Artificial valve prosthesisThe technical field is as follows:
the invention belongs to the field of medical appliances, and particularly relates to a prosthetic valve prosthesis.
Technical background:
the human heart has four chambers and four valves, a mitral valve, a tricuspid valve, an aortic valve, and a pulmonary valve. The mitral valve is located between the left atrium and the left ventricle and is composed of valve leaflets, an annulus, papillary muscles, chordae tendinae and a boundary. The mitral valve acts like a one-way valve, and when the heart is in diastole, it opens and blood flows from the left atrium into the left ventricle, and when the heart is in systole, it closes to prevent backflow of blood from the left ventricle to the left atrium of the heart.
According to recent epidemiological survey data in developed countries in the western united states, mitral insufficiency (also known as mitral regurgitation) has been the most prevalent valvular disease in developed countries, affecting about 10% of the population over 75 years of age. At present, although China has no authoritative epidemiological survey data, the number of patients with mitral insufficiency is undoubtedly large based on the huge population base of China.
Mitral insufficiency can be classified into chronic and acute mitral insufficiency. Chronic mitral insufficiency is mostly caused by damage to leaflets, congenital malformations, calcification of the mitral annulus, etc. due to rheumatic fever. Acute mitral insufficiency is caused by chordae rupture, valve damage or rupture, papillary muscle necrosis or rupture, and post-prosthetic valve replacement dehiscence.
Traditional treatment approaches for mitral valve disease include drug therapy for mild cases and surgical treatment with surgical indications. To date, surgical replacement and repair of valves has been the first treatment of severe mitral insufficiency. In surgical procedures, chest opening and extracorporeal circulation establishment are required, the procedure is invasive and the risk of complications and infections is high. Data indicate that for many high-risk patients of advanced age with multiple system disease, the surgical success rate is only 50%, and that for patients with severe functional mitral insufficiency is as low as 16%.
With the increasing maturation of aortic valve intervention technology, companies began to enter the field of mitral valve intervention. Mitral valve disease treatment has entered a new era since the world's first human Transcatheter Mitral Valve Replacement (TMVR) was completed by the university of copenhagen rigshapitat, denmark, copenhagen, 12 d.6.2012.
TMVR is a therapeutic method using transcatheter intervention in which a prosthetic valve is compressed and loaded extracorporeally to a delivery system, delivered along a vascular path or transapically to the mitral annulus, and then released and secured within the mitral annulus to replace the diseased valve. Currently, this approach is only exploratory in patients with mitral regurgitation where surgery is contraindicated. Since the first human TMVR implantation in the world, approximately 20 or more TMVR valves are under study, and 7 have entered clinical trials. The planning structure of the mitral valve complex is more complicated, for example, the mitral valve ring is saddle-shaped and is not in the same plane; the mitral annulus is soft in texture and does not provide radial support for the valve prosthesis; the mitral valve is close to the left ventricular outflow tract, and the valve prosthesis is overlong to easily cause obstruction of the left ventricular outflow tract and the like. Therefore, no mature product is published internationally.
Patent CN 105188611 a describes a valve prosthesis for replacing the mitral valve by edwards life sciences. An implantable prosthetic valve comprising: a radially collapsible and radially expandable annular frame comprising: an annular body defining a cavity therethrough; at least one ventricular anchor coupled to a ventricular end portion of the body; and an atrial portion coupled to and extending radially away from the body, wherein the atrial portion comprises a plurality of radially extending arms, wherein at least one of the arms comprises a segment that spirals or spirals; and a valve member supported inside the frame. In the technology, a main body is annular, and a plurality of radially extending arms are uniformly distributed and arranged along the circumferential direction of the main body. The annular body does not conform well to the mitral annulus anatomy resulting in paravalvular leakage or atrial contraction due to excessive body support to the annulus. Because the number of the arms extending in the radial direction is large, the operation difficulty of the device is increased, and meanwhile, the axial rigidity of the atrium is also increased, and the normal movement of the heart is influenced.
Patent CN 103079498A describes a method of endo-osker for anchoring a prosthetic valve in a patient's heart, said method comprising: providing the prosthetic valve, wherein the prosthetic valve comprises an anchor having an atrial skirt, an annular region, a ventricular skirt, and a plurality of valve leaflets, wherein the anchor has a collapsed configuration for delivery to the heart and an expanded configuration for anchoring with the heart; positioning the prosthetic valve in a heart of a patient; expanding the atrial skirt radially outward to place it on an upper surface of the patient's native mitral valve and anchoring the atrial skirt against a portion of the atrium; radially expanding the annular region of the anchor to conform and engage the native mitral annulus. This patent avoids excessive compression of the non-circular mitral annulus by the stent, as compared to a stent having an annular cross-section, which would result in narrowing of the left ventricular outflow tract. The problem with this patent is that even though there is good anastomosis and coaptation with the native mitral annulus, radial expansion of the stent lattice in contact with the mitral annulus can still cause compression of the tissue surrounding the annulus. Meanwhile, as can be seen from the drawings of the embodiment of the patent, the caliber of the valve prosthesis is the caliber of the stent, the cross-sectional area of the stent is at least the area of the mitral valve annulus, and the huge stent structure has influence on the left ventricular outflow tract. Finally, the leaflets are sewn on the non-circular stent, and the attachment of the leaflets in the non-circular region is inevitably affected, reducing the service life of the valve.
In conclusion, the market for treating mitral regurgitation is huge, and related enterprises are stimulated to research and develop novel valve prostheses. The existing valve prosthesis has certain effect, but can not completely meet the clinical requirement.
The invention content is as follows:
the invention aims to overcome the defects of the prior art and provides a prosthetic valve prosthesis aiming at a patient with mitral insufficiency and needing interventional therapy. The invention solves the problem of semi-leakage caused by that the artificial valve prosthesis in the prior art can not be well attached to the anatomical structure of the mitral valve; also solves the problem of pressing the annulus tissue after the mitral valve annulus is radially expanded due to the fixation requirement. On the basis of ensuring reliable fixation, the influence of the valve on the outflow channel is reduced, the compression on cardiac tissues and the influence on cardiac motion are also reduced, and the leakage-proof effect is better.
The purpose of the invention is realized by the following scheme:
the utility model provides a prosthetic valve prosthesis, includes support and valve, the support includes that the valve makes up section and atrium section, the valve is fixed connection in the section is made up to the valve, the valve make up the section with the atrium section is connected, atrium section comprises radial pole shape support piece, pole shape support piece includes two main tributary support pieces and at least one auxiliary support piece, pole shape support piece's one end with section fixed connection is made up to the valve is the stiff end, pole shape support piece's the other end is free to be the free end, and is adjacent be provided with flexible shirt rim between the pole shape support piece, can the self-adaptation be D shape structure when atrium section releases completely, the line of the free end of main tributary support piece constitutes the straightway of D shape structure, auxiliary support piece's free end is located on the arc line segment of D shape structure.
The aim of the invention can be further realized by the following scheme:
preferably, the stent is of conical configuration.
Preferably, the rod-shaped support is formed by extending a partial rod of the valve sewing section.
Preferably, in a cross section perpendicular to the axis of the valve sewing section, the included angle between the main supporting pieces is 90-120 degrees.
Preferably, in a cross section perpendicular to an axis of the valve sewing section, a length from a free end of the main support to a center of the valve sewing section is greater than a length from a free end of the auxiliary support to the center of the valve sewing section.
Preferably, on a cross section perpendicular to the axis of the valve sewing section, the perpendicular distance from the straight line segment of the D-shaped structure to the axis of the valve sewing section is larger than the perpendicular distance from the arc line segment of the D-shaped structure to the axis of the valve sewing section.
Preferably, when the atrial segment is fully released, the free ends of the two main support pieces can correspond to the joint valve of the mitral valve, respectively.
Preferably, the number of the auxiliary supports is two.
More preferably, the two auxiliary supports and the two main supports are symmetrically arranged along the axis of the valve sewing section.
More preferably, in a cross section perpendicular to the axis of the valve sewing section, the included angle between the two auxiliary supports is 40 ° to 90 °.
Preferably, the free end of the main support is provided with a developing point.
More preferably, the development site is a tantalum ring.
Preferably, the outer side of the valve sewing section is further provided with a leakage prevention device, the leakage prevention device is in a shape of a mussel with one large end and one small end and is perpendicular to the cross section of the axis of the valve sewing section, and the two ends of the mussel shape are respectively positioned below the free ends of the two main supporting pieces.
More preferably, the leakage-proof device has a memory skeleton structure, the skeleton structure is partially or completely coated with a film, and the film material comprises terylene, polytetrafluoroethylene, polyethylene, metal materials or animal-derived materials and the like.
More preferably, the animal-derived material is bovine pericardium or porcine pericardium.
Preferably, rod-shaped support piece be provided with buffer structure on the free end, buffer structure is S-shaped, circular, oval, straight tooth form, perhaps buffer structure is in the flexible piece of parcel on rod-shaped support piece' S the free end.
More preferably, the flexible member comprises dacron, polytetrafluoroethylene, silicon rubber, polyethylene, or animal-derived materials.
Preferably, the flexible skirt is composed of memory alloy wires and a covering film, the diameter of the memory alloy wires is within the range of 0.2-0.4mm, and the covering film comprises terylene, polytetrafluoroethylene, silicon rubber, polyethylene, animal-derived materials and the like.
Preferably, the prosthetic valve prosthesis further comprises a fixation member, the fixation member being connected to the atrial segment.
More preferably, the fixing member is connected with the rod-shaped support member.
More preferably, the fixing member and the rod-shaped support member are connected by a tantalum ring or a medical grade stainless steel ring.
More preferably, the fixing member is located outside the leak-proof device, and on a longitudinal section parallel to the axis of the valve sewing section, the fixing member extends from the fixed end to the proximal end, passes through a first bending point and extends to the distal end to form a valve leaflet accommodating cavity, and the native valve leaflet is folded and clamped in the valve leaflet accommodating cavity when the fixing member is completely released.
More preferably, the fixing piece is of an inverted U-shaped structure, or the fixing piece is of a multi-section arc structure.
More preferably, the limited gripping height of the securing member is less than the height of the native leaflets.
More preferably, the fixing member is made of an alloy wire having a shape memory property, and the diameter of the alloy wire is in the range of 0.4-0.8 mm.
More preferably, the fixing member is provided with barbs or barbs.
Compared with the prior art, the invention has the advantages that:
1. the atrium section among the prior art adopts network structure to constitute mostly, and huge holding power causes the oppression to the atrium easily, can influence atrium shrink blood supply when serious. In the present invention, the atrial section is comprised of radial rod-shaped support members including two primary support members and at least one secondary support member, the number of rod-shaped support members being small. Meanwhile, the flexible skirt is arranged between the adjacent rod-shaped support members, which has the advantage of providing enough support force for the artificial valve and simultaneously has minimal influence on the movement of the atrium. The flexible skirt can be better attached to the non-uniform contour of the atrial wall or the autologous valve ring of the patient, and the perivalvular leakage prevention effect is better.
2. The atrial section of the prior art is mostly circular. In the invention, the atrium section can be self-adaptive to a D-shaped structure when being completely released, the connecting line of the free ends of the main supporting pieces forms the straight line section of the D-shaped structure, and the free ends of the auxiliary supporting pieces are positioned on the arc line section of the D-shaped structure, so that the design is favorable for the atrium section of the artificial valve to better fit the structure of the atrium of the patient, and the leakage-proof effect is good. Meanwhile, the self-adaptive D-shaped structure is softer, conforms to the motion of the atria and has little influence on the contraction of the heart.
3. In the invention, the main supporting pieces and the auxiliary supporting pieces are few, and when the atrium section is completely released, the free ends of the main supporting pieces can respectively correspond to the joint valve of the mitral valve.
4. The leak-proof device of the valve sewing section in the prior art is mostly circular, but in the invention, on the cross section perpendicular to the axis of the valve sewing section, the leak-proof device is in the shape of a mussel with one large end and one small end, and two ends of the mussel are respectively positioned below the free ends of the two main supporting pieces. Such design more fits the physiology structure of patient's valve ring, and the leak protection effect is better. Meanwhile, when the model is selected, the artificial valves with various opening areas can not be prepared because the difference of the opening areas of the valve rings of the patients is large, so that the burden of production is reduced.
5. The fixing piece and the support in the prior art are of an integrated structure, the fixing piece extends out from the side of the bottom of the support positioned in a ventricle, the valve leaflet accommodating cavity is a space between the outer side of the support and the fixing piece, and the clamping force of the fixing piece is influenced by the radial expansion degree of the support. In the invention, the fixing piece is positioned outside the leakage-proof device, on a longitudinal section parallel to the axis of the valve sewing section, the fixing piece extends from the fixed end to the proximal end, passes through the first bending point and extends to the distal end to form a valve leaflet containing cavity, and when the fixing piece is completely released, the native valve leaflets are folded and clamped in the valve leaflet containing cavity. The fixing part is positioned outside the leakage-proof device, and the clamping force of the fixing part is not influenced by the radial contraction and expansion of the support. The native valve leaflet can fill the space of the valve leaflet containing cavity after being folded, so that the clamping force of the fixing piece is larger, and the clamping is more reliable.
Drawings
Fig. 1 a-1 b are schematic structural diagrams of an embodiment of the present invention.
Fig. 2 is a schematic view of a bare stent structure of a prosthetic valve prosthesis of the present invention having one auxiliary support.
Fig. 3 is a schematic view of a bare stent structure of a prosthetic valve prosthesis of the present invention having two auxiliary supports.
Fig. 4 is a schematic view of an eccentric configuration of the prosthetic valve of the present invention.
Fig. 5 is a structural diagram of the main support piece of the prosthetic valve prosthesis of the present invention in which the buffer structure is S-shaped.
Fig. 6 is a schematic view of the buffering structure on the main support of the prosthetic valve prosthesis of the present invention being a structure with straight teeth.
Fig. 7 is a schematic view of the free ends of the rod-shaped supports of the prosthetic valve prosthesis of the present invention wrapped with a flexible material.
Fig. 8 is a structural view illustrating the arrangement of the visualization points at the free ends of the main support of the prosthetic valve prosthesis according to the present invention.
Fig. 9 is a schematic view of the D-shaped configuration of the atrial section of the prosthetic valve of the present invention and the mussel-like configuration of the leak protection device.
Fig. 10 is a schematic view of the fixture and the leaflet containing cavity of the fixture of the prosthetic valve of the present invention.
Fig. 11a is a cut-away view of a stent of a prosthetic valve of the present invention, and fig. 11b is a schematic view of a bare stent of a prosthetic valve of the present invention with barbs.
Fig. 12 is a schematic structural view of a prosthetic valve prosthesis of the present invention provided with double fixtures.
Fig. 13 is a schematic view of the arrangement of barbs on the retaining member of the prosthetic valve prosthesis of the present invention.
Fig. 14 is a schematic view of a fixing member with a dacron sewing region of the prosthetic valve of the present invention.
Fig. 15 is a schematic view of the fixing means and the supporting means of the prosthetic valve prosthesis according to the present invention.
Fig. 16 is a schematic structural view showing the two ends of the fixing member of the prosthetic valve prosthesis of the present invention tilted.
FIG. 17 is a schematic view of the placement of the retaining member of the prosthetic valve prosthesis of the present invention on the leak-proof ring.
The specific implementation mode is as follows:
in order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and examples.
To more clearly describe the structure of the prosthetic valve prosthesis of the present invention, the terms "proximal" and "distal" are defined herein, which terms are conventional in the field of interventional medical devices. In particular, "proximal" refers to the end of the heart that is closer to the apex of the heart, and "distal" refers to the end of the heart that is further from the apex of the heart.
The first embodiment is as follows:
currently, most prosthetic valve anchoring methods involve radially expanding a stent against the annulus, and in order to achieve sufficient radial support, the surgeon may choose a prosthetic valve that is larger than the patient's own annulus. The large-sized artificial valve not only can cause oppression to heart tissues and influence the heart movement, but also can influence the blood running of the left ventricular outflow tract. Meanwhile, the leakage-proof effect is not satisfactory due to the fact that the leakage-proof structure can not be well attached to the atrium wall and the non-uniform physiological structure of the valve ring of the patient.
We have therefore proposed a new prosthetic valve prosthesis which addresses the above-mentioned problems. In one embodiment, as shown in fig. 1a and 1b, aprosthetic valve prosthesis 100 for mitral valve intervention comprises astent 110 and avalve 120, wherein thestent 110 comprises asewing segment 111 and anatrial segment 112, and thevalve 120 is fixedly connected to thesewing segment 111. Thevalve sewing section 111 is connected to theatrial section 112, theatrial section 112 is composed of radial rod-shapedsupports 1120, the rod-shapedsupports 1120 include twomain supports 1121 and at least oneauxiliary support 1122, one end of the rod-shapedsupport 1120 is fixedly connected to thevalve sewing section 111 as a fixed end, and the other end of the rod-shapedsupport 1120 is free as a free end. Aflexible skirt 1130 is provided between adjacent ones of the bar-shapedsupports 1120. Theatrial portion 112 is adapted to be in a D-shape when fully released, the connection line of the free ends of theprimary support members 1121 forms a straight line segment of the D-shape, and the free ends of thesecondary support members 1122 are located on an arc segment of the D-shape. A leakage-proof device 1110 is arranged outside thevalve sewing section 111.
In one embodiment, as shown in FIG. 2, the rod-shapedsupport 1120 is formed by extending a partial rod of thesewing segment 111. The rod-shapedsupport 1120 includes twomain support members 1121 and anauxiliary support member 1122, free ends of the twomain support members 1121 can respectively correspond to the joint valve of the mitral valve, and theauxiliary support member 1122 is located at the opposite side of the twomain support members 1121, and an included angle between the twomain support members 1121 is 120 ° in a cross section perpendicular to the axis of thevalve sewing segment 111. Aims to meet the basic axial supporting requirement of the valve prosthesis by using the minimum supporting pieces and is beneficial to reducing the influence of the artificial valve on the movement of the atrium.
In another embodiment, as shown in fig. 3, the rod-shapedsupport 1120 comprises twomain supports 1121 and twoauxiliary supports 1122, the free ends of the two main supports can correspond to the joint valve of the mitral valve, the twoauxiliary supports 1122 are located at opposite sides of the twomain supports 1121, and the twoauxiliary supports 1122 and the twomain supports 1121 are symmetrically arranged along the axis of thesewing segment 111. In a cross section perpendicular to the axis of thevalve sewing section 111, an included angle between the twomain support members 1121 is 120 °, and an included angle between the twoauxiliary support members 1122 is 80 °. The use of twoauxiliary supports 1122 makes the prosthetic valve axially more stable and reliable without affecting atrial motion. In a cross section perpendicular to the axis of thevalve sewing section 111, a length L1 from the free end of themain support 1121 to the center of thevalve sewing section 111 is greater than a length L2 from the free end of theauxiliary support 1122 to the center of thevalve sewing section 111.
In another embodiment, as shown in fig. 4, the prosthetic valve prosthesis of the present invention is an eccentric structure, and in the cross section perpendicular to the axis of thevalve sewing section 111, the perpendicular distance M1 from the straight line segment of the D-shapedstructure 1131 to the axis of thevalve sewing section 111 is greater than the perpendicular distance M2 from the arc segment of the D-shapedstructure 1131 to the axis of thevalve sewing section 111, which has the advantage of reducing the influence of the valve on the left ventricular outflow tract.
In one embodiment, a buffer structure is provided on the free end of the rod-shapedsupport 1120, and as shown in fig. 5, an S-shapedbuffer structure 1123 is provided on the free end of themain support 1121. In another embodiment, as shown in fig. 6, a straighttoothed buffering structure 1124 is provided on the free end of themain support 1121. In yet another embodiment, as shown in fig. 7, the buffering structure is aflexible member 1125 wrapped around the free end of the rod-shaped supportingmember 1120, and theflexible member 1125 comprises dacron, teflon, silicon rubber, polyethylene, or animal-derived materials. Preferably, the flexible member is bovine pericardium. In other embodiments, the buffer structure may be circular or oval, and the buffer structure is disposed on the free end of the rod-shapedsupport member 1120 to reduce the pressure on the atrial tissue by the rod-shapedsupport member 1120 and improve the compliance of the free end of the rod-shapedsupport member 1120.
In one embodiment, as shown in fig. 8, the free ends of the twomain support pieces 1121 are provided with avisualization point 1126, and thevisualization point 1126 is a tantalum ring, and the visualization point can improve the positioning accuracy of the prosthetic valve when the prosthetic valve is released.
In one embodiment, as shown in fig. 9, theflexible skirt 1130 may adapt to a D-shapedstructure 1131 when the atrial section is fully released, the line connecting the free ends of theprimary support members 1121 forms a straight segment of the D-shapedstructure 1131, and the free ends of thesecondary support members 1122 lie on an arc segment of the D-shapedstructure 1131. Theflexible skirt 1130 is made of memory alloy wire and a film. The benefit is that theflexible skirt 1130 can conform to the irregular contours of the atrial side, reducing the occurrence of paravalvular leaks. The valve sewing section is further provided with aleakage prevention device 1110, theleakage prevention device 1110 is amussel shape 1132 with one large end and one small end on the cross section perpendicular to the axis of the valve sewing section, and two ends of themussel shape 1132 are respectively positioned below the free ends of the two main supportingpieces 1121. In a preferred embodiment, theflexible skirt 1130 is integral with theleak protection device 1110, theleak protection device 1110 has a memory skeleton structure, the skeleton structure is partially or completely covered with a film, the memory skeleton structure is made of memory alloy wires, the memory alloy wires are made of nickel-titanium alloy, and the diameter of the memory alloy wires is 0.2-0.4 mm. The covering film comprises terylene, polytetrafluoroethylene, silicon rubber, polyethylene, or animal-derived materials and the like, wherein the animal-derived materials comprise bovine pericardium and porcine pericardium. In a more preferred embodiment, the cross-sectional area of the valve sewing section is slightly smaller than the area of the native annulus of the patient. The advantage of this is that themussel shape 1132, large at one end and small at the other, more conforms to the uneven contours of the mitral annulus, improving leakage prevention without affecting atrial motion.
In one embodiment, as shown in FIG. 10, the prosthetic valve prosthesis further comprises ananchor 130, theanchor 130 being attached to theatrial segment 112. The fixingmember 130 is located outside theleakage preventing means 1110, and in a longitudinal section parallel to the axis of thevalve sewing section 111, the fixingmember 130 extends from the fixed end to the proximal end, passes through a first bending point and extends to the distal end to form aleaflet housing cavity 131, and when the fixingmember 130 is completely released, the native leaflets are folded and clamped in theleaflet housing cavity 131. In a preferred embodiment, the fixingmember 130 is made of an alloy wire having a memory property, and the diameter of the alloy wire is in the range of 0.4 to 0.8 mm. The benefit is that clamping and folding of native leaflets within the holder pockets 131 is freed from the clamping of native leaflets between thestent 110 and theholder 130 by most prosthetic valve prostheses, the latter clamping force being influenced by the degree of stent expansion, the former being able to stack native leaflets upon release, allowing better occupation of pocket space and more reliable clamping.
The second embodiment is as follows:
in one embodiment, as shown in fig. 11a and 11b, aprosthetic valve prosthesis 200 for mitral valve intervention comprises astent 210 and a valve, wherein thestent 210 comprises avalve sewing section 211 and anatrial section 212, the valve is sewn on thevalve sewing section 211, and thevalve sewing section 211 is connected with theatrial section 212. The stent is a conical framework, the stentmain body 213 is a self-expanding structure, and the raw material of the stentmain body 213 is a memory alloy tube. Theatrial portion 212 is composed of radial rod-shapedsupports 2120, and the rod-shapedsupports 2120 include twomain supports 2121 and twoauxiliary supports 2122, one end of the rod-shapedsupports 2120 is fixedly connected to thevalve sewing portion 211 as a fixed end, and the other end of the rod-shapedsupports 2120 is free as a free end. In a preferred embodiment, the memory alloy tube is a nitinol tube with a diameter of 6mm and a thickness of 0.5mm, and thestent 210 is manufactured by laser cutting the nitinol tube. The support under theauxiliary support 2122 is provided with abarb 2123, and the angle between thebarb 2123 and the axis of the support is 30-60 °.
In one embodiment, as shown in fig. 12, a flexible skirt is disposed between the adjacent rod-shaped supports, the atrium section can be adapted to a D-shaped structure when completely released, the connecting line of the free ends of the main supports forms a straight line segment of the D-shaped structure, the free ends of the auxiliary supports are located on an arc segment of the D-shaped structure, and theleakproof device 2110 is disposed outside thesewing segment 211. Thevalve prosthesis 200 further includes two fixingmembers 230, namely a first fixingmember 231 and asecond fixing member 232. The fixingmember 230 is located outside theleakage preventing means 2110 and is coupled to the rod-shaped support member. In a longitudinal section parallel to the axis of thevalve sewing section 211, thefirst fixing element 231 extends from a fixed end thereof fixedly connected with the main support piece to a proximal end, passes through a first bending point and extends to a distal end to form a firstleaflet receiving cavity 2310. Thesecond fixing member 232 extends proximally from a fixed end thereof fixedly connected to the auxiliary support member, passes through the first bending point, and extends distally to form a secondleaflet receiving cavity 2320.Barbs 2123 provided under theauxiliary support 2122 penetrate the native posterior leaflet to facilitate the second fixingmember 232 to clamp and fold the native leaflet into the secondleaflet receiving cavity 2320.
In one embodiment, as shown in fig. 13, thefixture 230 is provided withbarbs 233, thebarbs 233 are downward in head, and engage withbarbs 2123 provided on the stent at the back of the leaflet, so as to improve the holding success rate and effect of thefixture 230.
In one embodiment, as shown in fig. 14, the fixingmember 230 is provided with adacron sewing region 234, which is to increase the friction force when the fixingmember 230 grabs the native valve leaflet, on one hand, and to improve the success rate. On the other hand, the pull string is fixed when the sheath is retracted, and the pull string passes through the terylene sewing area when the sheath is retracted, so that the reliability of the fixingmember 230 when the sheath is released is improved.
In one embodiment, as shown in fig. 15, the fixingmember 230 is connected to the rod-shaped supportingmember 2120 at both ends thereof by a tantalum ring or a stainless steelmedical ring 235, and the joint may be reinforced with biocompatible glue/adhesive if necessary, and the reinforcing time should be more than one hour.
In one embodiment, as shown in fig. 16, the fixingmember 230 has an inverted U-shaped structure, or a multi-segment arc structure. The two ends of the fixingmember 230 are tilted up by 45 ° in order to prevent the fixing member from being separated from the bracket when the fixing member and the rod-shaped supporting member are separated. In a preferred embodiment, thefixation elements 230 have a limited gripping height that is less than the native leaflet height, facilitating leaflet folding and enhancing the gripping effect.
In one embodiment, as shown in fig. 17, the middle of the fixingmember 230 is sewn to the leakage preventive means 2110 to enhance the connection effect between the fixingmember 230 and thestent 210 and improve the stability of clamping the leaflets.
Finally, it should be understood that the above-mentioned embodiments are merely preferred embodiments of the present invention, and the present invention is not limited thereto, and any modifications, equivalents and improvements that are within the spirit and principle of the present invention should be included in the protection scope of the present invention.