阅读说明：本技术 耐久性增强型带三叶生物瓣移植物及其制备方法 (Durability-enhanced tri-leaflet bioprosthetic valve graft and preparation method thereof ) 是由 景在平 李逸明 鲍贤豪 冯家烜 左辉 周建 冯睿 赵志青 李涛 赵玉玺 何潇敏 于 2019-10-08 设计创作，主要内容包括：本发明提供了一种耐久性增强型带三叶生物瓣移植物,具有这样的特征,包括：移植物主体；覆膜,包覆移植物主体外侧；以及三叶生物瓣体,设置在移植物主体内,具有三个瓣叶和两个加强突出部,其中,瓣叶具瓣叶主体和加强缝合部,瓣叶主体为类半椭圆状,具有大弯边缘、小弯边缘、位于大弯边缘与小弯边缘连接处的第一端部、第二端部,每个第一端部与相邻的瓣叶主体的第二端部之间重叠缝合在一起,加强缝合部重叠缝合在大弯边缘上,并缝合在支架骨架以及覆膜上,两个加强突出部分别连接在最外侧的两个瓣叶的相邻的大弯边缘的端部,并且两个加强突出部彼此重叠后缝合在支架骨架以及覆膜上,三个瓣叶主体与两个加强突出部一体化剪裁而成。(The invention provides a durability-enhanced tri-leaflet bioprosthetic valve graft, having the characteristics that: a graft body; covering a film to coat the outer side of the main body of the graft; and the three-leaf biological valve body is arranged in the graft body and is provided with three valve leaflets and two reinforcing protruding parts, wherein the valve leaflet is provided with a valve leaflet main body and a reinforcing sewing part, the valve leaflet main body is in a semi-elliptical shape and is provided with a large bending edge, a small bending edge, a first end part positioned at the joint of the large bending edge and the small bending edge and a second end part, each first end part is overlapped and sewn with the second end part of the adjacent valve leaflet main body, the reinforcing sewing part is overlapped and sewn on the large bending edge and is sewn on the support framework and the covering film, the two reinforcing protruding parts are respectively connected with the end parts of the adjacent large bending edges of the two valve leaflets at the outermost side, the two reinforcing protruding parts are overlapped and sewn on the support framework and the covering film, and the three valve leaflet main bodies and the two reinforcing protruding parts are integrally cut.)

1. A durability-enhanced tri-leaflet bioprosthetic valve graft, comprising:

the main body of the graft is a cylindrical stent framework;

A covering film, which is coated on the outer side of the stent framework; and

a tri-leaflet biological valve body disposed within the graft body and having three leaflets and two reinforcing projections,

Wherein the valve has a valve main body and a reinforced sewing part,

the valve leaf main body is similar to a semiellipse and is provided with a large bending edge, a small bending edge, a first end part and a second end part which are positioned at the joint of the large bending edge and the small bending edge,

each first end is overlappingly stitched together with the second end of the adjacent leaflet body,

The reinforcing suture part and the large bent edge have the same shape and size, are overlapped and sewed on the large bent edge, and the reinforcing suture part and the large bent edge which are overlapped and sewed are sewed on the stent framework and the covering film,

The two reinforcing protrusions are respectively connected with the end parts of the adjacent large bent edges of the two valve leaflets at the outermost side, and the two reinforcing protrusions are sewn on the stent framework and the covering film after being overlapped with each other,

The three leaflet main bodies and the two reinforcing protruding parts are integrally cut.

2. The durability-enhanced tri-leaflet bioprosthetic valve graft of claim 1, wherein:

Wherein, the material of the trilobe biological valve body is a pericardium material which is processed by antigen removal.

3. The durability-enhanced tri-leaflet bioprosthetic valve graft of claim 1, wherein:

Wherein the width of the reinforcing stitching part is not more than 1mm, and the width of the reinforcing protrusion part is not more than 1 mm.

4. the durability-enhanced tri-leaflet bioprosthetic valve graft of claim 1, wherein:

The support framework is a laser-engraved titanium alloy support framework and is composed of a plurality of continuous sine-wave-shaped support rings or a plurality of rhombic support rings.

5. The durability-enhanced tri-leaflet bioprosthetic valve graft of claim 1, wherein:

wherein, the material of tectorial membrane is polytetrafluoroethylene, sew up between tectorial membrane and the graft main part and link together.

6. A preparation method of a durability-enhanced tri-leaflet bioprosthetic valve graft is characterized by comprising the following steps:

Step 1, cutting a film with a proper size according to the support framework;

Step 2, marking the cut covering film;

Step 3, coating the marked film on the outer side of the support framework, and sewing;

Step 4, integrally cutting the processed pericardium material into three valve leaflet main bodies and two reinforcing protruding parts with preset sizes;

Step 5, cutting the processed pericardium material into three reinforced suture parts;

Step 6, overlapping and sewing each reinforcing sewing part with the large bending edge of each valve leaf main body;

Step 7, overlapping and sewing two adjacent reinforcing protruding parts;

Step 8, placing the three-leaf biological valve body in the stent framework, and sewing the sewed reinforced sewing part on the stent framework and the covering film according to the mark;

Step 9, overlapping and sewing the first end of each leaflet main body and the second end of the adjacent leaflet main body,

wherein the durably reinforced trilobal biological valve graft is the durably reinforced trilobal biological valve graft of any one of claims 1-6,

In the step 2, the specific process of marking on the coating film is that two marking lines perpendicular to the long axis are made along the long axis of the coating film so as to divide the coating film into three regions equally, the midpoints of all boundaries are marked, a connecting line between two adjacent midpoints in the short axis direction of the coating film is used as a bottom edge to make an elliptic arc marking line, so that the long axis of an arc passes through the midpoints on the long axis boundary of the coating film,

and 8, overlapping the sewed reinforced sewing part with the elliptical arc marking line on the covering film, and sewing in a mode of covering film feeding, large bent edge discharging, large bent edge feeding, covering film discharging and covering film feeding in a circulating sewing connection mode, and performing secondary sewing in a reverse needle feeding and discharging sequence on the same side.

7. The method of preparing a durability-enhanced tri-leaflet bioprosthetic valve graft of claim 6, wherein:

The sewing mode of the film and the stent framework is to carry out circular sewing according to the modes of sine wave trough downward feeding, wave waist upward discharging, wave waist downward feeding at the same height, wave peak upward discharging, wave peak downward feeding, wave waist upward discharging, wave waist downward feeding at the same height, wave trough upward discharging, wave trough downward feeding, wave waist upward discharging and wave waist downward feeding at the same height, and then carry out secondary sewing in the sequence of reverse needle feeding and discharging at the same side.

8. The method of preparing a durability-enhanced tri-leaflet bioprosthetic valve graft of claim 6, wherein:

Wherein the suture mode between the reinforced suture part and the large bending edge of the valve leaflet main body is pure intermittent suture.

9. The method of preparing a durability-enhanced tri-leaflet bioprosthetic valve graft of claim 6, wherein:

The diameter of a sewing needle adopted by the sewing is equal to that of a sewing thread, the diameter of the sewing needle is smaller than 10mm, the needle cannot be withdrawn during sewing, and otherwise, the needle is inserted again from the original needle hole.

Technical Field

the invention relates to the field of medical instruments, in particular to a durability-enhanced biological valve graft with three leaves and a preparation method thereof.

background

Valvular heart diseases are a group of diseases characterized by structural damage, fibrosis, adhesions, shortening, myxomatous degeneration, avascular necrosis, calcinosis or congenital developmental malformations of the heart valve (including the leaflets, chordae tendineae and papillary muscles). Aortic valve degenerative stenosis is the most common primary degenerative valvular disease, which is high in incidence, hidden in onset, rapid in progression and extremely poor in prognosis. In the population over 75 years old, the incidence rate of aortic stenosis is 4.6 percent, and the incidence rate of moderate and severe stenosis is 2.8 percent. The early stage of the disease has no obvious clinical manifestation. However, in the later stages of the disease, once the patient develops symptoms, the disease progresses rapidly, and severe heart failure can be caused in a short period of time, so that the patient dies. Statistically, the 5-year survival rate of the asymptomatic patients with active valve stenosis is 21%, while the survival rate of the patients with symptomatic aortic valve stenosis is lower than 50% in only 12 months.

surgical Aortic prosthetic Valve Replacement (SAVR) is a traditional open Surgical treatment for Aortic stenosis. It adopts an operation mode, after a diseased aortic valve is removed, an artificial biological or mechanical aortic valve is sutured on the aortic valve annulus to replace the original aortic valve. In the operation, thoracotomy and extracorporeal circulation are required, the operation wound is large, the operation time is long, and the operation death rate and complication rate are high. In addition, most patients suffering from degenerative aortic stenosis are often associated with multisystem disease themselves, and most cannot tolerate open surgery. Epidemiological investigations have shown that 40% of advanced (age > 75) patients with severe aortic stenosis cannot tolerate traditional open surgery, while 5.2% of the surgical patients are at high surgical risk.

by 2025, the proportion of the aged population in Shanghai city will increase to 39.6%, the aged population is about 600 million, 16 million patients with severe aortic stenosis are expected, and TAVI treatment adaptation patients will be not less than 5-8 million. However, the import system of the current marketed transcatheter aortic valve stent implantation system is expensive, the total price of the device is about 300,000 RMB, and the patient is difficult to bear. At present, the domestic industry standard of durability of the aortic valve stent is to complete more than 2 hundred million tests in an accelerated fatigue test, which is equivalent to 5 years of life. However, as China enters an aging society, for example, the average life of people in Shanghai city is as long as 82 years, and the age of patients is required to be more than or equal to 70 years in the operation, the durability of the conventional aortic valve stent can not meet the survival demand of the people.

Therefore, how to enhance the durability of the biological valve graft with three leaves and reduce the production cost is urgent and necessary, and great social and economic benefits are also provided. The durability-enhanced tri-leaflet bioprosthetic valve graft has great market demand and wide market prospect.

Disclosure of Invention

the invention aims to solve the problem of durability of a biological valve graft with three leaves, and aims to provide a durability-enhanced biological valve graft with three leaves and a preparation method thereof.

the invention provides a durability-enhanced tri-leaflet bioprosthetic valve graft, having the characteristics that: the main body of the graft is a cylindrical stent framework; covering a film on the outer side of the stent framework; and a tri-leaflet biological valve body, which is arranged in the graft main body and is provided with three valve leaflets and two reinforcing bulges, wherein, the main body of the valve leaflet is semi-elliptical and is provided with a large curved edge, a small curved edge, a first end part and a second end part which are positioned at the joint of the large curved edge and the small curved edge, each first end part is overlapped and sewed with the second end part of the adjacent valve leaflet main body together, the shape and the size of the reinforced sewing part and the large curved edge are the same, the reinforced sewing part and the large curved edge which are overlapped and sewed are sewed on the large curved edge, the reinforced sewing part and the large curved edge which are overlapped and sewed are sewed on the support framework and the covering film, two reinforced protruding parts are respectively connected with the end parts of the adjacent large curved edge of the two valve leaflets at the outermost side, and the two reinforcing protrusions are overlapped with each other and then sewn on the stent framework and the covering film, and the three leaflet main bodies and the two reinforcing protrusions are integrally cut.

In the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: wherein, the material of the three-leaf biological valve body is a pericardium material which is processed by antigen removal.

In the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: wherein the width of the reinforced sewing part is not more than 1mm, and the width of the reinforced protruding part is not more than 1 mm.

In the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: the support framework is a laser-engraved titanium alloy support framework and consists of a plurality of continuous sine-wave-shaped support rings or a plurality of rhombic support rings.

In the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: wherein, the material of tectorial membrane is polytetrafluoroethylene, sews up between tectorial membrane and the graft main part and links together.

the invention provides a preparation method of a durability-enhanced tri-leaflet bioprosthetic valve graft, which is characterized by comprising the following steps: step 1, cutting a film with a proper size according to a support framework; step 2, marking the cut covering film; step 3, coating the marked film on the outer side of the stent framework, and sewing; step 4, integrally cutting the processed pericardium material into three valve leaflet main bodies and two reinforcing protruding parts with preset sizes; step 5, cutting the processed pericardium material into three reinforced suture parts; step 6, overlapping and sewing each reinforced sewing part and the large bending edge of each valve leaf main body; step 7, overlapping and sewing two adjacent reinforcing protruding parts; step 8, placing the three-leaf biological valve body in a support framework, and sewing the sewed reinforced sewing part on the support framework and the covering membrane according to the mark; step 9, overlapping and sewing the first end of each valve leaflet main body and the second end of the adjacent valve leaflet main body, wherein the durability-enhanced tri-leaflet bioprosthetic valve graft is the durability-enhanced tri-leaflet bioprosthetic valve graft of any one of claims 1 to 6, the step 2 of marking the covering film comprises the specific process of marking two marking lines perpendicular to the long axis along the long axis of the covering film so as to equally divide the covering film into three areas, marking the middle points of all boundaries, and marking an elliptical arc marking line by taking a connecting line between two adjacent middle points in the short axis direction of the covering film as a bottom line so that the long axis of an arc passes through the middle points on the long axis boundary of the covering film, and the step 8 of overlapping and sewing the sewed reinforcing sewing part and the elliptical arc marking line on the covering film in a mode of sewing the covering film in, the large curved edge out and the large curved edge in, The film-covering outlet and film-covering inlet are connected by circular sewing, and the secondary sewing is carried out in the sequence of reverse needle inlet and outlet at the same side.

In the preparation method of the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: the sewing mode of the covering film and the stent framework is to carry out circular sewing according to the modes of sine wave trough downward feeding, wave waist upward discharging, wave waist downward feeding at the same height, wave peak upward discharging, wave peak downward feeding, wave waist upward discharging, wave waist downward feeding at the same height, wave trough upward discharging, wave trough downward feeding, wave waist upward discharging and wave waist downward feeding at the same height, and then carry out secondary sewing in the sequence of reverse needle feeding and discharging at the same side.

In the preparation method of the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: wherein, the suture mode between the reinforced suture part and the large bent edge of the valve leaflet main body is pure intermittent suture.

In the preparation method of the durability-enhanced tri-leaflet bioprosthetic valve graft provided by the invention, the durability-enhanced tri-leaflet bioprosthetic valve graft can also have the following characteristics: the diameter of a sewing needle adopted by sewing is equal to that of a sewing thread, the diameter of the sewing needle is smaller than 10mm, the needle cannot be withdrawn during sewing, and otherwise, the needle is inserted again from the original needle hole.

Action and Effect of the invention

according to the durability-enhanced tri-leaflet bioprosthetic valve graft of the present invention, since the graft comprises a graft main body, a covering film and a tri-leaflet bioprosthetic valve body, the tri-leaflet bioprosthetic valve body has three leaflets and two reinforcing protrusions, the leaflets have a leaflet main body and a reinforcing suture part, the leaflet main body has a large curved edge, a small curved edge, a first end and a second end, each first end is overlapped and sewn with the second end of the adjacent leaflet main body, the reinforcing suture part is overlapped and sewn with the large curved edge and sewn on the stent framework and the covering film, the two reinforcing protrusions are overlapped and sewn on the stent framework and the covering film, the connection durability at the leaflet boundary can be enhanced by overlapping and sewing between the first end and the second end of the adjacent leaflet main body, the reinforcing suture part is arranged to form a double-layer structure with the large curved edge and the reinforcing suture part of the leaflet main body, this can improve the durability of connection between the leaflet edge and the stent framework and the coating, and can improve the durability of connection at the leaflet boundary by connecting the two reinforcing projections in an overlapping manner (reinforcing suture for the long diameter of adjacent leaflets). Therefore, the durability-enhanced trilobe biological valve graft has high durability, can meet the long-term use requirement of patients, further meets the aging social requirement of China, reduces the death of the patients caused by the limitation of medical appliances, and can also reduce the treatment cost of the patients.

the preparation method of the durability-enhanced three-leaf-shaped biological valve graft is simple to operate, is suitable for both manual preparation and machine preparation for enterprise production, and is a set of proven safe, effective and universal preparation method.

Drawings

FIG. 1 is a schematic structural view of a durably reinforced tri-leaflet bioprosthetic valve graft according to one embodiment of the present invention;

FIG. 2 is a schematic structural view of a graft body according to a first embodiment of the invention;

FIG. 3 is a schematic structural diagram of a tri-leaflet biological valve body according to a first embodiment of the present invention;

FIG. 4 is a top view of a durably reinforced tri-leaflet bioprosthetic valve graft in accordance with one embodiment of the present invention;

FIG. 5 is a schematic illustration of a label for a cover film according to a first embodiment of the invention;

FIG. 6 is a schematic view of the first embodiment of the present invention showing the reinforced seam and the large curved edge being sewn to the stent framework and the cover;

fig. 7 is a schematic structural view of a graft body according to a second embodiment of the present invention.

Detailed Description

In order to make the technical means, creation features, achievement objects and effects of the present invention easy to understand, the following embodiments will specifically describe the durability-enhanced tri-leaflet bioprosthetic valve graft of the present invention and the preparation method thereof with reference to the accompanying drawings.

< example one >

The embodiment provides a durability-enhanced tri-leaflet bioprosthetic valve graft and a preparation method thereof.

Fig. 1 is a schematic structural diagram of a durability-enhanced tri-leaflet bioprosthetic valve graft according to one embodiment of the present invention.

As shown in fig. 1, the durability-enhanced type tri-leaflet bioprosthetic valve graft 100 in the present embodiment includes a graft main body 10, a cover film 20, and a tri-leaflet bioprosthetic valve body 30.

Fig. 2 is a schematic structural diagram of a graft body according to a first embodiment of the invention.

as shown in fig. 2, the graft body 10 is a cylindrical stent framework made of a titanium alloy (without limitation to metal and proportion), laser-engraved, and formed of a plurality of stent rings of continuous sinusoidal wave type. The titanium alloy has memory performance, the laser engraving operation is accurate, and the mechanical property of the continuous sine wave structure is very reliable. The proximal stent of the graft body 10 is provided with barbs outwardly of the stent to enhance anchoring in vivo to prevent stent migration. In this embodiment, the graft body 10 is about 4cm in diameter.

The covering film 20 is a thin film structure coated on the outer side of the graft main body 10, is made of polytetrafluoroethylene, has good biocompatibility and good mechanical property, and can prevent the perivalvular leakage to a certain extent. The edge portions of the cover film 20 are sewn to each other. The main body part of the covering film 20 is sewn and connected with the stent framework.

Fig. 3 is a schematic structural diagram of a tri-lobe biological valve body according to a first embodiment of the present invention.

As shown in fig. 1 and 3, the trifoliate biological valve body 30 is disposed in the graft main body 10, and has a first leaflet 31, a second leaflet 32, a third leaflet 33, a first reinforcing protrusion 34, and a second reinforcing protrusion 35.

The first leaflet 31, the second leaflet 32, and the third leaflet 33 are connected in sequence and have similar shapes and structures, and thus the first leaflet 31 will be described in detail as an example.

the first leaflet 31 has a leaflet main body 311 and a reinforcing suture part 312.

The leaflet main body 311 has a semi-elliptical shape, and has a large curved edge 3111, a small curved edge 3112, and a first end 3113 and a second end 3114 at the junction between the large curved edge 3111 and the small curved edge 3112.

The reinforcing sewed portion 312 has the same shape and size as the large bent edge 3111. The reinforcing sewed portion 312 overlaps the large bent edge 3111 and is sewed on the large bent edge 3111. The reinforcing suture portion 312 is also sewn to the stent frame and the cover 20. The width of the reinforced sewed portion 312 does not exceed 1 mm. The width of the reinforcing suture part 312 is 0.5mm in the present embodiment.

The portion corresponding to the small curved edge 3112 is an arc-shaped stopper portion connected to (specifically, integrally cut out from) the elliptical main body portion corresponding to the large curved edge 3111. And the baffle part is used for forming a certain blocking effect on blood when the durability-enhanced tri-leaflet bioprosthetic valve graft 100 is used, so that the function of a human valve is simulated.

fig. 4 is a top view of a durability enhanced tri-leaflet bioprosthetic valve graft in accordance with one embodiment of the present invention.

As shown in fig. 3 and 4, the first end 3113 of the first leaflet 31 is sutured to the second end of the third leaflet 33. The second end 3114 of the first leaflet 31 is sutured to the first end of the second leaflet 32. The length of the first end portion 31121/the second end portion 31122 is about 3 mm.

The second end of the second leaflet 32 is sutured to the first end of the third leaflet 33. The adjacent two valve leaflets are only connected through the corresponding first end and the second end by sewing, and other areas on the valve leaflets are not sewn. Thus, the first leaflet 31, the second leaflet 32 and the third leaflet 33 form a triangle-like opening therebetween through which blood can pass in one direction.

The first reinforcing protrusion 34 connects the end of the large curved edge 3111 of the first leaflet 31, which is remote from the second leaflet 32. The second reinforcing projection 35 connects the end of the large curved edge of the third leaflet 33, which is remote from the second leaflet 32. The first reinforcing protrusion 34 and the second reinforcing protrusion 35 have the same shape and size. The first reinforcing protrusion 34 is square in shape in the present embodiment, and has a single-layer structure. The width of the first reinforcing protrusion 34 does not exceed 5 mm. In the present embodiment, the first reinforcing protrusion 34 has a width of 2mm to 3mm and a length of 5 mm. The first reinforcing protrusion 34 and the second reinforcing protrusion 35 are completely overlapped and then sewn to the stent framework and the cover 20.

the first leaflet 31, the second leaflet 32 and the third leaflet 33 have the same size, and the reinforced sewing part of each leaflet main body has the same shape and size with the corresponding large curved edge, so that the two leaflets can be overlapped and sewn into a uniform double-layer structure. In the present embodiment, the major half-axes of the three leaflet bodies each have a length h1 of 19mm, and the lengths d1, d2, d3 of the corresponding leaflet bodies of the first leaflet 31, the second leaflet 32, and the third leaflet 33 each have a length of 29mm excluding the first reinforcing protrusion 34 and the second reinforcing protrusion 35.

In the three-leaflet biological valve body 30, the first reinforcing protrusion 34, the leaflet main body 311 of the first leaflet 31, the leaflet main body of the second leaflet 32, the leaflet main body of the third leaflet 33, and the second reinforcing protrusion 35 are integrally cut out.

the material of the tri-leaf biological valve body 30 is a pericardial material processed by antigen removal. The pericardium material can be a commercially available pericardium patch which is already subjected to antigen removal treatment, or can also be untreated donkey pericardium material which needs to be subjected to antigen removal treatment before use. The pericardium patch can be a pericardium patch of cattle, pig and the like. In this embodiment, the pericardial material is specifically donkey pericardial material.

the process for preparing the durability-enhanced tri-leaflet bioprosthetic valve graft 100 of this embodiment includes the steps of:

Step 1, cutting a covering membrane 20 with a proper size according to a stent framework, and then entering step 2. The size of the cover film 20 is suitable for covering the surface of the stent framework and reserving a section of area at the two ends of the stent framework.

And 2, marking the cut coating film 20, and then entering the step 3.

FIG. 5 is a schematic illustration of a label of a coating according to a first embodiment of the invention.

As shown in fig. 5, the specific process of marking the coating film 20 is as follows:

step 2-1, spreading the film 20 on a workbench, taking tools such as a marking pen and a ruler, and making two marking lines perpendicular to the long axis along the long axis of the film 20, thereby equally dividing the film 20 into three areas.

Step 2-2 marks the middle points of all the boundaries of the three regions, the middle points of the boundaries in the long axis direction of the coating film 20 are respectively marked as a1, a2 and a3, and the middle points of the boundaries in the short axis direction of the coating film 20 are respectively marked as b1, b2, b3 and b 4.

And 2-3, drawing an elliptic arc by taking b1 and b2 as the bottom edges, and enabling a connecting line between the vertex of the elliptic arc and a1 to be vertical to the long axis direction of the coating film 20. The base lines of b2 and b3 are elliptical arcs, and the line between the apex of the elliptical arc and a2 is perpendicular to the long axis direction of the coating film 20. The base lines of b2 and b3 are elliptical arcs, and the line between the apex of the elliptical arc and a3 is perpendicular to the long axis direction of the coating film 20. The three elliptical arc marking lines are taken as elliptical arc marking lines.

And 3, covering the marked film 20 on the outer side of the stent framework, sewing, and then entering the step 4.

The suture mode of the covering membrane 20 and the stent framework is as follows: circularly sewing a circle according to the modes of sine wave trough downward-feeding, wave waist upward-discharging, same height wave waist downward-feeding (the step of wave waist can be repeated), wave peak upward-discharging, wave peak downward-feeding, wave waist upward-discharging, same height wave waist downward-feeding, wave trough upward-feeding, wave waist upward-discharging, same height wave waist downward-feeding, and performing secondary sewing in the sequence of needle feeding and needle discharging in the same side reverse direction. The sewing strength is enhanced by sewing the front and the back twice. After sewing, b1 and b4 are overlapped.

Step 4, the donkey pericardial material is processed by antigen removal, specifically by applying glutaraldehyde with a concentration of 0.625%, and the processed donkey pericardial patch is integrally cut into a first reinforcing protrusion 34 with a predetermined size, a leaflet main body 311 (including a main body part and a flap part) of the first leaflet 31, a leaflet main body (including a main body part and a flap part) of the second leaflet 32 (including a main body part and a flap part), a leaflet main body (including a main body part and a flap part) of the third leaflet 33, and a second reinforcing protrusion 35, and then the process proceeds to step 5. The cut-out shape is shown in fig. 3.

And 5, cutting three reinforcing suture parts with preset sizes from the processed pericardium material (which can be the residual leftover material in the step 4), and then entering the step 6.

And 6, overlapping and sewing each reinforced sewing part and the large bent edge of the corresponding valve leaflet main body in a simple intermittent sewing mode, and then entering the step 7.

In step 7, the first reinforcing protrusion 34 and the second reinforcing protrusion 35 are overlapped and sewn together in a simple intermittent manner, and then the process proceeds to step 8.

Step 8, placing the three-leaf biological valve body 30 in the stent framework, overlapping the sewed reinforced sewed part with the elliptical arc marking line on the covering film according to the mark on the covering film 20, and then sewing, so that the sewed reinforced sewed part and the large bent edge are sewed on the stent framework and the covering film 20, and then, the step 9 is carried out.

Fig. 6 is a schematic view of the suture mode of the reinforced suture part and the large bent edge which are sewed on the stent framework and the covering film 20 in the first embodiment of the invention.

As shown in fig. 6, the manner of sewing the sewn reinforcing sewn portion and the large curved edge to the stent framework and the cover 20 is: the method comprises the following steps of performing circular sewing connection in a mode of film covering in-out of a large bent edge, large bent edge in-out of a film covering in-out, and performing secondary sewing in a reverse needle in-out sequence on the same side. In fig. 6, the first suture is realized, the second suture is shown by a dotted line, and the four straight lines sequentially show the covering film, the stent framework, the reinforcing suture part and the large-bending edge from top to bottom.

Step 9, overlapping and sewing the first end of each leaflet main body with the second end of the adjacent leaflet main body, thereby obtaining the durability-enhanced tri-leaflet bioprosthetic valve graft 100. The sewing method is as follows: the reinforcement stitching is performed in the order of the covering film 20, the first reinforcement protrusion 34, the second reinforcement protrusion 35, the first reinforcement protrusion 34- …, the first reinforcement protrusion 34, the second reinforcement protrusion 35, and the covering film 20.

the prepared durable reinforced tri-leaflet bioprosthetic valve graft 100 is sterilized and then placed in phosphate buffered saline solution containing antibiotics, and is stored at 4 ℃ for later use.

in the case of the suture mentioned in the above preparation, the diameter of the needle for suturing is equal to the diameter of the suture. The suture is a suture with a diameter smaller than the diameter of the suture and has good mechanical property, in the embodiment, the diameter of the suture is smaller than 10 mm. The suture is a prolene5-0 suture with the diameter of 9.3mm and good mechanical property. The needle can not be withdrawn when suturing, otherwise, the needle is inserted again from the original needle hole.

< example two >