Debulking catheter

Catheter to remove atheromatous or thrombotic occlusive material

The present invention relates, in general, to systems for extracting materials from body lumens. More particularly, the present invention relates to atherectomy catheters for excision of atheroma and other materials from blood vessels and stents.

Frequently, cardiovascular disease is the result of the accumulation of atheromatous material on the inner walls of vascular lumens, particularly arterial lumens of the coronary vasculature and other vasculatures, resulting in a condition known as atherosclerosis. Atherosclerosis occurs naturally as a result of aging, but it can also be aggravated by factors such as diet, hypertension, inheritance, vascular injury and the like. Atheromatous deposits and other vascular deposits restrict blood flow and can cause ischemia, which in acute cases, can result in myocardial infarction. Atheromatous deposits can have very variable properties, some being relatively soft and others being fibrous and / or calcified. In the latter case, deposits are often called plaque.

A conventional treatment for cardiovascular disease is the use of stents. Endoluminal stents are commonly used to treat clogged or weakened body lumens, such as blood vessels and other vascular lumens. Once deployed in the blood vessel, the stent can remain in the body lumen, where it will maintain the permeability of the lumen and / or support the walls of the surrounding lumen. One factor that prevents the success of stent technology in endoluminal treatments is the frequent occurrence of intra-stent restenosis, characterized by the proliferation and migration of smooth muscle cells within and / or adjacent to the implanted stent, causing a new closure. or blockage of the body lumen.

Atherosclerosis and restenosis can be treated in a variety of ways, including drugs, bypass surgery and a variety of catheter-based approaches, which are based on intravascular removal or removal of atheromatous material or other material that occludes a blood vessel. Particularly interesting for the present invention, a variety of procedures have been proposed for cutting or detaching material and removing said material from the blood vessel, generally referred to as atherectomy procedures. Atherectomy catheters intended to extract materials from the lumen of the blood vessels generally employ a rotating and / or axially transferable cutting blade that can be advanced into or beyond the occlusive material, in order to cut and separate said material from the lumen of the blood vessel. In particular, lateral cut atherectomy catheters generally employ a housing that has an opening on one side, a blade that is rotated or advanced through the opening, and a balloon to force the opening against the material to be removed.

US5695506 describes a catheter device for use in a biological conduit, in which the catheter device has a catheter body with a housing and a lumen for torsion cable, a torsion cable, a work element and a connector. The preamble of claim 1 attached is based on this description.

Although atherectomy catheters have proven very successful in the treatment of many types of intra-stent atherosclerosis and restenosis, conventional catheter designs suffer from certain limitations. For example, many lateral cut atherectomy catheters have difficulty capturing occlusive material in the cutting opening. To facilitate the capture of the material, frequently, the cutting opening is elongated to increase the area into which the material can penetrate. Although such elongation is effective, it requires equivalent elongation of the blade housing. Because most blade housings are rigid, such elongation makes it difficult to introduce the distal end of the catheter through tortuous regions of the vasculature. In addition, typically, conventional atherectomy catheters require a balloon positioned opposite the cutting window, to force the material into the cutting window. However, said balloons unduly increase the size of the distal catheter. Even with the balloon, the amount of material that can be removed by conventional atherectomy catheters is limited by the size of the cutting window.

For these reasons, it is desired to provide atherectomy catheters that can access small tortuous regions of the vasculature and that can withdraw atheromatous materials and other occlusive materials from inside the blood vessels and stents in a controlled manner. In particular, it is desired to provide atherectomy catheters that can facilitate the capture and invagination of atheromatous materials. Catheters and procedures for use in a variety of body lumens, including but not limited to coronary arteries and other arteries. The catheter and the method of the present invention, described below and in the claims, will achieve at least some of these objectives.

The present invention provides a catheter as described in claim 1. The catheters of the present invention are for use in a variety of body lumens, including, but not limited to, intravascular lumens, such as the coronary artery and other blood vessels. .

In one aspect, the catheters of the present invention may include a flexible proximal portion coupled to a rigid distal portion. A tissue extraction assembly may be arranged inside the rigid part to extract material from the body lumen. In exemplary embodiments, the rigid part is rotatably coupled to the flexible part, so that the rotation or deflection of the rigid part, in relation to the flexible part, can expose the tissue extraction assembly through a window in the catheter to extract material from the body lumen.

In exemplary embodiments, the movement of the material extraction assembly causes the diversion of the distal part. For example, the movement of the material extraction assembly, from a distal position to a proximal position can cause the distal part to deviate and cause the material extraction assembly to move out of the window, beyond an outside diameter of the catheter body.

The rigid distal part of the catheter can be rotatably coupled to a flexible part of a catheter through a connection assembly, such as one or more articulation elements, pivot bolts, one or more flexible joints or the like. A longitudinal axis of the distal part of the catheter body will form an angle or be offset with respect to a longitudinal axis of the blade and the rest of the catheter when it is deflected from the proximal part of the catheter. The deflection of the distal part of the catheter body to an angled or displaced configuration relative to the rest of the catheter body can force the distal part against the body lumen, to move the material extraction assembly against an opposite side of the wall of the lumen. Because the diversion of the distal part can increase the profile of the catheter and can displace the material extraction set against the body lumen without the use of a balloon, and because the material extraction assembly can be exposed outside of the window beyond a diameter of the distal part, so that the target tissue does not have to invade the window, the size of the rigid part of the catheter and the window (both longitudinally and radially) can be reduced to allow catheters to reach tortuous and smaller diameter body lumens and to reduce trauma to the body lumen (e.g., barotrauma due to the balloons) during the advance to the target site. In exemplary embodiments, the distal portion of the catheter includes a rigid housing that has a rigid length of about 6 mm to 8 mm.

The tissue material extraction assembly can take a variety of forms. In the embodiments, the tissue material extraction assembly is a mobile rotating blade having a cutting blade with serrated or smooth edge. Typically, the rotating blade is coupled to a drive shaft and a drive, so that activating the drive with an input device can activate the movement and / or rotation of the blade. In such embodiments, the blade can rotate automatically as the blade is moved out of the cutting window. Advantageously, the user will only have to activate a single switch or handle to activate the blade, deflect the blade against the material to be removed, and activate the rotation of the blade.

Depending on the type of occlusion in the body lumen, certain blade designs are more effective than other blade designs. In a specific embodiment, the blade may include a serrated blade. In other embodiments, the blade may include a non-serrated blade that has been found to be more effective in removing intra-stent restenosis. Optionally, the intra-stent restenosis blade may include a protuberance along its edge to reduce the interaction of the cutting edge with the stent

Typically, the deflection of the distal part of the catheter is caused by the actuation of an input device. For example, the input device can control the movement of the material extraction assembly between a first position and a second position. When the material extraction assembly is in a first position, it will be disposed within the catheter. The movement of the tissue material extraction assembly from a first position to a second position causes rotation / deflection of the rigid part relative to the flexible part and exposes the tissue material extraction assembly through the window. Next, the entire catheter body can be advanced through the body lumen to extract material from the body lumen with the set of extraction of exposed material.

In some embodiments, the blade is exposed through the window by contacting the blade with cams

or ramps on the distal part of the catheter as the blade is displaced proximally through the window. The interaction of the blade with the cams misaligns the distal part of the catheter with respect to the blade and the proximal part of the catheter and exposes the blade through the window. Typically, the blade is displaced outside the window beyond an outside diameter of the catheter body to extract the target tissue material. As the blade is displaced distally, the blade will move back to the window and lose coupling with the cams, and the distal part of the catheter will re-align with the rest of the catheter body. Said movement 3 10

from the distal part of the blade will align the blade with the tip so that the cut material can be directed to a collection chamber at the distal tip.

In some embodiments, a flexible distal tip may be attached to the rigid distal part of the catheter. The distal tip can be attached, detachably or integrally, to the distal part of the catheter. By integrating the tip with the distal part of the catheter body, the joint between the tip and the catheter body is removed, thereby providing a continuous inner diameter from the housing to the tip, resulting in better tissue packaging. In some embodiments, the distal tip has decreasing stiffness in the distal direction. The gradual change in stiffness results in the removal of a rigid joint and the decreasing stiffness of the tip can provide better access to the tortuous vessels, while it is less traumatic for the vessel wall. In other embodiments, however, the flexible distal tip may have constant flexibility along its length.

In other embodiments, the catheter may include a fixed wire tip. The fixed wire tip can be used to advance the catheter through the body lumen without the use of a separate guide wire. In still other embodiments, the distal tip is blunt to provide a non-traumatic advance through the body lumen. In one arrangement, the blunt tip may be rigid enough to allow the catheter to advance without the use of a guidewire. In an alternative arrangement, the blunt tip will have a lumen that can receive a guide wire.

Some embodiments of the catheter include a distal tip that facilitates rapid exchange of a guidewire. Typically, the distal tip will comprise a distal port and a guide wire lumen that can extend proximally from the distal port to a proximal port that is disposed proximal to the blade. In a particular embodiment, the proximal port is arranged approximately 30 cm from the distal port.

For a better understanding of the nature and advantages of the invention, reference should be made to the following description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a perspective view of a material extraction catheter of the present invention;

Figure 2 is an exploded view of an exemplary distal part of the material extraction catheter of the present invention;

Figure 3A is an end view of the distal part of the material extraction catheter of Figure 3A, wherein the blade is in a closed position in the catheter body;

Figure 3B is a sectional view along the line AA, of Figure 3A;

Figure 4A is an end view of the distal part of the material extraction catheter of Figure 4A, in which the blade is in an open position outside the cutting window;

Figure 4B is a sectional view along line AA of Figure 4A;

Figure 5A is an end view of the distal part of the material extraction catheter of Figure 5A in which the blade is in a packaging position within a tip of the catheter;

Figure 5B is a sectional view along line AA of Figure 5A;

Figures 6 to 8 illustrate a monorail supply system of the present invention;

Figure 9A is a perspective view of a blade of the present invention;

Figure 9B is an end view of the blade of Figure 9A;

Figure 9C is a sectional view of the blade along the line AA of the blade of Figures 9A and 9B;

Figure 10A is a perspective view of an intra-stent restenosis blade of the present invention;

Figure 10B is an end view of the blade of Figure 10A;

Figure 10C is a sectional view of the blade along the line BB of the blade of Figures 10A and 10B;

Figure 11A is a perspective view of another intra-stent restenosis blade of the present invention;

Figure 11B is an end view of the blade of Figure 11A;

Figure 11C is a sectional view of the blade along the line CC of the blade of Figures 11A and 11B;

Figure 12 illustrates a proximal handle and the blade drive of the present invention;

Figure 13 illustrates a blade drive with a handle cover removed;

Figures 14 to 16 illustrate three positions of the lever for controlling the blade;

Figure 17 is a simplified flow chart illustrating a method of use of the present invention;

Figures 18 and 19 illustrate a method not according to the present invention;

Figure 20 schematically illustrates another method not according to the present invention; and

Figure 21 illustrates a kit not according to the present invention.

The systems of the present invention and associated procedures are designed to extract atheroma and other occlusive materials from diseased body lumens and, in particular, coronary arteries, de novo lesions and intra-stent restenosis lesions. However, the systems, devices and procedures are also suitable for the treatment of strictures of the body lumens and other hyperplastic and neoplastic conditions in other body lumens, such as the ureter, bile duct, respiratory tract, pancreatic duct, the lymphatic duct and the like. Frequently, the growth of neoplastic cells will occur as a result of a tumor that surrounds and is introduced into a body lumen. In this way, the extraction of said material can be beneficial to maintain the permeability of the body lumen. Although the remaining description refers to extracting and passing through an atheromatous or thrombotic occlusive material in a coronary artery, it will be appreciated that the systems and methods of the present invention can be used to remove and / or pass through a variety of occlusive, stenotic or hyperplastic materials in a variety of body lumens.

An apparatus according to the present invention will generally comprise catheters having catheter bodies adapted for intraluminal introduction to the target body lumen. The dimensions and other physical characteristics of the catheter bodies will vary significantly, depending on the body lumen to be accessed. In the exemplary case of atherectomy catheters intended for intravascular introduction, the proximal parts of the catheter bodies will typically be very flexible and suitable for introduction over a guidewire to a target site within the vasculature. In particular, the catheters may be intended for the "over guide" introduction when a guide wire channel extends completely through the catheter body or for the "quick exchange" introduction, where the guide wire channel extends only to through a distal tip of the catheter body. In other cases, it may be possible to provide a fixed or integral helical tip or a guidewire tip at the distal part of the catheter or it can even dispense completely with the guidewire. For the convenience of illustration, the guidewires will not be shown in all embodiments, but it should be appreciated that they can be incorporated into any of these embodiments.

Catheter bodies intended for intravascular introduction will typically have a length in the range of 50 cm to 200 cm and an outside diameter in the range of 1 French to 12 French (0.33 mm: 1 French), usually 3 French to 9 French. In the case of coronary catheters, the length is typically in the range of 125 cm to 200 cm, the diameter is preferably less than 8 French, more preferably, less than 7 French and, more preferably, in the range from 2 French to 7 French. Typically, catheter bodies will be composed of an organic polymer that is manufactured by conventional extrusion techniques. Suitable polymers include polyvinyl chloride, polyurethanes, polyesters, polytetrafluoroethylenes (PTFE), silicone rubbers, natural rubbers and the like. Optionally, the catheter body may be reinforced with braids, helical wires, coils, axial filaments or the like, in order to increase the resistance to rotation, the resistance of the column, the hardness, the pushing capacity and the like. Suitable catheter bodies may be formed by extrusion, with one or more channels provided when necessary. The diameter of the catheter can be modified by heat expansion and contraction using conventional techniques. In this way, the resulting catheters will be suitable for introduction into the vascular system, often the coronary arteries, by conventional techniques.

The distal portion of the catheters of the present invention can have a wide variety of shapes and structures. One aspect of the present invention provides catheters having a reduced rigid length. Reduced rigid lengths can allow catheters to access and treat tortuous vessels and small-diameter body lumens. In most embodiments, a rigid distal part or housing of the catheter body will have a diameter that generally coincides with the proximal part of the catheter body, however, in other embodiments, the distal part may be larger or smaller than the flexible part of the catheter.

The rigid distal part of the catheter body can be formed from materials that are rigid or have very low flexibilities, such as metals, hard plastics, composite materials, NiTi, steel with a coating such as titanium, tantalum nitride, ME - 92®, diamonds or the like. More normally, the distal end of the catheter body will be formed of stainless steel or platinum / iridium. The length of the rigid distal portion can vary widely, typically being in the range of 5 mm to 35 mm, more typically, 10 mm to 25 mm and, preferably, between 6 mm and 8 mm. In contrast, typically, conventional catheters have rigid lengths of approximately 16 mm.

The windows with side opening of the present invention will typically have a length of approximately 2 mm. In other embodiments, however, the side opening cut window may be larger or smaller, but should be large enough to allow the blade to protrude a predetermined distance that is sufficient to extract material from the body lumen.

The catheters of the present invention may include a flexible, atraumatic distal tip, coupled to the rigid distal portion of the catheter. For example, an integrated distal tip can increase catheter safety by eliminating the joint between the distal tip and the catheter body. The integral tip can provide a softer inner diameter for greater ease of tissue movement to a pick-up chamber at the tip. During manufacturing, the transition from the housing to the flexible distal tip can be completed with a polymer laminate on the material housing. Normally, a joint with welding, crimping or screw is not required.

The atraumatic distal tip allows the distal catheter to advance through the blood vessel or other body lumen, while reducing any damage caused to the body's lumen by the catheter. Typically, the distal tip will have a guidewire channel to allow the catheter to be guided to the target lesion on a guidewire. In some exemplary configurations, the atraumatic distal tip comprises a coil. In some configurations, the distal tip has a rounded, blunt distal end. The catheter body can be tubular and can have a circular, forward-facing opening that communicates with the atraumatic tip. A collection chamber may be housed within the distal tip to store the material removed from the body lumen. The combination of the rigid distal end and the flexible distal tip is approximately 30 mm.

A rotating blade or other tissue material extraction assembly may be arranged in the distal part of the catheter to cut material that is contiguous or is received within the cutting window. In an exemplary embodiment, the blade is disposed, movably, in the distal part of the catheter body and movable through a window with side opening. A blade or other element with straight or serrated edge may be integrally formed along a distal or proximal edge of the cutting window to help cut material from the body lumen. In a particular embodiment, the blade has a diameter of approximately 1.14 mm. However, it should be appreciated that the diameter of the blade will depend primarily on the diameter of the distal part of the catheter body.

In exemplary embodiments, the activation of an input device can divert a distal part of the catheter with respect to the proximal part of the catheter, to expose a material extraction assembly. In some embodiments, the activation of the input device displaces the material extraction assembly on a ramp or cam so that a part of the rigid distal part and flexible tip are displaced out of the path of the material extraction assembly to expose the material extraction set through the window. The deviation of the distal housing increases the effective "diameter" of the catheter and causes the material extraction assembly to be pushed adjacent to the lumen wall and the target tissue.

In exemplary embodiments, the material extraction assembly comprises a rotating blade that can be moved out of the window. By moving the blade out of the cutting window, beyond an outside diameter of the distal part of the catheter, the blade is able to make contact with and cut the material that does not invade the cutting window. In a specific configuration, the rotating blade can be moved on the cam within the rigid part of the catheter body so that the cutting edge is displaced out of the window. By moving the rotating blade out of the cutting window and advancing the entire catheter body distally, a large amount of occlusive material can be removed. Therefore, the amount of material that can be removed is not limited by the size of the cutting window. As will be described in more detail below, in some situations it is preferable to provide a serrated cutting edge, while in other situations it may be preferable to provide a soft cutting edge. Optionally, the cutting edge of one or both of the blades can be hardened, for example, by applying a coating. A preferred coating material is a chromium-based material, available from ME-92, Inc., which can be applied according to the manufacturer's instructions. Other axially rotating and mobile cutting blades are described in US Patent Nos. 5,674,232, 5,242,460, 5,312,425, 5,431,673 and 4,771,774.

The catheters of the present invention may include a monorail delivery system to help 6

position the blade at the target site. For example, the tip of the catheter may include a lumen or lumens that are sized to receive a conventional guide wire (typically 0.0356 cm (0.014 ") in diameter) and the flexible proximal part of the catheter body may include a short lumen (for example, approximately 12 centimeters in length). Such a configuration moves the guide wire out of the rigid part so as not to interfere with the material extraction assembly.

In other embodiments, however, if desired, the guidewire lumen may be disposed inside or outside the flexible proximal part of the catheter body and may extend a longer or shorter length and, in fact, may extend as far as possible. along the entire length of the flexible part of the catheter body. The guidewire may be disposed within the lumen in the flexible part of the catheter body and may exit the lumen at a point proximal to the rigid part of the catheter. Next, the guidewire can enter a proximal opening in the tip lumen and can exit a distal opening of the tip lumen.

Optionally, the present invention can employ any of a wide variety of radiopaque markers, imaging devices and / or conventional transducers. In exemplary embodiments, the catheters of the present invention may include a radiopaque distal portion and / or radiopaque markers disposed on a distal portion of the catheter body, such as proximal and distal to the cutting window, on the cam.

or ramp, to allow the user to track the position of the blade, or the like. The catheters of the present invention will also be particularly useful with ultrasonic transducers, such as an IVUS, of a type that can be deployed linearly within the catheter body or circumferentially in the material extraction assembly. The linear deployment will allow observation along a discrete length of the catheter shaft, preferably adjacent to the cut-off point, usually along a length in the range of 1 mm to 30 mm, preferably 2 mm to 10 mm. The matrices in phase, circumferentially deployed, can subtend an arc of vision in the range of 5º to 360º, normally 180º to 360º. For image transducers located on the cutting blades inside a housing or second cutting element, the image acquisition field will generally be limited, by the dimensions of the opening. In some cases, however, it may be possible to manufacture all or part of the blade / blade housing in an ultrasonically translucent material. A more complete description of suitable image acquisition catheters is more fully described in US Patent Application No. 09 / 378,224, filed on August 19, 1999, and entitled "Atherectomy Catheter with Aligned Imager", now US Patent No. , 6,299,622 B1. In addition to ultrasonic matrix transducers, the image acquisition devices of the present invention may comprise optical coherence tomography devices, such as those described in US Patent No. 5,491,524, as well as Huang et al. (1991) Science 254: 1178-1181; Brzezinski et al. (1997) Heart 77: 397-403, and Brezinski et al (1996) Circulation 93: 1206-1213. In some cases, the present invention may also provide optical images using optical waveguides and the like.

Referring now to Figure 1, a catheter 20 constructed according to the principles of the present invention comprises a catheter body 22 having a proximal part 24 and a distal part 26. The proximal part 24 may be coupled to the distal part 26 with a connection assembly 27 to allow a pivot movement or a deflection of the distal part 26 relative to the proximal part 24. A proximal end of the catheter body 22 may have a handle 40 for handling by a user, a luer for connection to a fluid supply channel aspiration, or the like.

A material extraction assembly 28, such as a blade, is disposed within a lumen 30 of the catheter body 22. Typically, the blade is rotatable within the distal part about an axis that is parallel to the longitudinal axis of the rigid part 26 of the catheter and is axially movable along the longitudinal axis. The blade 28 can access the target tissue through a window 32 with side opening that is typically large enough to allow the blade 28 to protrude through and move out of the window a predetermined distance. The blade is coupled to a blade drive 34 through a helical drive shaft 36. The drive of a movable actuator or other input device 38 can activate the drive shaft 36 and the blade, move the blade 28 longitudinally on a cam in order to deflect the distal part and move the blade 28 out of the window 32 of cut. The cam movement of the blade 28 may cause the rigid distal portion 26 to pivot or deflect relative to the proximal portion 24 in order to deflect and push the blade into the tissue in the body lumen.

In some embodiments, the distal portion 26 of the catheter will be displaced at an angled or offset configuration of the longitudinal axis of the proximal portion 24 of the catheter and the blade 28. In some embodiments, the blade 28 may also be deflected from the axis of the portion proximal and / or distal catheter.

Typically, the catheters 20 of the present invention have a flexible proximal part 24, a rigid distal part 26 and a flexible distal tip 42. Typically, the flexible proximal part 24 of the catheter is a torsion axis and, typically, the distal part is a rigid tube. The torsion shaft 24 facilitates the transport of the catheter body 22 and the

blade 28 to the sick site. The proximal end of the torsion axis 24 is coupled to a proximal handle 40 and the distal end of the torsion axis is attached to the rigid distal portion 26 of the catheter through the connection assembly 27. The drive shaft 36 is positioned, movably, within the torsion axis 24 to rotate and move axially within the torsion axis 24. The drive shaft 36 and the torque shaft 24 are sized to allow the relative movement of each shaft without interfering with the movement of the other shaft. The catheter body will have a thrust and torsion capability so that the torsion and thrust of the proximal end will result in a movement to the distal portion 26 of the catheter body 22.

Figure 2 illustrates an exploded view of a distal end of the catheter. In said embodiments, the catheter 10 includes a connection assembly 27, a rigid housing 26, a distal tip 42 that defines, at least partially, a collection chamber 53 for storing the cut atheromatous material, and a lumen that can receive the wire guide. The distal tip 42 may have a distal opening 43 that is sized to allow an image acquisition guide wire or conventional guide wire (not shown) to be advanced distally through the tip.

A ramp or cam 44 can fit, at least partially, into the lumen in the distal housing. As will be described in detail below, the proximal movement of the blade 28 on the ramp 44 causes the deflection of the distal housing 26 and guides the blade 28 out of the cutting window 32. Attached to ramp 44, there is a housing adapter 46 that can connect one or more articulation elements 48 to the distal tip to create a rotation axis of the distal part 26. The housing adapter 46 and the articulation element 48 allow the distal end of the catheter to pivot and deflect against the body lumen. In the illustrated embodiment, there is only a housing adapter 46 and an articulation element 48, but it should be appreciated that the catheters of the present invention may include, two, three or more joints (eg, axis of rotation), if desired. In addition, the axes of rotation can be parallel or non-parallel, with respect to each other.

The catheter may also include a shaft adapter 50 and a collar 52 for attaching the articulation element 48 to the torsion shaft 22. The shaft adapter 50 can connect the housing to the torsion shaft and the collar 52 can be placed on a proximal end of the shaft adapter and crimped for secure attachment. A person of ordinary skill in the art should appreciate that although an exemplary catheter of the present invention has the above components, other catheters of the present invention may not include more or less of the components described above. For example, some components can be made integral with other components and some components may be completely left out. Thus, instead of having a separate ramp 44, the ramp can be integrated with the distal tip to direct the blade out of the cutting window.

As shown in Figures 3A to 5B, generally, the blades 28 of the present invention will be movable between two or more positions. During the advance through the body lumen, the blade will generally be in a neutral position (Figures 3A and 3B) in which the blade is distal to the cutting window 32. In some embodiments, an imaging device (not shown) may be coupled to the blade 28 to obtain images of the body lumen through the cutting window 32 when the blade 28 is in the neutral position. Once the catheter has reached the target site, the blade can be moved to an open position (Figures 4A and 4B) in which the blade is moved to a proximal end of the cutting window and will extend out of the window of cut a distance L1 beyond an outside diameter D of the rigid part 26. In most embodiments, in the open position, the blade will have deflected the distal part and the axis of rotation of the blade will generally be in line with the connection assembly 27, but will form an angle or be displaced from the longitudinal axis of the distal part of the catheter body.

Optionally, in some embodiments, the blade 28 may be moved to a packaging position, in which the blade is displaced distally, beyond the neutral position, to package the cut tissue in a distal collection chamber 53 (Figures 5A and 5B). However, it should be appreciated that although the exemplary embodiment displaces the blade to the positions described above, in other embodiments of the present invention, the blade may be positioned in other relative positions. For example, instead of having the distal neutral position with respect to the cutting window, the neutral position may be proximal with respect to the window, and the open position may be along the distal end of the cutting window, or Similar.

Referring again to Figures 4A and 4B, the interaction of the components of the rigid distal portions 26 in an exemplary embodiment of the present invention will be further described. As shown in Figure 4B, the cutting window 32 is typically a cutout opening in the distal portion 26. Although the size of the cutting window 32 may vary, the cutting window should be long enough to collect tissue and should be circumferentially wide enough to allow the blade to move out of the cutting window during cutting, but sized and shaped. so as not to expel emboli to the vasculature.

The cams or ramps 44 (more clearly shown in Figure 4B) may be arranged in the distal part of the

catheter body to guide or otherwise swing the blade 28 out of the cutting window 32 as the blade 28 is pushed proximally, tensioning the drive shaft 36.

A joint is located proximal to the cutting window 32 to provide a pivot point for performing a cam movement of the distal part 26 with respect to the proximal part 24. Flexion in a flexible joint 49 is caused by the interaction of the cams or ramps 44 with the blade 28 and the tensile force provided through the drive shaft 36. In the exemplary configuration, the joint includes a housing adapter 46 that is pivotally coupled to the rigid distal part 26. As shown in Figures 4A and 4B, the resulting pivot movement of the rigid distal part 26 relative to the proximal part causes a cam movement effect that forces the distal housing against the body lumen wall without the use of pushing means (for example, a balloon) that are positioned opposite the cutting window. In this way, the overall cross-sectional size of the catheter bodies can be reduced to allow the catheter to access lesions in smaller body lumens. In exemplary embodiments, typically, the distal shell may deflect the axis of the proximal catheter between 0 ° and 30 °, usually between 5 ° and 20 ° and, more preferably, between 5 ° and 10 °. The angle of deviation is directly related to the thrust. However, the thrust is not necessarily related to a force, but rather to the overall profile of the catheter. For example, the larger the angle of deviation, the greater the profile and the greater the lumen that can be treated. The intervals were chosen to allow the treatment of vessels ranging from less than 2 mm to more than 3 mm, within the limits of mechanical design of the components. However, it should be appreciated that the angles of deflection will vary depending on the size of the body lumen to be treated, the size of the catheter and the like.

The deflection of the distal part 26 of the catheter pushes the blade into position, so that the distal advance of the entire catheter body can move the rotating blade through the occlusive material. Because the blade is displaced a distance L1 beyond the outside diameter of the distal part of the catheter and outside the cutting window, the user does not have to invaginate the tissue in the cutting window. In exemplary configurations, typically, the blade can be displaced between about 0.08 mm and 0.64 mm, preferably between 0.25 mm and 0.50 mm and, more preferably between 0.28 and 0.38 mm beyond the outer diameter of the distal shell to make contact with the material within the body lumen. It should be appreciated that the blade excursion is directly related to the depth of cut. The more the blade moves out of the cutting window, the deeper the cut will be. The ranges are chosen in relation to efficacy and without risk of perforating the body lumen.

The action of pushing the entire catheter through the lesion removes tissue from the body lumen. The cut tissue is collected as the cut piece is directed to a collection chamber 53 at the tip through the blade 28. Once the catheter and the blade 28 have been displaced through the lesion, the blade 28 can be advanced distally to a "separation position" in which the blade is moved back to the cutting window 32 (Figure 3B). The tissue is collected as the cut pieces of tissue are directed to a collection chamber 53 by the distal movement of the blade 28 and the catheter. The tip collection chamber 53 and the distal portion 26 acts as a receptacle for the cut material to prevent the cut occlusive material from entering the body lumen and possibly causing downstream occlusions. The blade 28 can interact with the distal edge of the cutting window to separate the tissue and subsequently pack the cut tissue into the collection chamber 53 (Figure 3B). In exemplary embodiments, the drive motor may be programmed to stop the rotation of the blade in the separation position, so that the blade moves to a third position (Figure 5B) and can pack the material in the collection chamber in the tip without rotation. Typically, the collection chamber 53 will be large enough to allow the collection of multiple cuts before the device is removed from the body lumen. When the collection chamber is full, or as the user considers, the device can be removed, emptied and reinserted on the guide wire through a monorail system, as will be described below.

Figures 6 to 8 illustrate an exemplary monorail delivery system to help position the blade 28 at the target site. For example, the tip 42 of the catheter may include a lumen 54 having a distal opening 43 and a proximal opening 55 that is sized to receive a conventional guide wire (typically 0.03556 cm (0.014 ") in diameter) and, such As shown in Figure 8, the flexible proximal part of the catheter body may include a short lumen 56 (for example, approximately 12 centimeters in length). However, in some embodiments, the lumen 56 of guidewire may be arranged inside or outside the flexible proximal part of the catheter body and may extend a longer or shorter length and, in fact, may extend along the entire the length of the flexible part 24 of the catheter body. During use, the guidewire may be disposed within lumen 56 in the flexible part of the catheter body and may exit the lumen at a point proximal to the rigid part 26 of the catheter. Then, the guidewire can re-enter a proximal opening 55 in the lumen 54 of the tip and can exit through the distal opening 43 in the lumen of the tip. By moving the guide wire out of the rigid part 26 of the catheter body, the guide wire will be prevented from

entangled with the blade 28. Typically, the tip of the lumen 54 will be disposed along one side a bottom surface of the tip and the lumen 56 will be disposed along one side of the proximal part 22 of the catheter body, of so that the guide wire will be in a helical configuration.

The catheters of the present invention may include radiopaque markers to allow the user to track the position of the catheter under fluoroscopy. The rigid distal portion 26 may be radiopaque and the radiopaque markers may be arranged on the flexible shaft. Typically, the markers 59 will be arranged along the top proximal to the cutting window, and at the bottom of the catheter to allow the user to know the position of the blade and the cutting window with respect to the target site. If desired, the upper and lower markers may have different shapes in order to inform the user of the relative orientation of the catheter in the body lumen. Because the guide wire will form a helix in its transition from lumen 56 to lumen 54 of the tip, the user will be able to see the radiopaque markers 59, upper and lower, without interference from the guide wire. Some embodiments of the catheter may also include a blade radiopaque stop 61 (Figure 3B) that is crimped to the drive shaft 36 proximal to the blade that moves with the blade to allow the user to know when the blade is in the open position .

Figures 9A to 11C show some exemplary embodiments of the blade 28 of the present invention. The distal portion 60 of the rotating blade 28 may include a serrated blade edge 62 or a smooth blade edge 64 and a curved or recessed distal surface 66. A proximal part 68 of the blade 28 may include a channel 70 that may be coupled to the drive shaft 36 that rotates the blade. As shown in Figures 10A-10C, some embodiments of the blades may include a bulge or protuberance 69 that is provided to interact with a stent to reduce the interaction of the cutting edge with the stent.

Figures 12 to 16 illustrate an exemplary blade drive 34 of the present invention. As shown in Figures 12 and 13, the blade drive 34 can act as the handle for the user to manipulate the catheters 20 of the present invention, as well as a power source. Typically, the blade drives 34 of the present invention include a single input device, such as a lever 38 that controls the main operations of the catheter (for example, the axial movement to apply a pushing force, the rotation to cause the cutting, and axial movement for packaging). As shown in Figures 13 and 14, the blade drive 34 includes a power supply 72 (eg batteries), a motor 74, a microswitch 76 to activate the motor 74, and a connection assembly (not shown ) to connect the drive shaft 36 to the drive motor 74. In some embodiments, the drive motor can rotate the drive shaft 36 between 1,000 rpm and 10,000 rpm or more, if desired.

Figures 14 to 16 illustrate an exemplary method for operating the blade drive 34. During use, the catheter will be supplied to the target site with the blade drive not fixed and the blade in the neutral position (Figure 3B). The blade drive may be attached to the thrust lever 38 in a neutral position (Figure 14), which indicates that the blade is closed, but not in a packed position. The user can then move the catheter (and the blade drive unit, if desired) to position the distal portion 26 of the catheter adjacent to the target tissue. As shown in Figure 15, to activate the rotation of the blade, the thrust lever 38 can be moved proximally from the neutral position to move the blade proximally and out of the cutting window 32 (Figure 4B) and, simultaneously , press microswitch 76 to activate motor 74. At the end of the cutting procedure, as shown in Figure 16, the user can push the push lever 38 fully forward to a distal position to push the blade into a packaging position (Figure 5B). Once the thrust lever passes halfway through the stroke, the microswitch 76 can be released to deactivate the blade before reaching the packaging position, so that the packaging can be performed without the blade turning. It should be appreciated, although the figures illustrate the use of a push lever or thumb switch as an input device, the present invention may use other types of input devices, such as labeled buttons (eg, close window, remove tissue and package), or the like.

Advantageously, the blade drive 34 provides an automatic on / off control of the blade 28 that is keyed to the position of the blade. This configuration frees the user from the complicated task of remembering the sequence of operations to activate and deactivate the rotation and axial movement of the blade.

Although the blade drive 34 is illustrated as a unit powered by a disposable battery, it should be appreciated that in other embodiments, the blade drive may use other sources of energy to control the blade drive. It should also be appreciated that other blade drives can be used with the present invention. Although not preferable, it is possible to have separate controls to control the axial movement of the blade and the rotation of the blade.

Now, some exemplary procedures will be described. A procedure comprises supplying a catheter to a target site in the body lumen. A distal part of the catheter can be deflected with respect to a proximal part of the catheter to expose a tissue removal device in the catheter. Material can be extracted from the body lumen with the exposed extraction device. Specifically, as shown schematically in Figure 17, a specific procedure comprises advancing a catheter to a target site (Step 100). A blade can be rotated and can be moved outside the cutting window (Stages 102, 104). Preferably, a distal part of the catheter can be pivoted or can be deflected to position the blade adjacent to the target material. Next, the catheter and the rotating blade can be displaced through the body lumen to remove the target material from the body lumen (Step 106).

As shown in Figures 18 and 19, the catheter can be advanced percutaneously through a guide catheter or sheath and over a conventional guide wire or image acquisition using conventional intervention techniques. The material extraction catheter 20 can be advanced over the guide wire and out of the guide catheter to the diseased area. As shown in Figure 18, typically, the window 32 will be closed (with the blade or other material extraction device 28 in a first distal position). As shown in Figure 19, typically, catheter 20 will have at least one pivot joint or connection to allow pivot movement around one or more rotation axes to improve catheter supply to the tortuous anatomy without removing the guide catheter or other sheath. The blade can be positioned proximal to the lesion. Optionally, a transducer, IVUS or other imaging assembly can be used to verify the position of the material extraction catheter.

Once the position of the catheter is confirmed, the blade 28 will be retracted proximally and will be moved out of the cutting window 32 to its second exposed position. In some embodiments, the movement of the blade can deflect the distal part of the catheter to increase the profile of the catheter at the target site. Typically, the movement of the blade is caused by the proximal movement of the lever 38 and the tension in the drive shaft 36. The movement of the lever can be scaled to any movement ratio or a direct 1: 1 movement ratio between the handle and the blade. When the blade is displaced proximally, it contacts the ramp or cam surfaces to guide the blade up and at least partially out of the cutting window 32. In addition, as shown by arrow 80, the distal part of the body 26 of the catheter rotates around the joint 49 to provide a pushing force for the blade (and the body of the catheter) to move towards the diseased area.

Subsequently, as shown by arrow 82, the operator can move the entire catheter body 22 through the lesion to cut the tissue. As the blade 28 and the catheter body 22 are advanced distally through the lesion, the tissue that is trapped between the cutting edge 52 and the cutting window 32 is cut from the body lumen. To separate the tissue, the operator can stop pushing the device distally and the blade can be advanced distally inside the cutting window by advancing the handle 38. During the distal movement of the blade, the blade 28 moves again on the ramps 44 and directs the blade back into the cutting window 32. Said movement causes the distal part 26 of the catheter to move in line with the blade and the proximal part 24 (Figure 5B). When the blade has moved to its distal position, the blade separates the cut tissue and pushes the cut tissue into a collection chamber 53 at the distal tip 42. Optionally, after the blade 28 has separated the tissue, the lever 38 and, thus, the non-rotating blade 38, can be advanced distally to package the tissue in the collection chamber 53 (Figure 5B). The use of the blade to pack the cut tissue will allow the operator to collect multiple samples before removing the catheter 20 from the body lumen. When it is determined that the collection chamber is full, the catheter can be removed from the body lumen and the collection chamber can be emptied.

In another procedure, as shown in Figure 20, an input device is arranged in a first position to position a tissue extraction element in a neutral position (Step 120). The input device is activated to rotate the tissue extraction element and to axially move the tissue extraction device to an active position (Step 122). The input device can then be activated again to move the tissue extraction element to a packaging position (Step 124). In one example, the input device is a lever or switch activated with the thumb that can be moved to correspond to the movement of a cutting element in the catheter. Thus, as the lever is displaced proximally, the blade is rotated and displaced proximally to an open position. When the lever is moved to a distal position, the rotation of the blade can be stopped and the blade can be displaced distally to pack the cut tissue into a collection chamber.

Figure 21 describes kits that include catheters 200, instructions 202 for use and packages 20 4. Generally, catheters 200 will be as described above, and instructions for use (IFU) 202 will establish any of the procedures described above. The package 204 may be any conventional medical device package, including bags, trays, boxes, tubes or the like. Generally, the instructions for use 202 will be printed on a separate sheet of paper, but they can also be printed, in whole or in part, on a part of the package 204.

Although the above is a complete description of the preferred embodiments of the inventions,

5 various alternatives, modifications and equivalents can be used. For example, although the preferred blades are displaced proximally to move the blade out of the cutting window, alternative embodiments may distally move the blade to move the blade out of the cutting window. In addition, in some embodiments, the material extraction assembly may be exposed through the window without causing a deviation from the distal part of the catheter. In addition, instead of having a distal tip that can rotate relative to

10 In the proximal part of the catheter, the catheter may include a shape memory material, so that the catheter forms a "jog" or a pre-folded shape when it reaches its target area. Although the foregoing invention has been described in detail for the sake of clarity of understanding, it will be apparent that certain modifications can be made within the scope of the appended claims.