Catheter with integrated embolic protection device

Abstract

To provide a catheter with a suitable integrated embolic protection device. [Solution] The artificial heart valve delivery catheter includes an embolic filter to provide integrated embolic protection to prevent the release of embolus into the aorta, aortic arch, or branch vessels and other vascular systems during transvascular heart valve replacement procedures. The embolic filter will typically be fixed or movably attached to the shaft of the delivery catheter proximal to the artificial heart valve.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of prior provisional patent application No. 62 / 844,941 (Attorney Docket No. 41959 - 714.102), filed on May 8, 2019, and No. 62 / 804,909 (Attorney Docket No. 41959 - 714.101), filed on February 13, 2019, the entire disclosures of which are incorporated herein by reference.

[0002] The present invention relates to devices and methods for providing embolic protection within a patient's vasculature. Specifically, it relates to catheters for trans - catheter heart valve delivery and other transvascular interventional procedures that incorporate an embolic filter.

Background Art

[0003] Cerebral embolism is a known complication of cardiac surgery, cardiopulmonary bypass, and catheter - based interventional cardiology, and electrophysiology procedures. Embolic particles, which may include thrombi, atheromas, and lipids, can be dislodged during surgery or catheter manipulation, enter the bloodstream, and embolize within the downstream brain or other vital organs. Cerebral embolism can lead to neuropsychological deficits, stroke, and even death. Other downstream organs can also be damaged by embolism, resulting in reduced function or organ failure.

[0004] Preventing embolism would benefit patients and improve the outcomes of these procedures. Given that potential embolisms are often released during catheter-based procedures, deploying an embolism protection system as part of a catheter-based vascular procedure such as transcatheter aortic valve replacement (TAVR) would be advantageous. Furthermore, the use of transcranial Doppler (TCD) during TAVR has shown that cerebral embolisms primarily occur during the procedure step of crossing the natural valve and deploying the TAVR valve (see Kahlert, et al., Circulation, 2012). Therefore, integrating an embolism protection device onto the TAVR delivery system itself would have the advantage of providing protection for the most dangerous steps of the procedure. Another advantage would arise from integrating the embolism protection system onto the catheter itself used to perform procedures such as transcatheter valve delivery systems or electrophysiological catheters. Other embolism protection systems require separate procedure steps to place the protector prior to the intervention or diagnostic procedure and to remove it after the procedure. In many cases, different access sites are also required. The present invention avoids both the need for extra steps and extra access sites. Yet another advantage will arise from providing an integrated embolic protection device that does not increase the overall diameter of the catheter.

[0005] Devices for preventing embolism and similar events are described in the following patents and patent applications (incorporated herein by reference): U.S. Patent No. 10,166,094 (Patent Document 1), U.S. Patent No. 9,877,821, U.S. Patent No. 9,744,023, U.S. Patent No. 9,144,485, U.S. Patent No. 8,968,354, U.S. Patent No. 8,740,930, U.S. Patent No. 8,420,902, U.S. Patent No. 8,383,788, U.S. Patent No. 8,337,519, U.S. Patent No. 8,123,779, U.S. Patent No. 8,052,717, U.S. Patent No. 7,537,600, U.S. Patent No. 7,044,958, U.S. Patent No. 6,537,297, U.S. Patent No. 6,499,487, U.S. Patent No. 6,371,935, U.S. Japanese Patent No. 6,361,545, U.S. Patent No. 6,254,563, U.S. Patent No. 6,139,517, U.S. Patent No. 5,769,816, U.S. Patent Application No. 2019 / 0015152, U.S. Patent Application No. 2018 / 0206970, U.S. Patent Application No. 2018 / 0042390, U.S. Patent Application No. 2016 / 0317277, U.S. Patent Application No. 2015 / 0366650, U.S. National Patent Application No. 2014 / 0214069, U.S. Patent Application No. 2013 / 267993, U.S. Patent Application No. 2012 / 271340, U.S. Patent Application No. 2010 / 0312268, U.S. Patent Application No. 2010 / 0010535, U.S. Patent Application No. 2004 / 0215167, U.S. Patent Application No. 2003 / 0100940, and PCT Application No. WO2004 / 019817. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent No. 10,166,094 [Overview of the project] [Means for solving the problem]

[0007] An artificial heart valve delivery catheter with integrated embolic protection based on the principles of the present invention prevents the release of embolus into the aorta, aortic arch, or branch vessels, and other vascular systems during transvascular artificial heart valve replacement procedures, protecting the brain and other downstream organs from embolization. Unlike most other embolic protection solutions, the embolic filter is integrated into an intervention or diagnostic catheter, such as a transcatheter heart valve delivery system.

[0008] In a first aspect, the present invention provides an artificial heart valve delivery catheter system having integrated embolic protection. The catheter system typically comprises a catheter shaft having a distal portion, an artificial valve positioned on the distal portion of the catheter shaft, and an embolic filter positioned on the distal portion of the shaft at a location proximal to the artificial valve. The embolic filter has a folded configuration and an unfolded configuration, and the outer periphery of the filter is configured to contact the blood vessel wall in the unfolded configuration. In some embodiments, the embolic filter comprises a filter structure having a narrow end coupled to the shaft and an open end located distal to the narrow end.

[0009] In a specific embodiment, the narrow end of the filter structure may be fixedly attached to the catheter shaft. In an alternative embodiment, the narrow end of the filter structure may be slidably mounted on the catheter shaft. The catheter may further include at least one of a proximal stop for limiting the proximal movement of the embolic filter on the distal portion of the catheter shaft and a distal stop for limiting the distal movement of the embolic filter on the distal portion of the catheter shaft.

[0010] In a further specific embodiment, the filter may comprise a filter membrane and a support structure. The support structure may comprise a plurality of self-expanding axial supports connected to a catheter shaft at their proximal ends, such that when released from restraint, they open the distal ends of the filter members and form a cone. The axial supports may have non-traumatic distal tips.

[0011] In other embodiments, the filter may comprise a self-expanding conical filter. For example, the embolus filter comprises a porous material having a knitted, woven, or nonwoven fabric, filament, or wire. The porous material may be made from an elastic metal, polymer material, malleable material, plastically deformable material, shape memory material, or a combination thereof. The porous material will typically have pore sizes selected to prevent embolus exceeding a given size from passing through.

[0012] In a second aspect, the present invention provides a system comprising a catheter as described above in combination with an outer delivery sheath configured to maintain the embolic filter in a folded configuration.

[0013] In a third aspect, the present invention provides an artificial heart valve delivery catheter having integrated embolic protection. The artificial heart valve delivery catheter typically comprises a catheter shaft having a distal portion, an artificial valve positioned on the distal portion of the catheter shaft, and an embolic filter positioned on the distal portion of the shaft at a location proximal to the artificial valve. The embolic filter typically has a folded configuration and an unfolded configuration, and in the unfolded configuration, the outer periphery of the filter is in contact with the blood vessel wall. The embolic filter typically comprises a filter membrane and a support structure, the support structure comprising a cage having a distal collar attached to the distal portion of the catheter shaft and a proximal collar.

[0014] In specific embodiments, at least one of the distal collar and the proximal collar is slidably attached to the distal portion of the catheter shaft. In other embodiments, at least one of the distal collar and the proximal collar is fixedly attached to the distal portion of the catheter shaft. For example, at least one of the distal collar and the proximal collar is fixedly attached to the distal portion of the catheter shaft. In other examples, at least one of the distal collar and the proximal collar is configured to be translated axially to expand and contract the cage. Typically, the cage is self-expanding so that it can be radially constrained for delivery and released from radial constraint for deployment. In even further examples, the cage has a cone-elongated distal end, a cone-elongated proximal end, and a cylindrical wall portion between them, and the filter membrane covers at least the cone-elongated proximal end but not the cone-elongated distal end.

[0015] In a fourth aspect, the present invention provides an artificial heart valve delivery catheter having integrated embolic protection. The catheter comprises a catheter shaft having a distal portion, an artificial valve positioned on the distal portion of the catheter shaft, and an embolic filter positioned on the distal portion of the shaft at a location proximal to the artificial valve. The embolic filter typically has a folded configuration and an unfolded configuration, and the outer periphery of the filter is configured to contact the vascular wall. The embolic filter usually further comprises a cylindrical wall portion located proximal to the artificial valve and configured to cover the patient's aortic branch vessels, and a conical wall portion proximal to the cylindrical wall portion.

[0016] In specific embodiments, the cylindrical wall portion and the conical wall portion are not continuous. For example, at least one of the cylindrical wall portion and the conical wall portion may be fixedly attached to the distal portion of the catheter shaft. In other examples, at least one of the cylindrical wall portion and the conical wall portion is slidably attached to the distal portion of the catheter shaft. In yet another example, at least one of the cylindrical wall portion and the conical wall portion is self-expanding. In any of these examples, at least one of the cylindrical wall portion and the conical wall portion is balloon-expanding.

[0017] In a fifth aspect, the present invention provides an artificial heart valve delivery catheter having integrated embolic protection, the catheter comprising a catheter shaft having a distal portion, an artificial valve positioned on the distal portion of the catheter shaft, and an embolic filter positioned on the distal portion of the shaft at a location proximal to the artificial valve. The embolic filter typically has a folded configuration and an unfolded configuration, and the outer periphery of the filter is configured to contact the blood vessel wall. The embolic filter usually further comprises a cylindrical wall having an open distal end and a closed proximal end sealed and coupled to the catheter shaft, the proximal region of the cylindrical wall being movable abducted, allowing the open distal end to move axially parallel to the catheter shaft while the closed proximal end remains stationary relative to the catheter shaft.

[0018] In a specific embodiment, the closed proximal end is fixed to the catheter shaft.

[0019] For example, the closed proximal end may be slidably coupled to the catheter shaft. At least the distal portion of the cylindrical wall may be self-expanding, and at least the distal portion of the cylindrical wall may be equipped with a self-expanding filter. This specification also provides, for example, the following items: (Item 1) An artificial heart valve delivery catheter having integrated embolic protection, wherein the catheter is A catheter shaft having a distal portion, An artificial valve disposed on the distal portion of the catheter shaft, and an occlusion filter disposed proximal to the artificial valve on the distal portion of the shaft and comprising the occlusion filter has a folded configuration and a deployed configuration, and an outer periphery of the filter is configured to contact a blood vessel wall, the occlusion filter comprises a filter structure, the filter structure having a thin end coupled to the shaft and an open end located distally of the thin end, a catheter. (Item 2) The thin end of the filter structure is fixedly attached to the catheter shaft, the catheter according to item 1. (Item 3) The thin end of the filter structure is slidably mounted on the catheter shaft, the catheter according to item 1. (Item 4) The catheter further comprises a proximal stop on the catheter shaft, the proximal stop limiting proximal movement of the occlusion filter on the distal portion of the catheter shaft, the catheter according to item 3. (Item 5) The catheter further comprises a distal stop on the catheter shaft, the distal stop limiting distal movement of the occlusion filter on the distal portion of the catheter shaft, the catheter according to item 4. (Item 6) The filter comprises a filter membrane and a support structure, the catheter according to item 1. (Item 7) The support structure comprises a plurality of self-expanding axial struts, the axial struts being connected to the catheter shaft at their proximal ends and opening the distal end of the filter member to form a cone when released from restraint, the catheter according to item 6. (Item 8) The axial struts have non-invasive distal tips, the catheter according to item 7. (Item 9) The catheter according to item 1, wherein the filter comprises a self-expanding conical filter. (Item 10) The catheter according to item 1, wherein the stopper filter comprises a porous material comprising woven, knitted or non-woven fabric, filaments or wires. (Item 11) The catheter according to item 10, wherein the porous material is made of an elastic metal, a polymer material, a malleable material, a plastically deformable material, a shape memory material or a combination thereof. (Item 12) The catheter according to item 10, wherein the porous material has a pore size selected to prevent stoppers larger than a predetermined size from passing through. (Item 13) A system, wherein the system comprises the catheter according to item 1 and an outer delivery sheath configured to maintain the stopper filter in a folded configuration. A system comprising the above. (Item 14) An artificial heart valve delivery catheter having integrated stopper protection, wherein the catheter comprises a catheter shaft having a distal portion, an artificial valve disposed on the distal portion of the catheter shaft, and a stopper filter disposed on the distal portion of the shaft at a location proximal to the artificial valve. The catheter comprises the above. The stopper filter has a folded configuration and a deployed configuration, and an outer periphery of the filter is configured to contact a blood vessel wall. The stopper filter comprises a filter membrane and a support structure, the support structure comprises a cage, and the cage has a distal collar and a proximal collar attached to the distal portion of the catheter shaft. (Item 15) The catheter according to item 1, wherein at least one of the distal collar and the proximal collar is slidably attached to the distal portion of the catheter shaft. (Item 16) The catheter according to item 1, wherein at least one of the distal collar and the proximal collar is fixedly attached to the distal portion of the catheter shaft. (Item 17) The catheter according to item 1, wherein at least one of the distal collar and the proximal collar is fixedly attached to the distal portion of the catheter shaft. (Item 18) The catheter according to item 1, wherein at least one of the distal collar and the proximal collar is configured to be translated axially to expand and contract the cage. (Item 19) The catheter according to item 1, wherein the cage is self-expanding so that it can be radially constrained for delivery and released from radial constrainment for deployment. (Item 20) The catheter according to item 1, wherein the cage has a cone-shaped, elongated distal end, a cone-shaped, elongated proximal end, and a cylindrical wall portion between them, and the filter membrane covers at least the cone-shaped, elongated proximal end but does not cover the cone-shaped, elongated distal end. (Item 21) An artificial heart valve delivery catheter having integrated embolic protection, wherein the catheter is A catheter shaft having a distal portion, An artificial valve positioned on the distal portion of the catheter shaft, An embolic filter is positioned on the distal portion of the shaft at a location proximal to the artificial valve. Equipped with, The embolic filter has a folded configuration and an unfolded configuration, and the outer periphery of the filter is configured to contact the blood vessel wall. The embolic filter is a catheter comprising a cylindrical wall portion located proximal to the artificial valve and configured to cover the patient's aortic branch vessels, and a conical wall portion proximal to the cylindrical wall portion. (Item 22) The cylindrical and conical wall portions are not continuous, as described in item 21. (Item 23) The catheter according to item 21, wherein at least one of the cylindrical wall portion and the conical wall portion is fixedly attached to the distal portion of the catheter shaft. (Item 24) The catheter according to item 21, wherein at least one of the cylindrical wall portion and the conical wall portion is slidably attached to the distal portion of the catheter shaft. (Item 25) The catheter according to item 21, wherein at least one of the cylindrical wall portion and the conical wall portion is self-expanding. (Item 26) The catheter according to item 1, wherein at least one of the cylindrical wall portion and the conical wall portion is balloon-inflatable. (Item 27) An artificial heart valve delivery catheter having integrated embolic protection, wherein the catheter is A catheter shaft having a distal portion, An artificial valve positioned on the distal portion of the catheter shaft, An embolic filter is positioned on the distal portion of the shaft at a location proximal to the artificial valve. Equipped with, The embolic filter has a folded configuration and an unfolded configuration, and the outer periphery of the filter is configured to contact the blood vessel wall. The embolic filter comprises a cylindrical wall having an open distal end and a closed proximal end sealed and coupled to the catheter shaft, wherein the proximal region of the cylindrical wall is movable and abductible, allowing the open distal end to move axially parallel to the catheter shaft while the closed proximal end remains stationary relative to the catheter shaft. (Item 28) The catheter according to item 27, wherein the closed proximal end is fixed to the catheter shaft. (Item 29) The catheter according to item 27, wherein the closed proximal end is slidably coupled to the catheter shaft. (Item 30) The catheter according to item 1, wherein at least the distal portion of the cylindrical wall is self-expanding. (Item 31) The catheter according to item 1, wherein at least the distal portion of the cylindrical wall is equipped with a self-expanding filter. (Integrated by reference)

[0020] All published documents, patents, and patent applications referenced herein are incorporated herein by reference to the same extent as each individual published document, patent, or patent application is specifically and individually indicated as being incorporated by reference herein. [Brief explanation of the drawing]

[0021] Novel features of the present invention are specifically described in the appended claims. A deeper understanding of the features and advantages of the present invention will be obtained by referring to the following embodiments for carrying out the invention, which describe illustrative embodiments in which the principles of the present invention are utilized, and to the accompanying drawings.

[0022] [Figure 1-1] Figures 1A-1D show a first embodiment of the valve delivery system according to the present invention, which includes a balloon-deployable artificial heart valve with integrated embolic protection. [Figure 1-2]Figures 1A-1D show a first embodiment of the valve delivery system according to the present invention, which includes a balloon-deployable artificial heart valve with integrated embolic protection.

[0023] [Figure 2] Figures 2A-2D show a second embodiment of the valve delivery system according to the present invention, with a self-expanding artificial heart valve having integrated embolic protection.

[0024] [Figure 3] Figure 3 shows a third embodiment of the valve delivery system according to the present invention, which includes an integrated embolic protection comprising both an embolic deflector element and a separate embolic trapping element.

[0025] [Figure 4] Figure 4 illustrates the valve delivery system shown in Figure 3, deployed within the aortic arch with an artificial aortic valve implanted within the natural aortic valve.

[0026] [Figure 5A] Figures 5A-5D show a fourth embodiment of the valve delivery system according to the present invention, which has an elongated cylindrical filter mesh that is deployed to cover the aortic arch while delivering an artificial aortic valve into the natural aortic valve. [Figure 5B] Figures 5A-5D show a fourth embodiment of the valve delivery system according to the present invention, which has an elongated cylindrical filter mesh that is deployed to cover the aortic arch while delivering an artificial aortic valve into the natural aortic valve. [Figure 5C] Figures 5A-5D show a fourth embodiment of the valve delivery system according to the present invention, which has an elongated cylindrical filter mesh that is deployed to cover the aortic arch while delivering an artificial aortic valve into the natural aortic valve. [Figure 5D] Figures 5A-5D show a fourth embodiment of the valve delivery system according to the present invention, which has an elongated cylindrical filter mesh that is deployed to cover the aortic arch while delivering an artificial aortic valve into the natural aortic valve.

[0027] [Figure 6]Figure 6 shows a fifth embodiment of the valve delivery system according to the present invention, which has an embolic filter mounted around the valve system catheter during initial delivery.

[0028] [Figure 7] Figure 7 shows a sixth embodiment of the valve delivery system according to the present invention, which includes an embolic filter and an artificial valve similar to that in Figure 6, where the filter delivery sheath is deployed and retrieved via a separate catheter in a separate lumen of a valve delivery catheter located adjacent to the catheter containing the artificial valve.

[0029] [Figure 8] Figure 8 shows a seventh embodiment of the valve delivery system according to the present invention, which has an embolic filter mounted on a valve delivery system in which both ends of the support structure are attached to a delivery catheter.

[0030] [Figure 9-1] Figures 9A-9D show an eighth embodiment of the valve delivery system according to the present invention, which is similar to the valve delivery system in Figure 1. [Figure 9-2] Figures 9A-9D show an eighth embodiment of the valve delivery system according to the present invention, which is similar to the valve delivery system in Figure 1.

[0031] [Figure 10] Figure 10 shows a ninth embodiment of the valve delivery system according to the present invention, similar to that in Figure 1, in which the embolic filter has a self-supporting mesh basket without an additional support frame. [Modes for carrying out the invention]

[0032] For the purposes of this patent application, the term “distal” refers to the end of the device that is furthest from the operator and closest to the heart. This is also the “upstream” direction of blood flow. The term “proximal” refers to the end of the device that is closest to the operator and furthest from the heart, in the direction of the access site into which the device is introduced into the body. This is also the “downstream” direction of blood flow.

[0033] Figures 1A-1D show an integrated valve system 10 with integrated embolic protection according to the present invention. A self-expanding conical embolic filter 12 is mounted on the shaft 14 of a balloon valve delivery catheter, the shaft 14 having a balloon-expandable prosthetic heart valve 20 mounted on a distal balloon 18. The balloon-expandable aortic valve may be any of the various available and proposed balloon-expandable heart valves, such as the Edwards Sapien® valve. The conical embolic filter 12 can be mounted on the catheter shaft 14 using either fixed or sliding mounting. Fixed mounting simplifies both the construction and deployment protocols but limits the ability to adjust the position of the conical filter relative to the aortic valve during delivery. When fixedly mounted, the distal end of the conical filter is positioned 1 cm to 20 cm proximal to the proximal end of the prosthetic valve 20, and can typically be 1 cm to 10 cm proximal to the proximal end of the prosthetic valve. When slidably mounted, the distal end of the conical filter is adjusted to be positioned 1 cm to 30 cm proximal to the proximal end of the prosthetic valve 20 (before or during deployment), and can typically be located 1 cm to 20 cm proximal to the proximal end of the prosthetic valve.

[0034] A self-expanding conical embolic filter 12 typically comprises a mesh or other filter material having a mesh size suitable for embolic capture, and a self-expanding support structure such as a plurality of radially self-expanding struts 22 to ensure complete expansion of the mesh or other filter material. As shown in the figure, the radially self-expanding struts 22 have a non-traumatic distal end for contact with the aortic wall, and the distal end of the strut may be curved, coiled, have a protective pad, or have other structures to prevent tissue damage.

[0035] The self-expanding conical embolic filter 12 is typically deployed by retracting the restraint sheath 26 (compare Figures 1A and 1B), and can be folded by advancing the restraint sheath and / or retracting the catheter shaft 14 (compare Figures 1C and 1D). Optionally, after deployment of the valve 20, the restraint sheath may be used to cover the deflated balloon 18 and the conical filter (Figure 1D).

[0036] Figures 2A-2D show a second embodiment of a valve system 210 according to the present invention, having an embolic filter 212 integrated on a catheter shaft 214. The integrated valve system 210 is adapted to deliver a self-expanding prosthetic valve 220, such as a Medtronic CoreValve® heart valve, mounted on the distal end of the catheter shaft 214. The self-expanding prosthetic valve 220 is initially constrained for delivery by a first retractable constraining sheath 226, and the embolic filter 212 is initially constrained for delivery by a second retractable sheath 228.

[0037] After positioning the first restraining sheath 226 and the prosthetic valve 220 within the aortic valve V, the filter 212 is deployed by the retraction of the second sheath 228, which allows the filter to expand (Figure 2B). The prosthetic valve 220 is then deployed by the retraction of the second retractable sheath 228 (Figure 2C). After the valve deployment, the second retractable sheath 228 is advanced to fold the filter 212 and the first sheath 226 for removal of the system. As shown in Figure 2D, the first restraining sheath 226 may fold into the filter 212 to be folded, and then the filter 212 folds into the second restraining sheath 228. Alternatively, the first retractable restraining sheath 226 may be advanced by the advancement of the second retractable sheath 228 prior to the folding of the filter 212. In this alternative, the first restraining sheath 226 will be located distal to the second retractable sheath 228 as the catheter shaft 14 is withdrawn from the aorta.

[0038] Figures 3 and 4 show a third embodiment of a valve system 310 according to the present invention, having an embolic filter assembly 312 integrated on a catheter shaft 314. The embolic filter assembly comprises a distal cylindrical or panel-shaped deflector 312a (as described, for example, in US Patent No. 8,114,114 (the full disclosure thereof is incorporated herein by reference)) deployed across the great duct of the aortic arch AA, as shown in Figure 4, and a separate conical or other capture basket 312b located downstream or proximal to the deflector 312a in the descending aorta DA. The valve system 310 would include an artificial valve 320 that can be positioned and deployed in the patient's aortic valve V using either the balloon-expandable protocol or the self-expandable protocol described previously.

[0039] Figure 5A shows a fourth embodiment of a valve system 510 having an integrated embolic filter according to the principles of the present invention. The proximal portion 513 abducts to form a flexible section that can be reversibly "rolled" to adapt to bidirectional axial movement of the catheter shaft 514, while keeping the distal portion 516 of the embolic filter stationary relative to the vascular wall. This allows the proximal end of the embolic filter (fixed to the delivery catheter at the attachment joint 517) to move with the catheter shaft 514 when the catheter is advanced and retracted to position the valve for delivery, without requiring the distal filter portion to move and slide along the vascular wall when the catheter is advanced and retracted. Compare Figure 5B, which shows the filter 512 deployed in the aortic arch AA prior to the deployment of the artificial aortic valve 520, with Figure 5C, which shows the filter 512 after the artificial valve 520 has been advanced to its deployed position in the natural valve V. It should be noted that the attachment joint 517 at the proximal end of the embolic filter 512 is advanced forward, allowing the prosthetic valve 512 to be advanced to its fixed position without moving the main body of the embolic filter that covers the cerebral branch vessels of the aortic arch AA. After the deployment of the valve 512, the filter can be retracted back into the deployment sheath 526, as shown in Figure 5D.

[0040] Figure 6 shows a fifth embodiment of the embolic filter 612 according to the present invention, in which the filter is mounted around the shaft 614 of the valve system 610 catheter during initial delivery. After the filter 612 is deployed, the shaft 614 is free to move through the access port 616, which accommodates the catheter but prevents the release of embolic fragments. The filter 612 is held in place and retrieved using a tether 618 connected to the proximal end of the filter. The tether 618 can be rigid to allow both proximal and distal repositioning and retrieval. Retrieval can be performed by pulling the filter into a separate lumen of the delivery system (not shown). The filter can be folded for retrieval via a mechanism such as a “purse” loop 619 (shown) or an extension of the support frame.

[0041] Figure 7 shows a sixth embodiment of the embolic filter 712 according to the present invention, in which a filter delivery sheath 726 is deployed and retrieved through a separate lumen 728 within a valve delivery catheter 730. The valve delivery catheter 730 also has a lumen for a valve delivery shaft 714 that carries an artificial valve 720. When the embolic filter 712 is deployed, the artificial valve 720 can be advanced through the embolic filter to the valve implantation site. The filter catheter 726 can be advanced and retracted independently, thereby allowing the filter catheter 726 to be advanced ahead of the valve catheter 714 for deployment and positioning of the filter 720, and then withdrawn while the valve catheter is advanced beyond the filter catheter through an access port for filter mesh or other filter material. After valve deployment, the valve catheter 714 is withdrawn, and the filter catheter 726 can be advanced to assist in the retrieval of filter mesh or other filter material.

[0042] Figure 8 shows a seventh embodiment of the embolic filter 812 according to the present invention, in which the embolic filter is mounted with both ends of a filter support structure 822, such as a self-expanding cage, attached to a delivery catheter 814. When deployed, the embolic filter 812 opens at its distal end (free from the filter mesh) and closes proximal to capture debris. At least one of the proximal or distal ends of the filter support structure 822 is slidably attached to the delivery catheter 814 to allow radial opening and folding. In some cases, both the distal and proximal ends on the support structure 822 would be slidably attached to the catheter 814 to allow a balloon 818 and a valve 820 to be positioned after the filter 812 has been deployed. A conical guide structure 827 ("funnel") at the end of the restraining sheath 826 assists in the deployment and retrieval of the filter and support structure.

[0043] Figures 9A-9D show an eighth embodiment of the embolic filter 912 according to the present invention, in which both the prosthetic valve 920 and the filter 912 are balloon-expandable. The embolic filter 912 is mounted on the nearest balloon 916 of a double-balloon catheter 914. A balloon-expandable prosthetic valve 920, such as the Sapien® valve from Edwards Lifesciences, is mounted on the most distal balloon 922 on the catheter 914. Both the prosthetic valve 920 and the embolic filter 912 are therefore deployed by balloons, which are configured to inflate and deflate separately. As shown in Figure 9A, prior to deployment, the prosthetic valve 912 and the embolic filter 920 are pressed onto balloons 916 and 922, respectively. As shown in Figure 9B, the filter 912 is deployed by the inflation of balloon 916. The filter 920 is then deployed by the inflating balloon 922 (Figure 9C), which is deflated once the filter is deployed. While the filter 912 remains expanded, after the valve deployment, the balloon 922 is deflated, and the sheath 926 (previously used to deploy the valve delivery system) is advanced, folding the filter 912 and allowing the system to be removed.

[0044] Figure 10 shows a ninth embodiment of the embolic filter 1012 according to the present invention. The embolic filter 1012 is a self-supporting mesh basket without an additional support frame. It is deployed and retrieved by the retraction and advancement of a restraint sheath 1026, which is part of the delivery system for a balloon-expandable valve 1020, such as an Edwards Lifesciences Sapien® valve. In this example, the embolic filter 1012 is deployed via a self-expansion mechanism, although the prosthetic valve 1020 is deployed via the inflation of a deployment balloon 1022. The filter 1012 may be mounted on a separate filter deployment catheter 1014, which is deployed over the balloon catheter 1016, but inside the restraint sheath 1026. This configuration allows the balloon catheter 1016 to be advanced and withdrawn independently of the filter deployment catheter 1014 and associated mechanisms. The embolic filter 1012 can be deployed by either the retraction of the restraint sheath 1026 or the advancement of the catheter 1014, thereby releasing the embolic filter from the restraint sheath. After the filter is deployed, the artificial valve 1020 is deployed by the inflation of the deployment balloon 1022. After the valve 1020 is deployed, the deployment balloon 1022 is deflated, and the embolic filter 1012 is folded by drawing the embolic filter into the restraint sheath 1026 or by advancing the restraint sheath over the embolic filter. This may further include a downstream or proximal stop 1030 on the shaft of the catheter 1014 (when configured to slide on the shaft) that limits the proximal movement of the filter 1012 on the shaft, and an upstream or distal stop 1032 that limits the distal movement of the filter on the shaft.

[0045] Embolization filters can be meshes or other filter structures made from knitted, woven, or nonwoven fabrics, filaments, or wires, which will have pore sizes selected to allow blood to pass through but prevent embolus larger than a certain size from passing through. Embolization filters can also consist of nonwoven sheets, such as thin sheets of polymer or metal perforated with pores of a single or different size. Embolization filter materials can be made from metal, polymer, or a combination thereof, and optionally have an antithrombotic coating on their surface. Embolization filters can also consist of a combination of perforated sheets and fiber-based meshes, or other filter materials, or other filter structures. Embolization filters can consist of one or more layers of any of the above configurations, which can improve filtration efficiency and reduce the effective pore size.

[0046] The embolic protection device is delivered under non-deployed or retracted conditions. A tubular external delivery sheath may be used to maintain the embolic protection device under non-deployed conditions (Figures 2A-2D). The delivery catheter may optionally include a shoulder or stop positioned proximal to the embolic protection device to maintain its position on the catheter when the delivery sheath is withdrawn during deployment. Alternatively, a pusher catheter, such as the filter deployment catheter shown in Figure 10, which is inserted between the catheter and the delivery sheath, may be used to facilitate deployment.

[0047] Alternatively, the filter may be deployed via the inflation of a balloon inside the filter, which may be shaped cylindrical or conical, or otherwise, to match the geometric shape of the filter. Such a filter can be recovered by pulling it into a recovery sheath (Figure 9).

[0048] Another alternative delivery mechanism is designed to reduce the effective length of the embolic filter, with the component attached to either the distal or proximal end (or both). In embolic filters with designs such as those shown in Figures 2A-2D, longitudinal compression of the filter would result in an increase in the diameter of the filter structure and the resulting unfolding of the filter. During retrieval, the filter can be stretched, reducing its diameter and causing it to fold. This can be accomplished using two independent filter deployment catheters that can be advanced or retracted independently, resulting in a change in length.

[0049] Catheters can be configured as diagnostic catheters, induction catheters, or therapeutic catheters. A specific example would be a delivery system for transcatheter aortic valves.

[0050] An embolic filter will typically have at least one open end and define one or more internal collection areas to receive and capture embolus that enter with the blood flow through the open end. In other configurations, an embolic filter may have two open ends, for example, having a cylindrical configuration that allows blood to flow in at one end and out at the other.

[0051] In many embodiments, the filter membrane will be self-supporting under deployment conditions. “Self-supporting” means that the filter membrane can be deployed without further support to a three-dimensional structure that maintains sufficient contact with the vascular wall, and can form a proper seal to prevent embolus exceeding a certain size from passing around the outside of the embolic protection device. In one example, the embolic filter can be constructed of an elastic mesh or other filter material that can be compressed under non-deployment conditions and self-expand under deployment conditions. Such a structure is described in US Patent No. 9,877,821 (which is previously incorporated herein by reference).

[0052] In another example, an embolic filter may comprise a filter membrane, matrix, etc., and a separate support structure. The filter membrane may comprise any known structure for filtering embolus from blood, including mesh, perforated sheet, porous sheet, fibrous structure, etc., or any combination thereof. The filter membrane may be elastic, slack, plastically deformable, or a combination thereof.

[0053] The support structure may be located outside the filter membrane, inside the filter membrane, or both externally and internally. For example, the support structure may comprise a framework including one or more longitudinal struts or hoops attached to or otherwise engaging with the filter membrane to hold the filter membrane in its open or deployed configuration using the aorta or other target vessel. The hoops and / or struts may be formed from elastic metal, polymer, or other material to provide a self-expanding framework that takes on a thin or slender configuration when constrained by the sheath for delivery, and an expanded or deployed configuration when released from constraint. Alternatively, the framework or other support structure may comprise a malleable or plastically deformable material to provide expansion by applying a radially outward force to the interior of the support structure, typically using an inflatable balloon or other expansion mechanism.

[0054] Hybrid structures combining features of self-supporting and frame-supported structures may also be used. Hybrid deployment methods, such as self-expansion assisted by balloons or longitudinal compression of support structures, can also be utilized.

[0055] The support structure and filter membrane of an embolic filter will often be of the same length, but embolic filters in which the filter membrane is longer or shorter than the support structure can also be constructed. The specific relative longitudinal dimensions of the filter membrane of the embolic filter may be as shown in the drawing. In another alternative structure, the support structure and / or filter membrane may be conical, with the enlarged or proximal end of the cone positioned upstream.

[0056] The embolic filter can be retracted and withdrawn using a catheter after the diagnostic or intervention procedure is completed. Optionally, the embolic filter may include features to assist in retracting the device for retrieval from the patient's aorta. For example, a conical guide structure may be slidably attached to the catheter at the proximal end of the device, its purpose being to assist in the folding of the embolic filter as the retrieval sheath is advanced along the conical guide structure. In another example, a portion of the embolic filter may be constructed with a retraction member configured like a drawstring or lasso around the circumference of the device. A pull loop or other grippable structure near the downstream end of the embolic filter is connected to the retraction member by one or more connecting members. In one preferred embodiment, the embolic filter is configured to first close its upstream end to ensure that any captured embolus does not migrate out of the filter during retrieval. This can be accomplished by providing one or more pull loops for selectively retracting different sections of the device. The retraction member and connecting members may be fabricated from sutures, wires, plastic filaments, or a combination of these materials. In the alternative structure, the “stent” support structure described above may also be configured to function as a setback member.

[0057] The embolic filter may be fixedly attached to the catheter, attached via a sliding attachment, or a combination of both. The sliding attachment may consist of one or more rings, roller bearings, or other structures that allow the embolic protection device to slide freely on the catheter. The sliding attachment will preferably have a low coefficient of friction and / or a lubricating coating so that the movement of the catheter through the sliding attachment will either push the embolic protection device aside or not cause it to become detached. Alternatively, the sliding attachment may include additional sealing elements such as a resilient flap, an iris structure, or an expandable sealing material.

[0058] When folded for delivery, the overall unfolded diameter of the embolic filter (including the diameter of its restraint sheath) will preferably be smaller than the largest portion of the catheter (such as the folded diameter of the prosthetic valve including its restraint sheath), most likely in the distal portion of the catheter. In the case of valve delivery systems, the catheter is typically reduced in size proximal to the valve, which will potentially allow for the integration of the embolic filter and its restraint members without altering the overall tracking profile of the valve delivery system.

[0059] The embolic filter is in a non-deployed position on the catheter when inserted into the patient's aorta. Ideally, the embolic filter is deployed into the ascending aorta prior to the cerebral artery orifice. Optionally, a delivery sheath may be used to hold the embolic filter in a non-deployed position. The embolic filter can be constrained for delivery by compressing it onto the balloon catheter or by stretching its support structure to reduce its diameter.

[0060] The entire embolic filter or a portion thereof may be coated with an antithrombotic coating, such as a conjugated heparin coating, to reduce the formation of blood clots that could potentially lead to embolic states. Alternatively, or in addition, the embolic filter or a portion thereof may have a drug-eluting coating containing an anti-inflammatory or anti-stenotic agent. The embolic filters of the present invention may also be used for embolic protection of other organ systems. For example, the embolic filter may be deployed in the descending aorta of a patient to prevent embolic particles in the aortic blood flow from entering the renal artery and forming emboli in the patient's kidneys.

[0061] Preferred embodiments of the present invention are shown and described herein, but it will be apparent to those skilled in the art that such embodiments are provided only as examples. Numerous modifications, alterations, and substitutions will be conjured upon those skilled in the art without departing from the present invention. It should be understood that various substitutes for the embodiments of the present invention described herein may be employed in practicing the invention. The following claims define the scope of the present invention, and methods and structures within the scope of these claims and their equivalents are intended to be covered thereby.

Claims

[Claim 1] The invention as shown in the drawings.

Images