Transcatheter Valve Tear Device and Method

Abstract

A transcatheter valve tearing device (10, 100) includes a leaflet support frame (12, 112) and a leaflet cutting assembly (14, 114), both of which are movably mounted on a guiding structure (16, 116) and are movable between a contracted orientation and a deployed orientation. In the deployed orientation, the blade protectors (24, 124) of the leaflet support frame (12, 112) are positioned above the cutting elements (36, 136) of the leaflet cutting assembly (14, 114).

Description

Technical Field

[0001] The present invention generally relates to devices and methods for transcatheter tearing of heart valve leaflets (e.g., aortic valve leaflets). Background Art

[0002] Transcatheter aortic valve replacement (TAVR) is used to treat native aortic valve stenosis. TAVR is also an effective treatment for bioprosthetic surgical aortic valve failure, a treatment method called valve-in-valve TAVR.

[0003] A known complication of TAVR is coronary artery obstruction, which occurs when a transcatheter heart valve is externally replaced below the operative or native aortic valve leaflets and obstructs the coronary ostium, either by sealing the Valsalva sinus at the sinotubular junction or by covering the coronary ostium by the leaflets themselves due to low coronary ostium and insufficient sinus width. Coronary artery obstruction is more common in valve-in-valve TAVR ("redo TAVR after TAVR (TAVR-in-TAVR)") than in TAVR for native aortic valve stenosis. The possible reasons are that most surgical prostheses are supra-annular in shape, reducing the height of the coronary arteries relative to the valve leaflets, and because valve suturing pulls the coronary arteries closer together, reducing the sinus width. Another possible reason is that after valve-in-valve TAVR in patients with a large aortic root, blood can bypass the old valve and flow to the coronary arteries. However, in some patients with a small aortic root and low coronary arteries, the leaflets of the failing surgical bioprosthetic valve can impede blood flow to the coronary arteries.

[0004] Khan et al., "Transcatheter Tearing of the Aortic Valve to Prevent Coronary Artery Obstruction During Transcatheter Aortic Valve Replacement", Journal of the American College of Cardiology, Cardiovascular Interventions, Vol. 11, No. 7, April 9, 2018, pp. 677-689, proposed a new procedure to address these issues.

[0005] Their electro-surgical procedure is called BASILICA (Bioprosthetic Aortic Valve Sectoral Tear to Prevent Iatrogenic Coronary Artery Obstruction). BASILICA uses a charged guidewire passed through a catheter to cut the leaflets of the patient's failing bioprosthetic valve. Incising the leaflets prior to TAVR allows blood to flow into the coronary arteries through the divided leaflets when the new valve is deployed. Summary of the Invention

[0006] The present invention seeks to provide a transcatheter valve tearing device and method. The present invention is a method and device that can be used to perform BASILICA. The device is a cutting device that pays attention to preventing damage to adjacent tissues. The device of the present invention can be implemented in other cardiac surgeries, such as tricuspidalization of the mitral valve (converting the mitral valve into a tricuspid valve by cutting or dividing one of the mitral valve leaflets into two leaflets) or tricuspidalization of the quadricuspid valve (tearing one of the leaflets to convert the valve into a tricuspid valve), so as to prepare the patient for a safe TAVR or other surgeries involving cutting cardiac tissues.

[0007] According to a non-limiting embodiment of the present invention, the transcatheter valve tearing device includes a cutting element mounted on a guiding structure. The cutting element can expand and contract relative to the guiding structure. The guiding structure can be delivered to the heart valve, and the cutting element expands and moves towards the valve leaflets (in a direction that may be different from the expansion direction) to cut them. A support structure can be provided on the opposite side of the valve leaflets to act as an "anvil" against the cutting force of the cutting element and protect the tissues that should not be cut from the harm of the cutting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention will be more fully understood and appreciated from the following detailed description in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a simplified illustration of a transcatheter valve tearing device constructed and operated according to a non-limiting embodiment of the present invention, in a retracted (contracted) orientation for deployment to the surgical site;

[0010] Figure 2 is a simplified illustration of the transcatheter valve tearing device in an expanded (deployed) orientation for tearing the valve in situ;

[0011] Figure 3 is another view of the expanded orientation;

[0012] Figure 4A and Figure 4B are simplified illustrations of the leaflet cutting assembly in the corresponding retracted (contracted) orientation and expanded (deployed) orientation;

[0013] Figure 5A and Figure 5B are simplified illustrations of the sheath transmission system during and after introducing the aortic valve, respectively;

[0014] Figure 6A and Figure 6B are simplified illustrations of the transmission system after sheath removal in different perspective views;

[0015] Figure 7A and Figure 7Bis a simplified illustration of a leaflet support frame of a device being deployed, where Figure 7A shows deployment in situ at the valve site and Figure 7B shows the device itself being deployed;

[0016] Figure 8 is a simplified illustration of a leaflet support frame and a leaflet cutting assembly deployed in situ at the valve site;

[0017] Figures 9A to 9E is a simplified illustration of a method of using a transcatheter valve tearing device to tear aortic valve leaflets, where:

[0018] Figure 9A is a simplified illustration of a transcatheter valve tearing device introduced and positioned in its systolic orientation at the aortic valve;

[0019] Figure 9B is a simplified illustration of a leaflet support frame deployed (expanded) on one side of the aortic valve and a leaflet cutting assembly still in systolic orientation within the aortic valve;

[0020] Figure 9C is a simplified illustration of a leaflet support frame expanded and positioned against one side of the aortic valve and a leaflet cutting assembly still in systolic orientation on the other side of the aortic valve;

[0021] Figure 9D is a simplified illustration of a leaflet cutting assembly being radially outwardly deployed and expanded;

[0022] Figure 9E is a simplified illustration of a leaflet cutting assembly being axially moved to cut the leaflets;

[0023] Figure 10 is a simplified illustration of a transcatheter valve tearing device constructed and operated according to another non - limiting embodiment of the present invention;

[0024] Figure 11 is a simplified illustration of a flat aortic valve, showing the control capabilities of the tearing device and its ability to control the location where the cutting element will start cutting the leaflet tissue;

[0025] Figure 12A is a simplified illustration of a tricuspid aortic native valve complex, where Θ represents the angle defining the distance from the native commissure to the desired incision location;

[0026] Figure 12B is a simplified illustration of a mitral aortic native valve complex;

[0027] Figures 13A to 13G is a simplified illustration of a method of tearing native valve tissue as a TAVI precursor according to another non - limiting embodiment of the present invention;

[0028] Figure 14 is a simplified illustration of a transcatheter valve tearing device constructed and operated in accordance with another non - limiting embodiment of the present invention;

[0029] Figure 14A and Figure 14B are respectively Figure 14 a simplified exploded view and an illustration of the leaflet cutting assembly of the device of;

[0030] Figure 14C is a simplified illustration of a leaflet cutting assembly pivotally coupled to an opposite end of a first biasing device at a pivot joint;

[0031] Figure 14D and Figure 14E are simplified illustrations of a leaflet cutting assembly assembled with a distal spring and a frame;

[0032] Figure 14F is Figure 14 a simplified exploded view of the leaflet support frame of the device of;

[0033] Figure 14G is a simplified illustration of a leaflet support frame installed in a frame;

[0034] Figure 14H is a simplified illustration of a finished device with a blade protector;

[0035] Figure 15 is a simplified illustration of a leaflet support frame moving distally towards the leaflet cutting assembly, and the leaflet support frame has expanded radially outward;

[0036] Figure 16 is a simplified illustration of an initial radial outward expansion of the leaflet cutting assembly;

[0037] Figure 17 and Figure 18 are simplified illustrations of a further expansion of the leaflet cutting assembly such that ultimately, the tip of the cutting element approaches the blade protector of the leaflet support frame; and

[0038] Figure 19A and Figure 19B are simplified illustrations of a transcatheter valve tearing device constructed and operated in accordance with another non - limiting embodiment of the present invention, in its respective collapsed and expanded orientations, wherein the leaflet cutting assembly is configured as a collapsible articulated parallelogram. Detailed Description

[0039] Now referring to Figures 1 to 3 , Figures 1 to 3 illustrates a transcatheter valve tearing device 10 constructed and operated in accordance with a non - limiting embodiment of the present invention.

[0040] The device 10 includes a leaflet support frame 12 and a leaflet cutting assembly 14, both of which are mounted on a guide structure 16( Figure 1 ).

[0041] In Figure 2 and Figure 3 the illustrated embodiment, the leaflet support frame 12 includes strut arms 18, one end of each strut arm 18 being pivotally coupled at a pivot joint 22 to a first portion 19 of a support frame tube 20 (which is part of the guide structure 16), and the opposite end of the strut arm 18 being coupled to a blade protector 24. The blade protector 24 may be shaped as a semi-hemispherical tube. The strut arm 18 and the blade protector 24 may be collinear or may be inclined relative to each other. An actuator arm 26 has one end pivotally coupled at a pivot joint 28 to a second portion 21 of the support frame tube 20 and the opposite end pivotally coupled at a pivot joint 30 to the strut arm 18.

[0042] In Figure 2 and Figure 3 the illustrated embodiment, there are more than one strut arm 18 (three are shown spaced 120° apart, but there may be one, two or any other number, not necessarily spaced symmetrically about the guide structure). Only one strut arm 18 is coupled to the blade protector 24 (since there is only one cutting element); each other strut arm 18 is coupled to a positioning member 32 which is not required to protect any tissue from the cutting element but which can be used to properly position, self-center and align the leaflet support frame 12 relative to the valve structure. The strut arm 18 may have a double-arm structure in which two parallel arms are used; the actuator arm 26 is positioned between the parallel arms and is pivotally coupled to both by a pivot joint 30.

[0043] In Figure 2 and Figure 3 the illustrated embodiment, the leaflet cutting assembly 14 includes a cutting element 36 extending from a blade arm 38. The cutting element 36 and the blade arm 38 may be collinear or may be inclined relative to each other. The cutting element 36 has a sharp tip 37. The blade arm 38 has one end pivotally coupled at a pivot joint 42 to a first portion 39 of a first biasing device 40 (which is part of the guide structure 16). A blade actuator arm 44 has one end pivotally coupled at a pivot joint 46 to a separator tube 41 and the opposite end pivotally coupled at a pivot joint 48 to the blade arm 38. The separator tube 41 separates the first biasing device 40 from a second biasing device 50. The second biasing device 50 extends from the second portion 21 of the support frame tube 20 to the separator tube 41.

[0044] InFigure 2 and Figure 3 In the illustrated embodiment, there are more than one blade arms 38 (three are shown spaced 120° apart, but there can be one, two, or any other number and they need not be spaced symmetrically with respect to the guiding structure). Only one cutting element 36 is coupled to one of the blade arms 38, but in other embodiments, more than one cutting element 26 can be used. The blade arms 38 can have a double-arm structure where two parallel arms are used, and an auxiliary arm 47 ( Figure 3 ) instead of a cutting element 36 is positioned between the parallel arms and pivotally coupled to the blade actuator arm 44 using a pivot joint 48. The blade actuator arm 44 can also have a double-arm structure (two parallel arms).

[0045] Now refer to the attached Figure 4A and 4B . In Figure 4A , the leaf cutting assembly 14 is in a retracted (collapsed) orientation. In this orientation, the cutting element 36 is located between the double arms of the blade actuator arm 44. Thus, the blade actuator arm 44 serves as a cutting element protector in the retracted position of the device, protecting delicate tissue from being accidentally cut by the cutting element 36. The first biasing device 40 can be constituted by a series of repeated arcuate (e.g., wavy or sinusoidal) elements 43 that at least partially wind around the actuator tube 45.

[0046] In the illustrated embodiment, there are two or more rows of arcuate elements 43; these rows wind together around the circumference of the tube 45. The arcuate elements 43 can be made of an elastic material such as nitinol and can have a constant spring force. In the retracted position, the arcuate elements 43 of the first biasing device 40 are in a tensioned state and apply a tension on the blade arm 38 and the actuator arm 44 to hold them in the retracted position such that they are generally "closed" (i.e., in a folded orientation).

[0047] The actuator tube 45 has a distal cap 49 against which the most distal arcuate element 43 abuts. The actuator tube 45 is axially movable relative to the support frame tube 20 ( Figure 2 ), where the actuator tube 45 can slide within the support frame tube 20.

[0048] Similar to the first biasing device 40, the second biasing device 50 can be constituted by a series of repeated arcuate (e.g., wavy or sinusoidal) elements 53 ( Figure 3 ). The spring force of the first biasing device 40 is greater than the spring force of the second biasing device 50 (such as a ratio of 4:1, although the present invention is not limited to this ratio).

[0049] In Figure 4BIn [description], the leaflet cutting assembly 14 is in a deployed (expanded) orientation. This can be achieved by moving the actuator tube 45 proximally (towards the leaflet support frame 12). This action compresses the arcuate element 43 of the biasing device 40. The blade actuator arm 44 is now tilted relative to the tube 45 (arms 38 and 44 and tube 45 form a triangular structure), and serves as a guiding surface on which the leaflet tissue slides towards the tip 37 (and edge) of the cutting element 36.

[0050] Thus, the guiding structure 16 includes tubes 20 and 45.

[0051] Now refer to Figure 5A and Figure 5B , Figure 5A and Figure 5B illustrate the transcatheter valve tearing device 10 encapsulated in the sheath 52 during and after the introduction of the aortic valve 51, respectively. In Figure 5A and Figure 5B , the left side of the aortic valve 51 is the aortic side, and the right side is the left ventricular side.

[0052] Figure 6A and Figure 6B illustrate the delivery system after unsheathing (moving the sheath 52 proximally). The device 10 may include a smooth portion 54 distal to the leaflet cutting assembly 14.

[0053] Now refer to Figure 7A and Figure 7B , Figure 7A and Figure 7B illustrate the leaflet support frame 12 being deployed. Figure 7A shows the device deployed in situ at the valve site, and Figure 7B shows the device deployed with the valve omitted. The deployment is achieved by moving the actuator tube 45 proximally towards the leaflet support frame 12 ( Figure 2 and Figure 3 ). Due to the fact that the spring force of the first biasing device 40 is greater than the spring force of the second biasing device 50, as described above, the proximal movement of the actuator tube 45 first compresses the weaker second biasing device 50 without compressing the stronger first biasing device 40. The proximal movement of the actuator tube 45 causes the actuator arm 26 ( Figure 2 and Figure 3 ) to move radially outwards, thus causing the strut arms 18 and the blade protector 24 to deploy radially outwards. The first biasing device 40 has not been compressed, so the cutting element 36 remains in the closed retracted position.

[0054] Now refer to Figure 8Further proximal movement of the actuator tube 45 now compresses the first biasing device 40. This further movement of the actuator tube 45 causes the deployment of the blade actuator arm 44, which in turn deploys the blade arm 38 and the cutting element 36, causing them to expand radially outward against the leaflet tissue of the aortic valve 51. The sharp distal tip 37 of the cutting element 36 pierces the leaflet tissue.

[0055] Now referring Figures 9A to 9E , Figures 9A to 9E illustrates a method of using the transcatheter valve tearing device 10 to tear the aortic valve leaflets.

[0056] In Figure 9A , the device 10 is introduced at the aortic valve 51 and positioned in its systolic orientation.

[0057] In Figure 9B , the leaflet support frame 12 is deployed (expanded) on one side (aortic side) of the aortic valve, and the leaflet cutting assembly 14 remains in the systolic orientation within the aortic valve 51.

[0058] In Figure 9C , the leaflet support frame 12 expands and is positioned against one side (aortic side) of the aortic valve 51, and the leaflet cutting assembly 14 remains in the systolic orientation on the other side (left ventricular side) of the aortic valve 51.

[0059] In Figure 9D , the leaflet cutting assembly 14 is deployed and expanded radially outward.

[0060] In Figure 9E , the leaflet cutting assembly 14 is moved axially (in the proximal direction 57) to cut one or more leaflets.

[0061] After the completion of the procedure, the actuator tube 45 is moved distally to contract the leaflet cutting assembly 14 and the leaflet support frame 12. The biasing force of the first biasing device 40 helps to contract the leaflet cutting assembly 14. The biasing force of the second biasing device 50 helps to contract the leaflet support frame 12.

[0062] In summary, through three strut arms and three blade arms, the device 10 can have a triangular tripod structure for cutting element activation, where axial movement is converted into tripod expansion movement. The symmetric spacing of the strut arms provides self - positioning of the device onto the valve cusp. The support frame structure allows blade penetration and protection of adjacent tissues by ensuring that the tip of the blade (cutting element) expands beneath the blade protector. The blade action pierces the aortic valve leaflets, and then the leaflets are dissected by an axial proximal movement (pulling) of the frame and blade structure, which forces the leaflet centerline to be separated by the sharp blade. The fully articulated mechanism allows the mechanism to be folded to fit into the catheter tube of the delivery system. Other embodiments can be based on other radial and non - radial bending methods.

[0063] One or more protector elements and blades can be used. A constant - force biasing device pre - loads the mechanism to maintain its normal closed (folded) state.

[0064] Leaflet puncture is performed from within the left ventricle, with the blade tip making a circular upward movement towards the convex side of the leaflet. In this way, the cutting element pierces the leaflet while the blade protector ensures that the cutting element tip does not extend into the aorta and thus prevents damage to the aortic complex. The support frame deployment and positioning can be performed within the sino - tubular junction (STJ) volume with minimal contact with adjacent elements in the aortic complex.

[0065] Embodiments of the support frame structure can include features and struts that prevent the valve leaflets from fully closing during the dissection action. This is done to ensure complete dissection of the valve leaflets along their axial direction.

[0066] Now referring to Figure 10 , Figure 10 , there is illustrated a transcatheter valve tearing device constructed and operated in accordance with another non - limiting embodiment of the present invention. The device includes one or more tissue tearing elements configured to radially extend from a contracted position (during delivery to the target site) to an expanded position (during the tearing action).

[0067] The tearing device includes a support element deployable on the aortic (downstream) side of the aortic valve, and a cutting blade positioned within the ventricular side of the valve (specifically, positioned within the outflow tract). The support element can be radially controlled to land within the aortic sinus by defining the segmentation length and radial length of the incision. Additionally, the orientation of the incision relative to the centerline of the leaflet can be adjusted.

[0068] Figure 11It is a diagram of a flat aortic valve, showing the control ability of the tearing device and its ability to control the position where the cutting element will start cutting the leaflet tissue. By adjusting the degree of radial expansion of the support element, the depth at which the cutting element pierces the leaflet on the ventricular side can be controlled. In addition, if multiple cuts are required, the rotational position of the support arm can be adjusted to make an "off-center" cut.

[0069] Figure 12A It is a schematic diagram of a native tricuspid aortic valve complex. Θ represents the angle that defines the distance from the native commissure to the position of the desired incision. By manipulating Θ, the length of the incision "r" is also defined.

[0070] Figure 12B It is a schematic diagram of a native mitral aortic valve complex. The hash area represents the raphe - a thickened area, roughly located at the center of the larger of the two leaflets. The shape and thickness of the raphe generally affect the degree and progression of valve degeneration. Figure 12B Two dashed lines representing longitudinal incisions are shown, which are designed to release the area around the raphe to facilitate the implantation of an artificial valve.

[0071] Figures 13A to 13G An example shows a method of tearing the tissue of a native valve as a precursor to TAVI. Figure 13A An example shows a tissue tearing device introduced into the native valve complex such that the support element is located on the arterial side of the valve leaflets and is set in a specific orientation, usually placed in the sinus of Valsalva. The tearing element is placed in the ventricular outflow tract such that one or more tearing nails (cutting elements) face the native leaflets.

[0072] Figure 13B It is a diagram of a nail that penetrates the tissue of the leaflet and enters the corresponding nail holder within the support element arm. The support element then retracts while the nail remains embedded in the leaflet tissue, with its tip firmly fixed to the nail holder.

[0073] Figure 13C It is an enlarged view of the nail embedded in the leaflet, with its tip fixed inside the nail holder.

[0074] Figure 13D It shows the tearing device left within the native valve complex, which is tethered to an external handle (not shown) by a separate wire.

[0075] Figure 13E It shows the implantation process of a self - expanding TAVI valve (a self - expanding valve is shown, but any TAVI device can be used). The valve is still partially captured by its delivery system, which is shown in a partially open state. Before the artificial valve is fully released, the surgeon can position the artificial valve at the desired location before tearing the native valve leaflets.

[0076] Figure 13F Illustrates a native valve leaflet with tacks embedded before and after a tearing operation. It can be seen that the native leaflet is longitudinally cut. The cutting step is performed by pulling the outer end of the wire that holds the tacks. By pulling the wire, the tacks and their tack holders move towards the skull and cut through the calcified native leaflet.

[0077] Figure 13G Illustrates the final step of TAVI, where the prosthesis is fully released after the tearing step.

[0078] Now refer to Figure 14 , Figure 14 illustrates a transcatheter valve tearing device 100 constructed and operated according to a non - limiting embodiment of the present invention. Device 100 is similar to device 10, but there are differences as described below.

[0079] Device 100 includes a leaflet support frame 112 and a leaflet cutting assembly 114, both of which are mounted on a guiding structure 116 ( Figure 14 ). Now refer to Figures 14A to 14H to describe Figure 14 the sub - assemblies of device 100.

[0080] As Figure 14A and Figure 14B shown, the leaflet cutting assembly 114 includes a cutting element 136 extending from a blade arm 138. The cutting element 136 and the blade arm 138 can be collinear or can be inclined relative to each other. The cutting element 136 has a sharp tip 137. The blade arm 138 can be fixed to a first blade support arm 103 (in the illustrated embodiment, it is fixed to a pair of first blade support arms 103), for example, can be fixed to the first blade support arm 103 by a pin 105 or other means. The blade arm 138 can be pivotally coupled to a second blade support arm 107 (in the illustrated embodiment, it is pivotally coupled to a pair of second blade support arms 107), for example, can be pivotally coupled to the second blade support arm 107 by another pin 105 or other means.

[0081] In the absence of the cutting element 136 and the blade arm 138, the assembly of the first blade support arm 103 pivotally coupled to the second blade support arm 107 is referred to as a multi - arm assembly. As will be clear from the following description, the multi - arm assembly is used multiple times in device 100, and the use of the same components reduces manufacturing and inventory costs. Alternatively, the positioning arm support struts 103 and 107 can be of different sizes, but can be constructed in a similar manner to the cutting assembly.

[0082] As seen in Figure 14C (in a manner similar toFigure 4A in a manner similar to that described for the device 10 in, one end of the leaflet cutting assembly 114, which includes a cutting element 136 and a blade arm 138, is pivotally coupled to opposite ends of a first biasing device 140 (which is part of the guide structure 116) at pivot joints 142 and 146. The first biasing device 140 can be formed by or coupled to the distal sliding tube 141. The first biasing device 140 provides a safety feature in particular: after using the device to cut tissue, the first biasing device 140 contracts to ensure that the assembly of the first blade support arm 103 and the second blade support arm 107 returns to the contracted state and does not protrude outwardly, and also does not damage nearby tissue. Thus, when contracted, the first biasing device 140 serves as a limiter that restricts the amount by which the cutting element 136 can move radially outward.

[0083] As Figure 14D and Figure 14E shown, the distal spring 121 can be mounted on the distal sliding tube 141. The leaflet cutting assembly 114 can be mounted in a frame 157 having an open side 159. A frame plug 155 can be mounted on the distal sliding tube 141 between the distal end of the frame 157 and the proximal end of the distal spring 121.

[0084] As Figure 14F shown, the leaflet support frame 112 includes a pair of multi-arm assemblies 119 that are pivotally coupled to a first pivot joint 122 and a second pivot joint 123 that are fixed to a spacer frame tube 120 (which is part of the guide structure 116). A second biasing device 150 is disposed on or a part of the spacer frame tube 120 and is located between the first pivot joint 122 and the second pivot joint 123. Similar to the first biasing device 140, the second biasing device 150 provides a safety feature in particular: after using the device to cut tissue, the second biasing device 150 contracts to ensure that the assembly of the first blade support arm 103 and the second blade support arm 107 returns to the contracted state and does not protrude outwardly, and also does not damage nearby tissue. Thus, when contracted, the second biasing device 150 serves as a limiter that restricts the amount by which the positioning arms 103 and 107 of the multi-arm assembly 119 can move radially outward.

[0085] As Figure 14G shown, the multi-arm assembly 119 of the leaflet support frame 112 and the spacer frame tube 120 are mounted in the frame 157. A guide spring 160 can be mounted on the proximal end of the spacer frame tube 120.

[0086] As Figure 14HAs shown, the strut arm 118 from which the blade protector 124 extends can be fixed to the first blade support arm 103 (the arm on the same side as the opening 159) of the multi-arm assembly 119. Similar to the device 10, the blade protector 124 can be shaped as a semi-hemispherical tube, and the strut arm 118 and the blade protector 124 can be collinear or can be inclined relative to each other. A cable assembly 170 made of a shape memory alloy such as Nitinol can be coupled to the guide structure 116 adjacent to the distal end of the distal spring 121. In cases where the contraction of the assembly is somewhat difficult, the cable assembly 170 can assist the distal spring 121 in folding the cutting element 136 and the multi-arm assembly 119.

[0087] Referring again to Figure 14 . The device 100 can be delivered to the surgical site using a sheath (not shown) that covers the leaflet support frame 112 and the leaflet cutting assembly 114, such that the device 100 is delivered as an elongated tubular structure. Figure 14 The device 100 after sheath removal is shown. This initially causes the blade protector 124 to expand (move) radially outward, as Figure 14 shown. In this initial position, the leaflet support frame 112 is axially spaced proximally from the leaflet cutting assembly 114.

[0088] Now referring to Figure 15 . The guide structure 116 (such as, but not limited to, a stainless steel or Nitinol wire or tube) is moved distally such that the leaflet support frame 112 moves distally toward the leaflet cutting assembly 114. The distal end (distal arm 103) of the leaflet support frame 112 can abut against a seat 99 formed at the distal end of the opening 159 in the frame 157. The seat 99 can serve as a safety stop to limit the outward movement of the blade protector 124. Note that the distal portion of the blade protector 124 is now positioned above the tip 137 of the cutting element 136.

[0089] The spring forces of the biasing devices 140 and 121 are greater than the spring forces of the biasing devices 150 and 160 (such as a ratio of 2:1, although the present invention is not limited to this ratio). Thus, the leaflet support frame 112 expands outward before the leaflet cutting assembly 114 begins to expand outward.

[0090] Now referring to Figure 16 . Further distal movement of the guide structure 116 begins to compress the first biasing device 140 and the distal spring 121 (not seen here), such that the leaflet cutting assembly 114 begins to expand radially outward.

[0091] Figure 17 and Figure 18Illustrated is a further expansion of the leaflet cutting assembly 114 such that the tip 137 of the final cutting element 136 is close to the blade protector 124. The device 100 can be used to tear tissue as described for the device 10.

[0092] Now referring to Figure 19A and Figure 19B , Figure 19A and Figure 19B illustrate a transcatheter valve tearing device 200 constructed and operated in accordance with another non - limiting embodiment of the present invention. As with other embodiments, the device 200 includes a leaflet support frame 212 and a leaflet cutting assembly 214.

[0093] The leaflet cutting assembly 214 can be configured as a collapsible articulated parallelogram 218, where axial movement is converted into radial movement to affect leaflet anatomy.

[0094] The leaflet support frame 212 can be a triangular frame support structure that supports the leaflets by self - aligning to the valve cusps due to the geometry of the support members of the frame 212 (which can be spaced approximately 120°). The support frame structure allows blade penetration and alignment by ensuring a double - strut design for the blade to pass through the frame. The blade pierces the aortic valve leaflets and then dissects the leaflets by pressing the aortic valve leaflets against the support frame 212 to produce an anvil - like action.

[0095] A fully articulated mechanism allows the mechanism to be folded to fit into the delivery system catheter tube. Other embodiments can be based on other radial and non - radial bending methods.

[0096] The cutting elements are configured as a three - lobe mechanism to allow simultaneous 120° positioning for all leaflet cuts.

[0097] Activation of the leaflet support frame 212 and the leaflet cutting assembly 214 can be accomplished by the reverse movement of two coaxial tubes.

[0098] A constant - force biasing device 216 (such as but not limited to a Nitinol - tube - based spring) can pre - load one or more blades of the leaflet cutting assembly 214 mechanism in a normally closed or folded position. The biasing device 216 serves as a centering and radial support against the LVOT (left ventricular outflow tract) wall in its loaded position.

[0099] As with other embodiments of the present invention, leaflet puncture can be performed from within the left ventricle, where the blade tip makes a circular motion towards the aorta to prevent damage to the aortic complex. The frame support allows the cutting blade to dissect the leaflet at any desired location without applying any force on the leaflet annulus. The support frame deployment and positioning can be performed within the STJ (sinotubular junction) volume. An indicator that can be placed on the activation handle can indicate that the dissection action has been completed.

Claims

1. A transcatheter valve tearing device (10, 100), the transcatheter valve tearing device (10, 100) comprising: A leaflet support frame (12, 112) and a leaflet cutting assembly (14, 114), both the leaflet support frame (12, 112) and the leaflet cutting assembly (14, 114) being movably mounted on a guiding structure (16, 116) and being movable between a contracted orientation and a deployed orientation, wherein, in the deployed orientation, a blade protector (24, 124) of the leaflet support frame (12, 112) is positioned above a sharp tip (37, 137) of a cutting element (36, 136) of the leaflet cutting assembly (14, 114), and the sharp tip (37, 137) is positioned to first puncture the leaflet, and the cutting element (36, 136) is then capable of cutting the leaflet by an axial movement of the leaflet cutting assembly (14, 114), wherein the leaflet cutting assembly (14, 114) includes support arms (44, 103, 107) coupled to a first biasing device (40, 140), and the leaflet support frame (12, 112) includes frame arms (26, 119) coupled to a second biasing device (50, 150), wherein contraction of the first biasing device (40, 140) causes an outward movement of the support arms (44, 103, 107) and deployment of the leaflet cutting assembly (14, 114), and contraction of the second biasing device (50, 150) causes an outward movement of the frame arms (26, 119) and deployment of the leaflet support frame (12, 112), wherein the first biasing device (40, 140) has a stronger biasing force than a biasing force of the second biasing device (50, 150), such that deployment of the leaflet support frame (12, 112) precedes deployment of the leaflet cutting assembly (14, 114).

2. The transcatheter valve tearing device (10, 100) according to claim 1, wherein, In the deployed orientation, the blade protector (24, 124) is positioned radially outward relative to the cutting element (36, 136).

3. The transcatheter valve tearing device (10, 100) according to claim 1 or 2, wherein, The cutting element (36, 136) is configured to tear tissue located between the cutting element (36, 136) and the blade protector (24, 124).

4. The transcatheter valve tearing device (10, 100) according to claim 1, wherein, The support arms (44, 103, 107) include a blade actuator arm (44), and the cutting element (36) is located between two arms of the blade actuator arm (44).

Images