Heart valve tissue cutting device

Abstract

A heart valve tissue cutting device includes: a housing formed with an elongated opening; a cutting guide arm pivotally connected to the housing by a hinge assembly, the cutting guide arm forming a slot; and an actuator wire coupled to the cutting guide arm. Movement of the actuator wire causes the cutting guide arm to pivot outwardly away from the housing. A cutting element including a blade having a sharp end is coupled to a track link arranged to travel along a track in the housing. An activation slider is coupled to the elongate element and is movable in the passage in the housing. Movement of the activation slider causes the track link and the cutting element to move along the track. When the track link is at one end of the track, the blade does not protrude out of the housing, and when the track link is not at the end of the track, the blade protrudes out of the housing.

Description

Technical Field

[0001] The present invention generally relates to devices and methods for transcatheter modification of body tissue, such as heart valve leaflet tissue, for example, aortic valve leaflets. Background Art

[0002] PCT patent application PCT / IB2020 / 054729 describes a transcatheter valve tearing device and method. The present invention is a method and device that can be used to perform a BASILICA (intentional tearing of a bioprosthetic or native aortic valve to prevent iatrogenic coronary artery obstruction) or a LAMPOON procedure (for the mitral valve). The device is a cutting or splitting device that takes care to prevent damage to adjacent tissue. The device can be implemented in other cardiac procedures such as a bicuspid trileafletization (converting a mitral valve into a tricuspid valve by cutting or splitting one of the mitral valves into two leaflets) or a bicuspid trileafletization (tearing one of the leaflets to convert the valve into a tricuspid valve) or splitting the AML (anterior mitral valve leaflet) to prevent LVORO (left ventricular outflow tract obstruction), thereby preparing the patient for a safe transcatheter aortic or mitral valve replacement (TAVR / TMVR), or for other procedures involving modified heart / vascular tissue. Summary of the Invention

[0003] The present invention seeks to provide a device and method for cutting heart valve tissue, such as, but not limited to, aortic valve tissue, as described in more detail below. For example, the present invention can be used to replace the charged guidewire (which is the cutter used in the prior art BASILICA) to traverse and tear the aortic leaflets downward along the centerline.

[0004] The devices of the present invention are particularly useful for tearing aortic valve leaflets by delivery through the aorta; however, the present invention can be used to cut any cardiac tissue from a variety of methods and for cutting cardiac tissue at other valves or portions of the heart.

[0005] The term "cutting" refers to any kind of reduction in size or any modification in shape or form, such as, but not limited to, cutting, splitting, tearing, slicing, fracturing, chopping, etc., and these terms are used interchangeably throughout.

[0006] Thus, according to one non-limiting embodiment of the present invention, a heart valve tissue cutting device is provided, comprising: a housing forming an elongated opening; a cutting guide arm pivotally connected to the housing by a hinge assembly, the cutting guide arm forming a slot; an actuator wire coupled to the cutting guide arm, wherein movement of the actuator wire causes the cutting guide arm to pivot outwardly away from the housing; a cutting element comprising a blade having a sharpened tip, the cutting element coupled to a track link arranged to travel along a track in the housing; and an actuating slider coupled to the elongated element and movable in a passage in the housing, wherein movement of the actuating slider causes the track link and the cutting element to move along the track, and wherein the blade does not protrude beyond the housing when the track link is at one end of the track, and the blade protrudes beyond the housing when the track link is not at the end of the track.

[0007] According to a non-limiting embodiment of the present invention, the hinge assembly includes a four-hinge mechanism.

[0008] According to a non-limiting embodiment of the present invention, the blade protector rib is pivotally connected to the cutting guide arm, and wherein the four-hinge mechanism includes a first hinge link, which is pivotally connected to the first part of the housing at a first hinge and pivotally connected to the blade protector rib at a second hinge, and wherein the second hinge link is pivotally connected to the second part of the housing at a third hinge and pivotally connected to the cutting guide arm at a fourth hinge.

[0009] According to a non-limiting embodiment of the present invention, as the cutting guide arm pivots outward, a portion of the four-hinge mechanism passes through the elongated rib aperture and through the slot.

[0010] According to a non-limiting embodiment of the present invention, the housing includes end caps that limit the movement of the four-hinge mechanism and define the limits of the outward pivotal movement of the cutting guide arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be more fully understood and appreciated from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0012] Figure 1A is a simplified side schematic view of a heart valve tissue cutting device according to a non-limiting embodiment of the present invention.

[0013] Figure 1B It is a simplified top view of a heart valve tissue cutting device.

[0014] Figure 1C It is a simplified bottom view of a heart valve tissue cutting device.

[0015] Figure 2A is a simplified side schematic view of a heart valve tissue cutting device including an outwardly pivoted cutting guide arm forming a slot for guiding the cutting action of the cutting element.

[0016] Figure 2B is similar to Figure 2A 1 is a simplified side view schematic diagram showing the internal components of a heart valve tissue cutting device, specifically showing a pivoting cutting element in a stowed position inside the cutting device and an activation slide coupled to the pivoting cutting assembly.

[0017] Figure 3 is a simplified side view schematic illustration of the deployment of a cutting assembly of a heart valve tissue cutting device, wherein the starting slider has moved from a first end (e.g., a distal end) of the device toward a second end of the device (e.g., proximally), such that the pivoting cutting element has deployed outward toward the cutting guide arm such that the blade of the cutting element is about to enter the narrow slot of the cutting guide arm.

[0018] Figure 4A and Figure 4B A simplified side schematic view and a lower perspective schematic view, respectively, in which the activation slide has been moved further towards the second end of the device so that the blade of the cutting element has entered the slot of the cutting guide arm.

[0019] Figure 5A and Figure 5B A simplified side schematic view and an upper perspective schematic view, respectively, in which the activation slide has been moved further towards the second end of the device so that axial advancement of the blade of the cutting element enables slicing of tissue.

[0020] Figure 6 is a simplified side view of the cutting element blade reaching the limit of its axial travel.

[0021] Figure 7A and Figure 7B is a simplified side schematic view of a heart valve tissue cutting device according to another non-limiting embodiment of the present invention, which includes a grasping member for grasping a leaflet or other tissue before and during cutting, the grasping member being shown in respective stowed and deployed positions.

[0022] Figure 7C is a simplified side schematic view of a heart valve tissue cutting device with the blade of the cutting element deployed when the gripping member is in its deployed position.

[0023] Figure 7D is a simplified perspective schematic illustration of a heart valve tissue cutting device with the grasping member in its deployed position. DETAILED DESCRIPTION

[0024] Now refer to Figures 1A to 1C , which shows a heart valve tissue cutting device 10 according to a non-limiting embodiment of the present invention.

[0025] The heart valve tissue cutting device is particularly useful for cutting aortic valve tissue (such as the aortic valve leaflets) and can be delivered via the aorta to cut the aortic valve tissue by first piercing or puncturing the tissue with the sharp, pointed tip of a blade positioned at the distal end of the device and then slicing the tissue axially by moving the blade toward the proximal end (in a direction back toward the aorta). For this method, the distal end is the left end in the accompanying drawings, while the proximal end is the right end in the accompanying drawings. It should be understood that distal and proximal are relative, non-limiting terms, and the present invention can be used in other orientations. The present invention is not limited to aortic valve leaflets. The device of the present invention can be implemented in other cardiac procedures such as bicuspid trileafletization (converting a mitral valve into a tricuspid valve by cutting or splitting one of the mitral valve leaflets into two leaflets) or bicuspid trileafletization (tearing one of the leaflets to convert the valve into a tricuspid valve) or splitting the AML (anterior mitral valve leaflet) to prevent LVORO (left ventricular outflow tract obstruction), thereby preparing the patient for safe transcatheter aortic or mitral valve replacement (TAVR / TMVR), or for other procedures involving modified heart / vascular tissue.

[0026] The heart valve tissue cutting device 10 may include a (eg, elongated cylindrical) housing 12 formed with an elongated opening 14, which may have rounded ends. The housing 12 may be made of medical grade stainless steel or any other suitable material.

[0027] like Figure 1C As best seen, the housing 12 can include a guidewire lumen 16 along the lower axial length of the housing 12 ("lower" in the sense of the drawings; not necessarily lower when the device is in use). Thus, the device 10 can be delivered over a guidewire 18 that passes through the guidewire lumen 16. The housing 12 can include a first end cap 13 and a second end cap 15 ( Figure 1A ).

[0028] The heart valve tissue cutting device 10 may include a cutting guide arm 20 ( Figure 1A and Figure 1B ), the cutting guide arm 20 is connected to the cutting guide arm 20 by a hinge assembly (as described below Figure 2A and Figure 2BThe blade guard rib 22 may be pivotally connected to the cutting guide arm 20 ( Figure 1B ).exist Figure 1A 、 Figure 1B and Figure 1C In the retracted orientation, the blade guard rib 22 is located within the elongated rib aperture 23 ( Figure 1B , and in Figure 5B The cutting guide arm 20 may be formed with a slot 21 for guiding the cutting action of the cutting element (see Figure 4B ), as described below.

[0029] Now refer to Figure 2A and Figure 2B . The cutting guide arm 20 can be pivotally connected to the housing 12 by means of a four-hinge mechanism. A first hinge link 26 can be pivotally connected to a first portion of the housing 12 at a first hinge (pivot) 25 and pivotally connected to the blade protector rib 22 at a second hinge 27. The second hinge 27 can be a sliding hinge in which a pin slides in a channel attached to the blade protector rib 22. A second hinge link 28 can be pivotally connected to a second portion of the housing 12 (near the first portion) at a third hinge 29 near the first hinge 25 and pivotally connected to the cutting guide arm 20 at a fourth hinge 30. Figure 2A and Figure 2B In the orientation wherein the cutting guide arm 20 is pivoted outwardly, the first hinge link 26, part of a four-hinge mechanism, passes through the elongated rib opening 23 (e.g. Figure 5B As shown) and slot 21 (as Figure 4B As shown). The slot 21 is formed on a portion of the cutting guide arm 20 below the elongated rib opening 23 (so the elongated rib opening 23 is below the elongated rib opening 23). Figure 4B The second end cap 15 acts as a (proximal) stop for the second hinge link 28 and defines the limit of the deployed position of the cutting guide arm 20.

[0030] like Figure 2B As can be seen, an actuator wire 17 can be provided for pivoting a first hinge link 26 about a first hinge (pivot) 25 for deploying the cutting guide arm 20. Pulling the actuator wire 17 proximally causes the cutting guide arm 20 to pivot about the first hinge 25 and the third hinge 29. Alternatively, a biasing device (such as a coil spring or a leaf spring) can be used to spring-load the cutting guide arm 20 so that it can pivot about these hinges.

[0031] Now refer to Figure 3, which shows the deployment of the pivoting cutting assembly. The pivoting cutting assembly may include a cutting blade 32 having a sharp pointed end 33. A portion of the cutting blade 32 may be pivotally connected to a blade support arm 34 at a first pivot (hinge) 35, and another portion of the cutting blade 32 may be pivotally connected to a track 36 at a second pivot 37. The track 36 extends axially along a longitudinal portion of the housing 12. The blade support arm 34 may be coupled to a track link 38, such as by a pin or rivet 39. (Alternatively, they may be a single piece.) The track link 38 is arranged to travel along the track 36 by means of one or more pins 31 that are slidably received in the track 36. In Figure 2B In the position, the track link 38 is on the distal curved portion 40 of the track 36 so that the cutting blade 32 is retracted and does not protrude outward. The proximal curved portion 40 of the track 36 curves from the central portion of the housing 12 toward the outer contour of the housing 12.

[0032] The start slider 42 is arranged to move axially along the guide wire 18 (at Figure 1C The bottom of the actuation slide 42 is shown in FIG. 4 ). The actuation slide 42 may be coupled to a wire or other elongated member 47 ( Figure 3 ), to move the activation slide 42 along the guidewire 18. The elongated element may be used for both pulling and pushing; alternatively, it may be used only for pulling, and a biasing means, such as a coil spring, may be provided that is compressed by the proximal movement of the activation slide 42 for returning the activation slide to its initial position.

[0033] exist Figure 2B In the orientation of the first end cap 13, the starter slide 42 is adjacent to the first end cap 13. The starter slide 42 abuts against the track link 38. The starter slide 42 can be oval and in the passage 44 (see Figure 5B ), the passage 44 is complementarily shaped to accommodate the shape of the starting slider 42 to guide the axial movement of the starting slider 42. For example, the cross-sectional shape of the passage 44 may be elliptical to match the elliptical shape of the starting slider 42, with sufficient tolerance to allow easy and smooth movement of the starting slider 42.

[0034] exist Figure 3 In the orientation of , the activation slide 42 has moved from the first end (e.g., distal end) of the device toward the second end of the device (e.g., proximally as indicated by arrow 43) such that the pivoting cutting blade 32 has deployed outwardly toward the cutting guide arm 20 such that the blade 32 is about to enter the slot of the cutting guide arm 20. Figure 3 In the position of , the starter slide 42 has pushed the track link 38 proximally away from the distal curved portion 40 of the track 36, which causes the blade support arm 34 to move outward to deploy the cutting blade 32 outward. The track link 38 now slides on the straight portion of the track 36.

[0035] exist Figure 3 In the orientation of , the sharp tip 33 of the blade 32 is able to pierce (penetrate) the heart valve tissue located between the blade 32 and the cutting guide arm 20.

[0036] Now refer to Figure 4A and Figure 4B The start slide 42 has moved further towards the second end of the device so that the blade 32 has entered the slot 21 of the cutting guide arm 20 ( Figure 4B ). The slot 21 will now guide the axial slicing action of the blade 32 as it moves proximally. Figure 4B As can be seen in FIG, the slot 21 may be formed with a widened portion 45 (which may be diamond-shaped or have other shapes) at its distal portion. The widened portion 45 accommodates any turning of the blade at the initial penetration point and allows the blade to smoothly enter the rest of the slot 21.

[0037] Now refer to Figure 5A and Figure 5B The activation slide 42 has been moved further toward the second end of the device, enabling axial advancement of the blade 32 to section tissue.

[0038] Now refer to Figure 6 , which shows the blade 32 reaching its axial travel limit at the first hinge link 26. At this limit, the first hinge link 26 acts as an anvil to ensure that the blade 32 properly cuts through the entire thickness of the leaflet or other tissue (the cutting action on this "anvil" is similar to the final cut in a guillotine or paper cutter).

[0039] Now refer to 7A to 7D , which shows a heart valve tissue cutting device 10 according to another non-limiting embodiment of the present invention. This embodiment includes a gripping member 50 for gripping a leaflet or other tissue before and during cutting. The gripping member 50 can be spring-loaded or wire-activated, similar to that described above for deploying the cutting guide arm 20.

[0040] like Figure 7D As best seen in FIG, the gripping member 50 may include a pair of arms having a plurality of ends 52 and 54 connected to each other by a bridging member 56. After the cutting guide arm 20 is positioned at the desired location on the leaflet or other tissue to be cut or sectioned, the gripping member 50 may be raised to hold the leaflet or other tissue in place (clamp it in place) while the blade 32 is activated.

Claims

1. A heart valve tissue cutting device, comprising: a housing, the housing being formed with an elongated opening; a cutting guide arm pivotally connected to the housing via a hinge assembly, the cutting guide arm being formed with a slot; an actuator wire coupled to the cutting guide arm, wherein movement of the actuator wire causes the cutting guide arm to pivot outwardly away from the housing; a cutting element including a blade having a sharpened tip, the cutting element coupled to a track link arranged to travel along a track in the housing; as well as an activation slide coupled to the elongated member and movable in a passage in the housing, wherein movement of the activation slide causes the track link and the cutting element to move along the track, and wherein the blade does not protrude out of the housing when the track link is at one end of the track, and wherein the blade protrudes out of the housing when the track link is not at the end of the track.

2. The heart valve tissue cutting device according to claim 1, wherein: The hinge assembly includes a four-hinge mechanism.

3. The heart valve tissue cutting device according to claim 2, wherein: The blade protector rib is pivotally connected to the cutting guide arm, and wherein the four-hinge mechanism includes a first hinge link that is pivotally connected to the first portion of the housing at a first hinge and pivotally connected to the blade protector rib at a second hinge, and wherein the second hinge link is pivotally connected to the second portion of the housing at a third hinge and pivotally connected to the cutting guide arm at a fourth hinge.

4. The heart valve tissue cutting device according to claim 3, wherein: As the cutting guide arm pivots outward, a portion of the four-hinge mechanism passes through the elongated rib aperture and through the slot.

5. The heart valve tissue cutting device according to claim 2, wherein: The housing includes end caps that limit the movement of the four-hinge mechanism and define the limits of outward pivotal movement of the cutting guide arm.

6. The heart valve tissue cutting device according to claim 3, wherein: The second hinge is a sliding hinge in which a pin slides in a channel attached to the blade protector rib.

7. The heart valve tissue cutting device according to any one of claims 1 to 6, wherein: The end of the track where the blade does not protrude outside the housing includes a curved portion of the track that curves from a central portion of the housing toward an outer contour of the housing.

8. The heart valve tissue cutting device according to any one of claims 1 to 7, wherein: The blade is pivotally connected to a blade support arm at a first pivot, and another portion of the blade is pivotally connected to the track at a second pivot, with the blade support arm coupled to the track link.

9. The heart valve tissue cutting device according to any one of claims 1 to 8, wherein: During movement of the cutting element along the track, the blade moves through the slot.

10. The heart valve tissue cutting device according to any one of claims 1 to 9, further comprising a gripping member for gripping a leaflet or other tissue before and during cutting.

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