Heart valve tissue dissection device

Abstract

The cardiac valve tissue dissection device includes a housing having an elongated opening formed therein, a cutting guide arm pivotally attached to the housing at a distal pivot, the cutting guide arm having a slot formed therein, and a first actuator wire coupled to the cutting guide arm. Movement of the first actuator wire causes the cutting guide arm to rotate about the distal pivot. A cutting element having a blade is coupled to a track link configured to move along a track within the housing. A second actuator wire is connected to the track link. Movement of the second actuator wire causes the track link and cutting element to move distally or proximally along the track. When the track link is in a proximal portion of the track, the blade does not protrude from the housing, and when the track link is not in a proximal portion of the track, the blade protrudes from the housing.

Description

[Technical Field]

[0001] The present invention relates generally to devices and methods for transcatheter modification of bodily tissue, such as cardiac valve leaflet tissue, for example, the mitral and aortic valve leaflets. [Background technology]

[0002] International Patent Application PCT / IB2020 / 054729 describes a transcatheter valve dehiscence device and method. This invention describes a method and device that can be used to perform BASILICA (Bioprosthetic or native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction) or LAMPOON (mitral valve) procedures. The device is a resection or division device designed to prevent damage to adjacent tissue. This device can be used in other cardiac procedures, such as tricuspid conversion of a bicuspid valve (transforming a bicuspid valve into a tricuspid valve by dehiscence or division of one of the valve leaflets), tricuspid conversion of a quadricuspid valve (transforming a tricuspid valve by dehiscence of one of the valve leaflets), or division of the anterior mitral valve leaflet (AML) to prevent left ventricular outflow tract obstruction (LVOTO), thereby preparing patients for safe transcatheter aortic or mitral valve replacement (TAVR / TMVR) or other procedures involving cardiac / vascular tissue modification. Summary of the Invention

[0003] The present invention, as described in detail below, aims to provide devices and methods for dissecting heart valve tissue, such as, but not limited to, mitral and aortic valve tissue. For example, the present invention can be used in transcatheter mitral valve replacement (TMVR) to remove the anterior mitral valve leaflet hiatus to prevent obstruction of the left ventricular outflow tract (LVOT) when an implant valve is placed within the patient's native valve.

[0004] The mitral valve is located between the left atrium and left ventricle of the heart. It has two valves or cusps: the anterior medial mitral valve (AMVL) and the posterolateral mitral valve (PMVL).

[0005] The term "cutting" refers to any type of reduction in size or change in shape or form, including, but not limited to, cutting, dividing, dehiscing, slicing, crushing, chopping, etc., and the terms are used interchangeably throughout.

[0006] Thus, in accordance with non-limiting embodiments of the present invention, there is provided a heart valve tissue dissection device comprising: a housing defining an elongated opening; a cutting guide arm pivotally attached to the housing at a distal pivot, the cutting guide arm defining a slot; a first actuator wire coupled to the cutting guide arm, wherein movement of the first actuator wire causes the cutting guide arm to pivot about the distal pivot; a cutting element including a blade coupled to a track link configured to move along a track within the housing; and a second actuator wire coupled to the link, wherein movement of the second actuator wire causes the track link and cutting element to move distally or proximally along the track; wherein the blade does not protrude from the housing when the track link is in a proximal portion of the track; and wherein the blade protrudes from the housing when the track link is not in a proximal portion of the track.

[0007] According to a non-limiting embodiment of the present invention, the proximal portion of the track curves from a central portion of the housing toward the outer contour of the housing.

[0008] According to a non-limiting embodiment of the present invention, the cutting guide arm fits into an elongated opening when in a closed position.

[0009] According to a non-limiting embodiment of the present invention, as the cutting element moves distally along the track, the blade moves through a slot.

[0010] According to a non-limiting embodiment of the present invention, the second actuator wire is wrapped around the distal pivot.

[0011] According to a non-limiting embodiment of the present invention, the first actuator wire is coupled to a distal cam of the cutting guide arm, the distal cam pivoting about the distal pivot. [Brief explanation of the drawings]

[0012] The present invention will be more fully understood from the following detailed description when read in conjunction with the drawings. [Figure 1] FIG. 1 is a simplified side view of a heart valve tissue dissection device according to a non-limiting embodiment of the present invention. [Figure 2] FIG. 2 is a simplified plan view of a heart valve tissue dissection device. [Figure 3] FIG. 3 is a simplified side view of the heart valve tissue dissection device with the cutting guide arm pivoted outward to a first outer position and the cutting guide having a slot formed therein for guiding the cutting motion of the cutting element. [Figure 4] FIG. 4 is a simplified side view of the heart valve tissue dissection device showing the cutting guide arms pivoted outward to a second, outer position. [Figure 5] FIG. 5 is a simplified side view of the heart valve tissue dissection device in the position of FIG. 4 , with the cutting element in a retracted position within the dissection device, the cutting element coupled to a track link configured to move along a track, the track link resting on a proximal curved portion of the track such that the cutting element is retracted and its blade does not protrude outward. [Figure 6] FIG. 6 is a simplified diagram of a cutting element and its track link, showing the track link moving distally from the proximal end of the curved portion of the track, causing the blades of the cutting element to begin to protrude outward. [Figure 7] FIG. 7 is a simplified diagram of the cutting element and its track link shown as the track link moves further distally so that the blade of the cutting element is about to enter the slot in the cutting guide arm. [Figure 8] FIG. 8 is a simplified diagram of the cutting element and its track link shown with the track link moved further distally so that the blade of the cutting element protrudes through the slot in the cutting guide arm. [Figure 9] FIG. 9 is a simplified diagram of the cutting element and its track link, showing the track link moved further distally until the cutting element has reached the end of its distal travel along the track. [Figure 10] FIG. 10 is an opposite side view of FIG. [Figure 11] FIG. 11 is a perspective view showing the orientation of FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0013] Reference is now made to Figures 1-4, which illustrate a heart valve tissue dissection device 10 according to a non-limiting embodiment of the present invention.

[0014] The cardiac valve tissue dissection device 10 includes a housing 12 (e.g., elongated, cylindrical) with an elongated opening 14 formed therein, which may have rounded ends. The housing 12 may be made of medical-grade stainless steel or other suitable material. The proximal end 16 of the housing 12 is open to allow passage of an actuator wire (described below), which may be coupled to a manipulator (not shown) for manipulating the actuator wire. The distal end 18 of the housing 12 may be blunt to prevent harm to tissue. Optionally, the distal tip may be sufficiently open and / or include a guidewire channel or lumen to allow passage of a guidewire or the like completely through the device from the proximal end to the distal end.

[0015] 3 and 4, the elongated opening 14 may include a distal limiter 15, such as an inwardly tapered portion of the opening 14 that forms a kind of limiting pocket. The distal limiter 15 can be used to limit the position of the leaflet edge that is grasped by the device.

[0016] The heart valve tissue dissection device 10 may include a cutting guide arm 20 pivotally mounted to the housing 12 at a distal pivot 22. In a closed position (FIGS. 1 and 2), the cutting guide arm 20 fits into the elongated opening 14. The cutting guide arm 20 may have a slot 24 formed therein for guiding the cutting action of a cutting element, described below.

[0017] As shown in FIG. 5, a first actuator wire 26 may be coupled to the distal cam 28 of the cutting guide arm 20. The actuator wire may be made of medical-grade stainless steel, nitinol, polymer wire, or other suitable material. Pulling the first actuator wire 26 proximally (in the direction of arrow 27 in FIG. 3) rotates the cam 28, which in turn rotates the cutting guide arm 20 about the distal pivot 22. As shown in FIG. 3, the cutting guide arm 20 can be rotated outward about the distal pivot 22 to a first outward position. As shown in FIG. 4, the cutting guide arm 20 may be rotated outward to a second outward position. The purpose of one of the two positions is described after FIG. 11 in a description of one method of using the device. It will be understood that during use of the device, the cutting guide arm is used both as a positioning arm and as a grasping arm for grasping or clamping cardiac tissue to be cut.

[0018] Referring now to FIG. 5, the heart valve tissue dissection device 10 may include a cutting element 30, shown here housed within the dissection device. The cutting element 30 may include a blade 32. The cutting element 30 may be coupled to a track link 34 configured to move along a track 36. In the position of FIG. 5, the track link 34 is on a proximal curved portion 38 of the track 36, so that the cutting element 30 is housed and its blade 32 does not protrude outward. The proximal curved portion 38 of the track 36 curves from a central portion of the housing 12 toward the outer contour of the housing 12. A second actuator wire 40 may be coupled to the track link 34. As described above, the first and second actuator wires may be coupled to a manipulator (not shown) for manipulating the actuator wires.

[0019] Referring now to Figure 6, as the track link 34 moves distally from the proximal end of the curved portion 38 of the track 36, the blades 32 of the cutting element 30 begin to protrude outward.

[0020] Referring now to Figure 7, as the track link 34 moves further distally, the blade 32 of the cutting element 30 attempts to enter the slot 24 of the cutting guide arm 20.

[0021] Referring now to Figure 8, as the track link 34 moves further distally, the blade 32 of the cutting element 30 protrudes through the slot 24 in the cutting guide arm 20.

[0022] Referring now to Figure 9, as the track link 34 moves further distally, the cutting element 30 reaches the end of its distal travel along the track 36. Figure 10 is an opposite side view from Figure 9. In Figure 10, the second actuator wire 40 can be seen wrapped around the distal pivot 22. Alternatively, the second actuator wire 40 can be wrapped around a different pivot.

[0023] FIG. 11 is a perspective view of the orientation of FIGS. 9 and 10, clearly showing the blade 32 of the cutting element 30 protruding through the slot 24 in the cutting guide arm 20.

[0024] In one method of using the device, the device 10 can be percutaneously introduced through the vasculature with a delivery system to the desired site (e.g., the valve leaflet to be dissected, divided, or otherwise altered) (e.g., the device is first sheathed, delivered over a guidewire, and then the sheath is removed). The cutting guide arm 20 can first be extended outward to the first position shown in FIG. 3 . In this position, the cutting guide arm 20 is used as a positioning arm to bypass the ventricular leaflet. The actuator then moves the cutting guide arm 20 to the second position shown in FIG. 4 to grasp or clamp the leaflet while allowing visualization of the grasping position with an imaging system. The slot 24 or the shape of the device allows the surgeon to visualize the line of dissection or division. Once the surgeon confirms the appropriate cutting position, the blade 32 of the cutting element 30 is actuated and moved distally to cut or divide the leaflet while grasping the leaflet in the second position shown in FIG. 4 . The distal limiter 15 of the elongated opening 14 limits the position of the leaflet edge so that the final cutting action of the blade 32 can divide the leaflet edge.

[0025] Note that this method splits the leaflets by grasping them and beginning the cutting or splitting process away from the leaflet edge. That is, for the anterior leaflet, the splitting begins from the base of the leaflet toward the edge, toward the left ventricle. This splitting method allows for better control of the puncture point (the point at which the blade pierces the leaflet) and ensures a smoother split because the leaflet is under constant tension while being grasped and the splitter is actuated. Starting the split from the opposite direction can result in creases or distortions in the leaflet, compromising the quality of the split. However, the present invention can also be practiced in the reverse direction.

Claims

1. 1. A heart valve tissue dissection device, comprising: a housing having an elongated opening formed therein; a cutting guide arm pivotally attached to the housing at a distal pivot, the cutting guide arm having a slot formed therein; a first actuator wire coupled to the cutting guide arm, wherein movement of the first actuator wire causes the cutting guide arm to rotate about the distal pivot; a cutting element including a blade coupled to a track link configured to move along a track within the housing; a second actuator wire coupled to the track link, wherein movement of the second actuator wire moves the track link and the cutting element distally or proximally along the track, wherein the blade does not protrude from the housing when the track link is in a proximal portion of the track, and the blade protrudes from the housing when the track link is not in the proximal portion of the track.

2. The heart valve tissue dissection device of claim 1 , wherein the proximal portion of the track curves from a central portion of the housing toward an outer contour of the housing.

3. The heart valve tissue dissection device of claim 1 , wherein the cutting guide arm fits through the elongated opening when in a closed position.

4. The heart valve tissue dissection device of claim 1 , wherein the blade moves through the slot as the cutting element moves distally along the track.

5. The heart valve tissue dissection device of claim 1 , wherein the second actuator wire is wound around the distal pivot.

6. 2. The heart valve tissue dissection device of claim 1, wherein the first actuator wire is coupled to a distal cam on the cutting guide arm, the distal cam pivoting about the distal pivot.

7. The heart valve tissue dissection device of claim 1 , wherein the elongated opening has a distal, inwardly tapered portion.

8. 10. A method of dissecting heart valve tissue using the device of claim 1, comprising grasping a valve leaflet between the cutting guide arm and the housing, and moving the cutting element to dissect the valve leaflet while grasping the leaflet.

9. 9. The method of claim 8, wherein the leaflets have edges opposite a base, and the leaflets are dissected starting from the base toward the edges.

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