Tissue clamping piece and valve clamping device

Abstract

The invention discloses a tissue clamping piece which comprises a connecting frame and two clamping arms, and the connecting frame comprises two connecting pieces opposite to each other in a spaced mode; the two clamping arms are arranged on the opposite side edges of the two connecting pieces respectively, each clamping arm extends towards the side away from the other clamping arm, each clamping arm comprises a bent section connected to the corresponding connecting piece and a clamping section connected to the bent section away from the corresponding connecting piece, and the width of the bent section is smaller than that of the clamping section and smaller than that of the connecting pieces; according to the valve clamping device, the weight of the valve clamping device can be reduced, the pulling force needed by pulling the two clamping arms of the valve clamping device to be attached to the center shaft through the control wire can be reduced, the reverse acting force borne by the control wire is reduced, the control wire is prevented from being broken, and operation is facilitated. The invention further provides a valve clamping device provided with the tissue clamping piece.

Description

Technical Field

[0001] The present invention relates to the field of interventional medical devices, and in particular to a tissue clamp and a valve clamping device provided with the tissue clamp. Background Art

[0002] See also Figure 1 The mitral valve 1 is a one-way valve located between the left atrium 2 and the left ventricle 3 of the heart. A normal and healthy mitral valve 1 can control the blood flow from the left atrium 2 to the left ventricle 3, while preventing the blood from the left ventricle 3 to the left atrium 2. The mitral valve 1 includes a pair of leaflets, called the anterior leaflet 1a and the posterior leaflet 1b. The anterior leaflet 1a and the posterior leaflet 1b are fixed to the papillary muscle of the left ventricle 3 by chordae tendineae 4. Under normal circumstances, when the left ventricle 3 of the heart contracts, the edges of the anterior leaflet 1a and the posterior leaflet 1b are completely aligned to prevent blood from flowing from the left ventricle 3 to the left atrium 2. Please refer to Figure 2 When organic or functional changes occur in the leaflets of the mitral valve 1 or its related structures, such as partial rupture of the chordae tendineae 4, the anterior leaflet 1a and the posterior leaflet 1b of the mitral valve 1 are not properly aligned. As a result, when the left ventricle 3 of the heart contracts, the mitral valve 1 cannot be completely closed, causing blood to flow back from the left ventricle 3 to the left atrium 2, thereby causing a series of pathophysiological changes, known as "mitral regurgitation".

[0003] Surgery usually uses surgical methods such as valve edge-to-edge suture to treat mitral regurgitation. However, this type of surgical procedure has the disadvantages of complex surgical procedures, high surgical costs, high degree of patient trauma, high risk of complications, long hospital stay, and painful recovery process for patients. There is a minimally invasive treatment surgery, which is based on the principle of valve edge-to-edge surgery. The valve clamping device is delivered to the mitral valve through an interventional catheter, and then the anterior and posterior leaflets of the mitral valve are clamped at the same time, so as to pull the leaflets closer to each other and reduce "mitral regurgitation". This valve clamping device uses a pair of concave forceps arms and a tissue clamp made of shape memory material to cooperate with each other to fix the leaflets of the mitral valve between the forceps arms and the tissue clamp. That is, the forceps arms and the tissue clamp grasp the anterior and posterior leaflets of the mitral valve at the same time, so as to achieve the purpose of fixing the leaflets and reducing mitral regurgitation.

[0004] Specifically, when the valve clamping device is in the delivery state, the tissue clamping piece is pulled by the slender control wire and attached to both sides of the central axis of the valve clamping device, and is delivered to the vicinity of the mitral valve through the slender delivery catheter, and then the position of the valve clamping device is adjusted. After the control wire pulls the tissue clamping piece, the tissue clamping piece unfolds due to its own shape memory property and presses the valve leaflet into the clamp arm, thereby cooperating with the clamp arm to clamp the valve leaflet. Figure 3The tissue clamping member 3a includes a base 3a1 and clamping arms 3a2 arranged on opposite sides of the base 3a1, and each clamping arm 3a2 is provided with an opening 3a3 to reduce the stress at that part, reduce the pulling force, and increase the resilience; however, this clamping arm 3a2 reduces its own fatigue resistance; if the opening 3a3 is not provided on the clamping arm 3a2, the pulling force required to pull the clamping arm 3a2 up to the central axis of the valve clamping device is relatively large, and the requirements for the control wire and the proximal handle are relatively high, which can easily lead to the breakage of the control wire. Summary of the invention

[0005] In view of this, the present invention provides a tissue clamp and a valve clamping device, which can not only improve the fatigue resistance of the tissue clamp but also reduce the stress of the tissue clamp when it is in a retracted state, so as to reduce the pulling force required to pull the tissue clamp to the retracted state and prevent the control wire from breaking.

[0006] In order to solve the above technical problems, the present invention provides a tissue clamping piece, which includes a connecting frame and two clamping arms, the connecting frame includes two connecting plates that are spaced apart and opposite to each other; the two clamping arms are respectively arranged on the opposite sides of the two connecting plates, each of the clamping arms extends to a side away from the other clamping arm, and each clamping arm includes a bending section connected to the corresponding connecting plate and a clamping section connected to the bending section away from the corresponding connecting plate, the width of the bending section is smaller than the width of the clamping section, and smaller than the width of the connecting plate.

[0007] The present invention also provides a valve clamping device, which includes a fixed seat, a pair of clamp arms that open and close relative to the fixed seat, and a tissue clamping piece, wherein the tissue clamping piece is arranged between the fixed seat and the clamp arms, and the two clamping arms of the tissue clamping piece respectively cooperate with one of the pair of clamp arms to clamp the valve leaflet.

[0008] Each clamping arm of the valve clamping device provided by the present invention has a bending section, and the width of the bending section is smaller than the width of the clamping section and smaller than the width of the connecting piece; thereby not only reducing the weight of the valve clamping device, facilitating the rebound of the clamping arm, reducing the difficulty of clamping, and improving the fatigue resistance of the tissue clamping piece, but also reducing the pulling force required to pull the clamping arm up to fit the central axis through the control wire, reducing the reverse force borne by the control wire, preventing the control wire from breaking, improving the fatigue resistance of the valve clamping device for long-term implantation in the human body, and improving the safety and effectiveness of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 This is a schematic diagram of the mitral valve in its normal state.

[0011] Figure 2 This is a schematic diagram of a mitral valve disease.

[0012] Figure 3 It is a schematic diagram of the three-dimensional structure of a tissue clamp in the prior art.

[0013] Figure 4 It is a schematic diagram of the three-dimensional structure of a valve clamping device provided in one embodiment of the present invention.

[0014] Figure 5 yes Figure 4 A schematic diagram of the three-dimensional structure of the tissue clamping member and the fixing seat of the valve clamping device.

[0015] Figure 6 yes Figure 5 Schematic diagram of the three-dimensional structure decomposition of the tissue clamp and the fixing seat.

[0016] Figure 7 yes Figure 6 Side view of the tissue clamp in FIG.

[0017] Figure 8 yes Figure 6 A top view of the tissue clamp in FIG.

[0018] Fig. 9 yes Figure 7 A schematic structural diagram of another embodiment of the tissue clamp in FIG.

[0019] Fig.10 yes Figure 5 A side view of the tissue clamp and the fixing seat in FIG.

[0020] Fig.11 yes Fig.10 Enlarged view of section XI.

[0021] Fig.12 yes Figure 4 Side view of the valve clipping device in.

[0022] Fig.13 yes Figure 4 A diagram showing one of the usage states of the valve clamping device.

[0023] Fig.14 It is a schematic structural diagram of a valve clamping device provided in yet another embodiment of the present invention.

[0024] Fig.15 yes Fig.14 Schematic diagram of the structure of the clamping arm of the valve clamping device.

[0025] Fig.16 It is a statistical chart of the results of fatigue testing of the valve clamping device of the present invention and performance testing of the tissue clamping member. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In addition, the following descriptions of the embodiments are with reference to the attached drawings to illustrate specific embodiments in which the present invention may be implemented. The directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for better and clearer description and understanding of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0028] In the description of the present invention, it should be noted that in the field of interventional medical devices, the proximal end refers to the end closer to the operator, while the distal end refers to the end farther from the operator; the axial direction refers to the direction parallel to the line connecting the distal center and the proximal center of the medical device in the natural state. The above definitions are only for the convenience of expression and cannot be understood as limitations of the present invention.

[0029] Please also read Figure 4-Figure 6The first embodiment of the present invention provides a valve clamping device 100, including a fixed seat 20, at least one pair of clamp arms 40 hinged to the fixed seat 20, a tissue clamping member 60 connected to the fixed seat 20, and a driving assembly 70 for driving the clamp arms 40 to open and close relative to the fixed seat 20; the pair of clamp arms 40 open and close relative to the fixed seat 20, the tissue clamping member 60 is arranged between the fixed seat 20 and the clamp arms 40 to cooperate with the clamp arms 40 to clamp the valve leaflet, and the tissue clamping member 60 includes a connecting frame 62 and two clamping arms 64. When in use, the proximal end of the valve clamping device 100 is releasably connected to the delivery device, and the two clamping arms 64 of the valve clamping device 100 are pulled up to the center axis of the fit through the control wire. The operator pushes the valve clamping device 100 to the patient's mitral valve, and then remotely operates the valve clamping device 100 so that the clamp arm 40 opens relative to the fixing seat 20. The tension of the control wire on the two clamping arms 64 is then released, and the anterior leaflet and the posterior leaflet of the mitral valve are clamped together by the clamp arm 40 and the corresponding clamp arm 64, respectively, so that the leaflets of the mitral valve are aligned edge to edge. The connection between the delivery device and the valve clamping device 100 is then released, and the valve clamping device 100 is left in the patient's body as an implant to keep the leaflets in the aligned position together, thereby achieving "edge-to-edge repair" of the mitral valve and alleviating the patient's mitral regurgitation.

[0030] It should be noted that the valve clamping device 100 and the delivery device can be delivered into the patient's body using existing guiding devices such as adjustable bending sheath tubes and shaping sheath tubes.

[0031] Specifically, the connecting frame 62 includes a base plate 621 and two connecting pieces 623 arranged on opposite sides of the base plate 621; two clamping arms 64 are respectively arranged on opposite sides of the two connecting pieces 623, and each clamping arm 64 extends to a side away from the other clamping arm 64; each clamping arm 64 includes a bending section 641 connected to the corresponding connecting piece 623 and a clamping section 643 connected to the bending section 641 away from the corresponding connecting piece 623, and the width of the bending section 641 is smaller than the width of the clamping section 643 and smaller than the width of the connecting piece 623; the two clamping arms 64 of the tissue clamp 60 respectively cooperate with one of the pair of forceps arms 40 to clamp the valve leaf 300 (such as Fig.13 As shown), the clamping section 643 of each clamping arm 64 cooperates with a clamp arm 40 to clamp a leaflet 300.

[0032] In the present invention, each clamping arm 64 of the valve clamping device 100 has a bending section 641, and the width of the bending section 641 is smaller than the width of the clamping section 643 and smaller than the width of the connecting piece 623; thereby, not only the weight of the valve clamping device 100 can be reduced, which is beneficial to the rebound of the clamping arm 64, reduces the difficulty of clamping, and improves the fatigue resistance of the tissue clamping member 60, but also the pulling force required to pull the clamping arm 64 up to fit the central axis through the control wire can be reduced, the reverse force borne by the control wire can be reduced, and the control wire can be prevented from breaking, which can improve the fatigue resistance of the valve clamping device 100 implanted in the human body for a long time, and improve the safety and effectiveness of the device.

[0033] like Figure 4 As shown, in this embodiment, the valve clamping device 100 includes a pair of clamp arms 40 arranged opposite to each other, and each clamp arm 40 can be opened and closed relative to the fixing seat 20. Each clamp arm 40 includes a connecting portion 42 and a clamp frame 44 connected to one end of the connecting portion 42 away from the fixing seat 20. The ends of the connecting portions 42 of the two clamp arms 40 away from the clamp frame 44 are stacked on each other and hinged to the fixing seat 20. A leaflet accommodating space is formed between the clamp arm 64 and the clamp arm 40. The surface of each clamp arm 40 facing the clamp arm 64 is inwardly recessed to form a receiving groove 45, so that when the valve clamping device 100 is in the transport state, the clamp arm 64 is at least partially accommodated in the receiving groove 45 of the clamp arm 40, so as to reduce the outer diameter and volume of the valve clamping device 100, which is convenient for in vivo transport. After the clamp arm 40 and the clamping arm 64 cooperate to clamp the leaflet 300, the leaflet 300 is clamped in the receiving groove 45 to increase the contact area between the clamp arm 40 and the leaflet 300, and enable the clamping arm 64 to press the leaflet 300 into the receiving groove 45 of the clamp arm 40, thereby increasing the clamping force on the leaflet 300.

[0034] Specifically, each clamp arm 40 includes a rectangular connecting plate 442 and side plates 444 disposed on opposite sides of the connecting plate 442, and the connecting plate 442 and the two side plates 444 enclose a receiving groove 45. The connecting plate 442 is provided with a plurality of material removal holes 446 along its length direction to reduce the weight of the clamp arm 40. One end of the side plate 444 adjacent to the fixing seat 20 is extended obliquely and hinged on the fixing seat 20 to form a connecting portion 42 of the clamp arm 40, and the connecting portion 42 is provided with a pin hole for inserting a pin.

[0035] The clamp arm 40 is opened and closed relative to the fixed seat 20 through the driving assembly 70. The driving assembly 70 includes a driving shaft 72 passing through the fixed seat 20, a connecting seat 74 disposed at the far end of the driving shaft 72, and a pair of connecting rods 76 movably connected to both sides of the connecting seat 74. One end of each connecting rod 76 is connected to a corresponding clamp arm 40, and the other end is connected to the connecting seat 74 by pivoting, that is, each clamp arm 40 is rotatably connected to the far end of the connecting seat 74 of the driving assembly 70 through the connecting rod 76 on the corresponding side. The driving shaft 72 movably passes through the fixed seat 20 and is connected to the connecting seat 74. When the driving shaft 72 slides axially relative to the fixed seat 20, the connecting seat 74 moves axially to rotate the connecting rod 76 and drive the clamp arm 40 to open and close relative to the fixed seat 20.

[0036] like Figure 6 As shown, the fixing seat 20 includes a rectangular fixing frame 21, a connecting block 22 disposed at the proximal end of the fixing frame 21, and bosses 23 disposed at opposite sides of the fixing frame 21. The fixing seat 20 is provided with a through hole 24 that penetrates the connecting block 22 and the fixing frame 21 in the axial direction, and the through hole 24 is used to insert the driving shaft 72. Pin holes 26 are respectively provided at opposite ends of the connecting block 22, and the axis center line of the pin hole 26 is perpendicular to the axis center line of the through hole 24. The pin hole 26 is used to connect with the connecting portion 42 of the clamp arm 40 through a pin. The fixing frame 21 is provided with a first contact curved surface 212 and a second contact curved surface 214 at opposite sides of the connecting block 22, wherein the first contact curved surface 212 is closer to the connecting block 22 than the second contact curved surface 214, and the curvature radius of the first contact curved surface 212 is K1, and the curvature radius of the second contact curved surface 214 is K2.

[0037] The tissue clamp 60 is at least partially made of shape memory material and is heat-set. The tissue clamp 60 has a natural expanded state and a collapsed state. When manufacturing, the shape memory material is first cut into a desired shape by laser cutting, and then placed in a mold and heat-set at about 550°C to give it a specific shape. Figure 7As shown, in the natural state, the clamping arms 64 on both sides of the tissue clamping member 60 extend radially outward relative to the connecting frame 62; preferably, the clamping arms 64 extend obliquely toward the distal end so as to cooperate with the clamp arms 40 to clamp the valve tissue, that is, the angle between the clamping arms 64 on both sides in the natural expanded state should be slightly larger than the angle between the two clamp arms 40 to provide a more stable clamping force, thereby ensuring that there is a certain clamping force between the clamp arms 64 and the clamp arms 40 to clamp the leaflets located therebetween; specifically, the angle a between the length direction of the clamping section 643 of each clamping arm 64 and the axial direction of the fixing seat 20 is larger than the angle between the clamp arm 40 corresponding to the clamp arm 64 and the axial direction of the fixing seat 20 when the clamp arm 40 corresponding to the clamp arm 64 is fully opened relative to the fixing seat 20, thereby making the free end of each clamp arm 64 and the corresponding clamp arm 40 close to each other and have a certain clamping force to provide a more stable clamping force. Specifically, in the natural state, the angle a between the length direction of the clamping section 643 and the axial direction of the fixing seat 20 has an angle range of 0-150 degrees, that is, the angle between the two clamping sections 643 can reach a maximum of 300 degrees, preferably 160-200 degrees. In this embodiment, the angle between the two clamping sections 643 is greater than 180 degrees.

[0038] In this embodiment, the tissue clamp 60 is made entirely of superelastic nickel-titanium alloy, thereby providing elastic force for the tissue clamp 60 to drive the clamp arm 64 to move toward the clamp arm 40 to clamp the valve tissue, thereby reducing the difficulty of the production process, simplifying the process flow, and reducing production costs.

[0039] In other embodiments, different parts of the clamping arm 64 can be made of different materials and then fixedly connected. For example, the clamping section 643 of the clamping arm 64 is made of stainless steel to improve the clamping force, and the bending section 641 should have a bending function to provide the tissue clamp 60 with a natural expansion state and a folded state that is convenient for transportation, so the bending section 641 is made of a shape memory material.

[0040] In this embodiment, each connecting piece 623 is connected to the corresponding bending section 641 through a bent fixing piece 625, and the fixing piece 625 on each connecting piece 623 is bent toward the other connecting piece 623, and each bending section 641 is bent away from the other bending section 641. Each connecting piece 623 is provided with a slot 6230 along its length direction, and the slot 6230 extends into the corresponding fixing piece 625, which is used to cooperate and fix with the fixing seat 20. The shape of the slot 6230 can be rectangular, elliptical, prismatic or other shapes. In this embodiment, a rectangle is preferred for higher matching stability. The substrate 621, the two connecting pieces 623 and the two fixing pieces 625 surround a connecting frame 62 with a proximal opening, and the fixing seat 20 is accommodated in the inner cavity of the connecting frame 62. The driving shaft 72 is inserted into the fixing seat 20 and the connecting frame 62 through the proximal opening of the connecting frame 62. Specifically, the substrate 621 is provided with a through hole 6210, and after the fixing seat 20 is accommodated in the inner cavity of the connection frame 62, the through hole 24 of the fixing seat 20 corresponds to the through hole 6210 of the substrate 621, and the drive shaft 72 is penetrated through the through hole 24 of the fixing seat 20 and the through hole 6210 of the substrate 621. It can be understood that the fixing sheet 625 should have a certain deformation ability so as to be clamped outside the fixing seat 20, so the fixing sheet 625 should be made of a shape memory material, and other parts of the connection frame 62 can be made of a harder material such as stainless steel, so as to improve the connection strength. That is, the fixing sheet 625 of the connection frame 62 and the bending section 641 connected thereto can be integrally formed with nickel-titanium alloy, and the substrate 621 and the connecting sheet 623 of the connection frame 62 are integrally formed with stainless steel and then welded or bonded to the fixing sheet 625, and each bending section 641 is then welded or bonded to the clamping section 643.

[0041] like Figure 6-Figure 8As shown, the bending section 641 includes a first end 6412 connected to the corresponding fixing plate 625, and a second end 6414 connected to the corresponding clamping section 643. The bending section 641 is a variable diameter structure, that is, the width of the bending section 641 at the first end 6412 is greater than the width of the bending section 641 at the second end 6414, and the width of the bending section 641 gradually decreases from the first end 6412 to the second end 6414. In this embodiment, the width of the first end 6412 of the bending section 641 is equal to the width of the fixing plate 625, the width of the second end 6414 of the bending section 641 is equal to the width of the clamping section 643, and the first end 6412 and the second end 6414 of the bending section 641 are smoothly transitioned. Since the valve clamping device 100 often needs to be opened and closed repeatedly and the valve leaflets are captured multiple times during the operation, if the rebound stress of the clamping arm 64 is too large, the pulling force of the control wire is required to be higher, which will increase the risk of the control wire breaking. The use of a variable diameter structure in the bending section 641 can effectively reduce the stress of the clamping arm 64 when it is in the retracted state, thereby reducing the risk of the control wire breaking. In addition, in the prior art, in order to reduce stress, a hole is opened in the middle of the bending section, but microcracks are prone to appear at the opening position, and microcracks are often difficult to observe. When the valve clamping device is implanted in the human body and subjected to stress for a long time, microcracks near the opening position are prone to fatigue fracture. Therefore, this embodiment reduces stress through a variable diameter structure, while avoiding the risk of fatigue fracture caused by the opening.

[0042] Preferably, the width ratio of the second end 6414 of the bending section 641 to the first end 6412 is in the range of 0.4-0.8; more preferably, the width ratio of the second end 6414 of the bending section 641 to the first end 6412 is in the range of 0.5-0.65. If the width ratio of the second end 6414 to the first end 6412 is too large, that is, the width of the second end 6414 is too large, the stress of the bending section 641 when the clamping arm 64 is in the retracted state is large, the required pulling force is large and the risk of the control wire breaking is high; if the width ratio of the second end 6414 to the first end 6412 is too small, that is, the width of the second end 6414 is too small, it will affect the clamping force of the clamping arm 64 on the tissue, causing the clamping device 100 to slip easily.

[0043] like Figure 5-Figure 8 As shown, the clamping section 643 of each clamping arm 64 is provided with at least one row of barbs 6433 along its length direction, and the end of each barb 6433 is rounded to avoid piercing the leaflet. Specifically, the clamping section 643 includes a clamping piece 6431 connected to the second end 6414 of the bending section 641, and two barbs 6433 connected to both sides of the clamping piece 6431. In this embodiment, the number of barbs 6433 on each side of the clamping piece 6431 is four.

[0044] Each barb 6433 has an angle with the clamping piece 6431, and the angle range is 30 degrees to 85 degrees, preferably 45 degrees to 65 degrees. Too large or too small an angle will increase the difficulty of capturing the leaflet. The angle A between each barb 6433 and the clamping piece 6431 can be the same or different. In this embodiment, the angle A between each barb 6433 and the clamping piece 6431 is 60 degrees.

[0045] The effective length of each barb 6433 ranges from 0.3 mm to 2.0 mm, preferably from 0.5 mm to 1.2 mm. The effective lengths of the barbs 6433 can be the same or different. In this embodiment, the extension lengths of the barbs in each row of barbs 6433 are the same; specifically, the four barbs 6433 of the same barb on each side of the clamping sheet 6431, the effective lengths from one end of the adjacent bending section 641 to the end are L1, L2, L3, L4, respectively, and L1 = L2 = L3 = L4; in this embodiment, the effective lengths of L1, L2, L3, L4 are all 0.8 mm.

[0046] like Fig. 9 As shown, in another embodiment of the tissue clamp 60, the angle between the barbs in at least one row of barbs 6433 of each clamping section 643 and the corresponding clamping section 643 gradually increases along the extension direction of the clamping arm, and the effective length of the barbs 6433 from one end of the adjacent bending section 641 to the end also gradually increases. Specifically, the number of barbs 6433 in each row is four, and the angles between the barbs 6433 and the clamping section 643 from one end of the adjacent bending section 641 to the end are A1, A2, A3, A4, respectively, and A1≤A2≤A3≤A4; the effective lengths of the barbs 6433 from one end of the adjacent bending section 641 to the end are L1, L2, L3, L4, respectively, and L1≤L2≤L3≤L4. In this embodiment, the angle of A1 is 45 degrees, the angle of A2 is 50 degrees, the angle of A3 is 55 degrees, and the angle of A4 is 60 degrees; the effective length of L1 is 0.4 mm, the effective length of L2 is 0.8 mm, the effective length of L3 is 1.0 mm, and the effective length of L4 is 1.2 mm. The reason for this arrangement is that the thickness of the leaflets is uneven, the leaflets are thinnest at the edge, and the thickness gradually increases to the point where the leaflets are connected to the valve ring. According to the anatomical structure of the leaflets that gradually thicken from the edge to the middle of the leaflet, in order to ensure that the force depth of each barb 6433 at different contact positions with the leaflet tissue is roughly the same, to ensure the clamping force of the clamping section 643 on the leaflet, and not to pierce the leaflet, the angle of the barb 6433 is adjusted to adapt to the force depth of leaflet tissues with different thicknesses.

[0047] like Figure 8As shown, the ratio of the width D1 of the clamping section 643 (width D1=width of the clamping piece 6431+width of the barbs 6433 on both sides), the width D2 of the second end 6414 of the bending section 641, and the width D3 of the fixing piece 625 is in the range of (1.5-2):1:(1.5-2), that is, D1:D2:D3=(1.5-2):1:(1.5-2). In this embodiment, the width D1 of the clamping section 643: the width D2 of the second end 6414 of the bending section 641: the width D3 of the fixing piece 625=1.5:1:1.5. If the width of D2 is too narrow, the fatigue resistance and tensile strength of the valve clamping device 100 will be reduced; if D2 is too wide, it means that the weight of the valve clamping device 100 increases, which will cause the valve clamping device 100 to fall under the valve for a long time after implantation, which is not only easy to slip off, but may also tear the target tissue or even cause heart dysfunction; and, since the tissue clamp 60 is made of shape memory alloy, if D2 is too wide, the valve leaflets compressed by the bent section 641 will be subjected to greater pressure during the expansion and contraction of the heart, thereby causing excessive tissue damage.

[0048] like Fig.10 and Fig.11 As shown, the distal end of the fixing plate 625 is connected to the connecting frame 62, and the proximal end of the fixing plate 625 is connected to the bending section 641. The fixing plate 625 is used to realize the mutual interlocking and fixing of the tissue clamp 60 and the fixing seat 20, so as to prevent the tissue clamp 60 from being relatively displaced or loosened with the fixing seat 20 under the unilateral relay action of the control wire, thereby ensuring the reliability of the tissue clamp 60 in the process of capturing the valve.

[0049] In this embodiment, the fixing piece 625 includes a first snap-fit ​​position 6251 and a second snap-fit ​​position 6253. The first snap-fit ​​position 6251 is to prevent the connection frame 62 from moving up and down after being matched with the fixing seat 20, that is, it plays a role of near-far limit; the second snap-fit ​​position 6253 is to prevent the connection frame 62 from moving left and right after being matched with the fixing seat 20, that is, it plays a role of left and right limit. The curvature radius of the proximal part of the fixing seat 20 is greater than the curvature radius of the fixing piece 625. Specifically, the first snap-fit ​​position 6251 is a curved piece corresponding to the first contact curved surface 212 of the fixing seat 20, and the second snap-fit ​​position 6523 is a curved piece corresponding to the second contact curved surface 214 of the fixing seat 20, wherein the curvature radius of the first snap-fit ​​position 6251 is K3, and the curvature radius of the second snap-fit ​​position 6523 is K4. The curvature radius K3 of the first snap-fitting position 6251 is larger than the curvature radius K1 of the first contact surface 212 of the fixing seat 20, and the curvature radius K4 of the second snap-fitting position 6253 is smaller than the curvature radius K2 of the second contact surface 212 of the fixing seat 20, so that a first avoidance position P1 is reserved between the first contact surface 212 and the first snap-fitting position 6251, and a second avoidance position P2 is reserved between the second contact surface 214 and the second snap-fitting position 6523, and the contact point between the fixing plate 625 and the fixing frame 21 is just set between the first avoidance position P1 and the second avoidance position P2 to prevent interference in the connection between the fixing plate 625 and the fixing seat 20, thereby ensuring the stability of the first snap-fitting position 6251, that is, ensuring the stability of the proximal and distal limit.

[0050] like Figure 5 and Figure 6 As shown, when the fixing seat 20 is accommodated in the connecting frame 62, the two bosses 23 of the fixing seat 20 are respectively inserted into the two slots 6230 of the tissue clamping member 60, so that the fixing seat 20 and the tissue clamping member 60 are interlocked to prevent the tissue clamping member 60 and the fixing seat 20 from moving forward and backward, that is, playing the role of front and rear limiting.

[0051] To ensure safety after implantation, the fixing seat 20 and the clamp arm 40 are respectively made of biocompatible metal materials such as stainless steel, cobalt alloy, cobalt-chromium alloy, titanium alloy or nickel-titanium alloy; the driving component 70 is made of biocompatible polymer materials or metal materials such as polyester, silicone resin, stainless steel, cobalt alloy, cobalt-chromium alloy or titanium alloy. In this embodiment, the fixing seat 20, the clamp arm 40 and the driving component 70 are all made of stainless steel.

[0052] like Fig.12As shown, when the driving assembly 70 drives the clamp arm 40 to open and close relative to the fixing seat 20, the clamp arm 40 can be opened and closed within a large range relative to the fixing seat 20, and the angle between the two clamp arms 40 can reach a maximum of 300 degrees, that is, after the clamp arm 40 is opened relative to the fixing seat 20, it can be turned downward to a certain extent, which is conducive to clamping the valve in motion and improving the clamping success rate. If the clamping effect is not ideal, the valve leaflet can be loosened by turning the clamp arm 40 downward and re-clamping. In this embodiment, the angle between the two clamp arms 40 is preferably in the range of 0-240 degrees, and more preferably 120-180 degrees.

[0053] Preferably, an anti-slip structure (not shown) may be provided on the surface of the clamp arm 40 facing the clamping section 643 to enhance the friction force when the clamp arm 40 contacts the leaflet 300, thereby providing a stable clamping force and preventing the clamp arm 40 from causing damage to the leaflet 300. The anti-slip structure may be a protrusion or a groove provided on the inner surface of the receiving groove 45 of the clamp frame 44, or a gasket made of a biocompatible material with a high friction coefficient and attached to the inner surface of the receiving groove 45.

[0054] Preferably, active drugs may be applied to the inner surface of the receiving groove 45 of the clamp arm 40 and / or each clamping segment 643 to promote the endothelial cell crawling and growth of the valve tissue on the inner surface of the clamp arm 40 and the clamping arm 64 .

[0055] It should be noted that the two clamping sections 643 of the tissue clamping member 60 are also respectively provided with control wires, and the clamping section 643 can be pulled up to fit the central axis by pulling or loosening the control wires, so as to facilitate transportation; or the tension on the clamping section 643 is released so that the clamping arm 64 rebounds and restores its natural state due to its own elastic memory performance, and the clamping section 643 is unfolded relative to the fixing seat 20 to press the leaflet 300 toward the clamp arm 40 to clamp the leaflet 300. Specifically, the control wire can be a metal wire made of nickel-titanium alloy or the like, which is irrelevant to the improvement and creation of the present invention and is not described in detail here.

[0056] The following takes the mitral valve repair process as an example to illustrate the operation method of the valve clipping device of the present invention, which mainly includes the following steps:

[0057] The first step is to detachably connect the valve clamping device 100 to the distal end of the delivery device, and tighten the control wire toward the proximal end to control the clamping arm 64 to be retracted relative to the fixing seat 20, so that the clamping section 643 of the clamping arm 64 is attached to the surface of the fixing seat 20. Then, the driving shaft 72 is moved toward the proximal end to drive the connecting rod 76 to drive the clamp arm 40 to close relative to the fixing seat 20, so that the valve clamping device 100 is in a completely retracted state, and the tissue clamping member 60 and the clamp arm 40 are close to the surface of the fixing seat 20, and the retracted state remains unchanged.

[0058] Step 2: Femoral vein puncture, using the trans-septal approach, the distal end of the delivery device and the valve clamping device 100 are pushed from the left atrium through the adjustable curved sheath, through the mitral valve to the left ventricle.

[0059] Step 3: Adjust the relative position of the valve clamping device 100 and the mitral valve so that the valve clamping device 100 is close to the anterior leaflet and the posterior leaflet of the mitral valve.

[0060] Step 4: Move the drive shaft 72 toward the distal end, thereby driving the connecting rod 76 to drive the clamp arm 40 to open relative to the fixing seat 20.

[0061] Step 5: withdraw the entire valve clamping device 100 toward the proximal end, so that the forceps arm 40 holds the valve leaflet on the left ventricle side.

[0062] Step 6: Release the control of each control wire on the corresponding clamping arm 64 to release the clamping arms 64 on both sides. The clamping arm 64 on each side presses the valve leaflet 300 on the atrial side and cooperates with the clamp arm 40 on that side to clamp the valve leaflet (such as Fig.13 shown).

[0063] Step 7: Move the drive shaft 72 toward the proximal end, and the drive shaft 72 drives the connecting rod to drive the clamp arm 40 to close relative to the fixing seat 20 until the valve clamping device 100 is completely retracted.

[0064] Step 9: Release the connection between the valve clamping device 100, the delivery device and the control wire, and withdraw the delivery device and the control wire from the patient's body. At this time, the valve clamping device 100 pulls the anterior leaflet and the posterior leaflet of the mitral valve toward each other to obtain a double-pore mitral valve, completing the edge-to-edge repair of the mitral valve, and the valve clamping device 100 remains in the patient's body.

[0065] See also Fig.14 and Fig.15 The structure 100a of the valve clamping device provided in the second embodiment of the present invention is similar to the structure of the valve clamping device 100 in the first embodiment, except that the structure of the clamping arm 64a in the second embodiment is slightly different from the structure of the clamping arm 64 in the first embodiment. Specifically, a bending portion 645 is provided between the clamping section 643 of each clamping arm 64a and the corresponding bending section 641, and the bending portion 645 is bent toward the side away from the connecting frame 62, so that the clamping section 643 of the clamping arm 64 of the valve clamping device 100a is roughly parallel to the clamping frame 44 of the clamp arm 40 in the natural state. As a result, when the clamping arm 64a captures the valve leaflet, the gap between the barb 6433 and the clamping frame 44 of the clamp arm 40 is relatively uniform, and the barb 6433 can synchronously contact the valve leaflet 300 to improve the success rate and stability of capturing the valve leaflet 300.

[0066] The tissue clamps were subjected to performance tests and the valve clamping devices were subjected to fatigue tests.

[0067] Tissue clamp performance test

[0068] The same nickel-titanium alloy material and manufacturing process are used to make three groups of clamping arms, wherein the first group is the tissue clamping member ( Fig.16 The second group is the tissue clamping member with constant diameter (equal diameter and equal width) in the prior art ( Fig.16 The third group is a tissue clamp having equal width and constant diameter formed by laser cutting on the tissue clamp of equal width in the prior art ( Fig.16 The following performance tests were performed on several groups of tissue clamps, and the test results are shown in FIG. Fig.16 shown.

[0069] 1. Tissue clamp fatigue test

[0070] The fatigue resistance of the tissue clamp itself is tested using the AWT-1000 artificial heart valve fatigue resistance tester of Shanghai Heart Valve Testing Equipment Co., Ltd. The tissue clamp is tested to see if it breaks or cracks due to load during the fatigue test cycle. The test results are as follows: Fig.16 shown.

[0071] The fatigue test parameters are as follows: cyclic tension (peak): 0.80N±0.30N, amplitude: 1mm, frequency: 50Hz, water bath temperature: 37℃±0.5℃, cycle: ≥400 million times.

[0072] 2. Test of the closing force of the control wire on the tissue clamp

[0073] Test the closing force of the same control wire on three groups of tissue clamps. The test equipment is the HY-0580 electronic universal tensile testing machine produced by Shanghai Hengyi Precision Instrument Co., Ltd. The test method is as follows: Connect the valve clamping device to the simple handle, and use two U-shaped control wires to pass through the control holes at the two free ends of each clamping arm. The control wires pass through the proximal end of the simple handle, and fix the simple handle on the table of the tensile machine. The moving end of the tensile machine hooks the proximal end of the control wire, and moves the moving end at a uniform speed of 4.5mm / min. Record the force value when the tissue clamps are closed until the clamping sections on both sides are basically parallel. The test results are as follows. Fig.16 shown.

[0074] 3. Test of fatigue resistance of control wire

[0075] The fatigue resistance of the control wires of three groups of tissue clamps was tested. The test equipment is the HY-0580 electronic universal tensile testing machine produced by Shanghai Hengyi Precision Instrument Co., Ltd. The test method is as follows: Connect the valve clamping device to the simple handle, and use two U-shaped control wires to pass through the control holes at the two free ends of each clamping arm. The control wires pass through the proximal end of the simple handle, and fix the simple handle on the machine table of the tensile machine. The moving end of the tensile machine hooks the proximal end of the control wire, and repeats the action of the tissue clamps being retracted and released under the control of the control wire. The test number is 50 times. Observe the control wire after the test. If any of the scratches, wear, cracks, and breaks are found, it is judged as failing the test. The test results are as follows: Fig.16 shown.

[0076] from Fig.16 The test results shown show that:

[0077] 1). The present invention can effectively reduce the closing force required to control the closing of the tissue clamp by providing a variable diameter structure on the tissue clamp, thereby ensuring the fatigue resistance of both the control wire and the tissue clamp itself;

[0078] 2) The tissue clamp of the prior art is not provided with a variable diameter structure, and the amount of retraction required to control the retraction of the tissue clamp is significantly larger. Although the fatigue resistance of the tissue clamp itself can be guaranteed, the fatigue resistance of the control wire cannot be guaranteed;

[0079] 3). The tissue clamp of the prior art has an opening, which can reduce the closing force required to control the closing of the tissue clamp and ensure the fatigue resistance of the control wire, but cannot ensure the fatigue resistance of the tissue clamp itself.

[0080] In summary, compared with the prior art, the tissue clamp of the present invention has better fatigue resistance, requires smaller pulling force and retracting force, and has a lower risk of breakage of the control wire.

[0081] Fatigue testing of valve clip devices

[0082] Fatigue testing is used to verify whether the valve clamping device using the tissue clamp of the present invention can meet the load requirements of 10 years of implantation as a medical device implant after clamping the two leaflets of the mitral valve. Before the test, the artificial mitral valve model is first fixed with the valve clamping device to simulate the edge-to-edge treatment effect, and then the mitral valve model with the valve clamping device is placed in a fatigue testing machine that simulates the beating of the left heart system of the human heart, and a non-destructive fatigue test is performed to record the sliding of the valve clamping device caused by the load and the damage to the leaflets during the fatigue test cycle.

[0083] Testing equipment: AWT-1000 artificial heart valve fatigue resistance testing machine produced by Shanghai Heart Valve Testing Equipment Co., Ltd.

[0084] Test standard: Tested in accordance with the "fatigue test" method in ISO 5840 and GB12279-2008 "Cardiovascular Implant Artificial Heart Valves", cycle: ≥ 400 million times. The test results show that the valve clamping device of this embodiment meets the relevant requirements, the valve clamping device did not slide during the test cycle, and the valve clamping device did not cause damage to the valve leaflets.

[0085] It should be noted that the above contents are all described by taking the valve clamping device for alleviating or treating "mitral valve regurgitation" as an example. It is understandable that in other embodiments, the valve clamping device can also be used to alleviate or treat "tricuspid valve regurgitation", and its principle and structure are roughly the same as the principle and structure of the valve clamping device for solving "mitral valve regurgitation" in the embodiment of the present invention, and it only needs to form multiple clamps through multiple groups of proximal clips and distal clips, and each clamp clamps a valve leaflet respectively, which will not be described in detail here.

[0086] The above is an implementation of the embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the embodiment of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A tissue clamp, characterized in that: include: A connecting frame, the connecting frame comprising two connecting pieces spaced apart and facing each other; Two clamping arms are respectively arranged on opposite sides of the two connecting pieces, each clamping arm extends to a side away from the other clamping arm, each clamping arm includes a bending section connected to the corresponding connecting piece, and a clamping section connected to the bending section and away from the corresponding connecting piece, the width of the bending section is smaller than the width of the clamping section, and smaller than the width of the connecting piece.

2. The tissue clamp according to claim 1, characterized in that: The bending section includes a first end connected to the corresponding connecting piece, and a second end connected to the corresponding clamping section, and the width of the bending section at the first end is greater than the width of the bending section at the second end.

3. The tissue clamp according to claim 2, characterized in that: The width of the bending section gradually decreases from the first end toward the second end.

4. The tissue clamp according to claim 1, characterized in that: Each of the connecting pieces is connected to the corresponding bending section via a bent fixing piece. The fixing piece on each of the connecting pieces is bent toward the other connecting piece, and each of the bending sections is bent away from the other bending section.

5. The tissue clamp according to claim 4, characterized in that: The bending section includes a first end connected to the corresponding fixing plate, and a second end connected to the corresponding clamping section. The width of the first end of the bending section is equal to the width of the fixing plate, and the width of the second end of the bending section is equal to the width of at least a portion of the clamping section. There is a smooth transition between the first end and the second end of the bending section.

6. The tissue clamp according to claim 1, characterized in that: The clamping section of each clamping arm comprises a main body portion and at least one row of barbs arranged along the length direction of the main body portion, and the end of each barb is configured as a rounded corner.

7. The tissue clamp according to claim 6, characterized in that: The extension length of the barbs in the at least one row of barbs gradually increases along the extension direction of the clamping arm, and the angle between the barbs in the at least one row of barbs and the corresponding clamping segments gradually increases along the extension direction of the clamping arm.

8. The tissue clamp according to claim 1, characterized in that: The tissue clamp is at least partially made of shape memory material and has a natural unfolded state and a folded state. In the natural state of the tissue clamp, the angle between the clamping sections of the two clamping arms is greater than 180 degrees.

9. A valve clamping device, characterized in that: It includes a fixing seat, a pair of clamp arms that open and close relative to the fixing seat, and the tissue clamp as described in claim 1, wherein the tissue clamp is arranged between the fixing seat and the clamp arms, and the two clamp arms of the tissue clamp respectively cooperate with one of the pair of clamp arms to clamp the valve leaflet.

10. The valve clamping device according to claim 9, characterized in that: The fixing seat is accommodated in the connecting frame, at least one connecting piece of the connecting frame is provided with a slot, and the fixing seat is provided with a protrusion buckled in the slot.

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