Percutaneous catheter directed intravascular occlusion devices

(54) Title: INTRAVASCULAR OBSTRUCTION DEVICES DIRECTED BY PERCUTANEOUS CATHETER (30) Unionist Priority: 12/28/2007 us 11 / 966,397 (73) Holder (s): Aga Medicai Corporation (72) Inventor (s): John C. Oslund, Kurt Amplatz, Matt Glimsdale, Xiaoping Gu (57) Summary: obstruction devices

INTRAVASCULAR DIRECTED BY PERCUTANEOUS CATHETER. The present invention relates to modalities for providing an improved vascular obstruction device for obstructing a passageway, cavity, or the like. According to one embodiment, a medical device for obstructing a left atrial appendage is provided. The medical device includes a first portion that has at least one obstruction plane that is configured to be positioned outside the left atrial appendage, and one second portion that has at least one obstruction plane that is configured to be at least partially positioned within a cavity defined by the left atrial appendage.

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Ρ 0806077-0

Invention Patent Descriptive Report for INTRAVASCULAR OBSTRUCTION DEVICES DIRECTED BY PERCUTANEOUS CATHETER.

BACKGROUND OF THE INVENTION 5 Field of the Invention

The present invention relates, in general, to intravascular devices for the treatment of certain medical conditions and, more particularly, it refers to intravascular obstruction devices for selective obstruction of a vessel, chamber, channel, orifice, cavity or similar, any10 anywhere in the circulatory system of the body where blood flow is to be stopped. Devices made in accordance with the present invention are particularly well-suited for delivery via a catheter or similar to a remote location in a patient's vascular system within a patient's body, so a passageway, cavity or the like must be obstructed.

Description of the Related Art

A wide variety of intravascular devices are used in various medical procedures. Certain intravascular devices, such as catheters and guidewires, are generally used simply to deliver fluids or other medical devices to specific locations within a patient's body, such as a selective location within the vascular system. Other often more complex devices are used to treat specific conditions, such as devices used to remove vascular obstructions or to treat septal defects and the like.

In certain circumstances, it may be necessary to obstruct a vessel, chamber, channel, orifice, patient's cavity or the like, such as to stop the flow of blood through them. For example, atrial fibrillation can result in the formation of a blood clot in the left atrial appendage (LAA), which can become dislodged and enter the bloodstream. By blocking the LAA, the release of blood clots from the LAA can be significantly reduced, if not eliminated. Several techniques have been developed to obstruct the LAA. For example, balloon-like devices have been developed to be fully implanted within the LAA cavity, although surgical techniques have also been developed where the LAA cavity is inverted and surgically closed.

Despite these LAA obstruction techniques, it would be advantageous to provide an improved obstruction device which offers increased flexibility, improved retention and improved thrombogenicity within a vessel, chamber, channel, orifice, cavity or the like. SUMMARY OF THE INVENTION

The present invention is well-suited for the selective obstruction of a vessel, lumen, canal, orifice, cavity or similar, such as the Patent Arterial Duet (here after PDA), a Defect in the Atrial Septum (here after ADS), a Defect in the Ventricular Septum (here after VSD), an arterial venous fistula (AVF), a venous malformation (AVM) or the left atrial appendage (LAA).

According to one embodiment, a medical device for LAA obstruction is provided. The medical device includes a first portion having at least one obstruction plane that is configured to be positioned outside the LAA and a second portion having at least one obstruction plane that is configured to be at least partially positioned within a cavity defined by the LAA. For example, the obstruction planes may comprise metal, polyester, other biocompatible polymers or a combination thereof.

According to various aspects, the medical device can include a first portion (for example, a disk portion) having a first diameter and a second portion (for example, a cylindrical portion) having a second diameter. The medical device can also include a transition segment coupling the first portion and the second portion and configured to provide flexibility between them, wherein the transition segment has a transition diameter substantially smaller than the first and second diameters. The second portion may have a second diameter smaller than the first diameter. In addition, the ratio of the first diameter to the third diameter can be about 6 to 4.5, the ratio of the second diameter to the third diameter can be about 2 to 4 and / or the first diameter can be at least about 10% larger than the second diameter. In addition, the medical device may include a third portion coupled to and extending distally from the second portion, the third portion having a smaller diameter than the second diameter. The first, second and third portions can be configured to be restricted to a smaller diameter than the expanded preset configuration for distribution to the LAA and auto-expand when unrestricted.

According to an embodiment of the medical device, the medical device includes at least one layer of obstructive material having a plurality of woven metal braids (for example, Nitinol). The medical device could also include a plurality of hooks extending from the second portion and configured to fit the defined cavity within the LAA. The plurality of hooks may have protuberances. The medical device can include a transition segment coupling the first portion and the second portion that is configured to provide flexibility between them and the first portion can be configured to flex up to about 30 degrees with respect to the second portion along an axis center extending through the first and second portions. The medical device can be configured to be restricted within a catheter having an outside diameter of less than about 11, 10 or 9 French. In addition, the medical device can be configured to extend to a depth of about 20, 15 or 10 mm or less within the LAA-defined cavity. According to an embodiment of the present invention, the medical device can be configured to obstruct at least a portion of the LAA in less than about 10, 5, 4, 3 or 2 minutes, with obstructions observed in testing as low as within 1 minute. The medical device can also include an obstruction material retained within the first portion and / or the second portion. The obstruction material may be in the form of a disc or surface extending through the interior of the cavity and / or extending over the opening of the cavity. The obstruction material can be retained in at least one layer of woven metal braids. In addition, the medical device can be configured to be distributed over a guidewire.

A further embodiment of the present invention provides a method for obstructing an AA with a medical device. The method includes restricting a medical device to a smaller diameter than an expanded preset configuration, wherein the medical device comprises a first portion having at least one obstruction plane and a second portion having at least one obstruction plane. The method also includes distributing the medical device near the LAA and implanting the medical device, so that the first portion expands and is positioned outside the LAA and the second portion expands externally to fit at least a portion of the cavity inside of the LAA.

Various aspects of the method include restricting the medical device within a catheter, where the implantation comprises retraction of the catheter in relation to the medical device. The method may also include advancing the catheter distally after the implantation step in order to restrict the medical device inside the catheter. The restriction step may include stretching the medical device along a longitudinal axis of the same to the smallest diameter. The implantation step may include implantation of the medical device, so that the first portion overlaps with an LAA opening. The method may additionally include perforation of the heart prior to delivery of the medical device proximal to the l_AA. The implantation step may also include unscrewing a distribution system with threaded filament attached to the medical device. In addition, the method may include repositioning the medical device into a catheter after implantation of the medical device into the catheter. In addition, the method may include imaging the l_AA using two-dimensional intracardiac echocardiography, angiography, magnetic resonance imaging, transesophageal echocardiography and / or color flow mapping by Doppler. The dispensing step may include dispensing the medical device over a guidewire. Another aspect of the method may also include checking for LAA obstruction by injecting a radiopaque contrast medium through the catheter into the left atrium adjacent to the implanted medical device and observing, via angiography, whether the contrast enters the cavity defined by LAA and even if any contrast that may have entered the cavity is stagnant, in which both observations indicate LAA obstruction. In addition, the method may include repositioning the medical device after unsuccessful LAA obstruction through contrast observation.

An alternative implantation method may include the step of positioning the distal end of the catheter inside the left atrium and outside the LAA cavity opening, retracting the catheter proximally with respect to the device, to partially implant the second portion of the medical device inside the medical device inside the left atrium, advancing the catheter and the device distally to insert the second portion at least partially into the cavity and implanting the rest of the device through additional proximal retraction of the catheter with respect to the device.

A further embodiment of the present invention provides a dispensing set for dispensing a medical device for obstructing an LAA. The distribution set includes a distribution device coupled to the medical device, wherein the medical device comprises at least one obstruction plane configured to be positioned outside the LAA and at least one obstruction plane configured to be at least partially positioned within a LAA-defined cavity. The delivery set also includes a catheter configured to overlap the delivery device and restrict the medical device therein, where the catheter is axially displaceable with respect to the delivery device.

Various aspects of the distribution set include a medical device having a plurality of obstruction planes positioned outside the LAA and within the cavity defined by the LAA. In addition, at least one obstruction plane can be configured to overlap an LAA opening. The catheter can have an outside diameter of less than about 11 French. The delivery device and catheter can be configured to be delivered to the left atrial appendix with a guidewire. In addition, the catheter can be axially displaceable with respect to the delivery device, so that the medical device is configured to be implanted from the catheter in response to displacement of the catheter with respect to the medical device. The medical device can be configured to be recaptured into the catheter in response to displacement of the catheter from the delivery device.

The obstruction device can provide several advantages. For example, the device may be smaller than conventional obstruction devices, not only in a restricted diameter for distribution to the LAA, but also the depth at which the device extends into the LAA cavity. The shallower depth at which the device extends into the LAA cavity can also allow the device to be more easily positioned and implanted in it. In addition, due to the fact that the device is smaller, the delivery device can also be smaller, so that the likelihood of tissue injury when dispensing the device is reduced and the device can be delivered more quickly, since the delivery device would be able to be more easily maneuvered within the vasculature. In addition, the articulation and flexibility of the device and the delivery system can improve the ability to bend around corners within the vasculature when dispensing the device. The device is also repositionable, since the device can be retracted into the catheter after implantation of the device. The device can also include a plurality of layers or obstruction planes, which can not only improve the thrombogenicity of the device, but also eliminate the need to include additional obstruction techniques, such as adding polyester layers to the device. For example, according to one embodiment, the device is capable of obstructing the LAA in less than about 10 minutes and even in less than about 5 minutes. The device can also result in minor complications, such as embolizations, leaks and effusion. In addition, the device can be distributed over-the-wire and visualization techniques, such as intracardiac echocardiography (ICE), can be used to properly size the LAA before implantation of the device and during the implantation procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described the invention in general terms, reference will now be made to the attached drawings, which are not necessarily drawn to scale and in which:

Figure 1A is a sectional view of an occlusion device according to an embodiment of the present invention;

Figure 1B is a perspective view of the device of Figure

1A;

Figure 2 is a partial exploded view of a single disc device and alternative distribution apparatus according to a modality of the invention;

Figures 3A to 3C represent progressive stages of implantation of the device of Figures 1A and 1B;

Figure 4 is a perspective view of an obstruction device for obstructing the LAA according to an embodiment of the present invention;

Figure 5 is a side elevational view of the obstruction device shown in Figure 4;

Figure 6 is a cross-sectional view of the obstruction device shown in Figure 5;

Figure 7 is an enlarged partial side view of the obstruction device shown in Figure 4 illustrating a hook;

Figures 8 and 9 are a perspective view of an obstruction device being implanted according to an embodiment of the present invention;

Figure 10 is a perspective view of an obstruction device implanted in the LAA according to an embodiment of the present invention; and

Figure 11 is a perspective view of an obstruction device implanted in the LAA according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all modalities of the invention, are shown. In fact, the present invention can be realized in many different ways and should not be construed as limited to the modalities presented here; rather, these modalities are provided so that the present description satisfies the applicable legal requirements. Similar numbers refer to similar elements everywhere.

Modalities of the present invention can provide an intravascular obstruction device 10 directed by a percutaneous catheter perfected for use in the vasculature of a patient's body, such as blood vessels, channels, lumens, an orifice through tissue, cavities and the like. Other physiological conditions in the body occur, where it is also desirable to obstruct a vessel or other passage to prevent blood flow in or through it. These device modalities can be used anywhere in the vasculature where anatomical conditions are appropriate for the design.

According to an embodiment of the present invention for forming a medical device 10 of the invention, a metallic fabric is formed of a plurality of wire filaments having a predetermined relative orientation with respect to each other. However, it should be understood that, according to additional embodiments of the present invention, device 10 can be formed using various techniques. For example, device 10 could be cut or laser cut from a tube to form an interstice geometry or the device could comprise an obstruction material coupled to a base structure or a plurality of pieces of a tubular element coupled together, such as through bonding. Furthermore, it should be understood that the device 10 may comprise one or more layers of obstruction material, so that the device can be a variety of obstruction materials capable of inhibiting, at least partially, blood flow through them in a manner facilitate thrombus formation.

Although the term filament is discussed here, filament is not intended to be limiting, as it should be understood that the fabric may comprise one or more threads, strings, fibers, filaments, cables, wicks or the like, so that such terms may be used interchangeably.

According to one embodiment, the obstruction material is a metallic fabric including a plurality of braids, such as two sets of essentially parallel filaments generally helical, with the filaments of a set having one hand, that is, a direction of rotation, opposite to that of the other set. The braids can be interwoven, intertwined or otherwise combined to define a fabric that is usually circular.

The pitch of the filaments (that is, the angle defined between the turns of the filaments and the braid axis) and the weft yarn of the fabric (that is, the number of strands of yarn filaments per unit length) can be adjusted as desired for a particular application. The thread strands of the metallic fabric used in one embodiment of the present method can be formed of a material that is resilient and can be heat treated to substantially conform to a desired shape. Materials which may be suitable for this purpose include a low thermal expansion cobalt based alloy referred to in the field as

Elgiloy, nickel-based super alloys with high resistance to high temperature commercially available from Haynes International under the trademark Hastelloy, thermally treatable nickel-based alloys sold under the Incoloy trademark by International Nickel and a series of different grades of stainless steel. The important factor in choosing a suitable material for the wire braids is that the threads retain an adequate amount of the deformation induced by the molding surface (as described below) when subjected to a pre-finished thermal treatment10 and return elasticly to that molded shape after substantial deformation.

A class of materials which meet these qualifications are so-called alloys with format memory. A particularly preferred shape memory alloy for use in the present method is Nitinol. NiTi alloys are also very elastic - they are said to be superelastic or pseudoelastic. This elasticity can allow the device to return to a pre-adjusted expanded configuration for implantation after passing in a distorted form through a delivery catheter. In addition, other materials may include those that are compatible with magnetic resonance imaging (MRI), since some materials can cause heat or torque resulting from MRI and some materials can distort the MRI image. Thus, metallic and / or non-metallic materials that reduce or eliminate these potential problems resulting from the use of MRI can be employed.

In forming a medical device according to the embodiment of the present invention, an appropriately sized piece of tissue is cut from a larger piece of tissue which is formed, for example, by braiding strands of wire to form a long tubular braid. When cutting the fabric to the desired dimensions, care must be taken to ensure that the fabric does not sew. It can be soldered, brazed, thermally welded, coated, glued, stapled, secured or otherwise affixed the ends of the desired length together (for example, with a biocompatible cementitious organic material).

In addition, one or more layers of tissue can be employed to form a medical device. For example, two layers of metallic fabric could be separately woven into tubular elements, with a tubular element coaxially disposed within the second tubular element. For further discussion regarding a multilayer interlaced device and methods for making such a device see US Patent Application Publication N⁹ 2007/0168019 for Am11 platz et et al., Which is incorporated herein by reference in its entirety.

The tubular braid used to manufacture obstruction devices according to one embodiment of the present invention can oscillate from a wire having a diameter of 38.1 to 127 pm (0.0015 to 0.005 inches), preferably in the range of 76.2 to 114.3 pm (0.003 to 0.0045 inches). The number of threads in the tubular braid can vary from 36 to 144, but is preferably in the range of 72 to 144. The count of braided weft threads can vary from 30 to 100. The fabric can have an average area between the supporting fibers of 0.0016 cm² and 0.25 cm².

Once an appropriately sized piece of metallic fabric is obtained, the fabric is deformed to conform generally to a surface of a molding element. Deformation of the fabric will reorient the relative positions of the wire strands of the metal fabric from their initial order to a second reoriented configuration. The shape of the impression element should be selected to deform the tissue substantially in the shape of the desired medical device when not restricted. Since the molding element is assembled with the metal fabric generally conforming to a molding surface of that element, the fabric can undergo a heat treatment while remaining in contact with that molding surface. After heat treatment, the fabric is removed from contact with the molding element and will substantially retain its shape in a deformed state.

Figures 1A and 1B illustrate an embodiment of a medical device 10 according to an embodiment of the present invention. Device 10 has a generally cylindrical body portion 12 and an externally extending front disc end 14. Body portion 12 is sized to be slightly larger (for example, about 10-30%) than the vessel to be be obstructed. This design is intended to provide an anchor for the device to prevent displacement. The disk portion 14 of the device 10 is intended to meet the adjacent wall surrounding the opening to prevent movement of the device towards the body portion and to assist in sealing the opening. According to one embodiment, the disk portion 14 is oversized so as to be able to overlap the LAA ostium or opening and rest adjacent to and in contact with flow with the atrium wall, as shown in Figures 10 and 11. The disk portion 14 may also be flexible so as to be able to conform to the curvature of the atrium wall. The disk portion 14 can be of various sizes and configurations, such as a flat disk, as shown in Figures 1A, 1B, 4 and 10 or a disk having a convex distal end, as shown in Figure 11. The disc portion 14 may have a depth or thickness depending on the thickness and number of layers employed, although the depth should be minimized due to the possibility of clotting around the disc portion and a reduced volume within the atrium.

The body portion 12 can be oversized so that it fits the lumen of the vessel, body organ or similar to be obstructed. The device 10. can then be held in place by combining the radial fit between the body portion and the lumen of the vessel, body organ or the like and the hooks 20 which fit into the wall. Over a relatively short period of time, thrombi will form in and over the device 10 and obstruct the lumen. Although the body portion 12 and the disk portion 14 may be of various sizes, the disk portion may be at least about 10% larger in diameter than the body portion according to one embodiment.

For example, Figure 10 illustrates the obstruction device 10 implanted within the LAA. The obstruction device 10 is positioned so that the disk portion 14 overlaps the LAA ostium, while the body portion 12 is positioned within the LAA. Thus, the disc portion 14 ensures that the body portion 12 is implanted at a predetermined depth of the LAA and the hooks 20 are configured to penetrate the wall of the LAA, as explained below. Over time, thrombi will form in and over the portion of. disc 14 and body 12 to block the LAA.

Those skilled in the art will appreciate that, in order to speed up obstruction of the vessel with the device, the device can be coated with a suitable thrombogenic agent, filled with a polyester fiber, braided with an increased number of filament yarns or include multiple layers of fabric. For example, device 10 may include one or more layers of polyester fiber positioned within body portion 12 and / or disc portion 14. In particular, a layer of polyester fiber can be sized and configured to be positioned within each of the disc portion 14 and the body portion 12 and sutured circumferentially around its periphery and around the inner circumference of the disk portion and the body portion, respectively. The polyester fiber is flexible and can be easily collapsed with device 10 for delivery via a catheter. The intertwined fiber can attach to a clot to retain the clot firmly inside the device as it forms the obstruction.

Therefore, device 10 can include a plurality of obstruction planes. An obstruction plane can be any surface, whether flat or irregularly shaped, which can be oriented generally across the blood flow to facilitate thrombus formation. For example, the body portion 12 and the disk portion 14 may include at least one obstruction plane, such as each surface or layer of the disk portion and each surface or layer of the body portion. In addition, additional layers of fabric and / or each layer of polyester fiber within the disc portion and / or body portion can add extra obstruction plans. In addition, the one or more obstruction planes associated with the disc portion 14 can be positioned to overlap the LAA ostium, while the one or more obstruction planes associated with the body portion 12 can be positioned within the cavity defined by l_AA. According to an embodiment of the present invention, the first portion and the second portion of the device 10 are configured to obstruct at least a portion of the LAA in less than about 10 minutes and even in less than 5 minutes, with obstructions observed in testing as low as well as within 1 minute.

The device 10 includes a transition segment 19 having a diameter H between the body portion 12 and the disk portion 14 which is substantially smaller in diameter than the cylindrical diameter B and the diameter of the disk A. This small transition diameter allows that the disk portion is easily oriented itself towards the vessel wall containing the opening where the wall is not truly perpendicular. According to one embodiment, the body portion 12 is capable of flexing at an angle M of up to about 30 degrees around the transition segment 19, as shown in Figure 1A. In addition, the recessed transition diameter H within a notch 15 at the end of the body element 12 may allow the device to conform to the anatomy in which the device is being positioned acting as a spring element for maintaining the axial tension between the disk and the cylindrical body. Separation between the disc and the cylindrical body may not have an impact on the performance of the device.

As shown in Figures 1A, 1B and 7, device 10 can include retaining hooks 20. Retaining hooks 20 can be made of Nitinol wire which is thermally cured into a hook formation at each end and has a curvature, for example , a curvature of less than about 180 degrees, in the segment of the median length of the wire to create 2 interconnected hooks. Hooks 20 can also extend within device 10, as shown in Figure 7. The ends of the hooks are oriented towards the disc and can be sutured or secured by any means known to the braided fabric over the body portion 12 of the device. According to one embodiment, the wires of the hooks 20 can be about 76.2-177.8 gm (0.003-0.007 inches) in diameter and 2-10 mm long and be flexible enough to be discharged to the delivery catheter or loaded, if introduced in a rectified configuration. The device can have any number of hooks 20, such as three pairs of hooks. The number of hooks would preferably range from 6 to 12. The hooks assist in retaining the device by resisting the movement of the device in the vessel in a direction that would cause the hooks to detach from the fabric. The hooks 20 have no protrusions, so that the fit is reversible by moving the device in the direction opposite to the open end of the hook. In addition, the hooks 20 can be configured to penetrate the LAA wall, but not to extend completely through the LAA wall. Thus, the hooks 20 reduce the incidence of effusion by not perforating through the LAA wall.

In one embodiment, the hooks 20 can be a part of the device - that is, individual threads within the braided structure that are insulated, cut and a short portion of the thread adjacent to the cut formed in an externally projecting thread or hook. The advantage of this configuration is that the device has a significantly smaller profile, since no additional material (separate hooks) contributes to the collapsed configuration during passage through a catheter. In addition, there is no need to suture the additional material or suture the nodes necessary to attach the hooks to the braided tissue, thereby reducing the stent profile as well.

As explained above, the cylindrical body portion 12 is adapted to be implanted within a vessel, cavity or similar to be obstructed, while the disk portion 14 is adapted to be positioned adjacent to the wall surrounding the opening associated with the vessel, cavity or similar to be obstructed. According to one embodiment, the device 10 extends from the disc clamp of the proximal end 15, radially outward from the maximum diameter of the disc A and radially backwardly against itself to the transitional diameter Η. The transitional diameter H extends distally a distance J, whereby the device 10 forms an inverted cone towards the disk 14 with a diameter K, where the device turns to be parallel to the disk, but spaced from the disk a distance E, radially to out in a diameter B. Device 10 continues to maintain a cylindrical diameter B distally a distance D. The device 10 can include a tapered surface of angle C, as shown in Figure 1A or not include a tapered surface, as shown in Figures 4-6 and define a body portion 12 having a total length G. According to one embodiment, the distal end clamp 18 and the proximal end clamp 16 prevent the twisted wire ends from unfastening. However, it should be understood that device 10 may include an end clamp at its proximal and / or distal end. For example, device 10 may include a proximal end clamp 16, while the distal end of the device is open. In addition, it should be understood that the ends of the device 10 can be coupled using various techniques other than gram 10, such as heat sealing, bonding, fasteners or the like. The proximal end clamp 16 also contains a threaded filament portion that reversibly connects to a distribution system (not shown), such as a cable or shaft with wires paired at its end. The proximal end clamp 16 and / or the distal end clamp 15 may be a radiopaque material, such as a platinum marker, to assist the surgeon in positioning the device 10 within the vessel or organ of the body.

The improvement in the flexibility of the disc and conformation to a wall of a vessel, body organ or similar which are not perpendicular to the axis of the vessel, body organ or similar to be obstructed originates from the maximum diameter of the disk A with respect to the smaller diameter H or the ratio of A / H. According to one embodiment, the ratio is in the range of 3 to 30, preferably about 10 to 25 and the B / H ratio is in the range of 2-25 and preferably 10-20. This proportion can reduce the bending force necessary to cause the disc to align with the vessel wall, body organ or similar or, alternatively, align the body portion to the vessel, body organ or similar to be obstructed. The transition diameter H has a length J which is about 2-5 times the diameter H. This length J may be necessary to allow a small dimension E between the inner surface of the disc and the wall of the proximal end of the body portion, as shown in Figure 1A. This can improve the fit of the device and the seal of the device. In order to modify the length J of the transition diameter Η, the device is shaped to form a conical surface at an angle L to the wall of the proximal end of the body portion. This conical surface can accommodate displacement of the user from the body portion of an adjacent disc by leveling the cone and thereby providing increased radial expansive force for retaining the device over the proximal cylindrical outside diameter. Additionally, the tapered surface can act as a spring to provide axial tension between the disc and the body portion when they are moved away from each other to keep the hooks 20 attached to the wall of the vessel being obstructed, thereby improving the device retention. In addition, the cylindrical portion can be purposefully placed a spaced distance from the disk portion, as seen through angiography, to ensure a holding force between the disk and cylindrical portions. The distance allows greater flexibility in placing the cylindrical portion and adaptability to a wide range of anatomical conditions.

According to one embodiment, the difference in length between dimensions B and K and between dimensions D and J can be kept constant for a variety of device sizes 10, while dimensions L and K can vary for different device sizes . According to another aspect of the present invention, the depth of the device (i.e., G + E) can be kept constant for different sizes of devices 10. For example, diameters B and A can be varied, while depth G + E remains the same for both devices. One aspect of the present invention regarding a device for obstructing the LAA includes a G + E depth of less than 10 mm.

The sizes of the body 12 and the disc 14 and the length of the device can be varied as desired for vessels, channels, lumens, holes, cavities or the like of different sizes. A table of exemplary dimensional ranges and for selecting devices is provided below in mm. The exemplary dimensions provided below are provided for a device 10 in its expanded position, at rest18, since the dimensions may change when implanted within the body (for example, the length of the device may vary if the body element 12 is flexed with respect to disk portion 14).

TABLE I

<td></td><td>THE</td><td>B</td><td>AND</td><td>F</td><td>G</td><td>H</td><td>J</td><td>K</td><td>L</td>

<td>Banner</td><td>6 to 40</td><td>2 to 30</td><td>0a 6</td><td>1 to 3</td><td>3 to 25</td><td>1 to 8</td><td>0 to 10</td><td>3 to 20</td><td>20 to 70</td>

<td>LAA</td><td> 20</td><td> 16</td><td> 0,5</td><td> 1,5</td><td> 7</td><td> 1,5</td><td> 4</td><td> 16</td><td> 80</td>

<td>LAA</td><td> 34</td><td> 30</td><td> 0,5</td><td> 1,5</td><td> 7</td><td> 1,5</td><td> 4</td><td> 30</td><td> 20</td>

With reference to Table I, device 10 having a diameter A of 20 mm is, in one embodiment, made of 144 filaments of Nitinol wire with 76.2 pm (0.003 inches) in diameter braided over a mandrel of 18 mm in diameter with a weft yarn count of 40. After thermal curing, the 20 mm device 10, in its final molded shape, having hooks formed from the filament itself, can be collapsed for distribution through a distribution catheter 29 having an internal diameter of 7 French and a 9 French external diameter (3 French = 1 mm).

Also with reference to Table I, device 10 having a diameter A of 34 mm is, in one embodiment, made of 144 filaments of 114.3 μιτι (0.0045 inch) Nitinol wire braided over a 30 mm mandrel in diameter with a weft yarn count of 25. After thermal curing, the 34 mm device 10, in its final molded shape, having hooks formed from the braid itself, can be collapsed for distribution through a distribution catheter 29 having an internal diameter of 9 French and a 11 French outer diameter.

The delivery system 28 shown in Figure 2 can be used to drive the device 10 through the catheter lumen or long introducer kit for implantation in the patient's body. The delivery system 28 can take any suitable shape, such as an elongated flexible metal shaft similar to a conventional guidewire, or it can be a hollow shaft. The delivery system 28 is used to advance the occlusion device 10 through Lumen 25 of a small diameter cylindrical tube, such as a delivery catheter 29 for implantation.

According to one embodiment, the device 10 is loaded into the lumen 25 by stretching it to place it in an elongated condition. The device 10 can be inserted in the lumen 25 during the procedure or pre-assembled in a manufacturing unit, in that the devices of the present invention do not take a permanent configuration when kept in a compressed state. When the device is implanted outside the distal end of the catheter, the device will still be retained by the delivery system. Once the appropriate position of the device 10 in the vessel, body organ or similar is confirmed, the axis of the distribution system 28 can be rotated around its axis to unscrew the clamp 16 from the threaded end of the distribution system . Naturally, the threaded filament connection could be at either end of the device, depending on the anatomical situation and the desired or available means of access to the treatment site.

By keeping the device 10 attached to the delivery system, the operator can still retract the device back into a delivery case for repositioning if it is determined that the device was not properly positioned on the first attempt. In cases where the device 10 is improperly implanted in a first attempt, the device can be recovered by pulling the delivery system 28 proximally, thereby retracting the device back into the delivery catheter 29 before a second attempt to position the device with respect to the vessel, body organ or similar. Thread filament attachment can also allow the operator to control the way in which device 10 is implanted at the distal end of the delivery catheter. As explained below, when the device exits the delivery catheter, it tends to return resiliently to an expanded shape, which was adjusted when the tissue was thermally treated. When the device returns to its shape, it may tend to act against the distal end of the catheter, effectively propelling it behind the end of the catheter. This spring action could possibly result in improper positioning of the device. Since the threaded filament clamp 16 can allow the operator to hold the device during implantation, the spring action of the device can be controlled and the operator can control the implantation to ensure proper placement.

Optionally, device 10 could be configured with a hollow internal clamp element 23 at both ends of the wire and an external proximal clamp element 21 and a distal external clamp element 26. The wire ends 24 are secured between the elements of internal and external clamp 21, 26 through sewing or, alternatively, can be connected or welded between the clamp elements. The inner clamp element is tubular and is dimensioned with an inside diameter to freely pass a driving wire 27. The distal outer clamp element 26 is dimensioned with an internal diameter sufficient to accommodate the twisted wire ends 24 surrounding the locking element. internal staple before sewing. The distal end on the distal outer clamp element 26 is solid (closed end) to accept the pushing force of the push wire 27 placed through both internal clamp elements against that solid end. The proximal external clamp element 21 is shown with external threads to connect reversibly to the distribution system 28, which can be an extruded inner tube of nylon block copolymer, such as Pebax, with 25.4 μηι (0.001 braided wire) inch) over the Pebax inner tube extrusion, followed by another Pebax outer layer to cover the braid. The catheter / case 29 can be similarly constructed, except that with a larger diameter to accommodate the passage of the device 10 and the delivery system 28. Such a construction is typical in intravascular catheters, where flexibility and torque transmission are required. Similar to staples 16, 18 above, the internal 23 and / or external 26 staple elements may be a radiopaque material, such as a platinum element, to assist a surgeon in positioning the device 10 in the lumen.

According to one embodiment, the delivery catheter case 29 may have a 25.4 μητι (0.001 inch) thick layer of PTFE to decrease friction for ease of passage of the positive device through it. The hollow distribution system sized to allow a 27.2 strand made of 203.2 355.6 μιτι (0.008-0.014 inch) stainless steel to pass through the distribution system and the proximal clamp and fit into the distal clamp to push the clip 5 is distant from the proximal clip in order to lengthen the device, facilitate release of the hooks and facilitate recapture of the device in the device case 29. The distal end of the drive wire 27 and the distal inner clamp 23 can be designed to attach via a threaded filament connection or other reversible means to ensure that the wire is not inadvertently positioned proximal to the distal inner clamp 23. By means of the distribution system 28 maintaining control of the proximal end of the device 10 and the bias wire 27 being able to exert a biasing force on the distal end of the device, the device can be lengthened or allowed to self-expand and contract from compression15 to, as desired. This assists in repositioning with the hooks being easily released by pushing the push wire to force the device in the distal direction. This also assists in extracting the device from the case 29 that needs to occur, such as when the device is incorrectly sized to anatomy. Although described as an impulse wire, 20 are used to drive the distal end of the device, the drive wire can be used as a guide wire according to one embodiment. Thus, the driving wire 27 can be configured to extend distally from the distal internal 23 and external 26 clip elements, so that the device 10 can be distributed over-the-wire, as explained in more detail below. In this embodiment, the distal clamp element 26 is tubular, with open ends and has a passage through it sufficient for the passage of the guide wire 27.

Figures 3A-C schematically illustrate how a medical device 10, generally as outlined above, can be used to obstruct a vessel, channel, lumen, orifice, cavity or the like which must be obstructed. Device 10 can be collapsed and attached to the distribution system 10 can be collapsed and attached to the distribution system

28, so that the collapsing device can be passed through a delivery catheter 29 and the distal end of the delivery catheter is adjacent to the opening 30 in the vessel wall 31, as shown in Figure 3A. The delivery system 28 is advanced distally, while holding the delivery catheter 29 to propel the distal end of the device 10 of the catheter 29 to elastically self-expand it to its predetermined thermally cured state, so it contacts the wall of the vase. At that point, the distal end of catheter 29 can react to the expansion force and move a small amount proximally, as shown in Figure 3B. The hooks 20 begin to make contact with the vessel wall to hold the device in place. If necessary to be positioned distally, this can be done because the hooks will release in that direction. In Figure 3C, the device has left the catheter 29 completely, but it is still attached to the delivery system 28. As shown in this Figure, the disc 14 self-aligns with the wall 31 through pivot movement around the small diameter H. After the device is positioned as desired, the distribution system is disconnected by turning the distribution system 28 in one direction to release the threaded filament connection on the proximal end clamp 16.

Generally, a method according to an embodiment of the present invention includes a method of treating a patient's physiological condition. According to this method, a medical device suitable for treating the condition, which can be substantially in accordance with one of the modalities described in detail above, is selected. For example, if the LAA has to be obstructed, the device 10 of Figures 1A, 1B and 4 can be employed. Device 10 can be distributed and appropriately placed using two-dimensional ICE, MRI, transesophageal echocardiography, angiography and / or color flow mapping by Doppler. With the advent of two-dimensional ICR, MRI, transesophageal echocardiography, two-plane angiography and color flow mapping by Doppler, the proximal anatomy of the defect can be visualized. The device 10 that is employed will be based on the approximate size of the vessel, cavity or similar to be obstructed. Once the appropriate medical device is selected, a catheter can be positioned within a channel of the patient's body to place the distal end of the catheter adjacent to the desired treatment site, such as immediately adjacent or within the LAA cavity.

The medical device 10 can be collapsed to its collapsed configuration and inserted into the catheter lumen. The collapsed configuration of the device can be any shape suitable for easy passage through the lumen of a catheter and proper implantation of the distal end of the catheter. For example, the devices shown in Figures 1A, 1B, 2 and 4-10 have a relatively elongated collapsed configuration, in which the devices are stretched along their axes for insertion into the catheter. This collapsed configuration can be achieved simply by stretching the device 10 generally along its axis, for example, by manually holding the opposite ends of the device and pushing them away from each other, which will tend to take the body portion 12 and the disk portion 14 of the device 10 collapsing internally towards the axis of the device. In this regard, device 10 is no different from Chinese cuffs, which tend to contract in diameter under axial tension.

The medical device 10 can also collapse by outlining the delivery system 28 coupled to the medical device proximally in an introducer tube (not shown) extending over the delivery system axis. Making the delivery system 28 proximally pulls the device 10 into the introducer tube dimensioned with an internal diameter to keep the medical device in a diameter and allow front loading on the catheter 29.

Once the medical device 10 is collapsed and inserted into the catheter, it can be propelled along the lumen of the catheter towards the distal end of the catheter. This can be accomplished using a delivery system or the like removably attached to the device to propel it along the catheter. When the device begins to exit the distal end of the catheter, which is positioned adjacent to the desired treatment site, it will tend to resiliently return substantially completely to its pre-adjusted expanded configuration. Superelastic alloys, such as Nitinol, are useful in this application because of their ability to readily return to a particular configuration after being elastically deformed to a great extent. Consequently, simply pushing the medical device from the distal end of the catheter tends to properly implant the device at the treatment site.

Although the device tends to resiliently return to its initial expanded configuration (that is, its shape before collapsing to pass through the catheter), it should be understood that it may not always fully return to that shape. For example, the body element 12 of Figures 1A, 1B, 2 and 4-11 is intended to have a maximum outside diameter15 in its expanded configuration at least as large as, and preferably greater than, the inner diameter of the lumen. in which it has to be implanted. If such a device is implanted in a vessel, body organ or the like having a small lumen, the lumen will prevent the device from returning completely to its expanded configuration. However, the device would be properly implanted because it could fit on the inner wall of the lumen to seat the device on it, as detailed above.

If the device is to be used to permanently obstruct a channel in a patient's body, such as devices 10 and 300 described above, you can simply disconnect the delivery system (for example, shown in Figure 6) by reversing reversible connection to the device and retraction of the catheter and the distribution system of the patient's body. This will leave the medical device implanted in the patient's vascular system, so that it can obstruct the blood vessel or other channel in the patient's body.

According to one embodiment, device 10 can be implanted into the LAA cavity using an over-the-wire technique. When implanted in the LAA transvascularly, the physician first accesses the right atrium through the femoral vein with a guidewire. A catheter can then be distributed over the guidewire and in the right atrium. A hollow needle shaft can then be placed over the guidewire, through the guidewire and used to pierce the septum of the heart. After forming an opening through the septum, the guidewire can be advanced close to the LAA. The catheter can be moved through the opening in the septum through the guidewire and near or inside the LAA. The needle can then be removed while the guidewire is left in position. The guidewire can then be removed and a delivery catheter having a device 10 restricted to it can be delivered close to the LAA. In the case of the device 10 having proximal and distal hollow clamps 21, 23, 26 designed to pass a guidewire through them, the guidewire can remain in place while the device is advanced over the guidewire.

The distal end of catheter 29 can be partially placed within the LAA. The delivery catheter 29 can then be retracted proximally while holding the delivery system 28 stationary, which compels the body element 14 distally from the delivery catheter 29, where it resiliently returns to its pre-defined expanded shape. The body element 12 expands to the diameter of the LAA but typically extends only partially within the depth of the LAA, as shown in Figure 10. As the body element 12 expands, the hooks 20 are released from the catheter and fit into the LAA to further secure device 10 in it. After fully released from catheter 29, delivery system 28 can be advanced to position the disc firmly against the atrium wall surrounding the LAA ostium or opening. According to one modality, a radiopaque contrast medium can be injected through catheter 29 and into the left atrium to view, when angiographic, whether the LAA is sealed or in communication with the left atrium. Where layers of polyester fiber are positioned within each of the body portion 12 and the disk portion 14, the contrast medium typically resides between the layers of polyester fibers26. If the contrast medium enters the LAA but remains after a predetermined period of time (for example, less than 10 minutes), then communication with the left atrium is negligible and the position of the device 10 is adequate. Otherwise, it may be necessary for device 10 to be repositioned. Thus, device 10 may be able to substantially obstruct the LAA in less than about 10 minutes, so that no visualization or monitoring of the LAA is necessary. Device 10 can be disconnected by rotating the distribution system 28 in one direction to release the threaded filament connection on the proximal end clamp 16. As shown in Figure 10, the disk 14 aligns itself with the LAA wall through pivot movement around the transitional segment 19, so that the disk covers the opening of the LAA.

Although a preferred embodiment of the present invention has been described, it is to be understood that various changes, adaptations and modifications can be made here without departing from the spirit of the invention and the scope of the appended claims. For example, it is envisaged that the body portion may be cylindrical, barrel-shaped, concave, convex, tapered or a combination of shapes without deviating from the invention here. Likewise, the distal and proximal ends of the body portion could have different shapes from the tapered recessed shape described, while still retaining the benefits described.

Many modifications and other embodiments of the invention presented here will become apparent to those skilled in the art to which the present invention belongs having the benefit of the teachings presented in the preceding descriptions and associated drawings. Therefore, it should be understood that the invention is not limited to the specific modalities described and that modifications and other modalities are intended to be included within the scope of the appended claims. Although specific terms are used here, they are used in a general sense and described only and not for the purpose of limitation.