Disclosure of Invention
The invention aims to provide an implantable aortic biological valve, which solves the problems that the fixation and sealing effects are poor and the stent size is large so as to easily influence the interference to coronary intervention operation only by means of the expansion of the stent after the stent is fixed in the prior art.
The implantable aortic biological valve comprises a valve support, a prosthetic valve, a skirt and a plurality of anchors, wherein the valve support is hollow in the valve support and penetrates through the two ends of the valve support, the prosthetic valve is arranged at a position corresponding to the cross section of the valve support and divides the valve support into a first area and a second area, the first area faces the blood outflow end of the aortic valve, the second area faces the blood inflow end of the aortic valve, the skirt is an annular surface wrapping the second area and extends towards one side of the blood inflow end of the aortic valve, the outer side wall of the skirt is used for abutting and sealing with valve leaflets of the aortic valve, the anchors are arranged in the first area and are arranged with or unevenly along the circumference of the valve support, and the anchors are provided with protruding structures protruding from the surface of the first area in the radial direction of the valve support and are used for abutting with the inner wall of the aortic valve.
Optionally, the skirt has a first end facing the blood outflow end of the aortic valve and a second end facing the blood inflow end of the aortic valve, the prosthetic valve being located between the first end and the second end in the axial direction of the valve holder, the axial dimension between the prosthetic valve and the second end being greater than the axial dimension of the second region.
By the technical scheme, the valve support and the aortic valve are kept sealed, and blood can only pass through the valve support through the artificial valve.
Optionally, the skirt is annular lamellar, and the outer diameter of the second end is greater than the outer diameter of the first end.
Through above-mentioned technical scheme, the side of shirt rim can be closely with the aortic valve, and flaky shirt rim also can increase the area of contact with the aortic valve to realize the seal between the two. Meanwhile, the outer diameter of the second end is increased, so that a certain clamping effect is generated between the skirt edge and the aortic valve, and the stent is smoothly fixed in the aortic valve.
Alternatively, the generating line of the skirt is a curve with continuously changing curvature, or the generating line of the skirt is a curve with inflection point.
Through the technical scheme, the cambered surface transition formed by the curvature change curve can further increase the contact area between the skirt edge and the aortic valve so as to improve the tightness between the skirt edge and the aortic valve. Curved surface transition with inflection points enables better clamping effect between the skirt edge and the aortic valve, and improves the installation stability of the valve stent.
Optionally, the first end of the skirt is sewn to the outside or inside of the valve holder.
Through above-mentioned technical scheme, the shirt rim can overlap the outside of establishing at the valve support to direct with aortic valve butt, the shirt rim also can laminate in the inboard of valve support, in order to play sealed effect to the second region of valve support.
Optionally, the first end of the skirt has a double-layered structure with a sandwich layer, and the valve holder is inserted into and fixedly connected to the holder.
Through above-mentioned technical scheme, insert the valve support in the intermediate layer for the joint strength between shirt rim and the valve support improves, can also ensure the direct butt of shirt rim and aortic valve simultaneously, in order to improve the leakproofness of valve support after the installation.
Optionally, the valve stent is in a grid structure, and each grid unit in the grid structure contracts or stretches towards two sides by taking a diagonal line parallel to the axis as a symmetry line, so as to drive the valve stent to compress or expand.
Through the technical scheme, when the valve stent is conveyed, the valve stent can be contracted so as to facilitate the movement of the valve stent, and after the valve stent moves to the aortic valve, each grid structure is expanded, so that the valve stent is supported at the aortic valve.
Optionally, the valve stent has a thickness of less than 0.6 mm and/or the valve stent has an axial length of greater than 8 mm and less than 40 mm.
According to the technical scheme, the thickness of the valve stent is set to be thinner, so that the contraction amplitude of the valve stent can be effectively improved, and the valve stent can be conveniently installed in a smaller conveying catheter. The whole length is smaller, so that the valve stent can be exposed out of the coronary artery after being expanded, thereby facilitating the implementation of other interventional treatments.
Optionally, the anchoring piece is a barb, one end of the barb is connected with the valve support, the other end of the barb is obliquely arranged towards one side far away from the valve support, or the anchoring piece is a bulge which bulges outwards in a radial direction.
Through above-mentioned technical scheme, after valve support expands, a plurality of barbs just can the butt on the inner wall of aorta to fix valve support in aortic valve department, make valve support can not fall into left ventricle. The bulge can be abutted to the inner wall of the aorta, and the contact area between the bulge and the aorta is larger, so that the valve support is uniformly stressed in all directions, the stability of the valve support is ensured, and the possibility that the valve support falls into the left ventricle is reduced.
Optionally, the skirt is made of polyethylene terephthalate or polytetrafluoroethylene or bovine pericardium or porcine pericardium.
According to the technical scheme, the polyethylene terephthalate has good physical and mechanical properties, very good creep resistance, fatigue resistance, friction resistance and dimensional stability, the polytetrafluoroethylene has very low friction coefficient, has very strong chemical stability, corrosion resistance, sealing property and the like, and the bovine pericardium and the porcine pericardium have good biocompatibility and small antigenicity, and are not easy to undergo rejection reaction, so that the polyethylene terephthalate can be used for manufacturing structures such as skirts and the like which are in direct contact with human tissues.
To achieve the above object, the present invention also provides another implantable aortic biological valve comprising a valve holder having a tubular shape and having a first end and a second end disposed opposite to each other in an axial direction, a prosthetic valve disposed in a lumen of the valve holder, the prosthetic valve dividing the valve holder into a first region and a second region disposed in sequence in the axial direction, a plurality of anchors disposed outside the first region and disposed at intervals in a circumferential direction of the valve holder, one end of each of the anchors being connected to the valve holder and the other end extending in a direction away from the valve holder, and a skirt surrounding the second region and a portion of the first region, the skirt having a first end and a second end disposed opposite to each other, the first end being disposed between the prosthetic valve and the anchors, the second end extending beyond the second region and the second end having an outer diameter larger than that of the first end.
The invention has the beneficial effects that:
The implantable aortic biological valve provided by the application is applied to an implantation operation of an aortic valve, a prosthetic valve is arranged in a valve bracket to replace an original aortic valve leaflet, and the skirt edges and the anchoring parts arranged on the valve bracket can fix the valve bracket at two sides of the valve bracket, so that the valve bracket is fixed on the aortic valve, the skirt edges can keep the sealing between the valve bracket and the aortic valve, the sealing property between the valve bracket and the aortic valve is effectively improved, the risk of leakage outside the valve bracket is reduced, when blood flows, the blood can only flow through a second area and a first area in sequence along with the opening of the prosthetic valve, and can not flow through the outside of the valve bracket, so that the possibility of blood flowing back into a left ventricle can be reduced. Simultaneously, the size of the implant can be effectively reduced, and the operation difficulty is reduced.
Detailed Description
The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.
In the description of the present invention, unless explicitly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may, for example, be fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements. 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 present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.
In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.
The implanted aortic biological valve provided by the invention is characterized in that the cylindrical grid-shaped valve support with two open sides is formed by processing an alloy material, and meanwhile, the thickness and the length of the support are smaller, so that the support can be contracted and placed into a smaller conveying catheter, the conveying catheter can be conveyed through femoral artery by percutaneous puncture or brachial artery, and the left and right coronary artery openings in the aorta are not influenced after the expansion, so that the subsequent coronary intervention operation is facilitated. And the artificial valve is fixed on the outer wall of the bracket or the outer wall by sewing. The skirt edge which is thin and horn-shaped can be arranged on the bracket, and the skirt edge can be sealed and attached to the aortic valve, so that the sealing between the bracket and the aortic valve is realized, and the possibility of perivalvular leakage is reduced. The artificial valve is positioned in the skirt, and blood can flow out only when the artificial valve is opened. The outer wall of one side of the stent far away from the skirt is also provided with a special anchoring structure, the anchoring structure can be abutted with the inside of the aortic cavity, and the anchoring structure and the skirt are matched on two sides of the valve stent to fix the valve stent, so that the possibility that the valve stent falls into the left ventricle or the aorta is reduced. Thereby improving the success rate of implantation of the artificial valve.
Fig. 1 is a schematic diagram of an implantable aortic bioprosthetic valve. Referring to fig. 1, the implantable aortic biological valve comprises a valve holder 100, a prosthetic valve 200, a skirt 300, and a plurality of anchors 400. The valve stent 100 has a tubular shape, and is hollow at its inside and penetrates at both ends. The prosthetic valve 200 is disposed in the lumen of the valve stent 100. Specifically, the prosthetic valve 200 is sewn on the cross section of the valve stent 100 and divides the valve stent 100 into a first region 110 and a second region 120, the first region 110 and the second region 120 are sequentially arranged along the axial direction of the valve stent 100, and the prosthetic valve 200 is used for selectively communicating or blocking the first region 110 and the second region 120. The first region 110 is oriented toward the blood outflow end of the aortic valve, i.e., in communication with the aortic lumen, and the second region 120 is oriented toward the blood inflow end of the aortic valve, i.e., in communication with the left ventricle.
The skirt 300 is an annular surface surrounding the second region 120. The skirt 300 has oppositely disposed first and second ends, the first end being connected to the valve holder 100 and facing the blood outflow end of the aortic valve, the second end facing the blood inflow end of the aortic valve, i.e. the left ventricle, and the outer sidewall of the skirt 300 being sealed against the leaflets of the aortic valve. The skirt 300 encloses the second region 120 and a portion of the first region 110, the prosthetic valve 200 is located between the first and second ends in the axial direction of the valve holder 100, and the axial dimension between the prosthetic valve 200 and the second end is greater than the axial dimension of the second region 120. That is, the second end of the skirt 300 extends beyond the second region 120.
A plurality of anchors 400 are disposed outside of the first region 110 and are spaced apart along the circumference of the valve stent 100. The first end of the skirt 300 may be located between the prosthetic valve 200 and the anchor 400. One end of each anchor 400 is connected to the valve stent 100 and the other end extends away from the valve stent. The plurality of anchors 400 may be evenly or unevenly distributed along the circumference of the valve stent 100. The anchor 400 has a protruding structure protruding from the surface of the first region 110 in the radial direction of the valve holder 100 for abutment with the interior of the aortic lumen to cooperate with the skirt 300 to secure the valve holder 100.
In particular, the valve stent 100 is cylindrical and radially expandable by contraction, which may be of an alloy material and have memory properties, and is capable of remaining contracted for placement in a delivery catheter during delivery, and expanded to be supported at a corresponding location after delivery to a designated location.
Fig. 2 is a schematic diagram of a prosthetic valve of an implantable aortic bioprosthetic valve according to some embodiments of the present invention. Referring to fig. 2, the prosthetic valve 200 may include a plurality of leaflets, such as three or four, circumferentially encircling and sequentially abutting the valve support 100, and each of the mutually abutting sides of the plurality of leaflets is an arc, and the junction of the three arc is located on the axis of the valve support 100, so that the three leaflets can be turned from the center of the valve support 100 to the edge of the valve support 100 for blood in the left ventricle to flow into the aorta. The valve leaflet can be directly sewn on the inner side or the outer side of the valve support 100, and the valve leaflet can also be of a double-layer structure which is respectively sewn and connected with the inner side and the outer side of the valve support 100. In an embodiment of the invention, three leaflets are provided to control the opening and closing of the aorta. It should be understood that in other embodiments of the invention, four or two leaflets may be provided.
The skirt 300 may be in a horn shape, the outer diameter of the second end face of the skirt 300 is larger than that of the first end face, the outer diameter of the skirt may gradually change from the first end to the second end, such as arc transition, or the outer diameter of the skirt may suddenly change from the first end to the second end, such as corner transition, etc. By the arrangement of the skirt 300, the skirt 300 is caused to conform to the leaflet-forming surface of the native aortic valve as the valve holder 100 expands, thereby forming a seal between the skirt 300 and the leaflets of the aortic valve. The anchor 400 is disposed on the valve stent 100, and the material of the anchor 400 may be the same as that of the valve stent 100, so that the anchor 400 expands with the expansion of the valve stent 100, so as to be able to abut against the inner wall of the aortic lumen. The shape of the anchor 400 may be an arc shape with protruding protrusions, barbs, or other shapes that can be attached to the inner wall of the aortic cavity, and specifically may be designed according to practical application conditions, which is not limited by the present invention.
When the prosthetic valve 200 is implanted, the first region 110 is directed to one side of the aorta and the second region 120 is directed to the left ventricle when the valve stent 100 is inserted into the middle of the aortic valve by the delivery system, the second end of the skirt 300 is directed to the left ventricle, the skirt 300 can be abutted against the aortic valve along with the expansion of the valve stent 100, the anchor 400 can be abutted against the inner wall of the aorta at this time, and the anchor 400 is matched with the skirt 300 to fix the valve stent 100 on both sides of the aortic valve, thereby fixing the valve stent 100 between the aortic valves. Meanwhile, the skirt edge 300 is attached to the valve She Mifeng of the aortic valve, so that the skirt edge 300 and the valve leaflets of the aortic valve are kept sealed, the sealing performance between the valve support 100 and the aortic valve is effectively improved, and the risk of perivalvular leakage outside the valve support 100 is reduced. When blood flows, since the prosthetic valve 200 is disposed within the skirt 300, blood can only flow through the second region 120 and the first region 110 in sequence with the prosthetic valve 200 open, and not through the outside of the valve holder 100, thus reducing the possibility of blood flowing back into the left ventricle.
In some embodiments of the invention, a valve stent 100 is provided with developable marker points. Marker points are provided on the outside of the first region 110 for indicating the position of the valve stent 100. Specifically, the marking points may be fixed on the outer side of the first area 110 in a mosaic manner, and the specific positions of the marking points may be designed according to the actual application scenario, which is not particularly limited in the present invention. The marking points can be made of platinum iridium alloy or tantalum alloy, and the marking points are made of tantalum alloy in the embodiment of the invention.
In some embodiments of the invention, the valve stent 100 is fabricated from a nickel-titanium alloy or stainless steel or cobalt-chromium alloy. The skirt 300 is made of polyethylene terephthalate (polyethylene terephthalate, abbreviated as PET) or polytetrafluoroethylene (Poly tetra fluoroethylene, abbreviated as PTFE) or bovine or porcine pericardium. The prosthetic valve 200 is made of bovine pericardium or porcine pericardium.
In particular, the valve stent 100 is preferably made of a nickel-titanium alloy, which is a shape memory alloy that can contract and expand to recover shape, while also having good wear resistance, corrosion resistance, etc. The valve stent 100 made of nitinol is effective to achieve both overall contraction and expansion. Polyethylene terephthalate has good physical and mechanical properties over a wide temperature range, as well as good creep resistance, abrasion resistance and dimensional stability. The skirt 300 of polyethylene terephthalate can be well sealed against the leaflets of the aortic valve. Polytetrafluoroethylene is nontoxic, corrosion-resistant, and good in sealing performance and stability, and the skirt 300 made of polytetrafluoroethylene can be in sealing fit with the valve leaflets of the aortic valve. The bovine pericardium and the porcine pericardium are processed by biological engineering, so that the bovine pericardium and the porcine pericardium have good biocompatibility, small antigenicity, difficult rejection reaction, and very good overall biological tissue stability, and can be used for manufacturing the skirt 300 and the artificial valve 200.
Fig. 3 is a schematic diagram of the skirt of an implantable aortic biological valve according to some embodiments of the application. Referring to fig. 1 and 3, in some embodiments of the application, the skirt 300 is annular and lamellar, and the outer diameter of the second end is greater than the outer diameter of the first end. Specifically, the skirt 300 may be integrally formed in a horn shape and sleeved on the valve holder 100, and the bus thereof is a curve with a continuously varying curvature, so as to form a cambered surface transition on the outer surface thereof, so that the first end and the second end are connected together. The skirt 300 outer sidewall of the cambered surface transition can better realize sealing fit with the aortic valve. The generatrix of the skirt 300 may also be curved with an inflection point to form a corner surface transition at its outer surface such that the first and second ends are connected together. For example, the angle of the break between the second end and the first end is ninety degrees, so that the second end of the skirt 300 can better snap onto the aortic valve. It should be understood that the degree of curvature continuous change or the angle and number of inflection points can be designed according to the actual requirement of the operation, and the present application is not limited thereto.
In some embodiments of the invention, the first end of the skirt 300 is sewn to the inside or outside of the valve holder 100. Specifically, the outer diameter of the first end of the skirt 300 may be larger than the outer diameter of the valve holder 100, in which case the first end of the skirt 300 is sleeved outside the valve holder 100, and the outer diameter of the first end of the skirt 300 may be smaller than the inner diameter of the valve holder 100, so that the skirt 300 is sleeved inside the valve holder 100. And the dimensions of the particular skirt 300 may be defined according to practical application requirements.
Referring to fig. 3, in some embodiments of the invention, at a first end of the skirt 300 is a double-layered structure with a sandwich into which the valve holder 100 is inserted, the valve holder 100 being sewn. Specifically, the side of the skirt 300 having the double-layer structure, which is adjacent to the first end, may be hollow, so as to form the above-mentioned interlayer, into which the valve stent 100 is inserted, and then the valve stent 100 is fixedly connected with the skirt 300 by sewing. With this, the strength of the connection between the valve stent 100 and the valve can be effectively improved by providing the interlayer.
Fig. 4 is a schematic view of a deployed configuration of a valve stent of an implantable aortic biological valve in accordance with some embodiments of the present invention. Referring to fig. 4, the valve stent 100 has a lattice structure, each lattice cell in the lattice structure has a symmetry line, the lattice cell can be contracted or stretched along the symmetry line at both sides, and the symmetry line is parallel to the axis of the valve stent 100 and is served by a diagonal line of the lattice cell. To drive the valve stent 100 to compress or expand. Specifically, the valve stent 100 is integrally formed, which may be specifically manufactured by laser engraving, electrochemical polishing, heat treatment, and the like. The lattice structures may be diamond-shaped or other polygonal shape with two opposite apices in the axial direction of the valve stent 100 and two opposite apices in the radial direction of the valve stent 100, the two radial apices being able to approach or depart from each other such that each lattice structure compresses or expands, thereby achieving compression or expansion of the valve stent 100. It should be understood that the specific shape of the grid structure may be designed according to practical application requirements, for example, may be hexagonal, etc., and the present invention is not limited in particular.
In some embodiments of the invention, the valve stent 100 has a thickness of less than 0.6 millimeters. Specifically, the thickness of the valve stent 100 may be between 0.05mm and 0.6 mm, so as to improve the radial compressibility of the valve stent 100, so that the valve stent 100 with an inner diameter of 50 mm after expansion can be compressed to a smaller diameter so as to be conveniently installed into a delivery catheter with a smaller inner diameter, and the outer diameter of the delivery catheter may be 8 to 16F (feet), so that the valve stent 100 can be delivered through the femoral artery by percutaneous puncture or through the brachial artery, and various access modes are improved for interventional treatment.
Fig. 5 is a schematic diagram of the expanded valve stent of an implantable aortic biological valve in accordance with some embodiments of the invention. Referring to fig. 5, in some embodiments of the invention, the valve stent 100 has a length greater than 8 millimeters and less than 40 millimeters. Specifically, the length of the valve stent 100 may be any value between 12 mm and 30 mm, so that the valve stent 100 can be effectively fixed between aortic valves, and coronary arteries in the main arterial lumen can be prevented from leaking, so that the valve stent 100 can be prevented from shielding the coronary arteries, and a feasible scheme is provided for performing other interventional treatments through the coronary arteries in the later stage, wherein the coronary arteries refer to a Right Coronary Artery (RCA) and a Left Coronary Artery (LCA).
Fig. 6 is a schematic view of the configuration of barbs extending toward the left ventricle of an implantable aortic bioprosthetic valve according to some embodiments of the present invention. Referring to fig. 1 and 6, in some embodiments of the invention, the anchor 400 is a barb. One end of the barb is connected with the valve support 100, and the other end of the barb is obliquely arranged towards one side far away from the valve support 100, so that one side far away from the valve support 100 is abutted with the inner wall of the aorta. Specifically, the barb is a semi-annular structure formed by two arc rods, one end of each arc rod is fixedly connected with two fulcrums of one grid structure of the valve support 100, or is connected with two side rods of one grid structure of the valve support 100, and the other ends of the two arc rods are intersected and fixed, so that the semi-annular structure is formed. The inclination direction of the barbs can be one side facing the aorta or one side facing the left ventricle, and the specific direction of the barbs can be designed according to practical application scenes, so that the invention is not limited.
The plurality of barbs may be uniformly arranged in a circle, and two adjacent barbs may be connected to each other. The plurality of barbs may also be spaced apart, i.e. adjacent barbs are spaced apart by a distance. The plurality of barbs may also be unevenly distributed, i.e. the distance between any two adjacent barbs is not the same. The distribution mode of the barbs can be designed according to the practical application scene, so that the valve support 100 can be firmly and stably fixed on an aortic valve, and the valve support 100 cannot fall into a left ventricle from the aorta.
Referring to fig. 3, in some embodiments of the invention, the anchor 400 may also be a radially outwardly bulging protrusion. The raised ring is provided on the outside of the valve holder 100, the raised sides being intended to abut against the inner wall of the aorta. Specifically, the protrusions may be "D" shaped, and the protrusions may be formed by an arc-shaped rod fixed separately on the outer side of the valve stent 100 and the outer side wall of the valve stent, or may be formed by protruding the mesh structure of the valve stent 100 to form the protrusions. The protrusions may or may not be evenly distributed along the circumference of the valve holder 100. The protrusions may also be in the form of blocks or other shapes, and the invention is not limited to the specific shape of the protrusions. The contact area between the protrusions and the inside of the aorta is relatively large, so that the valve stent 100 can be well fixed, and the valve stent 100 does not fall into the left ventricle. The protrusions and barbs may be provided either alone or in combination, and may be circumferentially spaced apart along the valve holder 100 to improve the stability of the installation of the valve holder 100.
It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the invention. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.