radially spaced from an outer surface of the central member. The protruding member can be generally cylindrical in shape, oval in shape or annular in shape. The protruding member can be an annular ring, a cylindrical sleeve, or other such structure. However, the protruding member may also have one or more radially extending protrusions that do not extend around the entire circumference of the central member. The protruding member can also be configured to extend along at least a portion of the axial length of the intermediate portion of the central member.

The abutment or protruding member may be formed from a material that can be shrink-fit into the central member. The abutment or protruding member can also be configured to comprise one or more materials. For example, in some embodiments, the protruding member can be formed from a material that is 30% BaSO4. The protruding member can define an axial length of between about 1mm and about 5mm. In some embodiments, the projecting member can define an axial length of between about 2mm and about 4mm. Also, in some embodiments, the projecting member can define an axial length of approximately 2mm. The protruding member can define an internal diameter of between about 0.127 mm (0.005 inches) and about 0.381 mm (0.015 inches). The internal diameter can also be between approximately 0.223 mm (0.009 inches) and approximately 0.33 mm (0.013 inches). In some embodiments, the internal diameter can be about 0.152mm (0.006 inches), about 0.178mm (0.007 inches), or about 0.279mm (0.011 inches). Furthermore, in some embodiments, the protruding member may define an outer diameter of between about 0.33mm (0.013 inches) and about 0.762mm (0.030 inches). The outer diameter can also be between about 0.483mm (0.019 inches) and about 0.635mm (0.025 inches). In some embodiments, the outer diameter can be about 0.356mm (0.014 inches) or about 0.508mm (0.020 inches).

The protruding member can be integrally formed with the central member as a single, continuous piece of material. For example, the protruding member may be an enlarged portion of the central member having a diameter or profile that is dimensioned larger than a diameter or profile of the axially adjacent portions of the central member. However, the protruding member can also be formed separately from and attached to the central member. For example, in some embodiments further discussed herein, the projecting member can be rotatably coupled to the central member. Alternatively, the projecting member can also be fixedly coupled to the central member.

Also, one or more protruding members can be used in some embodiments. For example, as shown in Figure 6, core assembly 840 is illustrated with a first projecting member 844 and a second projecting member 846 positioned along a core member 860. The first and second protruding members 844, 846 may be configured or operated in accordance with the configurations and functions discussed herein with respect to any of the protruding member embodiments. Furthermore, the first and second projecting members 844, 846 may be configured to slide relative to each other or otherwise cooperate to support the stent in the central assembly 840.

Referring again to Figure 3A, the protruding member 340 is shown as a radially prominent component that is integrally formed with the central member 160 from a continuous piece of material. The protruding member 340 is a generally cylindrical shaped component having a proximal section 342. Proximal section 342 may comprise a proximal wall extending in a radial upward direction from central member 160, an outer circumferential surface extending generally parallel to a longitudinal axis of central member 160, and / or a formed edge. between the proximal wall and the outer circumferential surface. The edge can be rounded or shaped having a generally perpendicular orientation.

The protruding member 340 may alternatively comprise a component that is separate from the central member 160 (see, for example, Figure 1). Such a protruding member may comprise, for example, a tube of polymer or other suitable material that is attached to the central member 160 through adhesives, thermal shrinkage, or any other suitable technique. In one embodiment, the protruding member 340 comprises a polymeric tube surrounding the central member 160, which passes through a lumen of the tube. One or more coils of wire rope (such as platinum or platinum alloy wire, not shown) can be wound around and welded to central member 160, and thereby interposed between the central member and polymeric tube to serve as a mechanical interlock. between them. Preferably, the tube is a heat-shrinkable material, such as PET, which is heat-shrinkable on the outer surface of the coil or coils, such that the contracted tube adheres 24

ES 2 744 583 T3 closely to the coil or coils and becomes securely attached to central member 160. A protruding member 340 that can rotate about, and / or move longitudinally along, central member 160 is you can build in a somewhat similar way. In this case, the underlying coil or coils may have a luminal inner diameter that is slightly larger than the outer diameter of the central member 160. The desired coil lumen inside diameter can be established by winding the coil or coils on an appropriately sized mandrel. The polymeric tube is then heat-shrunk on the coil (s) (or otherwise attached thereto) to form the outer portion of the protruding member 340. The resulting protruding member 340 then slides over central member 160 to its desired position therein, where the protruding member can rotate and / or translate relative to the central member. A stop or stops may be formed on the proximal and / or distal central member 160 of the rotatable / translatable projecting member 340, to establish limits for any longitudinal movement of the projecting member and allow it to rotate. Such abutment (s) may be formed in the manner described above for the fixed protruding member, with an underlying coil welded to the central member and an overlapping shrink tube, but with an outer diameter somewhat smaller than the protruding member.

As illustrated in Figure 3A, proximal portion 206 of stent 200 may extend over protruding member 340 and proximal end 202 of stent may extend into capture area 350 formed radially between restriction member 320 and central member. 160. In this embodiment, these components cooperate to form stent retention assembly 300, which can secure, engage, or grip proximal end 202 and / or proximal portion 206 of stent 200. Thus, during axial advancement or withdrawal of stent 200 within lumen 116 of catheter 110 or during expansion of stent 200 within the vessel, proximal portion 206 of stent 200 can be controlled by stent retention assembly 300. .

In particular, the protruding member 340 and the restriction member 320 may cooperate to engage, secure, or grasp the stent 200 in a snap fit, an interference fit, or a friction fit, as illustrated in Figures 3A-4B. . The presence of the protruding member 340 can create a slight increase in the diameter of the stent 200 axially adjacent to the distal end 324 of the restriction member 320. In this way, the diameter of the proximal end 202 of the stent 200 within the capture area 350 can become smaller than the diameter of the stent 200 that extends over the projecting member 340. Instead of, or in addition to, these conditions, stent 200 may be in frictional contact with a distal inner surface 331 and / or edge 332 of the side wall of restriction member 320 and proximal section 342 of projecting member 340. , thereby securing, hooking, or gripping stent 200 therebetween.

Furthermore, in some embodiments, the protruding member 340 may have an external diameter or profile that is sized approximately equal to or greater than an internal profile or internal diameter of the lumen of the restriction member 320. The relative sizing of the profiles of the protruding member 340 and the restriction member 320 can be configured such that the protruding member 340 can be positioned axially adjacent to the restriction member 320 for the purpose of "catching", securing, gripping or engaging proximal portion 206 of stent 200 into a press fit or interference fit. The external profile of the protruding member 340 may also be configured to be dimensioned less than the internal profile of the lumen of the restriction member 320 if the thickness of the stent is sufficient to create interference or otherwise restrict or slow motion of the limiting limb. protrudes 340 into or through the lumen of restriction member 320. For example, a collective outer profile of stent 200 and projecting member 340 can be sized larger than the inner profile of the lumen of restriction member 320. In some embodiments, the collective outer profile may be an outer diameter measured by adding the outer diameter. of the protruding member 340 and twice the thickness of the stent 200. However, in other embodiments, the outer and inner profiles (which can be measured as a size or shape of a cross section of the corresponding component (s)) may be non-circular, comprise one or more radial protrusions, or otherwise comprise shapes. that are other than circular or rounded.

Furthermore, while the embodiment illustrated in Figure 3A illustrates that the stent 200 can be secured, grasped, or hooked without having the protruding member 340 enter the lumen of the restriction member 320, in some embodiments the protruding member 340 extends toward or at least partially received in the lumen of restriction member 320.

Figure 3B illustrates an alternative embodiment of a stent retention assembly. As noted herein, the configuration of the central member, the stop member, and the retaining member can be varied according to various embodiments. Figure 3B illustrates a stent retention assembly 300 'in which a stop member is formed as a recess 170 within a body of a central member 160'. Recess 170 may extend circumferentially around central member 160 'to provide a capture area 350' configured to receive at least a portion of proximal end 202 'of stent 200'. Alternatively, recess 170 may comprise one or more slits into which a portion of proximal portion 206 'of stent 200' can be received.

Thus, in the illustrated embodiment of Figure 3B, the central member 160 'may have a generally constant diameter (or a conical diameter) and the recess 170 may be configured to receive at least a portion 25

ES 2 744 583 T3 of a proximal part of the stent 200 '. The diameter of central member 160 'can be dimensioned larger along a protruding member section 340' than along a proximal section extending within a lumen of a restriction member 320 '. However, the relative diameters of the central member sections 160 'can be varied and configured relative to the internal diameter or internal profile of the restriction member 320', as discussed similarly above with respect to Figure 3A. Stent retention assembly 300 'may cooperatively engage, secure, or grip a proximal portion 206' of stent 200 'to provide superior control of stent 200' during operation.

Referring again to Figure 2, the system 100 can be configured such that the restriction member 320 can be removably coupled relative to the central member 160 through a removable, detachable, or breakable (or other) coupling 360. mode, selectively longitudinally movable, adjustable, or retractable relative to central member 160). Coupling 360 is preferably located near proximal end 162 of central member 160, or at another location on the central member that is accessible to the physician outside of the patient's body, proximal of hub 122 or other proximal end portion of catheter 110. Restriction member 320 may extend distally from a proximal end 322 thereof at coupling 360 to a distal end 324 that is located slightly proximal of (or superimposed on) the projecting member 340.

A longitudinal or axial position of restriction member 320 relative to central member 160 can be maintained or modified by coupling 360. Coupling 360 can be located at a proximal location that is outside of a body lumen such that a physician It can activate the engagement 360 either to maintain or to change the relative axial positioning of the restriction member 320 relative to the central member 160. Accordingly, in some cases, a physician may disengage or break a link between coupling 360 and restriction member 320 in order to move distal end 324 of restriction member 320 relative to central member 160. The physician may hold , therefore, a stent latching, securing, or gripping using the stent retention assembly until the stent is positioned at a desired location at the treatment site. Once the stent is in the desired location and lands properly, the clinician can unhook and release the stent thereafter by actuating engagement 360 to proximally withdraw restriction member 320 relative to central member 160 (or allow subsequent removal). proximal of the restriction member).

Furthermore, in some embodiments, coupling 360 and restriction member 320 may be configured with one or more stop points along a range of longitudinal movement of restriction member 320 relative to central member 160. Such stop points they can control relative axial movement between restriction member 320 and central member 160, causing the restriction member to stop at one or more desired locations. For example, a first stop point can be provided where the restriction member 320 is in an engaged position (eg, where the proximal portion of the stent is grasped by the stent retention assembly 300). The first stop point can tactilely indicate to the physician that the restriction member 320 is positioned to grasp the proximal portion of the stent. Instead of, or in addition to, the first stop point, a second stop point may be provided that tactilely signals to the physician that the restriction member 320 has been retracted proximally relative to the central member 160 and / or the stop member. by a distance that is sufficient to ensure that the stent has been released from the stent retention assembly.

The embodiments described herein provide useful advantages. In addition to those discussed herein, the stent retention assembly can provide a system with superior flexibility and therefore reduce the dispensing force required to advance the system to the treatment site. To some extent, the stent retention assembly retains a portion of the stent in a folded configuration which will tend to decrease the amount of frictional engagement between the stent and the internal surface of the catheter, further decreasing the required dispensing force.

In addition, as further discussed herein, some examples may provide a delivery system in which the distal end of the stent automatically expands upon exiting the distal end of the catheter, thereby eliminating the need for a structure that controls characteristics. expansion of the distal end of the stent. For example, some examples described herein would not require a distal cover that would have to be rotated or otherwise moved to disengage from the distal end of the stent.

In addition, the stent retention structure can allow a physician to recapture, fold, remove, or re-sheath the stent within the catheter after partial expansion of the stent. Even in situations where the entire stent has exited the catheter lumen, some embodiments of the stent retention structure described herein may allow the clinician to recapture, fold, remove, or re-sheath the proximal portion of the stent and thereby therefore, the entire stent in the catheter lumen so that the core assembly can be removed completely or allow the stent to be repositioned and re-landed at the desired location at the treatment site.

As noted above, the stop member or projecting member of the core assembly can be integrally formed with the core member as a single continuous piece of material or formed separately from the core assembly.

ES 2 744 583 T3 central member and be coupled thereto. In some embodiments, the projecting member can be rotatably coupled to the central member.

For example, referring to Figures 4A-B, alternate embodiments of the stop member or projecting member are shown. As shown in Figure 4A, similarly to Figure 3A, the core assembly 600 comprises a restriction member 620, a distal cover 630, a protruding member 640, a core member 660, and a stent 670. The protruding member 640 can be formed from a single, continuous piece of material with the central member 660, as discussed above with respect to some embodiments.

However, Figure 4B illustrates another central assembly 700 comprising a restriction member 720, a distal cover 730, a projecting member 740, and a central member 760. The projecting member 740 is formed separately from the central member 760. The projecting member 740 may optionally be configured to rotate relative to central member 760. Accordingly, in central assembly 700, central member 760 is freely rotatable within restriction member 720, protruding member 740, and stent 770. In some such embodiments, a distal tip assembly 780 of central assembly 700 can be rotatably coupled relative to central member 760, which may allow central member 760 to also rotate freely relative to distal tip assembly 780 in place of or in addition to the protruding member 740 and the stent 770.

In embodiments using a stop member or rotatable protruding member, the core assembly can exhibit improved flexibility and also reduce torque on the stent mounted therein. Accordingly, while the core assembly is being dispensed to the treatment site, the freedom of rotation of the core member can allow the core member to adjust as it traverses tortuous pathways without transferring a torque to the stent. This improved rotational ability can reduce “thrashing”. Furthermore, the improved flexibility of the core assembly can also reduce the required dispensing force.

Furthermore, in some embodiments, the abutment member or the rotatable protruding member can be rotatably coupled relative to the central member while the distal tip assembly is fixedly coupled relative to the central member so that the assembly of distal tip and central member rotate as a unit. In such embodiments, the rotational ability of the protruding member can be affected indirectly through contact of the stent with the distal tip assembly and the protruding member. Although the stent may not be rotatably attached with relative to the distal tip assembly, the interaction between the distal tip assembly and the stent may create some resistance to rotation of the stent relative to the central member that would otherwise be freely permitted. at the interconnection of the protruding member and the central member. However, once the distal tip assembly exits the catheter and the distal end of the stent is allowed to expand, the central member is free to rotate relative to the protruding member and the stent.

According to aspects of some embodiments, the abutment or protruding member may also be configured to slide longitudinally relative to the central member, instead of or in addition to any rotational capabilities. For example, the abutment or protruding member and the central member can be configured such that the central member comprises one or more protrusions or boundaries against which the abutment or protruding member may abut to limit longitudinal (proximal) movement. or distal) of the abutment or protruding member.

The protruding member preferably comprises a relatively soft or compressible cylindrical member, and can be formed from a suitable polymer or elastomer. In some embodiments, the outer diameter of the protruding member is preferably small enough relative to the inner diameter of the catheter to prevent the protruding member from gripping or pushing the stent against the inner wall of the catheter and thereby generating significant friction between the catheter. stent and catheter. For example, as illustrated in Figure 1, the protruding member 340 may leave sufficient radial space between the outer surface of the protruding member 340 and an inner surface or wall 118 of the catheter 110 to allow the wall of the stent to move radially. between the protruding member 340 and the inner surface of catheter 118 when not otherwise restricted. Alternatively, the protruding member 340 may be sized and configured to grip the stent 200 against the inner surface 118 of the catheter 110.

In the core assembly 140 shown, the restriction member 320 and projecting member 340 can grip the stent 200 to facilitate dispensing of stent 200 through lumen 116 of catheter 110, and re-sheathing of stent 200 when expanded. partially, while completely or substantially isolating catheter 110 from the gripping forces involved in gripping stent 200 by core assembly 140. In this way, core assembly 140 can securely grip the proximal end of stent 200 - secure enough even to facilitate re-sheathing - without generating high radial frictional forces between stent 200 and inner surface 118 of catheter 110. that can impede advancement of the stent through catheter 110. Instead, only relatively light radial frictional forces can exist between stent 200 and catheter 110, generated by self-expanding stent against internal surface 118, that do not significantly impede axial advancement of stent 200 within lumen 116 of catheter 110. .

ES 2 744 583 T3

It can also be seen that stent delivery system 100 can grip stent 200 radially and / or axially between components that do not move (or need not move) relative to each other during axial movement of the stent within the lumen 116 of catheter 110, thereby reducing the friction that can arise between two components (core assembly 140 and catheter 110) that can move relative to each other a significant distance during delivery of stent 200. Catheter 110 can remain relatively stationary within the patient's vasculature while central assembly 140 and stent 200 are advanced toward and / or through the distal end of catheter 110. During this advance, the restriction member 320 and the protruding member 340 may remain stationary with respect to each other, and either one or both remain stationary with respect to the stent 200.

Structures other than the embodiments described herein of restriction member 320 and projecting member 340 in core assembly 140 can be used to move stent 200 along catheter 110. For example, restriction member 320 and the protruding member 340 can be omitted and the proximal cushion 220 employed for that purpose. Instead of, or in addition to, buffer 220, additional pads or buffers may be mounted on central member 160, underlying stent 200 and configured to cooperate with radially adjacent portions of the catheter side wall to grasp stent 200 and facilitate movement along catheter 110.

According to some embodiments, the distal tip assembly of the central assembly may comprise a distal cover configured to reduce friction between the stent (eg, the distal portion or the distal end thereof) and the internal surface of the catheter. The distal tip assembly can be configured to comprise either or both of the distal tip structure and the distal cover.

Some embodiments can be provided in which the distal cover provides a restraining force that helps maintain the distal portion of the stent in a collapsed configuration until released by the clinician. However, the distal cover of other embodiments described herein does not by itself provide a restraining force to maintain the stent at a folded diameter.

For example, the distal cover can be configured as a flexible, lubricating structure that has a first end or free section that can extend over at least a part of the stent and / or the middle part of the central assembly and a second end or fixed section that can be coupled to the distal tip structure and / or the central member at a point of attachment. The second section is directly coupled to the central member or indirectly to the central member, being coupled to the distal tip structure. The distal cover has a first dispensing position, configuration, or orientation (see, for example, Figures 1, 2, 4A, 4B, 5A, 5B, 6, 13A, 13B) in which the distal cover extends proximally relative to to the distal tip structure or attachment point and, at least partially, surrounds or covers a distal portion of the stent. In addition, the distal cover can be moved from the first or dispensing orientation to a second position, configuration or orientation or back to sheath (see, for example, Figures 7B-7C, 8-12) where the distal cover flipped so that the first end of the distal cover is positioned distally relative to the second end of the distal cover to allow re-sheathing of the core assembly 140, either with the stent 200 retained by the stent retention assembly 300, or without the stent.

Figures 5A and 5B depict embodiments of the distal cover 400. The embodiments of Figures 5A and 5B may be similar to each other in structure, function, and method of use, except for the manner in which the cover 400 is attached to the central assembly 140. . Accordingly, in the discussion herein of the distal cover 400/400 ', any mention of a component having a reference number used in Figure 5A (eg 420) should be understood to include the corresponding number reference "prime" used in Figure 5B (eg 420 '), and applied with the same force to the component so designated in Figure 5B, and vice versa.

Referring to Figures 5A-5B, core assembly 140 includes distal cover 400 which, as noted above, can be configured to reduce radial friction between stent 200 (eg, distal portion 210 or distal end 204 thereof) and the inner surface 118 of catheter 110. The distal cover 400 may include a first section or free end 420 and a second section or fixed end 440. As illustrated, second section 440 indirectly engages central member 160 through distal tip structure 182, which is further discussed below.

Furthermore, as shown in Figures 5A-5B, at least a portion of the distal cover 400 may at least partially extend or be interposed radially between the distal portion 210 of the stent 200 and the inner surface 118 of the catheter 110 in the first position. , configuration or orientation. In the first orientation, the first section 420 of the distal cover 400 may extend from the second section 440 in a proximal direction to a point where the first section interposes between the distal portion 210 of the stent 200 and the inner surface 118 of the catheter 110. In this orientation, the first section of the distal cover may take on a "proximally oriented" position or configuration.

ES 2 744 583 T3

The core assembly 140 shown in Figures 5A-5B can operate as illustrated in Figures 7A-C. Referring to Figures 7A-C, core assembly 140 can be advanced distally until distal portion 210 of stent 200 is positioned distally beyond distal end 114 of catheter 110 to allow expansion of distal portion 210 of stent. 200 into a lumen 104 of blood vessel 102. As the distal portion 210 of the stent 200 expands, it can cause the distal cover 400 to open or move from the first orientation. Because stent 200 can foreshorten as it expands, stent 200 can be withdrawn from engagement with distal cover 400, as shown in Figure 7A.

After the distal cover 400 has become disengaged from the stent 200 to achieve the state shown in Figure 7A, the cover may transition to the second orientation as shown in Figure 7B or 7C, as the blood flow to Approaching drives the first section 420 distally. Alternatively, distal cover 400 may remain substantially in the distally extending, distally extending configuration shown in Figure 7A until core assembly 140 is withdrawn proximally on catheter 110, at which point the distal end of catheter 110 may force approximation. of the first section 420 of the cover 400 to flip or otherwise assume the second configuration as shown in Figures 10 or 12. In each case, the distal cover 400 may be moved to a flipped position or configuration in which the first section 420 of the distal cover 400 is flipped, flipped or rotated to extend in a distal direction or in a position or configuration. "Distally oriented". In some embodiments of a second distally oriented configuration, all or at least a portion of the first section 420 is located distal of all or at least a portion of the second section 440.

Stent 200 can be further unsheathed (as shown in Figure 8) and subsequently released (as shown in Figure 11), or stent 200 can be retracted and withdrawn back into catheter 110 (as shown in the Figures 9-10), if necessary. In either situation, when the distal portion of core assembly 140 is withdrawn into catheter lumen 110, distal cover 400 may retract onto catheter 110 in the second position, configuration, or orientation, in which distal cover 400 can be retracted. reversing, at least partially, as shown in Figures 9-10 and 12. This can facilitate complete re-sheathing of stent 200 and / or core assembly 140 within catheter 110.

In some embodiments, in the first orientation, the first section 420 of the distal cover 400 is positioned outside of a radial space 800 located between the tip assembly 180 and the catheter 110, as shown in Figure 5. The distal cover 400 it may extend proximally from the distal portion or tip assembly 180 and from the radial space 800 between the distal portion or tip assembly 180 and catheter 110. In addition, in some such embodiments, in the second orientation, the first section 420 of the distal cover 400 extends distally through the radial space 800 upon retraction of the core assembly 140 into the catheter 110, as shown in Figures 10. and 12.

Furthermore, in some embodiments, in the first orientation, at least a portion of the distal cover 400 may extend into a radial space 804 within the catheter lumen 116 located between a distal end 812 of the intermediate portion 814 of the central member 160 and the distal end 114 of catheter 110. For example, referring to Figures 5A-B, the first section 420 of the distal cover 400 may extend or be radially interposed between the distal end 812 of the intermediate portion 814 and the inner surface 118 of the catheter 110. Furthermore, in some embodiments, in the second orientation, the first section 420 of the distal cover 400 no longer extends or no longer interposes radially between the distal end 812 of the intermediate portion 814 and the inner surface 118 of the catheter 110 (and first section 420 can be positioned distally of such location), upon retraction of core assembly 140 into catheter 110, as shown in Figures 10 and 12.

In addition, in some embodiments, the first section 420 of the distal cover 400 may radially overlap the distal end 204 of the stent 200 at a point of overlap 820 along the central member 160. As illustrated in Figures 5A-B and 12, point of overlap 820 may be located along central member 160 proximal to tip assembly 180. In some embodiments, point of overlap 820 may be spaced from about 5mm to about 12mm from the proximal end of distal tip structure 182. In some embodiments, point of overlap 820 may be spaced from about 6mm to about 10mm. mm from the proximal end of the distal tip structure 182. Additionally, in some embodiments, the overlap point 820 may be spaced approximately 8mm from the proximal end of the distal tip structure 182. The point of overlap 820 may be located at or near the distal end 812 of the intermediate portion 814 of the central member 160, or at any location along the central member 160 that underlies an overlap of the (first section 420 of the) distal cover 400 over stent 200 when core assembly 140 is in its pre-deployment configuration shown in Figures 1-5B and 13A-13B. In addition, in some such embodiments, in the second orientation, the first section 420 of the distal cover 400 no longer overlaps the (distal end 204 of) the stent 200 at the point of overlap 820 (and the first section 420 overlaps can be located distally of such location), upon retraction of core assembly 140 into catheter 110, as shown in Figures 10 and 12.

ES 2 744 583 T3

In the second orientation, as shown in Figures 7A-8, there is no longer radial overlap of stent 200 and cover 400 at overlap point 820 or at distal end 812 of midsection 814. Thus, after Upon disengagement of distal cover 400 from stent 200, core assembly 140 may be withdrawn proximally on catheter 110 and distal cover 400 will generally extend in a distal direction away from point of overlap 820. As also shown in Figures 9-10, at such a time that stent 200 is re-sheathed or removed on catheter 110 after partial expansion, stent 200 and distal cover 400 will not overlap at the point overlap 820. Thus, distal cover 400 will not overlap stent 200 or overlap point 820 after at least partial expansion of stent 200 when core assembly 140 is withdrawn into catheter 110. In addition, once distal cover 400 is disengaged, intermediate portion 814 of central member 160 can be positioned radially adjacent to distal end 114 of catheter 110 with distal cover 400 being positioned outside of radial space 804 between intermediate portion 814 and catheter 110. Accordingly, the movement and configuration of the distal cover 400 may allow the central assembly 140 to provide a radial free margin between the central member 160 or the intermediate portion 814 and the catheter 110 to facilitate re-sheathing of the central member 160, as shown in Figures 9-10 and 12.

The distal cover can be engaged relative to the central member. The distal cover may be attached to the central member and / or the tip assembly 180 of the central assembly. In some embodiments, the distal cover can be threaded onto a coil of tip assembly 180. In the embodiment shown in Figure 5A, the distal cover 400 can be directly coupled to the distal tip structure 182 and indirectly coupled to the central member 160. . In the embodiment of Figure 5A, the distal tip structure 182 is rigidly coupled to the central member 160. However, the distal tip structure 182 can also be moved relative to the central member 160, to provide rotation or sliding relative to along central member 160, as discussed below with respect to Figure 5C.

For example, distal cover 400 and / or distal tip structure 182 can be configured to rotate around central member 160. For example, one end of distal cover 400 can be rotatably coupled with respect to central member 160. Thus, stent 200 can be configured to rotate around central member 160 at least in part by virtue of the rotational engagement of distal cover 400. Accordingly, in some embodiments, the stent can rotate relative to the central member 160 while minimizing any torque on the stent.

In the embodiment of Figure 5A, distal cover 400 comprises a retractable tube 460 configured to contract and adhere second section 440 to distal tip structure 182. Alternatively, the second section 440 of the distal cover 400 may be coupled to the distal tip structure 182 through other attachment devices or means, including, but not limited to, mechanical fasteners, welding techniques, adhesives, thermal bonding, combinations thereof, or the like. In yet another alternative, the second section 440 can be directly coupled to a distal portion or to the distal end 164 of the central member 160 itself using any suitable attachment.

In some embodiments, the distal tip structure 182 may comprise at least one member that can be oriented generally transverse or parallel to the central member. For example, tip structure 182 may comprise a coil or coils, a circumferentially extending band or bands of material, a jaw or jaws, and / or other structures that can smoothly pass into a vessel at the distal portion of the central member. . Furthermore, the at least one member may comprise at least one coil segment or other structure. According to some embodiments, distal cover 400 can be coupled to distal tip structure 182 by virtue of forming an enclosure that encloses the at least one member. For example, distal cover 400 may form an enclosure that encloses at least one coil segment of distal tip structure 182 by virtue of being at least partially wrapped around the segment.

Figure 5B illustrates another embodiment of a core assembly 140 '. The core assembly 140 'comprises a core member 160', a distal tip assembly 180 '(having a distal tip structure 182' in the form of a coil), and a distal cover 400 '. The distal cover 400 'comprises a first free section 420' and a second fixed section 440 '. Second section 440 'is attached to the coil of distal tip structure 182' by passing or looping between adjacent coil windings (or otherwise through one side of the coil or around one or more coil windings), as illustrated. Second section 440 'may comprise a looped portion 442' that extends between adjacent coil windings and proximally back in contact with another portion of second section 440 '. The overlapping aspects of the looped portion 442 'and the second section 440' may be fused or otherwise bonded or bonded together to securely attach the distal cover 400 'to the distal tip structure 182'. Other components of core assembly 140 'and catheter 110' are labeled similarly to Figure 5A, as illustrated.

Figure 5C is a rear perspective view of a distal cover 400 ". The distal cover 400 "may be similar in structure, function, and method of use to the distal cover 400 (for example, as shown in Figure 5A) and / or the distal cover 400 '(for example, as shown in Figure 5A). Figure 5B), but with additional or substituted structures, functions and uses as described herein. The 400 ”distal cover can be used instead

ES 2 744 583 T3 of the distal covers 400/400 'in the construction of any embodiment of the central assembly 140. The distal cover 400 "can be coupled to a distal tip assembly 180" in a manner similar to that illustrated in the Figure 5B. However, in this embodiment, distal tip assembly 180 "comprises a distal tip structure 182" that is longitudinally and / or rotatably movable relative to central member 160 ".

In some embodiments, the central member 160 "may comprise a proximal stop 430" and a distal stop 432 ". The proximal stop 430 "and the distal stop 432" can be configured to limit the range of sliding movement of the distal tip structure 182 ". The proximal stop 430 "and the distal stop 432" can be separated from each other along the central member 160 "by a distance that allows longitudinal movement of the tip structure 182" relative to the central member 160 ". In some embodiments, stops 430 ", 432" allow substantially zero longitudinal movement of tip structure 182 "and cover 400", but allow these components to rotate around center member 160 ". The distal tip structure 182 "may comprise an internal lumen that receives the central member 160" therein, such that the distal tip structure 182 "can slide and / or rotate relative to the central member 160". For example, some embodiments of the distal tip structure 182 "may comprise a coil. In this way, distal cover 400 "can rotate and / or slide relative to central member 160". Such movement may allow distal cover 400 "to move or rotate with the stent during delivery to reduce stress and push force as center assembly 140" traverses the patient's vasculature.

The distal cover may be one or more elongated strips, wings, or portions that engage the tip assembly and / or the central member of the central assembly. In some embodiments, the distal cover comprises no more than two elongated strips, wings, or elongated portions. The elongated strips, wings, or parts can be formed as separate components that are attached to the core assembly. In addition, the elongated strips, wings, or parts can also be formed from a single continuous piece of material that is attached to the core assembly. The elongated strips, wings, or parts may have free first ends, as well as second ends that engage the central assembly. The first free ends can cover at least a portion of the distal portion of the stent during delivery of the stent. In addition, when the core assembly is withdrawn proximally into the catheter, the elongated strips, wings, or portions can be flipped over, so that the first free ends of the elongated strips, wings, or portions are drawn together distally to the second ends.

For example, the distal cover can be made or otherwise cut from a tube of the material selected for the distal cover. As illustrated in Figures 5-6, in some embodiments, the first section 420 can be formed as multiple longitudinal strips cut from the tube, and the second section 440 can be an uncut length of the tube. Accordingly, the second tubular section 440 and the proximally extending strips of the first section 420 can form a single and integral device or structure.

In some embodiments, the distal cover 400 may comprise a tube and the first section 420 may include two or more semi-cylindrical or partially cylindrical tube strips or portions separated by a corresponding number of otherwise formed or positioned longitudinally oriented generally parallel cuts or separations. on the side wall of the tube. Thus, when in the pre-expansion state, as shown in Figures 1, 2, 4, 5, and 6, the first section 420 may generally be in the form of a longitudinally split or longitudinally slotted tube. or interposed radially between the outer surface 208 of the stent 200 and the inner surface 118 of the catheter 110.

In various embodiments, the strips, wings, or elongated portions of the first section 420 may collectively span substantially the entire circumference of the outer surface 208 of the stent 200 (eg, where the cuts between the strips are divisions of substantially zero width), or be dimensioned somewhat smaller than the entire circumference (for example, where the cuts between the strips are grooves having a width other than zero). According to some embodiments, the width of the strips, wings, or elongated portions of the first section 420 may be between about 0.5mm and about 4mm. The width can be from about 0.5mm to about 1.5mm. According to some embodiments, the width can be about 1mm.

The elongated strips, wings, or portions of the first section 420 may also extend longitudinally over at least a portion of the distal portion of the stent. In some embodiments, the first section 420 may extend between about 1mm and about 3mm over the distal portion of the stent. In addition, the first section 420 can also extend between about 1.5mm and about 2.5mm over the distal portion of the stent. According to some embodiments, the first section 420 may extend approximately 2mm over the distal portion of the stent.

The first section 420 and the second section 440 may define an overall length of the distal cover 400. In some embodiments, the overall length may be between about 4mm and about 10mm. The total length can also be between about 5.5mm and about 8.5mm. In some embodiments, the total length can be about 7mm.

ES 2 744 583 T3

The strips of the first section 420 can be of substantially uniform size. For example, the first section 420 may comprise two strips that span approximately 180 degrees each, three strips that span approximately 120 degrees each, four strips that span approximately 90 degrees each, or may be otherwise divided to collectively cover the entire or part of the circumference of the stent, etc. Alternatively, the strips may differ in angular dimensioning and coverage area without departing from the scope of the description. In one embodiment, only two strips or tube portions are used in the first section 420. The use of only two strips can facilitate radial expansion, distal movement, and / or folding or flipping of the first section 420, as discussed herein, while minimizing the number of free or uncontained strips. in the lumen of the blood vessel and any possibility of damaging the vessel by virtue of contact between a strip and the vessel wall.

According to some embodiments, at or near distal end 204 of stent 200, first section 420 of distal cover 400 may be configured to flip or otherwise bend and / or within itself, thereby creating a folded portion. 480 extending or interposing radially between outer surface 208 of stent 200 and inner surface 118 of catheter 110, as shown in Figures 5A-B. As illustrated, the folded portion 480 may have an outer layer 482 and an inner layer 484, where the outer layer 482 is radially adjacent to the inner surface 118 of the catheter 110 and the inner layer 484 is radially adjacent to the outer surface 208 of the stent 200. In such embodiments, the configuration of inner layer 484, which is radially adjacent to outer surface 208 of stent 200, can advantageously facilitate expansion of stent 200 because stent 200 would not need to slide along inner layer 484. In Instead, the inner layer 484 can be turned over as the stent expands, thereby reducing any friction between the stent 200 and the distal cover 400.

Also, in some embodiments, distal cover 400 may be configured to fold back on itself, in a manner opposite to that shown in Figures 5A-B, such that layer 482 is the inner layer and layer 484 is the layer. external. In other embodiments, the first section 420 is not folded, flipped, or flipped at all, when in the first configuration or prior to expansion.

The distal cover can be manufactured using a lubricating and / or hydrophilic material, such as PTFE or Teflon®, but can be manufactured from other suitable lubricating materials or lubricating polymers. The distal cover can also comprise a radiopaque material. For example, one or more Teflon® strips can be attached to the central member or the distal tip structure in order to form the distal cover. The distal cover can define a thickness of between approximately 0.013mm (0.0005 ") and approximately 0.076mm (0.003"). In some embodiments, the distal cover can be one or more PTFE strips having a thickness of approximately 0.025mm (0.001 "). The distal cover material can also be attached by means of another material, such as shrink tube 460, fitted around the perimeter of the distal cover. Shrink tube 460 can define a radial thickness of between approximately 0.025mm (0.001 ") and approximately 0.051mm (0.002"). In some embodiments, the radial thickness of the shrink tube is approximately 0.038mm (0.0015 ") (based on a tubular shape having an internal diameter of approximately 0.406mm (0.016") had an external diameter of approximately 0.483mm (0.019 ")) . Thus, the radial free margin between the distal cover (when flipped over) and the inner surface of the catheter can be approximately 0.051mm (0.002 ") and approximately 0.102mm (0.004").

When the central assembly 140 is being removed, as shown in Figures 10 or 12, the distal cover 400 may extend distally through the annular space between the distal tip of the central member 160 and the inner surface 118 of the catheter 110 and provide a free margin between them. The free margin between the inner surface 118 and the distal cover 400 (when pushed against the distal tip of the central member 160) may be equal to or greater than the radial free margin between the outer surface of the restriction member 320 and the inner surface 118 catheter 110. Thus, as noted above, if the internal diameter of catheter 110 is approximately 0.762mm (0.030 ") and the external diameter of restriction member 320 is approximately 0.635mm (0.025"), the radial free margin between the surface internal 118 and distal cover 400 would be at least about 0.064mm (0.0025 "). In addition, as also noted herein, the outer diameter of the distal tip structure 182 can be approximately 0.381mm (0.015 ").

In operation, distal cover 400, and in particular first section 420 or folded portion 480, can generally cover and protect distal end 204 of stent 200 as stent 200 moves distally within catheter 110. Distal cover 400 may serve as a support or cushion layer that, for example, prevents the filament ends 212 of the distal end 204 of stent 200 (shown schematically in Figures 5A-B) from contacting the surface. internal 118 of catheter 110, which could damage stent 200 and / or catheter 110, or otherwise compromise the structural integrity of stent 200. Since distal cover 400 can be made of a lubricating material, distal cover 400 can exhibit a low coefficient of friction that allows distal end 204 of stent 200 to slide axially within catheter 110 with relative ease. The coefficient of friction between the distal cover and the internal surface of the catheter can be between about 0.02 and about 0.4. For example, in embodiments where the distal cover and catheter are formed from Teflon®, the coefficient of friction can be about 0.04. Such

Embodiments can advantageously improve the ability of the core assembly to pass through the catheter, especially in the tortuous vasculature.

Structures other than the herein described embodiments of distal cover 400 in core assembly 140 may be used to cover the distal end of stent 200. For example, a protective coil or other sleeve having a proximally open lumen may be employed. , longitudinally oriented. Such suitable shield coils include those described in US Patent Application Publication No. 2009/0318947 A1.

Additionally, as also noted herein, some embodiments can be configured such that the distal tip assembly (eg, distal tip structure 182) is rotatable and / or movable axially relative to central member 160. . Similarly, in embodiments where the distal tip assembly comprises only the distal cover 400, although the distal cover 400 can be fixedly coupled relative to the central member 160, the distal cover 400 can also be rotatably coupled and / or axially movable relative to central member 160. Furthermore, when the distal tip assembly comprises both the distal tip structure and the distal cover, the distal tip assembly can be rotatably and / or axially movable coupled relative to the central member; however, the distal tip assembly can also be fixedly coupled to the central member. Thus, as noted above, some embodiments of the distal cover may allow the central member to rotate freely relative to the distal cover and the stent, thereby avoiding torsional stress on the stent and / or the stent. distal cover as the core assembly is moved through the catheter to the treatment site.

As noted, embodiments of the distal cover can provide various advantages. For example, the use of the distal cover can allow the stent retention assembly to be easily pushed into the treatment site within the catheter. This can advantageously reduce the dispensing force required to move the core assembly through the catheter. Additionally, the distal tip assembly can be compactly configured and therefore provide excellent maneuverability as the stent retention assembly moves through tortuous anatomy. In addition, a flexible distal cover, such as the distal covers 400, 400 ', 400 "shown may also allow the distal portion of the stent to immediately open or radially expand as the distal portion of the stent exits the catheter. The distal cover can be easily pushed away from the first or encapsulating position or configuration so that expansion of the stent is not hindered and expansion can be predicted by the clinician. When used, this can be a significant improvement over prior art devices that used a relatively rigid tube, such as a coil to distally restrain a distal end of the stent, which could prevent or make correct expansion or deployment unpredictable. of an occlusion device, especially large diameter occlusion devices.

In addition, when the first portion 420 is flexible, can be flipped, and / or provides minimal cross section, the distal tip assembly can be easily recaptured within the catheter to facilitate re-sheathing for retraction of the catheter. core assembly within the catheter. In this way, the catheter can remain in place and the entire core assembly can be removed from it. This can allow the clinician to "telescope" one or more other occlusion devices (for example, by dispensing more than one occlusion device so that it overlaps another occlusion device) without having to remove the catheter, saving time and reducing trauma to the patient.

Figures 1 and 7-12 depict some methods of using the stent delivery system 100. First, the catheter 110 can be inserted into the patient's vasculature by a percutaneous access technique or other suitable access method. The distal end 114 of catheter 110 is then advanced to a treatment site or location in blood vessel 102. Blood vessel 102 may comprise a vein or artery, such as an artery in a brain or within a skull of the patient. As previously mentioned, catheter 110 can comprise a microcatheter. A guiding catheter can be used in place of, or in addition to catheter 110; For example, the guiding catheter may first be positioned in the vasculature so that it extends some or all of the way to the treatment site and then a microcatheter or other catheter is inserted through the guiding catheter to the treatment site.

The treatment location may be near an aneurysm (not shown) formed in a wall of blood vessel 102, and advancement of catheter 110 to the treatment location may include advancing distal end 114 and / or distal opening 120 to a location that is distal to the aneurysm. Such advancement of catheter 110 may include advancement of distal end 114 and / or distal opening 120 distally through the ostium or neck of the aneurysm, to the location in the distal vessel 102 of the aneurysm.

Once catheter 110 has been inserted, it can extend proximally from distal end 114 and / or distal opening 120 at the treatment location, through the vascular access site, to proximal end 112 and / or hub. 122, which are preferably located outside the patient's body.

ES 2 744 583 T3

After catheter 110 has been placed, core assembly 140 (with stent 200 carried by it), the first distal end, can be inserted into lumen 116 of catheter 110 through hub 122 and / or end proximal 112. When the distal portion of core assembly 140 is initially contained within an introducer sheath (not shown), the introducer sheath can be inserted midway into catheter lumen 116 and core assembly 140 is advanced distally through the introducer sheath to the distal portion and stent 200 exit the distal end of the introducer sheath and pass into (direct contact with) the lumen 116 of catheter 110. Core assembly 140 and stent 200 are at that point disposed on catheter 110 generally as depicted in Figure 1, but at a proximal portion of catheter 110. In particular, stent 200 and the distal portion of core assembly 140 may be positioned in lumen 116 of catheter 110, with proximal end 202 of stent 200 received in restriction member 320 and the remaining portions of stent 200 extending distally and generally in contact with the inner surface 118 of the catheter, except where the first section 420 of the distal cover 400 is extending or interposed radially between the distal end 204 of the stent 200 and the inner surface 118 of the catheter 110. In addition, central member 160 and restriction member 320 may extend proximally from proximal end 112 and / or hub 122 of catheter 110 to a location outside of the patient's body so that coupling 360 and ends are easily accessible. proximal 162, 322 of central member 160 and restriction member 320.

The central assembly 140 with stent 200 can then be advanced axially distally within lumen 116 of catheter 110, toward distal end 114 of catheter 110 and the treatment location. In general, during advancement of core assembly 140 into catheter 110, restriction member 320 and projecting member 340 can secure, grip, or engage stent 200 to facilitate pushing of the stent distally through catheter 110, substantially without transmit any clamping force to catheter 110 or otherwise independently of catheter 110. Restriction member 320 and projecting member 340 can secure, grip, or engage stent 200 during distal advancement through catheter 110 without relative axial movement between restriction member 320 and projecting member 340, while member restriction 320, protruding member 340 and stent 200 move distally relative to catheter 110 and the vasculature.

As stent 200 and distal cover 400 are advanced toward distal end 114 and the treatment location, first section 420 of distal cover 400 remains radially extending or interposed between outer surface 208 and / or distal end. 204 of stent 200 and inner surface 118 of catheter 110. In this manner, distal cover 400 may prevent distal end 204 of advancing stent 200 (eg, filament ends 212 thereof) from damaging, wearing, or pinching catheter 110, thereby impeding progress of stent 200. along catheter 110. This, in turn, can prevent damage to stent 200 such as longitudinal compression resulting from the high friction generated between distal end 204 of stent 200 and catheter 110 while a distally directed force is applied to proximal portions of stent 200. .

When the treatment location is near an aneurysm and the distal end 114 and / or the distal opening 120 of catheter 110 has been advanced to a location that is distal to the aneurysm, the advancement of central assembly 140 with stent 200 toward the distal end 114 and the treatment location may include advancing the distal portion of core assembly 140 and distal end 204 of stent 200 distally through catheter 110 through the ostium or neck of the aneurysm, to a location in the distal vessel 102 of the aneurysm.

To begin expansion of stent 200 (see Figure 7, i.e., Figures 7A-7C), core assembly 140 can be held stationary and catheter 110 can be withdrawn proximally over stent 200 and the distal portion of core assembly. 140, until distal end 114 of catheter 110 is uniform with or proximal of distal end 324 of restriction member 320 or uniform with or proximal of proximal end 202 of stent 200 or proximal retention member 220, as shown in Figure 8. (Optionally, the core assembly and stent can be advanced distally while performing this step, instead of or in addition to removal of the catheter). As a result, stent 200 (except for the portion retained in restriction member 320) can be released and allowed to expand in engagement with the inner wall of blood vessel 102, as shown in Figure 8. Some embodiments of stent 200 (such as certain braided stents) can be shortened axially while expanding radially. As a result of (i) any axial foreshortening of stent 200, (ii) radial expansion of stent 200, and / or (iii) radial expansion of distal cover 400 in response to radial expansion of stent 200, the strips or The tubing portions of the first section 420 of the distal cover 400 may disengage from contact with the distal end 204 of the stent 200, while in some embodiments they also separate and move radially outward.

In some examples, as distal cover 400 disengages from the stent, it unfolds or otherwise unravels from its folded configuration 480 (see Figures 7-8). Once distal cover 400 is disengaged or disengaged, it no longer covers distal end 204 of stent 200; instead, its first section 420 is now spaced distally from the stent's distal end 204 as shown in Figures 7-8. In this state, the strips or tube portions that form the proximal end may be free or unconfined within the lumen of blood vessel 102. As similarly noted above, the strips or tube portions

ES 2 744 583 T3 may have free first ends, as well as second ends that mate to the core assembly 140. The free first ends may cover at least a portion of the distal portion of the stent during stent delivery. In addition, when the stent is expanded and / or the core assembly 140 is withdrawn proximally into the catheter, the strips or tube portions can be turned over, so that the first free ends of the elongated strips, wings, or portions are they draw the second ends thereof together distally.

Retraction of catheter 110 (and / or distal movement of core assembly 140) and expansion of stent 200 can be done in multiple discrete steps. For example, catheter 110 may initially be retracted proximally only part of the way to the location depicted in Figures 7A-C, and only distal portion 204 of stent 200 expands in engagement with the vessel wall. Such initial partial expansion facilitates anchoring of the distal portion of the stent in vessel 102, which in turn facilitates longitudinal stretching or compression of stent 200 as desired by the clinician during or prior to expansion of the remaining portions of the stent 200 in vessel 102. Initial partial expansion may also facilitate clinician confirmation that the distal portion of stent 200 has "landed" in the desired location in vessel 102 (eg, distal to the neck or ostium of any aneurysm formed in the wall of the vessel) prior to expansion of the remaining portions of stent 200. Generally, when an aneurysm is present in vessel 102, proper placement of stent 200 may include placing a distal portion of stent 200 in the lumen of the distal aneurysm neck vessel and a proximal portion of the stent in the lumen of the proximal vessel of the aneurysm. neck of the aneurysm, such that stent 200 extends through the neck. When the expanded stent 200 is properly configured, it can then perform a flow-diverting therapeutic function with respect to the aneurysm.

While the stent delivery system 100 is in the configuration shown in Figure 8, with the proximal end 202 of the stent 200 retained within the restriction member 320, the partially expanded stent 200 can be proximally re-sheathed or retracted into the tube. catheter 110 as shown in Figures 910. The coupling mechanism, for example, restriction member 320 and projecting member 340, may secure, grip, or engage stent 200 to a sufficient degree to allow catheter 110 to be advanced distally over partially expanded stent 200 ( and / or central member 160 withdrawn proximally relative to catheter 110) until stent 200 is repositioned in lumen 116 of catheter 110. In this way, the central assembly coupling mechanism 140 can exert a proximal force on stent 200 as stent 200 is withdrawn or retracted into catheter 110.

Figure 9 shows a first aspect of a re-sheathing process of stent 200, in which stent 200, including distal end 204, has been attracted into lumen 116 of catheter 110. Because the stent pre-engaging portion (eg, first section 420) of distal cover 400 has moved radially outward from central member 160 and / or distally relative to central member 160, it does not prevent entry. of the distal portion and distal end 204 of stent 200 into distal opening 120 of catheter 110 during re-sheathing. Accordingly, the re-sheathing process of Figures 9-10 may comprise moving stent 200 (including distal end 204) into catheter 110 through distal opening 120 while the portion pre-engaging the stent (by For example, the first section 420) of the distal cover 400 is in a second configuration, flipped or re-sheathed, wherein the stent engaging portion is disposed radially outward from the center member 160 and / or the first section 420 of the distal cover 400 is distally distal relative to the center member 160, the second section 440, and / or the distal tip structure 182, compared to a first encapsulating or dispensing configuration (eg, FIG. 1) of the stent engaging portion (eg, first section 420) of distal cover 400.

While Figure 9 illustrates an initial aspect of the re-sheathing process, Figure 10 shows a second aspect of the re-sheathing process currently under discussion. In this aspect of the process, core assembly 140 can be further moved proximally within catheter 110 (and / or catheter 110 is further moved distally over core assembly 140) until distal cover 400 enters catheter 110 through distal opening 120. As noted above, the first section 420 of the distal cover 400 is preferably flexible enough to be flipped over and thereby obtain the second, flipped or re-sheathed configuration shown in Figures 9-10. In the second configuration, flipped or re-sheathed, the first section 420 of the distal cover 400 may extend generally in a distal direction, away from the stent 200, and / or extend distally from the second section 440 of the cover. distal 400. In addition, first section 420 of distal cover 400 may also radially overlap distal tip structure 182. Instead of, or in addition to, these aspects of the second flipped or re-sheathed configuration, distal cover 400 may be radially small enough to extend into lumen 116 of catheter 110, or partially as depicted in FIG. Figure 9, either fully as depicted in Figure 10, and / or the entire distal cover 400 can be detached distally from the distal end 204 of stent 200 at lumen 116 of catheter 110.

Accordingly, according to some examples of methods described herein, when operating the stent delivery system, a physician can check the initial partial expansion of the stent 200 (eg, as shown in Figures 7A-8) and , if the initial placement is unsatisfactory or if the initial expansion of the

ES 2 744 583 T3 stent 200 is unsatisfactory, the physician may recapture, fold, remove or re-sheath stent 200 onto catheter 110, as previously described with respect to Figures 9 and / or 10. After re-wrapping sheathing, the clinician may attempt to land the stent again, as described herein, starting with, for example, the state depicted in Figure 9 or 10, and resulting, for example, in the state depicted in Figure 7A. . A re-sheathing can also be performed, and the stent delivery system 100 and stent 200 are completely removed from the patient, if, for example, delivery and / or expansion of stent 200 damages or reveals a defect in, or improper sizing of either the stent 200 or the delivery system 100. After an initial partial expansion of stent 200, the depicted core assembly 140 can optionally be completely removed with stent 200 from catheter 110 without the need to remove catheter 110 from blood vessel 102. In this manner, access to the treatment site into blood vessel 102 can be maintained through catheter 110 and, if desired, additional attempts can be made to dispense stent 200 through catheter 110.

If the initial expansion of stent 200 in vessel 102 is successful, full expansion can be completed to result in the state depicted in Figure 11. Coupling 360 is removed, broken, or otherwise disengaged to allow the restriction member 320 is moved relative to central member 160. Proximal end 202 of stent 200 can then be released from restriction member 320 and protruding member 340 by keeping central member 160 stationary and withdrawing restriction member 320 proximally relative to central member 160 and stent 200 until the end distal 324 is approximately uniform with the proximal retention member 220, or otherwise proximal of the proximal end 202 of stent 200. (If distal end 114 of catheter 110 has not yet been withdrawn to a proximal location of proximal end 202 of stent 200, that can also be done.) No longer constrained by restriction member 320 and projecting member 340, proximal end 202 of stent 200 can now expand in contact with vessel wall 102, as shown in Figure 11. (Note that up to this point, according to one aspect of some examples, the partially expanded stent 200 had been completely re-sheathed). When vessel 102 includes an aneurysm, proximal end 202 is preferably located in proximal vessel 102 of the neck of the aneurysm after expansion.

After complete expansion of stent 200, core assembly 140 can be drawn back onto catheter 110, as shown in Figure 12. Both catheter 110 and core assembly 140 can be removed from the patient, or simultaneously or sequentially. However, when the stent has been successfully delivered, core assembly 140 can also be completely removed from catheter 110, with catheter 110 remaining in place, and a second core assembly can be inserted into the lumen. The second core assembly can be configured to deliver a second stent to the treatment site in order to perform, for example, a telescopic procedure.

In another example of a method, the stent 200 may be initially partially expanded (eg, as shown in Figure 8) into a blood vessel 102 where a branch vessel (not shown) joins the blood vessel at a junction located along the portion of vessel 102 where stent 200 has partially expanded. The patency of the branch vessel can then be checked, for example, by injecting a contrast agent near the confluence and observing through, for example, fluoroscopy whether the agent can flow from vessel 102 into the branch vessel. In this way, it can be determined whether a portion of the stent 102 has occluded the branch vessel. If the branch vessel appears to have been occluded, stent 200 can be repositioned within vessel 102 without re-sheathing, or stent 200 can be re-sheathing using any of the techniques discussed herein. After re-sheathing, the stent 200 can be partially expanded again, and the patency of the branch vessel is again checked.

Numerous references are made to moving catheter 110 axially on core assembly 140, and moving core assembly 140 axially within catheter 110. Except where specifically noted otherwise, all such references to one form of this relative movement should be understand that it includes the other as an alternative.

As discussed above, stent delivery system 100 can also be configured to allow the clinician to control articulation and delivery of the system by orienting a portion of the system. For example, referring to Figures 13A-B, the stent delivery system 100 may optionally include a stent tip assembly 900. The steerable tip assembly 900 can allow a physician to avoid a perforation or abrasion of the vessel wall from a vessel bifurcation or a sharp turn in the vessel while the procedure is being performed. As noted above, in some embodiments, steerable tip assembly 900 may include central member 160, which may have a curvilinear distal end 164. Optionally, in some embodiments, the steerable tip assembly 900 may be employed with one or more protruding members 340 that are rotatably mounted on the central member 160. Accordingly, the central member 160 can be configured to be steerable during expansion of the stent, or when the stent is in the catheter or partially expanded within the vessel while being rotatable relative to stent 200, catheter 110, and / or other components. of the stent delivery system 100.

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In use, the physician can advance stent delivery system 100 to the treatment location axially within vessel 102. In preparation for deployment and expansion of stent 200, the clinician can inspect the surrounding vasculature of the treatment site and determine if there is a risk of having the distal end of the central member wear or puncture a vessel wall as the central member is advanced distally as anticipated during expansion of the stent or during advancement of system 100 to the treatment location. In general, central member 160 and distal tip assembly 180 are often advanced distally in the course of expansion of a stent, so anticipated distal movement may result from deployment of the stent near a bifurcation or sharp turn in the glass. If there is a risk that an abrasion or perforation of a vessel may occur, the clinician can carefully land the stent and thereafter (or beforehand) rotate the central member to reorient or redirect the distal end or point of the member. central toward the vessel path and away from the vessel wall.

The risk of abrasion or perforation can be substantially greater when the treatment location is adjacent to a bifurcation or sharp turn in the vessel. For example, Figures 13A-B illustrate a scenario in which an apex 940 of a branch 942 is in the anticipated path of the distal end 164 of the central member 160. Thus, if distal end 164 is advanced distally toward apex 940 in the position, configuration, or orientation shown in Figure 13A (and especially if the central member and distal tip are straight and not curved), there is a probability of that the apex of the bifurcation is worn away or pierced by the distal tip of the central member.

However, as shown in Figure 13B, in order to avoid abrasion or perforation, the distal end 164 of the central member 160 can be rotated to reorient the curved portion of the distal end 164 toward a less risky path, such as a desired branch glass. The distal end 164 can be formed from a radiopaque material to make the distal end 164 visible under electromagnetic radiation or other imaging, and thus facilitate the physician's recognition of the orientation of the distal end 164 with respect to to the surrounding vasculature. Having observed the orientation of the distal end 164, the physician can determine how to "target" the distal end 164 of the central member 160 to avoid abrasion or perforation of the vessel wall. For example, according to some embodiments, after determining the appropriate direction after viewing the position of distal end 164, the physician can rotate and reorient distal end 164 to point center member 160 in a desired or lower risk direction by rotating one end. proximal central member 160. Furthermore, as noted herein, rotation of the central member relative to the stent can allow the physician to avoid dislodging the stent from the vessel wall after initial expansion of the stent and also prevent abrasion or perforation of the blood vessel. In this way, the stent delivery system may advantageously allow a physician to orient and control the articulation of the stent delivery system to ensure that vessels adjacent to the treatment site are not damaged as the stent is deployed and the core assembly is advanced 140.

Information regarding the stent delivery system 100, and additional details and components that may be optionally used or implemented in the stent delivery system described herein, can be found in US Patent Application Publications. US 2011/0152998 A1 and US 2009 / 0318947A1. The stent delivery system 100 described herein may optionally be similar to any of the delivery systems described in these publications, except as further described herein.

The apparatus and methods discussed herein are not limited to the expansion and use of a stent or occlusion device within any particular vessel, but can include any number of different types of vessels. For example, in some aspects, the vessels can include arteries or veins. The glasses may have forks and / or sharp turns. The vessels can be supra-thoracic vessels (for example, vessels in the neck or higher), intrathoracic vessels (for example, vessels in the thorax), subthoracic vessels (for example, vessels in the abdominal area or lower), lateral thoracic vessels (for example, vessels on the sides of the chest, such as vessels in the shoulder area and beyond), or other types of vessels and / or branches thereof.

Supraracic vessels can comprise at least one of intracranial vessels, cerebral arteries and / or any branch thereof. For example, supratoracic vessels may comprise at least one of a common carotid artery, an internal carotid artery, an external carotid artery, a middle meningeal artery, superficial temporal arteries, an occipital artery, a lacrimal (ophthalmic) artery, a meningeal artery. accessory, an anterior ethmoidal artery, a posterior ethmoidal artery, a maxillary artery, a posterior auricular artery, an ascending pharyngeal artery, a vertebral artery, a left middle meningeal artery, a posterior cerebral artery, a superior cerebellar artery, a basilar artery, a left internal acoustic (labyrinthine) artery, an anterior inferior cerebellar artery, a left ascending pharyngeal artery, a posterior inferior cerebellar artery, a cervical artery deep, a higher intercostal artery, a costocervical trunk, a subclavian artery, a middle cerebral artery, an anterior cerebral artery, an anterior communicating artery, an ophthalmic artery, a posterior communicating artery, a facial artery, a lingual artery, a superior laryngeal artery, a superior thyroid artery, an ascending cervical artery, a inferior thyroid artery, a thyrocervical trunk, a

ES 2 744 583 T3 internal thoracic artery and / or any branch thereof. Supraracic vessels may also comprise at least one of a medial orbitofrontal artery, a recurrent (Heubner's) artery, medial and lateral lenticulostriate arteries, a lateral orbitofrontal artery, an ascending frontal artery (candelabra), an anterior choroidal artery, pontine arteries, an internal acoustic (labyrinthine) artery, an anterior spinal artery, a posterior spinal artery, a posterior medial choroidal artery, a posterior lateral choroid artery and / or branches thereof. The supraracic vessels may also comprise at least one of the perforating arteries, a hypothalamic artery, lenticulostriate arteries, a superior pituitary artery, a lower pituitary artery, an anterior thalomostriate artery, a posterior thalomostriate artery and / or branches thereof. Supraracic vessels may also comprise at least one of a precentral (pre-Rollandic) and central (Rollandic) arteries, anterior and posterior parietal arteries, an angular artery, temporal arteries (anterior, middle, and posterior), a paracentral artery, an artery pericallosal, a callosomarginal artery, a frontopolar artery, a precuneal artery, a parieto-occipital artery, a calcarine artery, an inferior vermian artery and / or branches thereof.

Supraracic vessels may also comprise at least one diploic vein, an emissary vein, a cerebral vein, a middle meningeal vein, superficial temporal veins, a frontal diploic vein, an anterior temporal diploic vein, a parietal emissary vein, a temporal diploic vein posterior, an occipital emissary vein, an occipital diploic vein, a mastoid emissary vein, a superior cerebral vein, efferent pituitary veins, infundibulum (pituitary stalk) and long pituitary portal veins, and / or branches thereof.

Intrathoracic vessels can comprise the aorta or branches thereof. For example, intrathoracic vessels may comprise at least one of an ascending aorta, a descending aorta, an arch of the aorta, and / or branches thereof. The descending aorta can comprise at least one of a thoracic aorta, an abdominal aorta and / or any branch thereof. The intrathoracic vessels can also comprise at least one of a subclavian artery, an internal thoracic artery, a pericardiacophrenic artery, a right pulmonary artery, a right coronary artery, a brachiocephalic trunk, a pulmonary trunk, a left pulmonary artery, an anterior intraventicular artery , and / or branches thereof. Intrathoracic vessels may also comprise at least one of a lower thyroid artery, a thyrocervical trunk, a vertebral artery, a right bronchial artery, an upper left bronchial artery, a lower left bronchial artery, aortic esophageal arteries, and / or branches thereof. .

The intrathoracic vessels may also comprise at least one of a right internal jugular vein, a right brachiocephalic vein, a subclavian vein, an internal thoracic vein, a pericardiacophrenic vein, a superior vena cava, a right superior pulmonary vein, a left brachiocephalic vein, a left internal jugular vein, a left superior pulmonary vein, an inferior thyroid vein, an external jugular vein, a vertebral vein, a right higher intercostal vein, a right intercostal vein 6^to, an azygous vein, an inferior vena cava, a left upper intercostal vein, an accessory hemiazygous vein, a hemiazygous vein and / or branches thereof.

The subthoracic vessels may comprise at least one of the renal arteries, inferior phrenic arteries, a celiac trunk with common hepatic, left gastric and splenic arteries, superior adrenal arteries, a middle adrenal artery, a inferior adrenal artery, a right renal artery, a subcostal, right lumbar arteries ia to 4a, common iliac arteries, one iliolumbar artery, one internal iliac artery, lateral sacral arteries, an external iliac artery, a testicular (ovarian) artery, an ascending branch of the deep circumflex iliac artery, a superficial circumflex iliac artery, an inferior epigastric artery, a superficial epigastric artery, a femoral artery, a vas deferens, and a testicular artery, a superficial external pudendal artery, a deep external pudendal artery and / or branches thereof. The subthoracic vessels may also comprise at least one of a superior mesenteric artery, a left renal artery, an abdominal aorta, a inferior mesenteric artery, colic arteries, sigmoid arteries, a superior rectal artery, 5th lumbar arteries, a middle sacral artery, an upper gluteal artery, an upper umbilical and bladder artery, an obturator artery, a lower bladder artery and a vas deferens artery, a middle rectal artery, an internal pudendal artery, an inferior gluteal artery, cremasteric and pubic branches (anastomotic obturator) of the inferior epigastric artery, a left colic artery, rectal arteries and / or branches thereof.

The lateral thoracic vessels may comprise at least one of the brachial arteries, a transverse cervical artery, a suprascapular artery, a dorsal scapular artery and / or branches thereof. The lateral thoracic vessels may also comprise at least one of an anterior circumflex brachial artery, a posterior circumflex brachial artery, a subscapular artery, a circumflex scapular artery, a brachial artery, a thoracodorsal artery, a lateral thoracic artery, a lower thyroid artery, a thyrocervical trunk, a subclavian artery, a superior thoracic artery, a thoracoacromial artery and / or branches thereof.

Delivery system 100 may include an expandable occlusion device (eg, stent 200) configured to be placed through an aneurysm. The occlusion device can be dispensed through the distal portion of the catheter, out of a distal tip assembly, and into the vasculature adjacent to an aneurysm in, for example, the middle cerebral artery. A proximal part of the catheter may remain partially or totally within a guiding catheter during dispensing, and an intermediate part, a conical part, and a distal part of the catheter

ES 2 744 583 T3 may extend distally from the guide catheter. The occlusion device can be released at the target location and can be used to occlude blood flow to the aneurysm. The catheter can be used to reach target locations (eg, aneurysms) located in other parts of the body as well, including, but not limited to, other arteries, branches, and blood vessels, such as those described above.

The apparatus and methods discussed herein are not limited to the deployment and use of an occlusion device or stent within the vascular system, but may include any number of additional treatment applications. Other treatment sites may include areas or regions of the body such as organ bodies.

Although the detailed description contains many specific details, these should not be construed as limiting the scope of the technology in question, but merely as illustrating different examples and aspects of the technology in question. It should be appreciated that the scope of the technology in question includes other embodiments not discussed in detail above. Various other modifications, changes, and variations may be made in the arrangement, operation, and details of the subject technology described herein without departing from the scope of the present disclosure, as defined in the appended claims. Unless stated otherwise, reference to an element in the singular is not intended to mean "one and only one" unless explicitly stated, but rather is intended to mean "one or more".