Devices and methods for providing embolic protection during transcatheter procedures

Abstract

Methods and apparatus for providing embolic protection during transcatheter procedures are disclosed. In one arrangement, a device includes an elongate sheath insertable through a vasculature into a target site. A filter assembly extends from the distal end of the sheath. The sheath tube can be switched between a radial contraction state and a radial expansion state. The sheath in a radially expanded state defines a central lumen allowing insertion of a device for transcatheter operations. The filter assembly includes a porous membrane switchable between a radially contracted state and a radially expanded state. The radially expanded state refers to a cross-section across the blood vessel to prevent debris from passing through the porous membrane. A filter actuation system switches the porous membrane between a radially contracted state and a radially expanded state.

Description

[0001] This disclosure relates to devices and methods for providing embolic protection during transcatheter procedures. The disclosed arrangements are particularly suitable for use in the aorta during interventional cardiac procedures, such as during transcatheter aortic valve implantation (TAVI).

[0002] TAVI, sometimes called TAVR (Transcatheter Aortic Valve Replacement), is a minimally invasive surgical procedure used to replace a narrowed aortic valve that cannot open properly (a condition known as aortic stenosis). It is increasingly used due to its safety advantages over open heart surgery alternatives.

[0003] TAVI surgery has been associated with silent ischemic cerebral embolism and even clinical stroke caused by surgical debris reaching the cerebrovascular system during TAVI prosthesis deployment. In recent large-scale trials, approximately 5-6% of cases eventually resulted in stroke or transient ischemic attack, and stroke was associated with a 3.5-fold increased mortality rate during the first month after TAVI. For example, aortic debris can be generated due to the use of large-sized catheters and rigid delivery systems in calcified natural valves and aortic walls. Additional balloon aortic valve repair may be required during TAVI prosthesis deployment, which increases the risk of displacement and embolism of aortic debris and shattered calcified natural valves. These embolic particles can enter the bloodstream and embolize to the brain or other downstream organs. Cerebral embolism can lead to vascular occlusion, causing neuropsychological deficits, stroke, and even death.

[0004] The risk of embolism has led to the development of cerebral embolic protection devices (CEPDs) to protect patients from these risks and improve surgical outcomes. CEPDs typically consist of a filter or protective sheath designed to capture or deflect emboli entering the brain during TAVI procedures, preventing embolic fragments from reaching the supra-aortic vessels. In a typical TAVI procedure, a CEPD can be percutaneously inserted via the radial or femoral artery before the TAVI prosthesis is deployed. For example, a CEPD can be placed across the origin of the supra-aortic vessels. In some known CEPD devices, a filter covering some or all branches of the aortic arch (brachiocephalic artery, left common carotid artery, and left subclavian artery) is deployed to prevent fragments from entering the cerebral circulation. Such devices protect vessels in cerebral regions, but they do not prevent fragments from entering non-cerebral regions. Another type of device aims to provide complete circumferential coverage of the aortic arch, thus protecting all supra-aortic vessels and preventing fragment migration to both cerebral and non-cerebral regions. However, this device uses a separate woven mesh filter, which is relatively expensive and requires considerable skill to master its deployment.

[0005] As described above, CEPD devices offer varying levels of embolic protection and / or their manufacture and / or use can be expensive and / or complex. Furthermore, in addition to the vascular access required for TAVI prosthesis delivery, dedicated vascular access is needed, which can be stressful for the patient and complicate the procedure.

[0006] The purpose of this disclosure is to at least partially address one or more of the challenges described above.

[0007] According to one aspect of the present invention, a device for providing embolic protection during transcatheter procedures is provided, the device comprising:

[0008] A slender sheath, insertable through a subject's vascular system to deliver the distal end of the sheath to a target site within the vascular system; and a filter assembly configured to extend from the distal end of the sheath, wherein: the slender sheath is switchable between a radially constricted state and a radially expanded state, wherein the radially expanded sheath defines a central lumen to allow insertion of a device for transcatheter manipulation through the central lumen into the target site; the filter assembly includes a porous membrane switchable between a radially constricted state and a radially expanded state, wherein the radially expanded state refers to a cross-section of the vessel at the target site to prevent upstream-generated debris from passing through the porous membrane while allowing blood to flow through the porous membrane; and a filter actuation system configured to switch the porous membrane between the radially constricted state and the radially expanded state.

[0009] Therefore, a device using a switchable porous membrane is provided, which can be inserted into the target site in a radially contracted state before switching to a radially expanded state to provide protection against unwanted downstream migration of debris from the debris-generating transcatheter procedure. A slender sheath can be in a radially contracted state, allowing for efficient insertion into the subject, and then switched to a radially expanded state to allow the device to pass through the central lumen of the sheath for transcatheter procedures. Thus, the same sheath serves both to provide debris protection (by housing the porous membrane and associated actuation system) and to provide access for transcatheter procedures. This allows for multiple functions, requiring multiple corresponding incisions in the subject and associated procedural complexity and increased trauma. The porous membrane can be completely transverse across the vessel, for example, at a distal location in the ascending aorta, thereby allowing for systemic debris protection (i.e., the porous membrane can prevent debris from entering branch vessels and the descending aorta).

[0010] In one embodiment, the filter actuation system includes one or more drive wires extending through and from the distal end of a sheath; and the filter actuation system is configured such that longitudinal movement of the drive wires facilitates or causes the porous membrane to switch between a radially contracted state and a radially expanded state. It has been found that using drive wires configured in this manner provides operational flexibility, high reliability, and is not overly complex or expensive to implement.

[0011] In one embodiment, each of the one or more drive wires is an elastic drive wire directly or indirectly mechanically coupled to the porous membrane; and the filter assembly includes a constraint component configured to constrain the elastic drive wires such that longitudinal movement of the elastic drive wires deforms them in a manner that causes the porous membrane to expand radially. Because the drive wires provide a dual function, this configuration is structurally simple and compact, allowing the actuation process to occur via their longitudinal movement while also providing elasticity to push open the porous membrane 18.

[0012] In one embodiment, the constraint assembly includes one or more pairs of tubular members corresponding to each drive wire. Each pair of tubular members includes: a first tubular member having a first lumen and a first distal opening; and a second tubular member having a second lumen and a second distal opening. The drive wire of each pair of tubular members passes through the corresponding first lumen, forms a protruding loop extending between the corresponding first distal opening and the corresponding second distal opening, and passes through the corresponding second lumen. This configuration effectively provides the required functionality while maintaining a robust and reliable structure.

[0013] In one embodiment, the first and second tubular members of each pair of drive members are configured to align with each other at their distal ends parallel to the longitudinal axis of the sheath when the filter assembly is in a radially contracted state, and to diverge from each other in the distal direction when the porous membrane is in a radially expanded state. It has been found that this configuration is particularly easy to implement from a structural perspective, while providing efficient switching between the radially contracted and radially expanded states.

[0014] In one embodiment, the constraint assembly includes a plurality of elastic constraint wires fixedly connected to a sheath and mechanically coupled to a porous membrane; each drive wire is connected to a corresponding constraint wire in a distal connection region spaced apart from the distal end of the sheath, the connection at the distal connection region causing the constraint drive wire to deform in a radially outward direction when the drive wire is longitudinally advanced outside the sheath, thereby causing the porous membrane to expand radially. It has been found that providing constraint wires can provide a high degree of flexibility and control the switching of the porous membrane between radially contracted and radially expanded states.

[0015] In one embodiment, the filter assembly includes a plurality of resilient support wires fixedly connected to a sheath and mechanically coupled to a porous membrane; and the filter actuation system includes a plurality of drive wires coupled to the support wires and configured such that longitudinal movement of the drive wires drives the plurality of support wires to deform the porous membrane in a radially expanding manner. This configuration has been found to provide a high degree of flexibility and to control the switching of the porous membrane between a radially contracted state and a radially expanded state using a simple and robust structure.

[0016] In one embodiment, the plurality of support wires includes one or more pairs of support wires; each pair of support wires is fixedly connected to each other at a distal connection region spaced apart from the distal end of the sheath, and is spaced apart from each other in a longitudinal deformation region between the connection region and the distal end of the sheath. Using support wires in pairs in this manner promotes mechanical balance and reliable actuation.

[0017] In one embodiment, the filter actuation system further includes a plurality of guide wires and corresponding plurality of sliding couplings configured to slide longitudinally along their respective guide wires; and the connection area of ​​each pair of support wires is fixedly connected to the corresponding sliding coupling, such that longitudinal movement of the drive wire causes corresponding movement of the sliding coupling and associated guidance of deformation of each pair of support wires via the guide wires. Providing guide wires enhances mechanical robustness and facilitates reliable and controllable actuation.

[0018] In one embodiment, the sheath includes a tubular body defining an internal lumen, the body having a cross-sectional profile in which the stiffness of the body varies with azimuth angle to facilitate inward folding of the body within one or more predetermined ranges of azimuth angle. The body is configured to fold inward more in one or more ranges when the sheath is in a radially contracted state than when the sheath is in a radially expanded state. This configuration provides the desired functionality while maintaining reliable operation and robust structure.

[0019] According to another aspect, a method for providing embolism protection during transcatheter procedures is provided, the method comprising: inserting an elongated sheath through a subject's vascular system to bring the distal end of the sheath to a target site in the vascular system, wherein, during insertion, a porous membrane in a radially constricted state extends from the distal end of the sheath; switching the porous membrane to a radially expanded state such that the porous membrane spans a cross-section of the vessel at the target site to prevent upstream-generated debris from passing through the porous membrane while allowing blood to flow through the porous membrane; switching the sheath from a radially constricted state to a radially expanded state to define a central lumen, and inserting a device for performing the transcatheter procedure through the central lumen to the target site.

[0020] Embodiments of this disclosure will now be further described by way of example only with reference to the accompanying drawings.

[0021] Figure 1 and Figure 2 The features of human anatomy associated with the apparatus and methods of this disclosure are schematically depicted.

[0022] Figure 3 This is a perspective view of the distal portion of a device for providing embolism protection, which has a sheath and a porous membrane in a radially constricted state.

[0023] Figure 4 Depicting Figure 3 The device in which the porous membrane is in a radially expanded state.

[0024] Figure 5 Depicting Figure 3 and Figure 4 The device is deployed at the target site in the aortic arch.

[0025] Figures 6 to 8 An exemplary pore structure of the porous membrane 18 is depicted.

[0026] Figure 9 and Figure 10 yes Figure 3 The front and side views of the device, corresponding to a single pair of support filaments and associated drive filaments in a radially contracted state, and the porous membrane in a radially contracted state.

[0027] Figure 11 and Figure 12 yes Figure 3 The front and side views of the device, showing a single pair of support filaments and associated drive filaments in a radially expanded state corresponding to the porous membrane in a radially expanded state.

[0028] Figure 13 yes Figure 3 and Figure 4 An axial end view of the device shows the support wire in a radially contracted state.

[0029] Figure 14 yes Figure 3 and Figure 4 An axial end view of the device shows the support wire in a radially expanded state.

[0030] Figure 15 yes Figure 3 A perspective view of a variant of the device, which includes a guidewire in a radially contracted state and an associated sliding connector.

[0031] Figure 16 Depicting a state of radial expansion Figure 15 The equipment.

[0032] Figure 17 and Figure 18 yes Figure 15 and Figure 16 An axial end view of the equipment.

[0033] Figure 19 yes Figure 3 A perspective view of a variant of the device, which includes a tubular member of an elastic drive wire in a radially contracted state and a protruding ring.

[0034] Figure 20 Depicting a state of radial expansion Figure 19 The equipment.

[0035] Figure 21 yes Figure 3 A perspective view of a variant of the device, which includes an elastic constraint wire in a radially contracted state.

[0036] Figure 22 Depicting a state of radial expansion Figure 21 The equipment.

[0037] Figure 23 Is with Figure 3 An end view of a sheath in a radially contracted state used with the equipment.

[0038] Figure 24 It is in a state of radial expansion. Figure 23 End view of the sheath.

[0039] Figure 25 It is used with Figure 15 and Figure 16 An end view of a sheath in a radially contracted state used with the equipment.

[0040] Figure 26 It is in a state of radial expansion. Figure 25 End view of the sheath.

[0041] Figure 27 It is used with Figure 19 and Figure 20 An end view of a sheath in a radially contracted state used with the equipment.

[0042] Figure 28 It is in a state of radial expansion. Figure 27 End view of the sheath.

[0043] Figure 29 It is used with Figure 21 and Figure 22 An end view of a sheath in a radially contracted state used with the equipment.

[0044] Figure 30 It is in a state of radial expansion. Figure 29 End view of the sheath.

[0045] Figures 31 to 37 Exemplary method steps are described in the context of a surgical procedure that includes introducing a prosthetic valve into a subject's natural aortic valve.

[0046] Figure 38 and Figure 39 An exemplary configuration of a self-sealing inlet assembly is depicted for allowing lateral access to the sheath 12 of a catheter (e.g., an angiography catheter).

[0047] This disclosure relates to methods and apparatus 10 for providing embolism protection during transcatheter procedures. Transcatheter procedures may include any cardiac procedure that may produce potentially problematic fragments (e.g., causing embolism), including, for example, the deployment of a prosthesis such as an aortic valve prosthesis or aortic valve repair.

[0048] Figure 1 and Figure 2 It describes the relevant features of human anatomy. Figure 3 and Figure 4 An exemplary device 10 is depicted. Device 10 includes an elongated sheath 12. Figure 3 and Figure 4Only the distal portion of sheath 12 is shown. Sheath 12 can be inserted through the subject's vascular system to bring the distal end 14 of sheath 12 to the target site 3 in the vascular system. The target site 3 may be in the aorta. (See reference...) Figure 1 The sheath 12 can be inserted, for example, via the femoral artery access 1 through the descending aorta 2 into or near the target site 3 of the aortic arch 4 above the heart 5. The target site 3 can be adjacent to arteries 6, including the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. Thus, the sheath 12 can be long enough to extend, for example, from the upstream iliac bifurcation of the abdominal aorta to the aortic arch.

[0049] The device 10 includes a filter assembly 16. The filter assembly 16 is configured to extend from the distal end 14 of the sheath 12. In some arrangements, the filter assembly 16 is, for example, rigidly attached to the distal end 14 of the sheath 12.

[0050] The filter assembly 16 includes a porous membrane 18. The porous membrane 18 is switchable between a radially contracted state and a radially expanded state. Therefore, the filter assembly 16 is configured to allow the porous membrane 18 to switch between a radially contracted state and a radially expanded state.

[0051] Figure 3 A porous membrane 18 in a radially constricted state is depicted. In one arrangement, the radially constricted state refers to allowing the sheath 12 and filter assembly 16 to be inserted through the vascular system (e.g., from the femoral artery access 1 to the target site 3 in the aortic arch 4) while the porous membrane 18 is in a radially constricted state.

[0052] Figure 4 A porous membrane 18 in a radially expanded state is depicted. The radially expanded state can refer to the cross-section of the blood vessel across the target site 3 to prevent, for example, debris generated upstream by catheter manipulation from passing through the porous membrane 18 (i.e., through the pores of the porous membrane 18) while allowing blood to flow through the porous membrane 18 (i.e., through the pores of the porous membrane 18).

[0053] Figure 5 The distal portion of the device 10 deployed in the aortic arch is schematically depicted. In this example, the porous membrane 18 will prevent debris generated below the distal end of the porous membrane 18 in the left portion of the figure from being carried through the porous membrane 18 into any artery 6 or downward along the descending aorta 3. The porous membrane 18 may contact adjacent walls, optionally continuously along a closed-loop path, and / or be pressed radially outward against the walls to minimize or eliminate any paths through the porous membrane 18 that do not involve passing through the porous membrane 18 (e.g., through the pores in the porous membrane 18). The porous membrane 18 in a radially expanded state may have a truncated conical or similar form, wherein the opening at the distal end is larger than the opening at the proximal end.

[0054] The porous membrane 18 can take various forms. For example, the porous membrane 18 may comprise a porous mesh material, such as a fabric of knitted, braided, woven, or nonwoven fibers, filaments, or silk. The porous membrane 18 may include pores 19. The size of the pores 19 can be selected to prevent emboli exceeding a predetermined size from passing through the pores 19. In some arrangements, when the porous membrane 18 is in a radially expanded state, the pore diameter of at least a subset of the pores 19 is in the range of about 50 µm to 250 µm. The size of the pores 19 can be set to allow other catheters (such as angiography catheters) to pass through the pores 19, for example, from the brachiocephalic artery, left common carotid artery, or left subclavian artery. Exemplary pore structures of the porous membrane 18 are shown below. Figures 6-8 As shown.

[0055] In some arrangements, the porous membrane 18 is configured to be elastic. The porous membrane 18 may comprise a fabric made of an elastic metal, polymeric material, ductile material, plastically deformable material, shape memory material, or a combination thereof. In some arrangements, the porous membrane 18 includes an antithrombotic coating. The porous membrane 18 may be configured to form folds, for example, by pleating, when in a radially contracted state. The pleats may be longitudinal pleats.

[0056] When it is necessary to withdraw the device 10, the porous membrane 18 can be switched back to the radially contracted state. Any debris collected in the porous membrane 18 is safely retained in the porous membrane 18 and can be removed from the body along with the porous membrane 18.

[0057] Device 10 includes a filter actuation system configured to switch the porous membrane 18 between a radially contracted state and a radially expanded state.

[0058] In some arrangements, the filter actuation system includes one or more drive wires 21 extending through the sheath 12 and from the distal end 14 of the sheath 12. The filter actuation system is configured such that longitudinal movement of the drive wires 21 facilitates or causes the porous membrane 18 to switch between a radially contracted state and a radially expanded state.

[0059] A single drive wire 21, or each of one or more drive wires 21, may extend along the entire length or most of the length of the sheath 12. The drive wire 21 may, for example, be configured such that when the distal end 14 of the sheath 12 is located at the target site 3, the drive wire 21 can be driven from outside the subject (e.g., longitudinally moved). The drive wire 21 may, for example, extend from the proximal end of the sheath 12 to the target site 3. The aforementioned drive wire 21, or each drive wire 21, may extend beyond the distal end 14 of the sheath 12. The portion of each drive wire 21 extending beyond the distal end 14 (which may be referred to as the "extension portion") may have a length ranging from about 50 mm to about 150 mm.

[0060] In some arrangements, including Figure 3 and Figure 4 For example, the filter assembly includes a plurality of resilient support wires 22 fixedly connected to a sheath 12 (e.g., embedded within the sheath 12) and mechanically coupled to a porous membrane 18. Each of one or more of the support wires 22 and / or drive wires 21 may be disposed, for example, radially inside the porous membrane 18, such that radial expansion (e.g., outward opening) of the support wire 22 mechanically pushes the porous membrane 18 (e.g., into a conical shape) from the inside out. Alternatively, each of one or more of the support wires 22 and / or drive wires 21 may be disposed radially outside the porous membrane 18 but mechanically connected thereto, such that radial expansion (e.g., outward opening) of the support wire 22 mechanically pulls the porous membrane 18 (e.g., into a conical shape) from the outside outward.

[0061] In this type of arrangement, the filter actuation system includes a plurality of drive wires 21 coupled to support wires 22 and configured such that longitudinal movement of the drive wires 21 drives the plurality of support wires 22 to deform (e.g., bend, as) the porous membrane 18 in a radially expanding manner. Figure 4 (As shown).

[0062] In one arrangement, the plurality of support wires 22 include one or more pairs of support wires 22. Figure 3 and Figure 4 In the example shown, the filter actuation system includes three pairs of support wires 22 and three corresponding drive wires 21. Figures 9 to 12 It shows Figure 3 The device has one pair of support wires 22 and an associated drive wire 21 to show how each pair of support wires 22 operates. Figure 9 and Figure 10 These are front and side views showing the support wire 22 in a radially contracted state, corresponding to the porous membrane 18 in a radially contracted state. Figure 11 and Figure 12 These are front and side views, showing the support filament 22 in a radially expanded state, corresponding to the porous membrane 18 in a radially expanded state.

[0063] Each pair of support wires 22 is fixedly connected to each other at a distal connection region 24. The distal connection region 24 is spaced apart from the distal end 14 of the sheath 12. Each pair of support wires 22 is spaced apart from each other in a deformation region 26. The deformation region 26 is located longitudinally between the connection region 24 and the distal end 14 of the sheath 12. A plurality of drive wires 21 include drive wires 21 connected to the connection region 24 of each pair of support wires 22. Each pair of support wires 22 is configured such that longitudinal movement of the drive wire 21 connected to the connection region 24 of each pair of support wires causes radial outward deformation of each pair of support wires 22. As an example, from Figure 9 and Figure 10 The state shown Figure 11 and Figure 12 The transition shown can be achieved by pulling the drive wire 21 downwards (i.e., along the longitudinal proximal direction). This causes the support wire 22 to... Figure 12 The orientation shown is bent to the left. Multiple pairs are configured in this manner and positioned at different angular locations around the axis of the sheath (e.g., at...). Figure 3 and Figure 4 In the example of three azimuth ranges centered at positions 120 degrees apart, deformation of the support wire 22 can cause the porous membrane 18 (e.g., to expand outward) to expand radially and thus appropriately cross the blood vessel.

[0064] Figure 13 and Figure 14 This is an axial end view showing the deformation of the three pairs of support wires 22 by pulling the drive wire 21. Figure 3 and Figure 4 Example radial expansion of support wire 22. Figure 13 In this configuration, the sheath 12 is in a radially contracted state (forming a triple-symmetrical S-shape in this case), where the drive wire 21 and the support wire 22 are straight. Figure 14 In the process, the sheath 12 is in a radially expanded state, with the drive wire 21 and support wire 22 bent and pointing outward under tension. The drive wire 21 can be pulled simultaneously and / or by the same amount to achieve uniform expansion of the porous membrane 18 at an azimuth angle. Alternatively, two or more drive wires 21 can be pulled differently to cause the porous membrane 18 to expand more asymmetrically, for example, to achieve better fit within the curved portions of the subject's anatomy.

[0065] Figures 15 to 18 Depicting Figure 3 , Figure 4 as well as Figures 9 to 14 A variation of device 10, wherein the filter actuation system further includes a plurality of guide wires 28 and a plurality of corresponding sliding couplers 30 configured to slide longitudinally along each of the corresponding guide wires 28. In the example shown, there are three guide wires 28 and three corresponding sliding couplers 30 (one sliding coupler 30 for each guide wire 28). The connection area of ​​each pair of support wires 22 is fixedly connected to the corresponding sliding coupler 30, such that longitudinal movement of the drive wire 21 (e.g., in...) Figure 15 and Figure 16 The upward and downward movement shown in the diagram causes a corresponding movement of the sliding connector 30 and an associated guidance of the deformation of the pair of support wires 22 via the guide wire 28.

[0066] In some arrangements, each of one or more drive wires 21 is an elastic drive wire 21 directly or indirectly mechanically coupled to the porous membrane 18. In these arrangements, the filter assembly includes a constraint assembly configured to constrain the elastic drive wire 21 such that longitudinal movement of the elastic drive wire 21 deforms the elastic drive wire 21 in a manner that radially expands the porous membrane 18. Figures 19-22 An example of this arrangement is shown.

[0067] In some arrangements, such as Figure 19 and Figure 20 As illustrated, the elastic drive wire 21 is configured such that the portions of the drive wire 21 extending beyond the distal end 14 of the sheath 12 are substantially aligned with each other at the distal end parallel to the longitudinal axis of the sheath 12 when the porous membrane 18 is in a radially contracted state, and bifurcate with each other in the distal direction when the porous membrane 18 is in a radially expanded state (i.e., such that the separation between them increases with the distance from the distal end 14 of the sheath 12).

[0068] In some arrangements, such as Figure 19 and Figure 20 As shown, the constraint assembly includes one or more pairs of tubular members 32 corresponding to each drive wire 21. Each pair of tubular members 32 includes a first tubular member and a second tubular member. The first and second tubular members can be arbitrarily selected and can be identical to each other. An example of the first tubular member is shown in... Figure 19 and Figure 20 The first tubular member 32A is designated as 32A. It has a first lumen and a first distal opening 34A. An example of a second tubular member is shown in... Figure 19 and Figure 20 The first tubular member 32B is designated 32B. The second tubular member 32B has a second lumen and a second distal opening 34B. Each pair of drive wires 21 passes through a corresponding first lumen (e.g., through the first tubular member 32A), forming a protruding ring 36 extending between the corresponding first distal opening 34A and the corresponding second distal opening 34B, and passes through the corresponding second lumen (e.g., through the second tubular member 32B). Figure 19 and Figure 20 In the example shown, three pairs of tubular members 32 can be identified, each pair having a single protruding ring 36 extending between the pairs of tubular members 32. In the example shown, each pair adjacent to the azimuth angle shares its tubular member (such that the total number of tubular members 32 is equal to the total number of pairs of tubular members 32), but this is not necessary.

[0069] The tubular member 32 and the drive wire 21 are configured such that longitudinal displacement of the drive wire 21 in the distal direction (e.g., pushing the drive wire 21 in the distal direction) causes an increase in the length of the protruding ring 36. This increase in the length of the protruding ring 36 (and the elastic properties of the drive wire 21 forming the protruding ring 36) forces the portion of the drive wire 21 within the tubular member 32 to separate, thereby deforming the drive wire 21 in a manner that causes the porous membrane 18 to expand radially. In some arrangements, each pair of first tubular members 32A and second tubular members 32B is configured to align with each other at the distal end 14 parallel to the longitudinal axis of the sheath 12 when the filter assembly is in a radially contracted state, and to bifurcate with each other in the distal direction when the porous membrane 18 is in a radially expanded state (i.e., such that the separation between them increases with distance from the distal end 14 of the sheath 12). Figure 19 and Figure 20 In the example, it can be seen that the three protruding rings 36 are in Figure 19 The middle is relatively short, wherein the tubular member 32 is aligned in the axial direction of the sheath 12 and in Figure 20 The middle section is relatively long, in which the tubular member 32 is separated by the elastic push of the drive wire 21 in the protruding ring 36 so as to branch radially (open outward).

[0070] In some arrangements, such as in Figure 21 and Figure 22 As illustrated in the example, the constraint assembly includes a plurality of elastic constraint wires 38 that are fixedly connected to the sheath 12 and mechanically coupled to the porous membrane 18. Figure 21 and Figure 22 In the example, the constraint wire 38 is substantially linear, but other shapes can be used. Each drive wire 21 is connected to the corresponding constraint wire 38 in a distal connection region 40 spaced apart from the distal end 14 of the sheath 12. The connection at the distal connection region 40 restricts the deformation of the drive wire 21 in the radially outward direction as it is advanced longitudinally to the outside of the sheath 12, thereby causing the porous membrane 18 to expand radially. Advancing each drive wire 21 distally increases the length of the guide wire 21 between the sheath 12 and the connection region 40. The elasticity of the guide wire 21 forces the connection region 40 and the porous membrane 18 radially outward. In some arrangements, such as Figure 21 and Figure 22 As illustrated by the example, the constraint wires 38 are configured to align with each other at their distal ends parallel to the longitudinal axis of the sheath 12 when the porous membrane 18 is in a radially contracted state (e.g., as shown in the example). Figure 21 As shown), and when the porous membrane 18 is in a radially expanded state, it branches radially in the distal direction (as shown). Figure 22 (As shown).

[0071] In any of the arrangements described above and / or in others, the elongated sheath 12 can switch between a radially contracted state and a radially expanded state. Examples of such radially contracted and radially expanded states are shown in... Figures 23-30 As shown in the diagram. The sheath 12 may include any suitable material for achieving the required functionality and biocompatibility, such as FEP, PTFE, polyimide, polyamide, polyethylene, polypropylene, polyurethane, silicone elastomer, C-Flex, and / or latex rubber. In some arrangements, the sheath 12 includes reinforcements such as coils, supports, or expandable rings. Reinforcements can help maintain the shape of the sheath 12 during radial expansion and contraction.

[0072] The sheath 12 in its radially constricted state can define a relatively small central lumen 44. This allows for a relatively small overall external dimension of the sheath 12, facilitating insertion and advancement into the subject and through the vascular system to the target site 3. However, even when the sheath 12 is in its radially constricted state, the central lumen 44 can be large enough to accommodate a guidewire. The sheath 12 in its radially expanded state can define a significantly larger central lumen 44. For example, a larger central lumen 44 can be adapted to allow a device to be inserted through the central lumen 44 into the target site 3 for transcatheter manipulation. For example, the sheath 12 can be configured such that its outer cross-sectional diameter (radius R) in the radially constricted state is... f (twice as large) is smaller than the inner diameter (radius R) of the central lumen 44 in a radially expanding state. e Twice the size of (e.g., radius).

[0073] The porous membrane 18 in a radially expanded state may include a proximal opening leading to a central lumen 44 and a distal opening larger than the proximal opening. Thus, the central lumen 44 extends distally into a region within the porous membrane 18 (e.g., within the conical shape defined by the porous membrane 18).

[0074] The sheath 12 can be configured to expand from a radially contracted state to a radially expanded state. Alternatively or further, the sheath 12 can be configured to expand by longitudinal movement through the sheath 12 of the device used for performing transcatheter procedures. Figures 23-30 As shown, the sheath 12 may include a tubular body 46 defining a lumen 44. The body 46 may have a cross-sectional profile in which the stiffness of the body 46 varies with azimuth angle to facilitate inward folding of the body 46 within one or more predetermined ranges of azimuth angle. The body 46 may be configured to fold inward more extensively within one or more ranges when the sheath 12 is in a radially contracted state than when the sheath 12 is in a radially expanded state. The variation in stiffness of the body 34 with azimuth angle may be defined at least in part by the corresponding variation in the radial thickness of the body 46 with azimuth angle.

[0075] exist Figures 23-30 In the example shown, the body 46 is configured such that when the sheath 12 is in a radially contracted state ( Figure 23 , Figure 25 , Figure 27 and Figure 29 When the sheath 12 is folded inward in three azimuth regions, it forms three corresponding folds 48. It can be seen that the radial thickness of the body 46 of the sheath 12 is smaller in each of the three azimuth regions corresponding to the folds 48 than elsewhere around the circumference of the sheath 12. For example, it can be seen that the radial thickness of the wall portion marked 46A corresponding to the fold 48 is smaller than the radial thickness of the wall portion marked 46B that is not folded inward.

[0076] The sheath 12 defines one or more peripheral lumens 50 formed outside the central lumen 44 within the body 46. The central lumen 44 contains the longitudinal axis of the sheath 12, while the peripheral lumens are laterally located outside the axis and do not contain the axis. The peripheral lumens 50 can be blind (i.e., open only at one end) or continuous (i.e., open at both ends, e.g., at the proximal and distal ends of the sheath 12). The peripheral lumens 50 can be configured to receive corresponding drive wires 21, support wires 22, guide wires 28, tubular members 32, and / or constraint wires 38. Figure 23 and Figure 24 In the example, the sheath 12 may include a peripheral lumen 50A for driving the wire 21 and a peripheral lumen 50B for supporting the wire 22. Figure 25 and Figure 26 In the example, the sheath 12 may include a peripheral lumen 50A for driving the wire 21, a peripheral lumen 50B for supporting the wire 22, and a peripheral lumen 50C for guiding the wire 28. Figure 27 and Figure 28 In the example, the sheath 12 may include a peripheral lumen 50D for the tubular member 32. Figure 29 and Figure 30 In one example, the sheath 12 may include a peripheral lumen 50A for driving the wire 21 and a peripheral lumen 50E for constraining the wire 38.

[0077] Any of the device arrangements disclosed herein can be used in methods for providing embolic protection during surgical procedures. The method may include inserting a slender sheath 12 through the subject's vascular system to bring the distal end 14 of the sheath 12 to a target site 3 in the vascular system. A porous membrane 18 in a radially constricted state may extend from the distal end 14 of the sheath 12 during insertion. The method includes switching the porous membrane 18 to a radially expanded state, such that the porous membrane 18 spans the cross-section of the vessel at the target site 3 to prevent upstream-generated debris from passing through the porous membrane 18 while allowing blood to flow through the porous membrane 18. Switching the porous membrane 18 from a radially constricted state to a radially expanded state can be performed using any of the device elements and techniques described above. The method may also include switching the sheath 12 from a radially constricted state to a radially expanded state to define a central lumen 44; and inserting a device for performing transcatheter procedures through the central lumen 44 into the target site 3. The method may also include using the device for transcatheter procedures while the porous membrane 18 is in a radially expanded state. The method may further include trapping debris generated during the transcatheter procedure within the porous membrane 18 by switching the porous membrane 18 from a radially expanded state to a radially contracted state after the procedure. The sheath 12 and the porous membrane 18 can then be withdrawn from the subject.

[0078] exist Figures 31-37 Exemplary method steps are described in the context of a surgical procedure that includes introducing a prosthetic valve 64 into the subject's natural aortic valve.

[0079] Figure 31 The relevant areas of the aortic arch and surrounding vessels before the introduction of device 10 are schematically depicted.

[0080] In the first step of this method, such as Figure 32 As depicted, device 10 is introduced and advanced from a femoral artery access to a target location, where filter assembly 16 and associated porous membrane 18 are located in the ascending aorta. During insertion, an introducer 60 with a tapered tip can be advanced through the central lumen 44 of sheath 12 to protrude in front of filter assembly 16, making the insertion process smoother.

[0081] In subsequent steps, such as Figure 33 As depicted, the introducer 60 is removed and the porous membrane 18 is switched from a radially contracted state to a radially expanded state to cross the blood vessel.

[0082] In subsequent steps, such as Figure 34As shown, a device 62 for performing transcatheter procedures (in this case, implanting an artificial valve 64) is inserted into the target site through the central lumen 44 of the sheath 12. As the device 62 is pushed along the central lumen 44, it expands the central lumen 44, thereby switching the sheath 12 to a radially expanded state.

[0083] In subsequent steps, such as Figure 35 As shown, device 62 places the prosthetic valve 64 within the aortic valve. A contrast agent catheter can be used to inject contrast agent into the target site to aid visualization (e.g., via [see below]). Figure 38 and Figure 39 The entry component 66 (discussed) is used, for example, to facilitate observation of the valve's position. Device 62 is retracted, and sheath 12 folds back to its radially constricted state due to elasticity.

[0084] In subsequent steps, such as Figure 36 and Figure 37 As depicted, the porous membrane 18 is switched back to a radially constricted state, in preparation for removal of the device 10 from the aorta. During this process, debris particles collected within the porous membrane 18 during the implantation of the prosthetic valve 64 can be trapped within the porous membrane 18. Therefore, when the device 10 is removed, the debris particles can be safely removed from the subject.

[0085] In some arrangements, such as Figure 38 and Figure 39 As shown, the sheath 12 includes a self-sealing inlet assembly 66. The inlet assembly 66 is positioned intermediately between the proximal end and the distal end 14 of the sheath 12. The inlet assembly 66 is configured to allow a catheter (such as a contrast agent catheter 68) to be inserted into the sheath 12 through the inlet assembly 66 when the distal end 14 of the sheath 12 is at a target site in the vascular system. The intermediate position can be in different locations, such as in the region via the femoral artery 70 or the region via the left subclavian artery 80 (e.g., Figure 38 (As shown). In one arrangement, the inlet assembly 66 includes a flexible membrane 76 and a plurality of slits 78 formed in the membrane 76. Each slit 78 can be configured to allow a catheter to be inserted through the slit 78 into the sheath 12 and to self-seal when the catheter is withdrawn from the sheath 12. The self-sealing of the inlet assembly prevents leakage of debris that has entered the sheath 12 (e.g., generated by catheter-related operations).

[0086] In one arrangement, the entrance component 66 includes six entrance sub-segments, which are distributed in three groups along the circumference, with two in each group. Figure 38 (Left) One of these three groups (comprising inlet sub-segments 74A and 74B) is shown in cross-section. Each inlet sub-segment includes a portion of the flexible membrane 76 and a cutout 78.

[0087] The flexible membrane 76 may comprise any suitable material, including, for example, thin PTFE, polyimide, polyamide, polyethylene, polyurethane, and / or silicone elastomers. In some arrangements, the flexible membrane 76 is formed of the same material as the sheath 12 but with a smaller thickness to increase flexibility. Multiple slits 78 may be provided in the flexible membrane 76 to make the slits 78 easier to locate when the catheter 68 is inserted. The catheter to be inserted can be inserted through any slit 78. Different shapes of slits 78 may be used, including, for example, crosses (as depicted), asterisks, and / or stars. The slits 78 may be configured to close in their relaxed (natural) state to provide a self-sealing function. Thus, the slits 78 may define resilient folds that are biased when the folds are flush against each other and prevent debris from passing through any slit 78.

Claims

1. A device for providing embolic protection during transcatheter procedures, the device comprising: A slender sheath that can be inserted through the subject's vascular system to bring the distal end of the sheath to a target site in the vascular system; as well as A filter assembly, configured to extend from the distal end of the sheath, wherein: The elongated sheath is capable of switching between a radially contracted state and a radially expanded state, wherein the sheath in the radially expanded state defines a central lumen to allow insertion of a device for transcatheter manipulation into the target site through the central lumen; The filter assembly includes a porous membrane capable of switching between a radially contracted state and a radially expanded state, wherein the radially expanded state refers to a cross-section of a blood vessel at the target site to prevent upstream-generated debris from passing through the porous membrane while allowing blood to flow through it; and A filter actuation system configured to switch the porous membrane between the radially contracted state and the radially expanded state.

2. The device according to claim 1, wherein, The target site is located within the subject's aorta.

3. The device according to claim 1 or 2, wherein, The transcatheter procedures include cardiac procedures associated with fragmentation, such as the deployment of aortic valve prostheses or aortic valve repair.

4. The device according to any one of claims 1 to 3, wherein, The sheath is configured to self-expand and / or to expand by longitudinal movement of the sheath of the device for performing transcatheter procedures.

5. The device according to any one of the preceding claims, wherein: The filter actuation system includes one or more drive wires extending through the sheath and extending from the distal end of the sheath; and The filter actuation system is configured such that longitudinal movement of the drive filament facilitates or causes the porous membrane to switch between the radially contracted state and the radially expanded state.

6. The device according to claim 5, wherein: Each of the one or more drive wires is an elastic drive wire directly or indirectly mechanically coupled to the porous membrane; and The filter assembly includes a constraint component configured to constrain the elastic drive wire such that longitudinal movement of the elastic drive wire causes the elastic drive wire to deform in a radially expanding manner of the porous membrane.

7. The device according to claim 6, wherein, The elastic drive wires are configured such that the portions of the drive wires extending beyond the distal end of the sheath are substantially aligned with each other at the distal end parallel to the longitudinal axis of the sheath when the porous membrane is in the radially contracted state, and radially bifurcate with each other in the distal direction when the porous membrane is in the radially expanded state.

8. The device according to claim 6 or 7, wherein: The constraint assembly includes one or more pairs of tubular members corresponding to each drive wire, each pair of tubular members comprising: A first tubular member having a first lumen and a first distal opening; and The second tubular member has a second lumen and a second distal opening. The drive wire of each pair of tubular members passes through the corresponding first lumen, forming a protruding ring extending between the corresponding first distal opening and the corresponding second distal opening, and passes through the corresponding second lumen. The device is configured such that longitudinal displacement of the drive wire in the distal direction causes an increase in the length of the protruding ring, the increase in length forcing the drive wire to separate multiple portions within the tubular member, thereby deforming the drive wire in a manner that causes the porous membrane to expand radially.

9. The device according to claim 8, wherein, The first and second tubular members of each pair of tubular members are configured to align with each other at the distal end parallel to the longitudinal axis of the sheath when the filter assembly is in the radially contracted state, and to branch off from each other in the distal direction when the porous membrane is in the radially expanded state.

10. The device according to claim 6, wherein: The constraint assembly includes a plurality of elastic constraint wires that are fixedly connected to the sheath and mechanically coupled to the porous membrane; Each drive wire is connected to a corresponding constraint wire in a distal connection region spaced apart from the distal end of the sheath. The connection at the distal connection region constrains the drive wire to deform in a radially outward direction when the drive wire is longitudinally advanced outside the sheath, thereby causing the porous membrane to expand radially.

11. The device according to claim 10, wherein, The constraint wires are configured to align with each other at the distal end parallel to the longitudinal axis of the sheath when the porous membrane is in the radially contracted state, and to branch radially in the distal direction when the porous membrane is in the radially expanded state.

12. The device according to claim 5, wherein: The filter assembly includes a plurality of elastic support wires that are fixedly connected to the sheath and mechanically coupled to the porous membrane; and The filter actuation system includes a plurality of drive wires coupled to the support wires and configured such that longitudinal movement of the drive wires drives the plurality of support wires to deform the porous membrane in a radially expanding manner.

13. The device according to claim 12, wherein: The plurality of support wires includes one or more pairs of support wires; Each pair of support wires is fixedly connected to each other at a distal connection region spaced apart from the distal end of the sheath, and spaced apart from each other in a longitudinal deformation region between the connection region and the distal end of the sheath.

14. The device according to claim 13, wherein: The plurality of drive wires include drive wires connected to the connection region of each pair of support wires; and Each pair of support wires is configured such that longitudinal movement of the drive wire connected to the connection region of each pair of support wires causes radial outward deformation of each pair of support wires.

15. The device according to claim 14, wherein: The filter actuation system further includes multiple guidewires and corresponding multiple sliding couplers configured to slide longitudinally along their respective guidewires; and The connection area of ​​each pair of support wires is fixedly connected to the corresponding sliding connector, such that the longitudinal movement of the drive wire causes a corresponding movement of the sliding connector and associated guidance of the deformation of each pair of support wires through the guide wire.

16. The device according to any one of the preceding claims, wherein, The sheath includes a tubular body defining the internal lumen, the body having a cross-sectional profile in which the stiffness of the body varies according to an azimuth angle to facilitate inward folding of the body within one or more predetermined ranges of the azimuth angle, the body being configured to fold inward more within the one or more ranges when the sheath is in the radially contracted state than when the sheath is in the radially expanded state.

17. The device according to claim 16, wherein, The stiffness of the body varies with the azimuth angle, which is at least partially determined by the corresponding change in the radial thickness of the body with the azimuth angle.

18. The device according to claim 16 or 17, wherein, The sheath defines one or more peripheral lumens formed in the body and located outside the central lumen, the peripheral lumens being configured to accommodate corresponding drive wires, support wires, guide wires, tubular members and / or constraint wires.

19. The device according to any one of the preceding claims, wherein, The sheath includes a self-sealing inlet assembly located at an intermediate position between the proximal and distal ends of the sheath, the inlet assembly being configured to allow a catheter to be inserted into the sheath through the inlet assembly when the distal end of the sheath is at a target site in the vascular system.

20. The device according to claim 19, wherein, The inlet assembly includes a flexible membrane and a plurality of slits formed in the membrane, each slit being configured to allow a catheter to be inserted into the sheath through the slit and to self-seal when the catheter is withdrawn from the sheath.

21. The device according to any one of the preceding claims, wherein, In the radially contracted state, the outer diameter of the sheath is smaller than the inner diameter of the central lumen in the radially expanded state.

22. A method for providing embolic protection during transcatheter procedures, comprising: A slender sheath is inserted through the subject's vascular system to bring the distal end of the sheath to a target site in the vascular system, wherein, during the insertion, a porous membrane in a radially constricted state extends from the distal end of the sheath. The porous membrane is switched to a radially expanded state, such that the porous membrane spans the cross-section of the blood vessel at the target site, in order to prevent upstream debris from passing through the porous membrane while allowing blood to flow through the porous membrane. The sheath is switched from a radially contracted state to a radially expanded state to define a central lumen, and a device for performing transcatheter manipulation is inserted through the central lumen into the target site.

23. The method of claim 22, further comprising: The transcatheter operation is performed using the device when the porous membrane is in the radially expanded state.

24. The method of claim 23, further comprising: By switching the porous membrane from the radially expanded state to the radially contracted state after a transcatheter operation, the debris generated during the transcatheter operation is trapped in the porous membrane; and The sheath and the porous membrane were withdrawn from the subject's body.

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