CN111671547B

CN111671547B - Valve clamp with covering film and valve clamp system

Info

Publication number: CN111671547B
Application number: CN201910706071.6A
Authority: CN
Inventors: 张庭超; 张伟伟; 郑贤章; 王泽涛
Original assignee: Hangzhou Valgen Medtech Co Ltd
Current assignee: Hangzhou Valgen Medtech Co Ltd
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2025-01-17
Anticipated expiration: 2039-07-31
Also published as: CN111671547A

Abstract

The invention provides a valve clamping system, which comprises a pushing device and a valve clamp with a covering film. The valve clip includes a pushrod, a covering membrane, and proximal and distal clips radiating away from the pushrod. The distal clamping piece is connected to the push rod, the proximal clamping piece is arranged between the push rod and the distal clamping piece, a valve accommodating space is formed between the proximal clamping piece and the distal clamping piece, the push rod can drive the distal clamping piece to radiate and spread, and the proximal clamping piece approaches the distal clamping piece after being spread elastically by the push rod so as to clamp valve tissues in the valve accommodating space. The cover film comprises a first cover film covering at least one side of the proximal clip facing the valve accommodating space and/or a second cover film covering at least one side of the distal clip facing the valve accommodating space. The invention also provides a valve clip with a covering film. The present invention can reduce or avoid damaging the clamped valve tissue by covering at least a portion of the surface of the proximal clip and/or the distal clip with a coating.

Description

Valve clamp with covering film and valve clamp system

Technical Field

The invention relates to the field of medical instruments, in particular to a valve clamp with a tectorial membrane and a valve clamping system.

Background

Referring to fig. 1, mitral valve 1 is a one-way valve between left atrium 2 and left ventricle 3 of the heart, and a normally healthy mitral valve 1 can control blood flow from left atrium 2 to left ventricle 3 while avoiding blood flow from left ventricle 3 to left atrium 2. The mitral valve 1 includes a pair of leaflets, called anterior leaflet 1a and posterior leaflet 1b. Anterior leaflet 1a and posterior leaflet 1b are anchored to the papillary muscles of left ventricle 3 by chordae tendineae 4. Normally, when the left ventricle of the heart contracts, the edges of the anterior leaflet 1a and the posterior leaflet 1b are completely coaptated, avoiding blood flow from the left ventricle 3 to the left atrium 2. Referring to fig. 2, when the leaflets of the mitral valve or their associated structures are organically or functionally changed, such as the chordae tendineae 4 are partially ruptured, the anterior leaflet 1a and the posterior leaflet 1b of the mitral valve 1 are poorly coaptated, whereby, when the left ventricle 3 of the heart contracts, the mitral valve 1 cannot be fully closed, resulting in blood regurgitation from the left ventricle 3 to the left atrium 2, thereby causing a series of pathophysiological changes, called "mitral regurgitation".

The existing minimally invasive treatment surgery is characterized in that the valve She Gaqian is conveyed to the mitral valve through a conveying device, and then the front leaf and the rear leaf of the mitral valve are clamped simultaneously through the relative opening and closing of the clamp, so that the front leaf and the rear leaf of the mitral valve are fixed, and the purposes of reducing the gap between the valve leaves and reducing the mitral regurgitation are achieved. However, in the prior art, the distal and proximal jaws of the clip are both made of a metallic material, which may cause tissue allergy or inflammatory reactions, and sharp edges of the metal may cause pinching or scoring of the leaflets, resulting in mitral valve symptoms.

Disclosure of Invention

In view of this, the present invention provides a valve clamp and valve clamping system that reduces or avoids damage to valve tissue.

In order to solve the technical problems, the invention provides a valve clamp with a covering film, which comprises a push rod, the covering film, a proximal clamping piece and a distal clamping piece, wherein the proximal clamping piece and the distal clamping piece are unfolded in a radiation manner relative to the push rod, the distal clamping piece is connected to the push rod, the proximal clamping piece is arranged between the push rod and the distal clamping piece, a valve accommodating space is formed between the proximal clamping piece and the distal clamping piece, the push rod can drive the distal clamping piece to be unfolded in a radiation manner, the proximal clamping piece is folded close to the distal clamping piece after being unfolded by self elasticity so as to clamp valve tissues in the valve accommodating space, and the covering film comprises a first covering film covering at least one side surface of the proximal clamping piece facing the valve accommodating space and/or a second covering film covering at least one side surface of the distal clamping piece facing the valve accommodating space.

The invention also provides a valve clamping system which comprises a pushing device and the valve clamping device, wherein the pushing device comprises an operating handle and a pushing assembly, the proximal end of the pushing assembly is connected with the operating handle, and the distal end of the pushing assembly is detachably connected with the valve clamping device.

According to the valve clamp and the valve clamp system, the covering film is arranged on at least part of the surfaces of the proximal clamping piece and/or the distal clamping piece of the valve clamp, so that at least part of the metal surfaces and/or the sharp edges of the proximal clamping piece and/or the distal clamping piece can be wrapped, and at least part of the metal surfaces and/or the sharp edges of the valve clamp can be prevented from being in direct contact with valve tissues clamped in the valve accommodating space, so that tissue allergy and inflammatory reaction are reduced or avoided, and damage to the clamped valve tissues is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a mitral valve in a normal state.

Fig. 2 is a schematic illustration of a mitral valve with lesions.

Fig. 3 is a schematic view of a valve clip according to one embodiment of the present invention in an open position.

Fig. 4 is a schematic view of the valve clamp of fig. 3 in a closed state.

Fig. 5 is a schematic view of the valve clip of fig. 3 without a covering membrane.

Fig. 6 is a schematic diagram of the structure of another view of fig. 5.

Fig. 7 is a schematic view of the valve clamp of fig. 4 without a covering membrane.

Fig. 8 is an enlarged schematic view of the portion VIII in fig. 6.

Fig. 9 is an exploded view of the stationary base of fig. 6.

Fig. 10 is a schematic view of the structure of the proximal clip of fig. 6.

Fig. 11 is a schematic view of the proximal clip of fig. 10 covering a first coating.

Fig. 12 is a schematic view of the distal clip of the valve clamp of fig. 3 as it rests under the leaflets.

Fig. 13 is a schematic view of the proximal clip of the valve clamp of fig. 3 closing the distal clip to clamp the valve.

Fig. 14 is a schematic view of the valve clamp of fig. 3 in position in use.

Fig. 15 is a schematic view of the mitral valve of fig. 14 after the valve holder has gripped the leaflets, with the heart contracted.

Fig. 16 is a schematic view of the mitral valve at diastole after the valve clamp of fig. 14 clamps the leaflets.

Fig. 17 is a schematic view of a portion of a valve clasper system in accordance with one embodiment of the present invention.

Fig. 18 is a schematic cross-sectional view of fig. 17.

Fig. 19 is a schematic view of a valve clip according to another embodiment of the present invention in an expanded state.

Fig. 20 is a schematic view of the valve clamp of fig. 19 in an uncoated state.

Fig. 21 is a schematic view of the valve clamp of fig. 19 with the distal clip flipped over.

Fig. 22 is a schematic view of a valve clip according to another embodiment of the present invention in an expanded state.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the positional or positional relationship indicated by the terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the positional or positional relationship shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "coupled," and the like are to be construed broadly, and may be fixedly connected, detachably connected, or integrally connected, or may be directly connected or indirectly connected via an intermediate medium, for example. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

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, the distal end refers to the end farther from the operator, and the axial direction refers to the direction parallel to the line connecting the distal center and the proximal center of the medical device.

Referring to fig. 3-5, the present invention provides a valve clip 100 comprising an axially extending pushrod 10, a proximal clip 21, a distal clip 23, and a covering membrane 30. The proximal clamping piece 21 and the distal clamping piece 23 are radially unfolded relative to the push rod 10, the distal end of the distal clamping piece 23 is connected to the push rod 10, the proximal clamping piece 21 is arranged between the push rod 10 and the distal clamping piece 23, a valve accommodating space 25 is formed between the proximal clamping piece 21 and the distal clamping piece 23, the push rod 10 can drive the distal clamping piece 23 to be radially unfolded, and the proximal clamping piece 21 is close relative to the distal clamping piece 23 due to elasticity of the proximal clamping piece 21 so as to clamp valve tissues in the valve accommodating space 25. The cover 30 comprises a first cover 31 covering at least a side of the proximal clip 21 facing the valve accommodation space 25 and/or a second cover 32 covering at least a side of the distal clip 23 facing the valve accommodation space 25.

Wherein a set of proximal 21 and distal 23 jaws respectively form a clamp 20.

To ensure safety after implantation, the proximal clip 21 and the distal clip 23 are made of biocompatible metal materials selected from commonly used implant metal materials such as stainless steel, cobalt alloy, cobalt chromium alloy, titanium alloy, or nickel titanium alloy. Wherein the proximal clip 21 is made of an elastic material with shape memory function, and the distal clip 23 is made of a rigid material to ensure that the two cooperate to clamp and secure valve tissue. In this embodiment, the proximal clip 21 is made of a nickel-titanium alloy having superelasticity, and the distal clip 23 is made of stainless steel or cobalt-chromium alloy having higher hardness.

Preferably, the first covering film 31 extends to cover the edge of the proximal clip 21, the second covering film 32 extends to cover the edge of the distal clip 23, the coverage rate of the first covering film 31 to the proximal clip 21 ranges from 50% to 90%, and the coverage rate of the second covering film 32 to the distal clip 23 ranges from 40% to 80%, so as to avoid damage to valve tissue by the edges of the proximal clip 21 and the distal clip 23.

In the present invention, by providing the first coating 31 and/or the second coating 32 on at least a portion of the surface of the proximal clip 21 and/or the distal clip 23 of the clamp 20, at least a portion of the metal surface and/or the sharp metal edge of the proximal clip 21 and/or the distal clip 23 can be wrapped to prevent at least a portion of the metal surface and/or the sharp metal edge of the clamp 20 from directly contacting valve tissue held in the valve receiving space 25, thereby reducing or avoiding tissue allergy, inflammatory reaction, and damage to the held valve tissue.

Specifically, referring to fig. 6 to 8, the push rod 10 is a rod-shaped body or a tubular body. In this embodiment, the push rod 10 is a round rod body, the proximal end of the outer circumferential surface of the push rod 10 is circumferentially provided with a ring groove 11, and the proximal end surface of the push rod 10 is also axially provided with an internal threaded hole 13. The distal end of the push rod 10 is provided with a connecting seat 15, and the connecting seat 15 comprises two opposite first planes and a side surface connecting the two first planes. The two opposite first planes are provided with through pin holes. The side surface comprises a curved surface at the distal end and a second plane at the proximal end and connected with the curved surface, the distal end of the push rod 10 is vertically fixed on the second plane, and the area of the second plane is larger than the cross-sectional area of the push rod 10. The cross-sectional dimension of the connecting seat 15 parallel to the second plane direction gradually decreases from the proximal end to the distal end, i.e. the shape of the connecting seat 15 may be a hemisphere, a spherical cap, a bullet-shaped structure, etc., so that the valve clamp 100 is easier to advance in the body.

The outer surfaces of the push rod 10 and the connecting seat 15 are smooth, so as to avoid damage to the valve leaflet or hooking of the chordae tendineae.

The push rod 10 and the connecting seat 15 are made of biocompatible materials such as stainless steel, cobalt alloy, cobalt-chromium alloy or titanium alloy, preferably stainless steel or cobalt-chromium alloy.

Further, referring to fig. 6, 7 and 9, the valve clip 100 further includes a fixing base 40, and the fixing base 40 includes a first seat 41 and a second seat 42 connected to a distal end of the first seat 41. The first and second housings 41 and 42 may be integrally or non-integrally formed. In this embodiment, the first seat 41 and the second seat 42 are integrally formed.

In this embodiment, the first seat 41 is a circular tube with two open ends, and the push rod 10 is disposed in the lumen of the first seat 41. The outer wall of the first seat 41 near the distal end is provided with an opening 411, a spring piece 413 is arranged in the opening 411, the spring piece 413 comprises a connecting end and a free end opposite to the connecting end, the connecting end is connected to the edge of the proximal end of the opening 411, and the free end extends to the inner cavity of the circular tube body. That is, in a natural state, the free end of the elastic piece 413 is inclined toward the inside of the lumen of the first seat 41 relative to the connecting end. The proximal end of the first housing 41 is provided with a connection 415, the connection 415 being for connection with a pushing device pushing the valve clamp 100 to the heart valve. In this embodiment, the connection portion 415 is at least one pair of T-shaped grooves formed on the outer wall of the first base 41, and preferably, the at least one pair of T-shaped grooves are symmetrically disposed with respect to the axis of the first base 41, and each T-shaped groove includes a first groove section and a second groove section perpendicularly intersecting the first groove section. The second groove section is located at the distal end of the first groove section, the extending direction of the first groove section is the same as the axial direction of the first seat 41, and the proximal end of the first groove section penetrates through the proximal end face of the first seat 41.

In this embodiment, the second base 42 includes two clamping plates 421 with opposite intervals, and the two clamping plates 421 are connected by two connecting rods 423. The two connecting rods 423 are arranged at intervals, the two connecting rods 423 and the two clamping plates 421 enclose a penetrating channel 425, the penetrating channel 425 corresponds to the pipe cavity of the first seat body 41, and the push rod 10 can be inserted into the pipe cavity of the penetrating channel 425 and the pipe cavity of the first seat body 41 and can axially move. Further, fixing holes 427 are formed at two opposite ends of the two clamping plates 421.

The through channel 425 may be a square channel or a circular channel. In this embodiment, the through-channel 425 is a square channel.

It should be understood that only one embodiment of the fixing base 40 is shown here, and in fact, the fixing base 40 may have other structures, which are not described here.

Referring to fig. 5 and 10, the proximal clip 21 includes a connecting end 211 and a free end 212 disposed opposite to each other, and the connecting end 211 is fixed on the fixing base 40. In this embodiment, the connection ends 211 of the two proximal clamping pieces 21 are integrally connected through the connection piece 213, the connection piece 213 is provided with a through hole, the middle of the connection piece 213 is fixedly connected to the connection position of the first seat 41 and the second seat 42, so as to fix the connection ends 211 of the two proximal clamping pieces 21 to the fixing base 40, and the through hole of the connection piece 213 corresponds to the inner cavity of the first seat 41. It should be appreciated that in other embodiments, the connection end 211 of the proximal clip 21 may be directly fixed to the connection between the first housing 41 and the second housing 42.

Wherein the proximal clip 21 is at least partially made of an elastic material having a shape memory function. The proximal clip 21 is formed in a unfolded U-shape in a natural state by heat setting, i.e., the proximal clip 21 is disposed at an angle to the pushrod 10 so as to cooperate with the distal clip 23 to clamp valve tissue. The angle between the extending directions of the two sides of the proximal clip 21 is in the range of 0-200 degrees. In this embodiment, the proximal clip 21 is cut from nickel-titanium alloy and then placed into a shaping mold, the shaping mold is placed into an electric heating type circulating air box furnace, shaping heat treatment is performed at 300-650 ℃, and the proximal clip 21 is obtained by taking out and rapidly cooling the proximal clip in purified water and removing the shaping mold. Specifically, in the present embodiment, the proximal clip 21 is integrally made of nitinol, so as to provide elastic force to the proximal clip 21 to urge the proximal clip 21 toward the distal clip 23 to clamp the valve tissue. In other embodiments, the connecting end 211 of the proximal clip 21 is made of an elastic material, the free end 212 of the proximal clip 21 may be made of a non-elastic material such as aluminum alloy, and the elastic force of the connecting end 211 urges the proximal clip 21 toward the distal clip 23.

It should be noted that the free end 212 of the proximal clip 21 extending radially outwardly and proximally relative to the push rod 10 may be controlled by an adjustment wire, such that in the delivery state, the free end 212 of the proximal clip 21 is pulled by the adjustment wire and engages the surface of the fixed base 40 to abut the push rod 10, and after releasing the control of the free end 212 by the adjustment wire, the connecting end 211 of the proximal clip 21 springs back due to its elastic memory properties, the proximal clip 21 returns to its natural state, and presses the valve against the distal clip 23. Preferably, the angle between the extending directions of the two sides of the proximal clip 21 in the naturally unfolded state should be slightly larger than the angle between the two distal clips 23 to provide a more stable clamping force, i.e. the angle between each extending direction of the proximal clip 21 and the push rod 10 is larger than or equal to the angle between the distal clip 23 and the push rod 10 when the distal clip 23 corresponding to that side is unfolded to the maximum state, so as to ensure a certain clamping force between the distal clip 23 and the proximal clip 21 to clamp valve tissue between the distal clip 23 and the proximal clip 21.

Further, the proximal clip 21 further includes a first surface 214 facing the distal clip 23 and the valve accommodating space 25, and a second surface 215 facing away from the first surface 214, and the first surface 214 is provided with a clamping reinforcement 216 to increase friction between the proximal clip 21 and valve tissue clamped in the valve accommodating space 25 and to increase clamping force of the valve clamp 100 on the valve tissue. Specifically, in this embodiment, the clamping reinforcement 216 is two rows of spaced barbs disposed on opposite sides of the first surface 214. The barbs may be integrally formed on the proximal clip 21 or may be formed of the same or different material as the proximal clip 21 and attached to the first surface 214 of the proximal clip 21, for example, nitinol wires or nitinol rods may be secured to the first surface 214 by sleeves. The root of the barb is connected to the proximal clip 21, and the end of the barb opposite the root is the cantilevered end which, in the naturally deployed state, faces the distal clip 23. The angle between the direction of extension of the barbs and the first surface 214 is less than or equal to 90 degrees to enhance the gripping force of the valve clip 100 against valve tissue. Further, the hanging end of each barb is a smooth arc-shaped surface, so that valve tissues are prevented from being damaged.

In other embodiments, the number of barbs may be 1,2, or other reasonable number.

In other embodiments, the gripping reinforcement 216 may be a rib, boss, or other irregularly distributed protrusion protruding from the first surface 214, or a roughened surface at least partially covering the first surface 214 to enhance the gripping force on the valve tissue.

Wherein, a plurality of openings are arranged on the proximal clamping piece 21 to lighten the weight of the proximal clamping piece 21, prevent the overweight clamp 10 from falling under the valve leaflet for a long time to generate slipping or damage to the valve leaflet, and simultaneously facilitate endothelial cell climbing and growth.

Referring to fig. 5 to 7, the valve clip 100 includes two distal clips 23 disposed axially symmetrically with respect to the pushrod 10, each distal clip 23 includes a distal connecting section 231 and a clamping section 232 disposed at a proximal end of the connecting section 231, the proximal end of the connecting section 231 is rotatably connected to the second base 42 of the fixed base 40, and the distal end of the connecting section 231 is movably connected to the connecting seat 15 of the pushrod 10. In this embodiment, each distal clip 23 is rotatably connected to the second base 42 of the fixed base 40 by a first pin 51, two distal clips 23 are located at opposite ends of the first base 42, and the distal ends of the two distal clips 23 intersect and are movably connected to the connecting base 15 of the push rod 10 by the same second pin 52.

In other embodiments, the first pin 51 and/or the second pin 52 may be replaced with bolts.

In this embodiment, the connection section 231 of each distal clip 23 includes two connection pieces with opposite intervals, the proximal end of each connection piece is provided with a connection hole, the distal end of each connection piece is provided with a sliding groove, and the sliding groove extends from the distal end of the connection piece to the proximal direction. Obviously, in other embodiments, the connection section 231 may comprise only one connection piece.

Specifically, one end of the first pin 51 passes through the connecting hole on the connecting piece on one side of the distal clip 23, then passes through the corresponding fixing hole 427 of the second base 42, and finally is inserted into the connecting hole on the connecting piece on the opposite side of the distal clip 23, and a first blocking piece is welded at the end of the first pin 51 to prevent the first pin 51 from slipping off, so that the proximal end of the connecting section 231 of the distal clip 23 is rotationally connected to the second base 42 of the fixing base 40. The connecting sections 231 of the two distal clamping pieces 23 on the same side of the second base 42 are mutually stacked, the sliding grooves of the two connecting sections 231 are communicated, one end of the second pin 52 sequentially penetrates through the sliding grooves of the two connecting pieces of the two distal clamping pieces 23 on the same side of the connecting base 15, then penetrates through the pin holes of the connecting base 15, finally is inserted into the sliding grooves of the two connecting pieces of the two distal clamping pieces 23 on the opposite side of the connecting base 15, and a second baffle is welded at the end of the second pin 52 to prevent the second pin 52 from sliding off, so that the distal ends of the connecting sections 231 of the two distal clamping pieces 23 are movably connected to the connecting base 15 of the push rod 10 through the same second pin 52.

When the push rod 10 axially moves in the through channel 425 and the lumen of the first seat 41, the second pin 52 penetrating the pin hole of the connecting seat 15 can slide in the sliding groove on the connecting piece of the distal clamping piece 23, so as to drive the distal clamping piece 23 to rotate around the first pin 51 by taking the connecting position of the proximal end of the connecting section 231 connected to the second seat 42 as a rotation center, and the clamping section 232 of the distal clamping piece 23 is opened and closed relative to the fixed base 40 and the push rod 10, and after the proximal clamping piece 21 is released and is freely unfolded due to the self elastic memory function, the distal clamping piece 23 can be closed to clamp valve tissue.

Further, the distal clip 23 further comprises a third surface 233 facing the proximal clip 21 and the valve receiving space 25 and a fourth surface 234 facing away from the third surface 233, the third surface 233 being opposite the first surface 214 of the proximal clip 21.

The third surface 233 may be a plane or a curved surface. In this embodiment, the third surface 233 is a curved surface, and the curvature direction of the curved surface faces the proximal clip 21. By providing the third surface 233 with a curved surface, the contact area and clamping area of the distal clip 23 with valve tissue can be increased, thereby providing a stable clamping force. Moreover, the curved third surface 233 forms a receiving groove in which the barbs on the first surface 214 of the proximal clip 21 can be received when the proximal clip 21 is closed toward the distal clip 23 to compress the leaflets in the leaflet receiving space 25 or minimize the volume of the valve clip 100 when the valve clip 100 is closed, thereby facilitating the delivery of the valve clip 100 in vivo.

The third surface 233 may be provided with a clamping enhancing structure, which may be a protrusion, a groove, or a gasket made of a biocompatible material with a high friction coefficient attached to the third surface 233. By providing protrusions, grooves or shims on the third surface 233, friction between the distal clip 23 and the valve tissue can be enhanced, thereby providing a stable clamping force.

Referring to fig. 3 and 6, in the present invention, in order to prevent the metal surface and/or sharp edges of the valve clamp 100 from damaging the clamped valve tissue, the valve clamp 100 is covered with a coating 30. Specifically, in the present embodiment, the cover 30 includes a first cover 31 covering the proximal clip 21 and a second cover 32 covering the distal clip 23.

Wherein the first coating 31 at least completely covers the first surface 214 of the proximal clip 21 and the second coating 32 at least completely covers the third surface 233 of the distal clip 23. Preferably, in the present embodiment, the first coating 31 completely covers the first surface 214 and extends to completely cover the second surface 215, and the second coating 32 completely covers the third surface 233 and extends to completely cover the fourth surface 234.

In other embodiments, the first coating 31 may extend to cover a portion of the second surface 215, and the second coating 32 may extend to cover a portion of the fourth surface 234, so as to reduce the coating amount and reduce the cost.

Wherein the first and second films 31 and 32 are made of at least one layer of biocompatible polymer material having biocompatibility, oxidation resistance and dissolution resistance, and the polymer material is at least one selected from PET, polyester, PTFE, silicone, or urethane. Further, the materials of the first coating 31 and the second coating 32 may be the same or different. In the present embodiment, the first film 31 and the second film 32 are each preferably a single-layer PET film.

Wherein the first cover film 31 and the second cover film 32 are fixed by any means of sewing, dip coating, bonding, fusing, binding, or the like. In this embodiment, the first cover 31 is adhesively secured to the proximal clip 21 and the second cover 32 is stitched to the distal clip 23.

In this embodiment, the two sides of the valve clamp 100 facing the valve accommodating space 25 and the edges thereof are completely wrapped by the covering film 30, so that the valve tissue clamped in the valve accommodating space 25 is not directly contacted with the metal parts of the clamp 20, thereby avoiding tissue allergy, inflammatory reaction, clamping injury or scratching of the valve tissue in the valve accommodating space 25.

In other embodiments, the valve clamp 100 may cover only the first covering film 31 or the second covering film 32, i.e. one side of the valve clamp 100 facing the valve accommodating space 25 and the edge thereof is completely covered by the covering film 30, specifically, the side of the proximal clip 21 facing the valve accommodating space 25 covers the first covering film 31 or the side of the distal clip 23 facing the valve accommodating space 25 covers the second covering film 32, which may also reduce valve tissue damage.

As shown in fig. 3 and 4, in the present embodiment, the second covering film 32 covering the two distal clips 23 covers the outer surface of the connecting portion (i.e. the portion where the second seat 42 and the connecting seat 15 of the push rod 10 are located) of the two distal clips 23 together, so as to wrap the sharp metal edge of the connecting portion, so as to avoid the sharp metal edge of the connecting portion damaging the valve tissue or the inner wall of the blood vessel during the pushing of the valve clip 100.

Of course, in other embodiments, the connection portion may not cover the second cover film 32.

Further, the coating 30 is provided with functional drugs by a treatment method such as biological modification, dipping, brushing, dripping or spraying. For example, the surface of the first coating 31 may be impregnated, sprayed, or the like with an anticoagulant such as heparin, or the surface of the first coating 31 may be biologically modified to have antithrombin characteristics, and a drug coating containing at least one of an anticoagulant, an antiplatelet drug, or an antihyperlipidemic drug may be applied to the first coating 31, so as to promote endothelialization, avoid tissue hyper-proliferation, reduce the incidence of the corresponding complications, and increase the post-operative survival rate. Similarly, the second coating 32 may be provided with corresponding functional medicines, which will not be described herein.

Referring to fig. 11, after the proximal clip 21 covers the first covering film 31, the free ends of the barbs 216 pierce and protrude from the first covering film 31 to facilitate grasping of valve tissue. Preferably, the thickness of the first coating 31 covering the area adjacent to the barbs 216 is greater than the thickness of the first coating 31 covering the other areas of the proximal clip 21 to avoid damage to valve tissue caused by too great a penetration depth of the cantilevered ends of the barbs 216 into the valve tissue due to too long a penetration length of the first coating 31.

Wherein the length of the barb at the free end thereof extending from the first film 31 is 0.2mm to 2mm, preferably 0.5mm to 1mm.

It will be appreciated that when the proximal clip 21 is not covered by the first coating 31, the sharp edges of the metal that are created by the machining are exposed, and that more of the exposed sharp edges are prone to damage to valve tissue. Referring to fig. 12 and 13, in the present invention, after the proximal clip 21 covers the first covering film 31, most of the sharp metal edges are covered in the first covering film 31, only the hanging end of the barb is exposed, so that the clamping force on valve tissue can be ensured, and serious damage to valve tissue can be avoided. Furthermore, when the barbs 216 clamp valve tissues, the first covering film 31 has a certain blocking control effect on penetration of the barbs 216, so that the depth of penetration of the barbs 216 into the valve tissues can be effectively controlled, and excessive damage to the valve caused by uneven stress is reduced. In addition, in some extreme cases, once the valve is pierced by the barbs 216, the first covering film 31 will immediately cover the puncture site, and the polymer material of the first covering film 31 has high biocompatibility, combined with the function of the functional medicine on the first covering film 31, can promote the tissue growth near the puncture site, thereby rapidly blocking the puncture hole, preventing blood from penetrating into the pericardial cavity, and reducing the risk of pericardial effusion and even cardiac arrest.

Similarly, after the second coating 32 is added to the distal clip 23, most of the metal surface is coated in the second coating 32, so as to avoid serious damage to the valve tissue caused by the distal clip 23.

In addition, the first covering film 31 and the second covering film 32 can also play a role in buffering, so that the clamped valve tissues are uniformly stressed, and damage caused by overlarge local stress of the valve tissues is avoided.

As previously described, in this embodiment, the valve clamp 100 can be used to reduce or treat "mitral regurgitation". Specifically, referring to fig. 14 to 16, the valve clamp 100 is placed at the position where the anterior leaflet 1a and the posterior leaflet 1b of the mitral valve cannot be properly aligned, so that one side of the distal clip 23 and the proximal clip 21 clamps the edge of the anterior leaflet 1a of the mitral valve, and the other side of the distal clip 23 and the proximal clip 21 clamps the edge of the posterior leaflet 1b of the mitral valve, so that the positions where the anterior leaflet 1a and the posterior leaflet 1b of the mitral valve cannot be properly aligned are clamped together, and the coating 30 on the valve clamp 100 can prevent the mitral valve from being scratched or scratched. As shown in fig. 15, when the heart is contracted, the anterior leaflet 1a and the posterior leaflet 1b are folded together, and the positions where the anterior leaflet 1a and the posterior leaflet 1b cannot be normally closed are partially or completely folded together, the area a of the mitral valve opening becomes small or the mitral valve can be completely closed, and only a small amount of blood flows back from the opening of the mitral valve into the left atrium, so that "mitral regurgitation" can be alleviated or treated. As shown in fig. 16, when the heart is relaxed, the anterior leaflet 1a and the posterior leaflet 1B are only put together at the position B where the valve clamp 100 is clamped, and the other positions of the anterior leaflet 1a and the posterior leaflet 1B are still normally relaxed, so that blood can enter the left ventricle from the left atrium, thereby ensuring the normal circulation of blood.

Wherein the arrow direction shown in fig. 15 and 16 is the blood flow direction.

The cover film 30 may or may not allow blood to permeate therethrough. Preferably, in the present embodiment, the first and second films 31 and 32 can allow blood to permeate therethrough to increase the blocking force applied during blood circulation, thereby reducing the blood pressure difference between the left atrium and the left ventricle.

Specifically, referring to fig. 3 and 4, the membrane 30 has one or more of a two-dimensional sieve structure, a porous membrane body, a microporous structure, a woven or non-woven mesh structure, a foam structure, and the like, so that blood can permeate and circulate through the membrane 30. In this embodiment, the first film 31 and the second film 32 are both in a woven mesh structure, and are provided with a plurality of meshes.

Wherein the aperture ratio of the first coating 31 is smaller than the aperture ratio of the second coating 32.

Wherein, the aperture ratio is the percentage of the open area to the whole covered area.

The second coating film 32 has a larger aperture ratio, so that the second coating film 32 has better elasticity and elongation than the first coating film 31, when the distal clamping piece 23 covered with the second coating film 32 is opened relative to the push rod 10, the second coating film 32 can follow the opening and closing of the distal clamping piece 23 to generate corresponding elastic deformation, and the second coating film 32 is always attached to the distal clamping piece 23.

Wherein the first cover film 31 has a mesh number in a range of 250 mesh to 2500 mesh per inch length, and the second cover film 32 has a mesh number in a range of 24 mesh to 250 mesh per inch length. In the present embodiment, the mesh number of the first cover film 31 per inch length is preferably 500 to 2500 mesh, and the mesh number of the second cover film 32 per inch length is preferably 50 to 150 mesh.

The mesh openings of the first and second films 31 and 32 pass through blood and prevent thrombus from passing. Further, the aperture of the mesh of the first coating film 31 is smaller than that of the mesh of the second coating film 32. Specifically, the mesh size of the first coating film 31 ranges from 0.01mm to 0.1mm, and the mesh size of the second coating film 32 ranges from 0.2mm to 0.5mm. In the present embodiment, the mesh size range of the first cover film 31 is preferably 0.01mm to 0.05mm, and the mesh size range of the second cover film 32 is preferably 0.2mm to 0.5mm.

Preferably, in some embodiments, the apertures of the mesh openings of the second cover film 32 disposed in the proximal-to-distal direction of the distal clip 23 are progressively larger, i.e., the mesh density of the second cover film 32 covering the proximal region (i.e., the gripping section 232) of the Yu Yuanduan clip 23 is higher than the mesh density of the second cover film 32 covering the distal region (i.e., the connecting section 231) of the distal clip 23.

Specifically, as shown in fig. 3 and 4, in the present embodiment, the aperture of the mesh of the second cover film 32 covering the proximal region (i.e., the clamping section 232) of the Yu Yuanduan clip 23 is smaller, and the second cover film 32 in this region is highly compact, so that the second cover film 32 is not easily worn by the proximal edge of the distal clip 23 and does not affect the opening and closing of the distal clip 23, while the aperture of the mesh of the second cover film 32 covering the distal region (i.e., the connecting section 231) of the distal clip 23 is larger, and the second cover film 32 in this region has better elasticity and elongation, and even under some conditions of larger opening and closing angle, the second cover film 32 near the push rod 10 can follow the corresponding deformation of the opening and closing of the distal clip 23, so as to ensure that the second cover film 32 is attached and fixed on the distal clip 23.

In the invention, the first covering film 31 is provided with a plurality of meshes, so that the first covering film 31 can allow blood to permeate through, normal flow of blood from the left atrium to the left ventricle is not influenced, blood is prevented from being detained in the left atrium, so that damage to a cavity of the left atrium is reduced, moreover, the number of the meshes and the pore diameter of the first covering film 31 are reasonably arranged, the first covering film 31 can form a manual barrier on the atrium side of valve leaflets to block thrombus in the blood, the opening of the whole valve clamp 100 facing the atrium side is closed, thrombus is prevented from entering the inside of the valve clamp 100 or the left ventricle, and the valve clamp 100 is prevented from falling off from the left atrium or the thrombus enters the blood circulation of a human body through an aorta, and in addition, as the first covering film 31 blocks the thrombus from entering between the first covering film 31 and the distal clamping piece 23, the impact force of the thrombus on the distal clamping piece 23 is reduced, the service life of the distal clamping piece 23 is prolonged, and the service life of the valve clamp 100 is prolonged. At the same time, the first covering film 31 can also increase the contact area between the proximal clip 21 and the blood, so as to buffer the inflow blood, and avoid the slipping caused by the deformation of the proximal clip 21 due to the impact of the inflow blood on the valve clamp 100.

In the present invention, too, the second membrane 32 having a plurality of meshes allows the blood flow to normally circulate in and between the left atrium and the left ventricle, thereby reducing the blood pressure difference between the left atrium and the left ventricle, and furthermore, the second membrane 32 can block a very small amount of thrombus entering the inside of the valve clamp 100 through the first membrane 31 to remain in the valve clamp 100, thereby preventing thrombus from entering the left ventricle and entering the blood circulation of the human body to induce stroke.

The static friction force refers to a resistance force that resists relative sliding when two objects that are in contact with each other have a tendency to slide relative to each other, but remain relatively stationary, and is referred to as static sliding friction force, and is generally denoted by F. The magnitude of the static friction force may vary between 0 and F _MAX, where F _MAX is the maximum static friction force, approximately equal to the sliding friction force F. The magnitude of the sliding friction force f is proportional to the positive pressure N, i.e., f=μn. μ is the dynamic friction factor, which is related to the material of the contact surface, the roughness and the elastic force between the contact surfaces. For the valve clamp 100 implanted on the leaflet, the first surface 214 of the proximal clip 21 facing the distal clip 23 contacts the upper surface of the leaflet, and the third surface 233 of the distal clip 23 facing the proximal clip 21 contacts the lower surface of the leaflet, since the leaflet tissue is slimy, and the surface is in constant high-speed motion, there is always a tendency for relative sliding between the first surface 214 of the proximal clip 21 and the upper surface of the leaflet, and between the third surface 233 of the distal clip 23 and the lower surface of the leaflet, and in order to avoid sliding or even falling between the jaws and the leaflet, the prior art merely employs methods of increasing barbs, friction pads, or simply increasing the contact area of the leaflet to avoid sliding. In the present embodiment, by coating the proximal clip 21 with elastic memory function with the first coating 31 with a relatively dense and relatively small aperture ratio and coating the distal clip 23 with the second coating 32 with a relatively sparse and relatively large aperture ratio, when the valve clip 100 is affected by blood flow scouring and valve leaflet beating, and the positive pressure N is unchanged, the dynamic friction factors μ between the first surface 214 of the proximal clip 21 and the upper surface of the valve leaflet and between the third surface 233 of the distal clip 23 and the lower surface of the valve leaflet are increased, so that not only are the two friction forces respectively increased, but also the dynamic balance is achieved when the two are matched, and the clamping force and the stabilizing force of the valve clip 100 are further improved.

Referring to fig. 17 and 18, the present invention further provides a valve clamping system, which includes a pushing device and the valve clamp 100, wherein the pushing device can be used to convey the valve clamp 100 to the mitral valve and adjust the valve clamp 100 to the proper position of the mitral valve. The pushing device comprises an operating handle and a pushing component, wherein the proximal end of the pushing component is connected with the operating handle, and the distal end of the pushing component is detachably connected with the valve clamp 100. Specifically, the push assembly includes a mandrel 210, a liner 220, and an outer tube 230 movably coaxially nested together, with the liner 220 being positioned between the mandrel 210 and the outer tube 230. The operating handle is capable of driving mandrel 210, liner 220, and outer tube 230, respectively, in relative motion.

The distal end of the mandrel 210 has external threads 211 that correspond to internal threads within the internally threaded bore 13 of the proximal end of the push rod 10. When the pushing assembly is connected with the valve clamp 100, the distal end of the mandrel 210 is in threaded connection with the proximal end of the push rod 10, and the mandrel 210 is driven to move by operating the handle, so that the push rod 10 moves axially.

A T-shaped spring 231 is provided on the distal end of outer tube 230 for mating with a connection 415 (i.e., a T-shaped slot) on the proximal end of first housing 41 to enable connection and unlocking of outer tube 230 to first housing 41. In a natural state, one end of the T-shaped elastic piece 231 is connected to the distal end of the outer tube 230, and the other end is inclined toward the axial position of the outer tube 230. Specifically, when the pushing assembly is connected to the valve clamp 100, the mandrel 210 is in threaded connection with the push 10, the operating handle drives the liner 220 to move, so that the liner 220 extends into the lumen of the first seat 41, the liner 220 jacks up the T-shaped elastic sheet 231 of the outer tube 230, so that the T-shaped elastic sheet 231 is embedded into the T-shaped groove of the first seat 41, at this time, the first seat 41 is in a connection state with the outer tube 230, and when the operating handle is operated, so that the liner 220 leaves the first seat 41, the T-shaped elastic sheet 231 of the outer tube 230 returns to a natural state, i.e. deforms inwards and is separated from the T-shaped groove at the proximal end of the first seat 41, so that the first seat 41 and the outer tube 230 are unlocked.

The pushing device further comprises a control member, namely the aforementioned adjustment wire, for binding the free end 212 of the proximal clip 21 to the surface of the fixed base 40 proximate to the push rod 10. The adjusting wire can be made of high polymer materials such as metal or PTFE.

The following illustrates the operation of the valve clamping system of the present invention, taking as an example the mitral valve repair procedure, which essentially comprises the steps of:

The first step is to bind the free end 212 of the proximal clip 21 to the surface of the fixed base 40 using an adjustment wire and then attach the push assembly to the valve clip 100. Specifically, the spindle 210 of the pushing assembly is rotated such that the spindle 210 is fixed with the push rod 10. And moves liner 220 axially distally to jack up T-shaped spring 231 of outer tube 230 such that T-shaped spring 231 is embedded into the T-shaped slot of first housing 41, such that first housing 41 is in a connected state with outer tube 230. At this time, the free end of the elastic piece 413 on the first seat 41 is located in the ring groove 11 of the push rod 10, so that the distal clip 23 and the proximal clip 21 are both close to the surface of the push rod 10 and keep the state unchanged.

The second step is to advance the valve clip 100 attached thereto from the left atrium, through the mitral valve, and to the left ventricle by a pusher assembly, using a transatrial approach.

Third, the relative position of the valve clamp 100 to the mitral valve is adjusted by the pushing assembly such that the valve clamp 100 approaches the anterior leaflet 1a and the posterior leaflet 1b of the mitral valve.

Fourth, the liner 220 is further moved axially distally so that the liner 220 lifts the free end of the resilient tab 413 of the first housing 41 such that the free end of the resilient tab 413 is disengaged from the annular groove 11 at the proximal end of the push rod 10. At this time, the push rod 10 can move axially to drive the distal clip 23 to open and close relative to the push rod 10.

And a fifth step of moving the mandrel 210 in a proximal direction by operating the handle, thereby driving the plunger 10 connected to the mandrel 210 to move in a proximal direction to drive the distal clip 23 to open relative to the plunger 10.

A sixth step is to orient the valve clip 100 such that the distal clip 23 is perpendicular to the mitral valve's line of fusion.

The seventh step is to withdraw the whole valve clamp 100 proximally so that the distal clip 23 holds the leaflet on the left ventricle side, release the constraint of the adjustment wire to the proximal clip 21, and the proximal clip 21 springs back to open against the pushrod 10 so that the leaflet is clamped between the proximal clip 21 and the distal clip 23, i.e. so that the anterior leaflet 1a and the posterior leaflet 1b of the mitral valve are clamped between a set of proximal clip 21 and distal clip 23, respectively.

Eighth, moving the mandrel 210 in the distal direction, the mandrel 210 drives the plunger 10 to move axially distally, thereby driving the distal clip 23 to close relative to the plunger 10 until fully collapsed.

And ninth, outer tube 230 is fixed, liner tube 220 is retracted to the proximal end for a certain stroke, and at this time, the free end of elastic sheet 413 of first seat 41 is clamped into annular groove 11 of push rod 10, so as to lock push rod 10 and ensure that distal clamping piece 23 is always folded. The spindle 210 is controlled to rotate by operating the handle so that the thread between the spindle 210 and the push rod 10 is unlocked. Liner 220 and mandrel 210 are retracted proximally until T-shaped tab 231 of outer tube 230 is unlocked from the T-shaped slot of first housing 41. At this point, the valve clip 100 is completely separated from the pusher assembly. The pushing assembly is withdrawn from the patient and the valve clip 100 is left in the patient to complete the leaflet edge-to-edge repair of the mitral valve. As shown in fig. 14, the proximal clip of the valve clamp 100 is fixed on the atrial side of the valve leaflet, the first coating 31 is in contact with the atrial side of the valve leaflet, the direct contact between the proximal clip 21 and the valve leaflet is isolated, the friction force of the metal proximal clip 21 on the valve leaflet is increased, the stress is more uniform, the barbs are uniformly stressed, damage to the valve leaflet caused by too deep penetration or uneven stress and too much stress is avoided, meanwhile, the second coating 32 can improve the adhesion of the distal clip 23 to the valve, increase the contact area of the distal clip 23 and the valve, play a buffering role on the surface of the distal clip 23, avoid the direct contact between metal and the valve, and reduce the mechanical force on the valve so as to avoid inflammatory reaction.

It will be appreciated that the valve clamp system of the present invention may also be employed to deliver a valve clamp to a mitral valve via a transapical or other route.

The valve clamping system of the present invention can be operated in vitro to clamp the valve clamp 100 to the valve leaflets, alleviating or avoiding the problem of "mitral regurgitation", and the cover 30 of the valve clamp 100 can reduce or avoid damaging the clamped valve tissue, and can also avoid damaging the valve tissue or other vascular tissue during the pushing process.

Referring to fig. 19 and 20, a valve clip 100a according to another embodiment of the present invention includes a push rod 10a, a distal clip 23a axially symmetrically disposed on an outer surface of the push rod 10a and capable of opening and closing opposite to the push rod 10a, a proximal clip 21a for clamping and fixing a leaflet in cooperation with the distal clip 23a, a first covering film 31a covering the proximal clip 21a, and a second covering film 32a covering the distal clip 23 a. When the distal clip 23a is closed with the pushrod 10a, it can be delivered through the sheath to the vicinity of the patient's valve. The structures of the proximal clip 21a and the first covering film 31a are the same as those of the proximal clip 21 and the first covering film 31 of the valve clip 100 in the first embodiment, and will not be described here again.

The connecting seat 15a is located at the distal end of the push rod 10a, and a round hole is formed at the proximal end of the connecting seat 15a for connecting the push rod 10a by means of threads, welding, etc. The two sides of the connection seat 15a are provided with pin holes, and a pair of connecting rods 16a are connected through pin hinges, that is, each connecting rod 16a is hinged to the connection seat 15a for relative rotation. The other end of link 16a is pinned to distal clip 23 a. The fixed base 40a is sleeved outside the push rod 10a, and the push rod 10a can move along the axial direction of the fixed base, so that the movement between the connecting seat 15a and the fixed base 40a is realized, and the opening and closing of the far-end clamping piece 23a relative to the push rod 10a are driven. Referring to fig. 21, in this way, a larger range of opening width of the included angle can be achieved, the included angle between the two distal clips 23a can reach 320 degrees at maximum, preferably the opening angle is from 0 degrees to 270 degrees, and further preferably from 120 degrees to 180 degrees, that is, the distal clips 23a can be turned down to a certain extent after being opened relative to the push rod 10a, and due to the elastic retraction function of the second covering film 32a, the second covering film 32a can be deformed and opened without obvious resistance when the distal clips 23a are opened, thereby facilitating the clamping of the valve leaflet continuously in motion and improving the clamping success rate.

Fig. 22 shows a valve clip 100b according to another embodiment of the present invention, which differs from the embodiment shown in fig. 3 in that the valve clip 100b includes a V-shaped proximal clip 21b and a distal clip 23b, and the proximal clip 21b and the distal clip 23b are moved relative to each other and overlap to clip two leaflets under the drive of the push rod 10 b.

Wherein a side of the proximal clip 21b facing the distal clip 23b and a side of the distal clip 23b facing the proximal clip 21b are at least partially covered with a cover film 30b.

Specifically, each proximal clip 21b is covered with a first coating 31b, each distal clip 23b is covered with a second coating 32b, and the connection portion between the two distal clips 23b is covered with the second coating 32b.

It will be appreciated that the connection between the two proximal clips 21b may also cover the first coating 31b.

The first film 31b and the second film 32b have the same structure and function as the first film 31 and the second film 32, respectively, and are not described here again.

It will be appreciated that the valve clamps 100a and 100b and the pushing device may also form a valve clamping system, and the usage steps are the same as those described above, and will not be repeated here.

It should be noted that the above description is given by taking the valve clamp 100 as an example for reducing or treating "mitral regurgitation". It will be appreciated that in other embodiments, the valve clamp 100 may be used to reduce or treat "tricuspid regurgitation", and the principles and structures of the valve clamp 100 are substantially the same as those of the valve clamp 100 for solving the "mitral regurgitation" in the embodiments of the present invention, and only a plurality of proximal and distal clamping pieces are required to form a plurality of clamps, each of which respectively clamps a leaflet, and the details are omitted herein.

It should be apparent that in other embodiments, the valve clamp 100 provided by the present invention may also be used in other minimally invasive surgical procedures where more than three sheets of valve tissue need to be clamped together.

The foregoing is a description of embodiments of the present invention, and it should be noted that, for those skilled in the art, modifications and variations can be made without departing from the principles of the embodiments of the present invention, and such modifications and variations are also considered to be within the scope of the present invention.

Claims

1. A valve clip having a cover, comprising:

a push rod;

A proximal clip and a distal clip which are radially expanded relative to the push rod, the distal clip being connected to the push rod, the proximal clip being disposed between the push rod and the distal clip, a valve accommodating space being formed between the proximal clip and the distal clip, the push rod being capable of driving the distal clip to radially expand, the proximal clip being elastically expanded by itself and then being brought closer to the distal clip to clamp valve tissue located in the valve accommodating space, and

A cover comprising a first cover covering at least a side of the proximal clip facing the valve receiving space and a second cover covering at least a side of the distal clip facing the valve receiving space;

The first covering film extends to wrap the edge of the proximal clamping piece, the second covering film extends to wrap the edge of the distal clamping piece, the first covering film and the second covering film both adopt net structures, and the aperture of the mesh holes arranged in the direction from the proximal end to the distal end of the distal clamping piece is gradually increased along the second covering film.

2. The valve clip of claim 1, wherein the proximal clip is made of a resilient material having a shape memory function and the distal clip is made of a rigid material.

3. The valve clip of claim 1, wherein the coverage of the proximal clip by the first cover film ranges from 50% to 90% and the coverage of the distal clip by the second cover film ranges from 40% to 80%.

4. The valve clip of claim 1, wherein the proximal clip includes a first surface facing the distal clip, the first cover film at least completely covering the first surface.

5. The valve clip of claim 4, wherein the proximal clip further comprises a second surface facing away from the first surface, the first cover film extending to cover at least a portion of the second surface.

6. The valve clip of claim 4, wherein the first surface is provided with at least one barb, a cantilevered end of the at least one barb being directed toward the distal clip, and at least one barb extending through the first cover.

7. The valve clip of claim 6, wherein the length of the cantilevered end of the barb extending out of the first cover film ranges from 0.2mm to 2mm.

8. The valve clip of claim 6, wherein a thickness of the first cover film covering the area proximate the barbs is greater than a thickness of the first cover film covering other areas of the proximal clip.

9. The valve clip of claim 1, wherein the distal clip includes a third surface facing the proximal clip, the second cover film at least completely covering the third surface.

10. The valve clip of claim 9, wherein the distal clip further comprises a fourth surface facing away from the third surface, the second cover film extending to cover at least a portion of the fourth surface.

11. The valve clip of claim 1, wherein the open porosity of the first coating is less than the open porosity of the second coating.

12. The valve clip of claim 1, wherein the first cover film has a mesh size in the range of 250 mesh to 2500 mesh per inch of length and the second cover film has a mesh size in the range of 24 mesh to 250 mesh per inch of length.

13. The valve clip of claim 1, wherein the mesh of the first cover film has a pore size that is smaller than the pore size of the mesh of the second cover film, the mesh of the first cover film having a pore size in the range of 0.01mm to 0.1mm, and the mesh of the second cover film having a pore size in the range of 0.2mm to 0.5mm.

14. The valve clip of claim 1, wherein the cover is made of at least one layer of biocompatible polymeric material selected from at least one of PET, polyester, silicone, PTFE, silicone, or urethane.

15. The valve clip of claim 14, wherein the first cover film is the same or different material than the second cover film.

16. The valve clip of claim 1, wherein the cover film is provided with a functional drug by a biological modification, dipping, brushing, dripping, or spraying treatment.

17. The valve clip of claim 1, wherein the cover is secured by stitching, dip coating, adhesive, fusion, or binding.

18. A valve clasper system comprising a pusher device and a valve clasper according to any one of claims 1 to 17, wherein the pusher device comprises an operating handle and a pusher assembly, wherein a proximal end of the pusher assembly is coupled to the operating handle, and wherein a distal end of the pusher assembly is detachably coupled to the valve clasper.

19. The valve clamping system of claim 18, wherein the push assembly comprises a mandrel, a liner, and an outer tube movably coaxially nested together, the liner being located between the mandrel and the outer tube.

20. The valve clasper system of claim 18, wherein the pushing mechanism further comprises a control for securing the proximal clip against the push rod.