CN116672126B

CN116672126B - Artificial blood vessel with adjustable cavity content under pressure

Info

Publication number: CN116672126B
Application number: CN202310937848.6A
Authority: CN
Inventors: 请求不公布姓名; 李春明; 李晓萌; 殷敬华
Original assignee: Shanghai Weigao Medical Technology Development Co ltd
Current assignee: Shanghai Weigao Medical Technology Development Co ltd
Priority date: 2023-07-28
Filing date: 2023-07-28
Publication date: 2023-10-03
Anticipated expiration: 2043-07-28
Also published as: CN116672126A

Abstract

The invention provides an artificial blood vessel with adjustable cavity content under pressure, which comprises: an intermediate section; the intermediate section comprises a deformable unit; the deformable unit comprises a multi-section wall surface area; the pipe wall of the multi-section wall surface area comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer from inside to outside; a synthetic rubber secondary compact layer and/or a synthetic rubber secondary fluffy layer and a hard ring structure are arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; the pipe wall of the multi-section wall surface area is provided with a convex structure and a concave structure. Compared with the prior art, the middle section of the artificial blood vessel provided by the invention has the convex structure and the concave structure with the blood vessel cavity content being pressed and adjustable, so that the characteristic of high radial elasticity is simulated by the low-elasticity material under the action of the hard ring serving as a supporting framework, and the problem that the blood flow dynamics is obviously changed due to the radial elasticity variation of the blood vessel wall after blood flows into the artificial blood vessel from the autologous blood vessel is solved.

Description

Artificial blood vessel with adjustable cavity content under pressure

Technical Field

The invention belongs to the field of vascular implantation medical instruments, and particularly relates to an artificial blood vessel with adjustable cavity content.

Background

At present, artificial blood vessels are classified into large-caliber artificial blood vessels and small-caliber artificial blood vessels.

The inner diameter of the large-caliber artificial blood vessel is 10-32 mm, and the large-caliber artificial blood vessel is mainly applied to aortic (aortic) replacement and is characterized in that: (1) In order to prevent the risk of death of patients caused by excessive blood permeation of the wall of the aortic replacement blood vessel, the whole product is of a small-pore or pore-free structure; (2) In order to avoid the risks of related diseases such as heart failure and the like caused by excessive blood flow in the artificial blood vessel cavity, the radial elasticity of the whole artificial blood vessel wall of the product is very low; (3) The normal state of the aortic blood vessel is limited in bending, and the blood vessel is driven to bend only when the peripheral spine is bent, so that the bending amount is low, and the effect can be achieved by the conventional corrugated braided structure or nickel-titanium alloy. In addition, for vascular prostheses using stents comprising nickel-titanium alloy or medical stainless steel, the main function is endovascular repair (e.g., isolating hemangiomas, reducing the risk of vascular stenosis, etc., the main purpose of the stent is to prop up the vessel wall), which is generally not used for vascular replacement.

The small-caliber artificial blood vessel has an inner diameter of about 6 mm, is mainly applied to small blood vessels except the aorta, and is generally used for establishing vascular access. The artificial blood vessel for dialysis has the function of establishing a new blood vessel passage for blood flow, the establishment of the passage is not based on the position of an autologous blood vessel, and daily puncture is carried out on the artificial blood vessel, so that the blood vessel wall has the characteristics of firmness, puncture resistance, easy puncture and small puncture blocking point. Meanwhile, in order to facilitate the daily life of a patient and increase the puncture points, the artificial blood vessel is generally implanted on limbs, generally is implanted in a U-shaped bending way, and an inner cavity is not collapsed and blocked after bending, so that the artificial blood vessel is required to have certain strength in the radial direction and has bending characteristics.

The current artificial blood vessel for dialysis belongs to a small-caliber artificial blood vessel, the inner diameter of the blood vessel is 3-8 mm, the artificial blood vessel is made of polytetrafluoroethylene as a main body material, and a supporting ring is introduced to improve the supporting property and the bending resistance of the artificial blood vessel, so that the blood vessel is not bent in bending use.

The artificial blood vessel product for classical dialysis is prepared from expanded polytetrafluoroethylene, has uniform and fine holes, can cause seroma due to ultrafiltration phenomenon in clinical use, and can carry out post-puncture dialysis after the complications disappear. Meanwhile, the artificial blood vessel is inelastic due to the fact that a needle hole generated after puncture cannot be automatically closed, local pressing is needed to assist closing, pressing time is long, and the probability of bleeding is high.

The new-born artificial blood vessel product introduces the elastic polymer interlayer, reduces or eliminates the seroma caused by ultrafiltration phenomenon, and simultaneously improves the elasticity of the artificial blood vessel wall interlayer, so that the puncture needle hole has a self-closing effect. The artificial blood vessel product can be punctured in a short time after being implanted into a patient, and the complications such as seroma do not need to be disappeared, so that the closing effect of a needle hole after puncturing is improved, the local pressing hemostasis time is reduced, and the probability of blood seepage risk is reduced.

However, the structure of the new-born artificial blood vessel is a multi-layer composite structure, compared with the classical artificial blood vessel, the new-born artificial blood vessel is thicker in wall (the thickness reaches 0.7-1.0 mm) due to the fact that the elastic polymer interlayer is added, and the anastomosis difficulty with the autologous blood vessel is affected. And because of the poor radial elasticity of polytetrafluoroethylene materials in the inner cavity and the outer layer of the blood vessel, the content of the artificial blood vessel cavity is basically unchanged under the influence of blood pressure, and the radial elasticity of the wall of the artificial blood vessel is suddenly reduced after blood flows into the artificial blood vessel, so that the change of blood dynamics is obvious, the risk of inducing stenosis/occlusion/blood flow reduction/thrombus is easily improved, and the smoothness of middle and long periods is reduced. The inner diameter change rate of the artificial blood vessel has obvious correlation with the patency rate, namely, the larger the difference between the inner diameter change rate and the real blood vessel is, the lower the long-term patency rate of the transplanted blood vessel is, for example, the real blood vessel has radial elasticity, and the one-year patency rate is 83% and the three-year patency rate is 62% when the artificial blood vessel is used for implantation; however, the one-year patency rate of the polytetrafluoroethylene artificial blood vessel is about 60 percent, which is basically equal to the three-year patency rate value of the autologous blood vessel, and the main reason is that the current polytetrafluoroethylene artificial blood vessel has low inner diameter change rate, which is less than about 0.2 percent, and the difference value of the inner diameter change rate of the polytetrafluoroethylene artificial blood vessel is close to 2 percent, and the difference value is basically equal to the inner diameter change rate value of the autologous blood vessel. This shows that the poor radial elasticity of the current polytetrafluoroethylene artificial blood vessel is an important reason for low patency rate and short service time.

Disclosure of Invention

In view of the above, the present invention aims to provide an artificial blood vessel with adjustable lumen content and a preparation method thereof.

The invention provides an artificial blood vessel with adjustable cavity content under pressure, which comprises: an intermediate section;

the intermediate section comprises a deformable unit; the deformable unit comprises a multi-section wall surface area; the pipe wall of the multi-section wall surface area comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer from inside to outside;

a synthetic rubber sub-compact layer and/or a synthetic rubber sub-fluffy layer are arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer;

a hard ring structure is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer;

the pipe wall of the multi-section wall surface area is provided with a convex structure and a concave structure.

The invention also provides an artificial blood vessel with adjustable cavity content under pressure, which comprises: an intermediate section;

the pipe wall of the multi-section wall surface area is provided with a convex structure and a concave structure;

the hard ring is wrapped or partially wrapped with a high polymer binding layer;

the hard ring structure is arranged at one side edge of the concave structure or at two side edges of the concave structure, the number of the concave structures in the deformable unit is more than or equal to 2, and the total number of the concave structures in the deformable unit is less than that of the concave structures in the deformable unit.

Preferably, the hard ring is wrapped or partially wrapped with a polymer binding layer.

Preferably, the hard ring structure is disposed within the synthetic rubber secondary compact layer, within the synthetic rubber secondary bulk layer, or between the synthetic rubber secondary compact layer and the synthetic rubber secondary bulk layer.

Preferably, the polymer bonding layer has a whole layer structure and is arranged in the synthetic rubber compact layer or the synthetic rubber sub-fluffy layer, and the synthetic rubber compact layer or the synthetic rubber sub-fluffy layer is divided into two layers; or the polymer bonding layer is of a whole layer structure and is arranged between the synthetic rubber sub-compact layer and the synthetic rubber sub-fluffy layer.

Preferably, a synthetic rubber secondary compact layer is arranged between the polytetrafluoroethylene compact base layer and the high polymer fluffy layer, the hard ring is arranged between the synthetic rubber secondary compact layer and the high polymer fluffy layer, and a synthetic rubber secondary fluffy layer is arranged between the hard ring and the high polymer fluffy layer;

And/or a synthetic rubber sub-fluffy layer is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer, the hard ring is arranged between the synthetic rubber sub-fluffy layer and the polytetrafluoroethylene compact base layer, and a synthetic rubber sub-compact layer is arranged between the hard ring and the polytetrafluoroethylene compact base layer.

Preferably, a synthetic rubber secondary compact layer and a synthetic rubber secondary fluffy layer are sequentially arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer;

the hard ring structure is arranged in the synthetic rubber secondary compact layer, the synthetic rubber secondary fluffy layer or between the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer.

Preferably, the polymer bonding layer has a whole layer structure and is arranged between the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer;

and/or the elastomeric secondary loft layer has an elasticity that is superior to the elasticity of the elastomeric secondary densified layer.

Preferably, the thickness of the polymer bonding layer is 0.05-0.45 mm;

the polymer bonding layer is formed by one or more of polypropylene, polyethylene terephthalate and polyamide.

And/or the thickness of the synthetic rubber secondary compact layer is 0.05-0.30 mm;

And/or the thickness of the synthetic rubber sub-fluffy layer is 0.05-0.60 mm.

Preferably, the axial length of the hard ring structure is less than or equal to 2 mm;

and/or the ratio of the axial length to the thickness of the hard ring structure is greater than or equal to 1.

And/or taking the axial direction of the artificial blood vessel and the central line of the hard ring structure as references, wherein the inclination angle of the hard ring structure is 15-90 degrees;

and/or the height difference between the highest point of the convex structure and the lowest point of the concave structure is 0.1-1 mm.

Preferably, the hard ring structure is arranged in a spiral structure in the deformable unit;

alternatively, the artificial blood vessel comprises a plurality of the hard rings, wherein the hard rings are in a parallel ring structure, and further, the parallel rings are basically perpendicular to the axis of the artificial blood vessel.

Preferably, the number of the hard ring structures in the deformable unit is greater than or equal to 1, and the hard ring structures are arranged at the convex structures and/or at one side edge of the convex structures and/or at two side edges of the convex structures and/or at one side edge of the concave structures and/or at two side edges of the concave structures;

when the number of the hard ring structures in the deformable unit is larger than 1, the distance between the adjacent hard rings is 0.8-8.5 mm.

Preferably, the hard ring structure is arranged at the convex structure, and the polytetrafluoroethylene compact base layer corresponding to the hard ring structure is provided with a structure convex inwards towards the central line of the artificial blood vessel;

and/or the pipe wall thickness of the multi-section wall surface area is 0.3-1.2 mm.

Preferably, the number of the convex structures and the number of the concave structures in the multi-section wall surface area are respectively and independently greater than or equal to 1, and when the number of the convex structures and/or the number of the concave structures are multiple, the convex structures and the concave structures are arranged at intervals.

Preferably, the deformable unit further comprises a smooth wall area; the pipe wall of the smooth wall surface area comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer which are sequentially arranged from inside to outside; the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer of the smooth wall area are provided with a synthetic rubber sub-compact layer and/or a synthetic rubber sub-fluffy layer.

Preferably, the length ratio of the multi-section wall surface area to the smooth wall surface area in the deformable unit is 1: (0-2);

and/or the wall thickness of the smooth wall surface area is 0.3-0.8 mm.

Preferably, the length of the deformable unit is 1-10 mm; the intermediate section comprises a plurality of deformable elements;

Preferably, the distance between two adjacent hard rings of adjacent deformable units is 0.8-8.5 mm.

Preferably, the elastomeric secondary densified layer is formed of silicone and/or polyurethane;

and/or, the elastomeric secondary fluff layer is formed from silicone and/or polyurethane;

and/or the macromolecule fluffy layer is formed by one or more of polytetrafluoroethylene, polyvinylidene fluoride, polypropylene, polyethylene terephthalate and polyamide;

and/or the porosity of the synthetic rubber secondary fluffy layer is 10-90%; the porosity of the macromolecule fluffy layer is 35-99%; preferably, the porosity of the polymer fluffy layer is 70% -99%.

And/or the synthetic rubber secondary fluff layer has a porosity less than the polymer fluff layer.

Preferably, the maximum inner diameter change rate of the multi-section wall surface area in a pressurized state (the pressurized value is 7 kPa to 24 kPa) is 0 to 13%, and the maximum relative inner diameter change rate is preferably 0.1 to 5%.

The invention provides an artificial blood vessel with adjustable cavity content under pressure, which comprises: an intermediate section; the intermediate section comprises a deformable unit; the deformable unit comprises a multi-section wall surface area; the pipe wall of the multi-section wall surface area comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer from inside to outside; a synthetic rubber sub-compact layer and/or a synthetic rubber sub-fluffy layer are arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; a hard ring structure is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; the pipe wall of the multi-section wall surface area is provided with a convex structure and a concave structure. Compared with the prior art, the middle section of the artificial blood vessel provided by the invention has the convex structure and the concave structure with the blood vessel cavity content being pressed and adjustable, so that the characteristic of high radial elasticity is simulated by the low-elasticity material under the action of the hard ring serving as a supporting framework, and the problem that the blood flow dynamics is obviously changed due to the radial elasticity variation of the blood vessel wall after blood flows into the artificial blood vessel from the autologous blood vessel is solved.

Drawings

FIG. 1 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 2 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 3 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 4 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 5 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 6 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 7 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 8 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 9 is a schematic diagram of a cross-section of a wall of an artificial blood vessel according to the present invention;

FIG. 10 is a schematic view of an artificial vascular wall according to the present invention;

FIG. 11 is a schematic view of a multi-segmented wall region of an artificial blood vessel according to the present invention;

FIG. 12 is a schematic axial cross-sectional view of an artificial blood vessel according to the present invention deformed at low and high pressures;

FIG. 13 is a schematic view of the structure of the wall of the middle segment of the artificial blood vessel according to the present invention;

FIG. 14 is a schematic view of the structure of the wall of the middle segment of the artificial blood vessel according to the present invention;

FIG. 15 is a schematic view of the structure of the wall of the middle segment of the artificial blood vessel according to the present invention;

FIG. 16 is a schematic view of the structure of the wall of the middle segment of the artificial blood vessel according to the present invention;

FIG. 17 is a schematic cross-sectional view of a deformable element of an artificial blood vessel according to the present invention;

FIG. 18 is a schematic view of the wall structure of the intermediate section of an artificial blood vessel according to the present invention;

FIG. 19 is a schematic view of the structure of the middle segment of the artificial blood vessel according to the present invention;

FIG. 20 is a schematic view of the structure of the middle segment of the artificial blood vessel according to the present invention;

FIG. 21 is a schematic view of the structure of the middle segment of the artificial blood vessel according to the present invention;

FIG. 22 is a schematic view of an artificial blood vessel according to the present invention;

fig. 23 is a three-dimensional partial cross-sectional view of the prosthesis illustrated in fig. 8 or 16 in a stiff annular helical arrangement provided by the present invention.

Detailed Description

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

According to the invention, the deformable unit comprises a multi-section wall surface area, the multi-section wall surface is provided with obvious deformation characteristics, the deformation can be obvious after pressurization, and the deformation can be recovered after depressurization. The pipe wall thickness of the multi-section wall surface area is preferably 0.3-1.2 mm. The pipe wall of the multi-section wall area comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer from inside to outside; meanwhile, in order to ensure the pinhole closing effect, the middle layer comprising the secondary compact layer, the bonding layer, the hard ring and the secondary fluffy layer needs to have a certain thickness, so that the defect of pinhole self-closing caused by no/low recovery elasticity is avoided.

The innermost layer of the pipe wall of the multi-section wall surface area is a polytetrafluoroethylene compact base layer; the density of the polytetrafluoroethylene compact base layer is preferably 2-20 g/cm ³ The method comprises the steps of carrying out a first treatment on the surface of the The polytetrafluoroethylene compact base layer is formed by polytetrafluoroethylene pressing, is low in elasticity, provides a cavity channel in direct contact with blood, has general elasticity in the length direction after heat setting, overcomes the problem of poor radial elasticity, and is used as a base of other layers; the thickness of the polytetrafluoroethylene compact base layer is preferably 0.005-0.255 mm; the dense base layer is soft and deformable under the condition of being thinner.

Because the surface of the polytetrafluoroethylene compact base layer is smoother, the polytetrafluoroethylene compact base layer is provided with the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer so as to avoid the problem that the hard ring structure slides to cause a cavity around the hard ring, if the polytetrafluoroethylene compact base layer enters a cavity area during puncture, high-flow-rate blood possibly separates the compact base layer from other layers after needle drawing, the blood rushes into the cavity to cause interlayer generation of artificial blood vessel walls, vascular stenosis is caused, the risk of vascular blockage is caused, and finally, the product is out of function, therefore, the compact base layer is required to be provided with the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer, and the synthetic rubber secondary compact layer is arranged on the optimized polytetrafluoroethylene compact base layer, so that the problem can be better avoided; the secondary compact layer and/or the secondary fluffy layer are/is required to be wrapped with a hard ring with a certain thickness and the bonding layer is not exposed, and meanwhile, the needle holes are ensured to be closed after puncture, and a certain thickness is required, wherein the thickness of the synthetic rubber secondary compact layer is preferably 0.05-0.30 mm; the thickness of the synthetic rubber sub-fluffy layer is preferably 0.05-0.60 mm; the synthetic rubber secondary compact layer and/or the synthetic rubber secondary fluffy layer are arranged on the polytetrafluoroethylene compact base layer, so that the middle elasticity of the middle section of the artificial blood vessel can be enhanced, and the pinhole closing effect after product puncture is enhanced; the synthetic rubber secondary compact layer is preferably formed by silicone and/or polyurethane, more preferably by 30% -100% (mass percent) of silicone solution and/or 30% -100% (mass percent) of polyurethane solution, and still more preferably by 40% -80% (mass percent) of silicone solution and/or 40% -80% (mass percent) of polyurethane solution; the synthetic rubber secondary fluffy layer or the synthetic rubber secondary compact layer is contacted with the polytetrafluoroethylene compact base layer, so that the pores of the compact layer can be plugged, and the synthetic rubber secondary compact layer is contacted with the polytetrafluoroethylene compact base layer as a preferable scheme, so that the pores of the compact layer can be plugged better; the porosity of the synthetic rubber sub-fluffy layer is preferably 10-90%; the synthetic rubber sub-fluff layer is preferably formed by silicone and/or polyurethane, more preferably by a silicone solution of 25% -60% (mass percent) and/or a polyurethane solution of 25% -60% (mass percent), and still more preferably by a silicone solution of 25% -50% (mass percent) and/or a polyurethane solution of 25% -50% (mass percent). In embodiments of the present invention having both a synthetic rubber secondary bulk layer and a synthetic rubber secondary compact layer, preferably, the elastic properties of the synthetic rubber secondary bulk layer are better than those of the synthetic rubber secondary compact layer, generally meaning that the elastic modulus of the synthetic rubber secondary compact layer is greater than that of the synthetic rubber secondary bulk layer; preferably, the preparation solution of the synthetic rubber sub-fluffy layer and the synthetic rubber sub-compact layer is selected from the same type of solution, for example, one of a silicone solution and a polyurethane solution is selected, the mass percentage of silicone or polyurethane adopted by the synthetic rubber sub-fluffy layer is smaller than that of the synthetic rubber sub-compact layer, the connection effect of the prepared synthetic rubber sub-fluffy layer and the synthetic rubber sub-compact layer is better, and meanwhile, under the condition of the same other conditions, a relation curve of the mass percentage and the elasticity can be obtained, so that the preparation solution with different mass percentages can be selected according to different elasticity requirements of the synthetic rubber sub-fluffy layer and the synthetic rubber sub-compact layer; of course, it will be appreciated by those skilled in the art that other components may be added thereto and/or the process conditions for preparation thereof may be altered under conditions that satisfy the fact that the elastomeric secondary densified layer has less elasticity than the elastomeric secondary loft layer.

In the embodiment of the invention with the synthetic rubber sub-fluffy layer and the synthetic rubber sub-compact layer, preferably, the synthetic rubber sub-fluffy layer has larger porosity than the synthetic rubber sub-compact layer, so that the product can be stretched longer in the length direction after bending, the risk of vascular bending collapse is reduced, (when an artificial blood vessel is bent, the distance between two opposite points of the cross section shape of the bending part is shortened, the ratio of the shortened distance to the original distance is reduced to a certain value or less, and the value is generally 50% or less), and as can be understood, the porosity is only one of the influencing factors of the vascular bending collapse risk; as the preferable scheme, the synthetic rubber sub-compact layer and the synthetic rubber sub-fluffy layer are sequentially arranged between the polytetrafluoroethylene compact layer and the high polymer fluffy layer, so that the artificial blood vessel has better flexibility, of course, for example, the synthetic rubber sub-compact layer between the polytetrafluoroethylene compact layer and the high polymer fluffy layer is replaced by the synthetic rubber sub-fluffy layer, namely, the synthetic rubber sub-fluffy layer is only arranged, and under the same other conditions, the product is easier to bend. In embodiments of the present invention having both a synthetic rubber sub-dense layer and a synthetic rubber sub-loft layer, the synthetic rubber sub-loft layer has a greater porosity than the synthetic rubber sub-dense layer. In the embodiment of the invention with the synthetic rubber sub-fluffy layer, the porosity of the synthetic rubber fluffy layer is larger than that of the synthetic rubber sub-compact layer, and meanwhile, the synthetic rubber sub-fluffy layer enables the product to be stretched longer in the length direction after being bent, so that the risk of vascular bending collapse is reduced.

A hard ring structure is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; in the invention, the axial length of the hard ring structure is preferably less than or equal to 2 mm, more preferably 0.1-1.5 mm; the invention has no special limitation on the cross section shape of the hard ring, and the hard ring can be rectangular, circular, elliptic or irregular polygonal, the thickness of the hard ring structure can ensure that the hard ring meets the use requirement, preferably, in order to avoid the excessive thickness of the whole pipe wall of the artificial blood vessel at the hard ring, the thickness of other layers at the hard ring of the artificial blood vessel is thinned, and the ratio of the axial length (namely the width of the cross section) of the hard ring structure to the thickness (namely the dimension along the radial direction of the artificial blood vessel) is preferably more than or equal to 1, wherein the cross section refers to the cross section of the axis of the artificial blood vessel; the hard ring structure is made of one or more of polyethylene, polypropylene, polyethylene terephthalate, polyvinylidene fluoride and perfluoroethylene propylene copolymer; in the invention, the hard ring structure is preferably arranged around the convex structure or the concave structure to fix the shape of the pipe wall, the hard ring does not have radial expansion and contraction, and the convex structure and the concave structure can improve the volume change rate and enable the artificial blood vessel to repeatedly expand or contract radially by taking the hard ring as the center. Further preferably, the hard ring structure is arranged at the convex structure and/or at one side edge of the convex structure and/or at two side edges of the convex structure and/or at one side edge of the concave structure or at two side edges of the concave structure; referring to fig. 1 to 3, fig. 1 to 3 are schematic cross-sectional views of a tube wall of an artificial blood vessel provided by the present invention, wherein 5 is a polymer fluffy layer, 7 is a polymer bonding layer, 8 is a synthetic rubber sub-dense layer (in other embodiments, the synthetic rubber sub-dense layer 8 in fig. 1 to 3 may be replaced by a synthetic rubber sub-fluffy layer), 9 is a polytetrafluoroethylene dense base layer, 10 is a hard ring structure, 11 is a convex structure, and 12 is a concave structure. The hard ring structures in fig. 1 and 2 are arranged at the convex structure, and the hard ring structures in fig. 3 are arranged at two sides of the lowest point of the concave structure; when the hard ring structures are arranged on two sides of the outer convex structure or two sides of the inner concave structure, the axial distance between the center of the hard ring structure and the inner concave structure or the outer convex structure is c, the axial length of the hard ring structure is r, and c is preferably less than or equal to 2r, as shown in fig. 3; in the invention, the hard ring structures are arranged at one side edge of the concave structure or at two side edges of the concave structure, the number of the concave structures in the deformable unit is more than or equal to 2, and the total number of the concave structures in the deformable unit is less than that of the concave structures in the deformable unit; in the invention, it is further preferable that the hard ring structure is arranged at one side edge of the concave structure or at two side edges of the concave structure, the number of the concave structures in the feasible variable units is 2, and the hard ring structure is only positioned in one of the concave structures; in the present invention, it is further preferable that the hard ring structure is not provided at the lowest point of the concave structure; in addition, when the hard ring parallel ring structure is arranged, an inclination angle can exist between the central line of the hard ring and the axis or the axial direction of the artificial blood vessel, and the inclination angle of the hard ring structure is preferably 15-90 degrees based on the axial direction of the artificial blood vessel and the central line of the hard ring, namely, the included angle between the central line of the hard ring and the axial direction of the artificial blood vessel is 15-90 degrees, referring to fig. 4, and further preferably, the inclination angle is approximately 90 degrees, namely, the hard ring is basically perpendicular to the axis of the artificial blood vessel. When the hard ring is in a spiral structure, the central line of the hard ring is a spiral line, the lift angle of the spiral line is between 0 and 65 degrees, and the central line refers to the connecting line of the central points of the cross section outlines of the hard ring.

The number of the deformable units, namely the hard ring structures in the multi-section wall surface area is preferably more than or equal to 1; when the number of the hard ring structures in the deformable units is greater than 1, the distance between two adjacent hard rings in each deformable unit is preferably 0.8-8.5 mm; when the number of the hard rings is multiple, the spacing between two adjacent hard rings can be uniformly changed, can have two or more repeatedly changed spacing, and can also be only one fixed spacing; for the uniformly-changed spacing of the hard rings, the variation of each spacing is preferably 0.001-0.150 mm; for two or more deformable elements of repeatedly varying spacing, the difference between adjacent two spacing is preferably 0.01 to 1.50 mm (e.g., an artificial blood vessel having two hard rings of repeatedly varying spacing, the difference between the first and second hard ring spacing and the second and third hard ring spacing for one of the adjacent three hard rings is 0.01 to 1.50 mm); when the number of the hard rings is plural, the hard rings may be arranged in parallel or in spiral. The parallel rings are closed annular hard rings and are parallel to each other; when the hard rings are spirally arranged, and the hard rings can be arranged in a plurality of spiral hard rings at two or more repeatedly-changed intervals, the number of the hard rings can correspond to the number of the repeatedly-changed intervals, for example, when the hard rings are arranged at two repeatedly-changed intervals, the number of the hard rings is 2, and the intervals between the hard rings can be adjusted wholly and conveniently during artificial blood vessel preparation. The hard rings are preferably arranged in parallel spirals when they are arranged in a spiral. When the spacing between the hard rings is uniformly changed, the whole bending resistance of the artificial blood vessel is consistent, and the artificial blood vessel can be bent at any position at will without collapse; too small a length of the deformable unit can increase the number of rigid rings in a unit length, which can lead to difficult bending of the artificial blood vessel, and too long a length of the deformable unit can reduce the number of rigid rings in a unit length, which can lead to collapse in bending of the artificial blood vessel. In the invention, the distance between two adjacent hard rings is 0.8-8.5 mm, and the distance comprises: when the hard ring is a parallel ring, the space between any two adjacent parallel rings is kept; when the hard ring is of a spiral structure, that is, a spiral ring structure, the space between any two adjacent spiral rings (when the spiral rings are single, the pitch of the spiral structure, and when the spiral rings are multiple, the distance between the two adjacent spiral ring structures) is defined. If a smooth wall area is provided between adjacent hard rings, it is preferable that the length of the smooth wall area is not taken into account, i.e. the distance preferably refers only to the distance between two adjacent hard rings in the multi-segment wall area. The outer diameter change rate of the artificial blood vessel provided by the invention can be adjusted according to the parallel ring spacing or the parallel spiral spacing of the hard ring structure, so that the capacity of the inner cavity of the product after being pressed is adjustable.

In the present invention, preferably, the hard ring structure is disposed in the synthetic rubber secondary compact layer, in the synthetic rubber secondary bulk layer, or between the synthetic rubber secondary compact layer and the synthetic rubber secondary bulk layer; as shown in fig. 1-3, the hard ring structure in fig. 1-3 is arranged in the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer; when, for example, the outer side of the hard ring is free of the synthetic rubber sub-bulky layer or the synthetic rubber sub-dense layer, the hard ring or the synthetic rubber sub-dense layer may be combined with weak bonding, and multiple bending or shaking may occur to separate and lose the function of resisting the collapse of blood vessels, so that it is further preferable that the hard ring structure is arranged in the synthetic rubber sub-bulky layer or the synthetic rubber sub-dense layer or between the synthetic rubber sub-dense layer and the synthetic rubber sub-bulky layer. In one embodiment of the present invention, a synthetic rubber sub-dense layer and a synthetic rubber sub-fluffy layer are sequentially disposed between the polytetrafluoroethylene dense base layer and the polymer fluffy layer, the hard ring structure is disposed in the synthetic rubber sub-dense layer, see fig. 5, fig. 5 is a schematic diagram of a wall section of the artificial blood vessel provided by the present invention, wherein 5 is a polymer fluffy layer, 6 is a synthetic rubber sub-fluffy layer, 7 is a polymer bonding layer, 8 is a synthetic rubber sub-dense layer, 9 is a polytetrafluoroethylene dense base layer, 10 is a hard ring structure, in fig. 5, the hard ring structure 10 is disposed in the synthetic rubber sub-dense layer 8 and is disposed between the hard ring structure and the polymer fluffy layer 5, the polymer bonding layer 7 is a whole layer structure disposed between the synthetic rubber sub-dense layer 8 and the synthetic rubber sub-fluffy layer 6, and partially wraps the hard ring structure; in one embodiment of the present invention, a synthetic rubber secondary compact layer and a synthetic rubber secondary fluffy layer are sequentially arranged between the polytetrafluoroethylene compact base layer and the polymer fluffy layer, and the hard ring structure is arranged between the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer; in another embodiment provided by the invention, a synthetic rubber secondary compact layer is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; the hard ring is arranged between the synthetic rubber secondary compact layer and the high polymer fluffy layer, and a synthetic rubber secondary fluffy layer is arranged between the vicinity of the hard ring and the high polymer fluffy layer, namely, only the synthetic rubber secondary fluffy layer is arranged between the hard ring and the high polymer fluffy layer at the moment, and the synthetic rubber secondary fluffy layer is not in a whole layer structure in other pipe wall areas; referring to fig. 6, fig. 6 is a schematic diagram of a cross section of a wall of an artificial blood vessel provided by the present invention, wherein 5 is a polymer fluffy layer, 6 is a synthetic rubber sub-fluffy layer, 7 is a polymer bonding layer, 8 is a synthetic rubber sub-dense layer, 9 is a polytetrafluoroethylene dense base layer, and 10 is a hard ring structure, and in fig. 6, only the synthetic rubber sub-fluffy layer 6 is provided between the vicinity of the hard ring structure 10 and the polymer fluffy layer 5. As another embodiment, a synthetic rubber sub-fluffy layer is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer, the hard ring is arranged between the synthetic rubber sub-fluffy layer and the polytetrafluoroethylene compact base layer, and a synthetic rubber sub-compact layer is arranged between the hard ring and the polytetrafluoroethylene compact base layer, namely, the artificial vascular structure is changed on the basis of fig. 6, a synthetic rubber sub-compact layer 8 is arranged between the vicinity of the hard ring structure 10 and the polytetrafluoroethylene compact base layer 9, and the synthetic rubber sub-fluffy layer 6 is a continuous complete layer.

In order to improve the binding force between the hard ring and the synthetic rubber sub-compact layer and/or the synthetic rubber sub-fluffy layer, the relative position of the hard ring is fixed, so that the hard ring is prevented from generating a cavity due to relative movement inside, and the hard ring is wrapped or partially wrapped by a high polymer binding layer; in the artificial blood vessel provided by the invention, the polymer binding layer can be only arranged on the surface of the hard ring structure wrapped outside the hard ring, as shown in fig. 1-3; the surface of the hard ring structure far away from the inner side of the pipe wall can also be wrapped and arranged between the hard ring structure and the synthetic rubber sub-fluffy layer and between part of the synthetic rubber sub-compact layer and the synthetic rubber sub-fluffy layer, as shown in fig. 6; similar to the structure of fig. 6, in other embodiments, the structure of the partial layer may be that a polymer bonding layer is disposed between the hard ring structure and the synthetic rubber sub-dense layer and between the synthetic rubber sub-dense layer and the synthetic rubber sub-fluffy layer, that is, the synthetic rubber sub-dense layer in fig. 6 is replaced with the synthetic rubber sub-fluffy layer, and the synthetic rubber sub-fluffy layer is replaced with the synthetic rubber sub-dense layer; the artificial blood vessel can also be of a partial layer structure, namely a polymer bonding layer is arranged between the hard ring structure and the synthetic rubber sub-fluffing layer and between the synthetic rubber sub-compact layer and the synthetic rubber sub-fluffing layer, see fig. 7, wherein fig. 7 is a schematic diagram of the cross section of the tube wall of the artificial blood vessel, and the artificial blood vessel is of a hard ring structure, wherein 5 is the polymer fluffing layer, 6 is the synthetic rubber sub-fluffing layer, 7 is the polymer bonding layer, 8 is the synthetic rubber sub-compact layer, 9 is the polytetrafluoroethylene compact base layer and 10 is the hard ring structure; the polymer bonding layer may also have a whole layer structure, as shown in fig. 5; in fig. 8 and 9, 5 is a polymer fluffy layer, 6 is a synthetic rubber sub-fluffy layer, 7 is a polymer bonding layer, 8 is a synthetic rubber sub-dense layer, 9 is a polytetrafluoroethylene dense base layer, 10 is a hard ring structure, 11 is a convex structure, and 12 is a concave structure. In fig. 8, the polymer bonding layer is wrapped on the surface of the hard ring structure and is arranged between the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer; in fig. 9, the polymer bonding layer wraps the hard ring structure while being bifurcated near the hard ring structure, and the intermediate region between the polymer bonding layer and the hard ring structure being bifurcated is filled with a synthetic rubber secondary densified layer or a synthetic rubber secondary fluffy layer material; when the polymer bonding layer is of a whole layer structure, the polymer bonding layer can be positioned in the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer, and in another embodiment provided by the invention, the polymer bonding layer is of a whole layer structure and is arranged in the synthetic rubber compact layer or the synthetic rubber secondary fluffy layer, so that the synthetic rubber compact layer or the synthetic rubber secondary fluffy layer is divided into two layers; in another embodiment of the present invention, as shown in fig. 8, 9 and 10, the polymer bonding layer is disposed between the elastomeric sub-dense layer and the elastomeric sub-bulky layer as a whole.

In one embodiment of the present invention, the polymer bonding layer is preferably a mesh structure, the synthetic rubber sub-dense layer or the synthetic rubber sub-fluffy on both sides of the polymer bonding layer is in contact with or bonded with mesh holes of the mesh shape, and the polymer bonding layer has a certain thickness, so that the friction force between the upper layer and the lower layer and the polymer bonding layer is increased; in another embodiment provided by the invention, the polymer bonding layer preferably has fluffiness, such as a porous structure or a surface hollow structure, so as to improve the adhesive force of the secondary compact layer or the secondary fluffy layer; the thickness of the polymer bonding layer is preferably 0.05-0.45 mm; the polymer bonding layer is preferably formed of one or more of polypropylene, polyethylene terephthalate and polyamide.

The polymer bonding layer is provided with a synthetic rubber sub-fluffy layer or a synthetic rubber sub-compact layer; the synthetic rubber secondary fluffy layer and the synthetic rubber secondary compact layer are the same as those described above, and are not repeated here; as the preferable proposal, the two sides of the macromolecule bonding layer are provided with the synthetic rubber sub-fluffy layer and the synthetic rubber sub-compact layer, the synthetic rubber sub-fluffy layer or the synthetic rubber sub-compact layer is closely contacted with the hard ring and the macromolecule bonding layer, thereby avoiding the separation of the hard ring/macromolecule bonding layer and the adjacent sub-compact layer or sub-fluffy layer in the area with bad wrapping after bending, reducing the formation of a cavity and increasing the risk of blood inflow after puncture to cause vascular interlayer.

The synthetic rubber secondary fluffy layer or the synthetic rubber secondary compact layer is provided with a macromolecule fluffy layer; the porosity of the macromolecule fluffy layer is preferably 35% -99%; in some embodiments provided by the invention, the porosity of the polymer fluffy layer is 70% -99%; the density of the macromolecule fluffy layer is preferably 0.88-1.40 g/cm ³ The method comprises the steps of carrying out a first treatment on the surface of the The high molecular fluffy layer is used for replacing a secondary fluffy layer with fewer surface gaps and enhancing the cell adhesion capacity, so long as the high molecular fluffy layer can be firmly attached to the surface of the secondary fluffy layer and the fluffy surface is exposed; in the invention, the thickness of the polymer fluffy layer is preferably 0.10-0.70 mm; the macromolecule fluffy layer is preferably formed by one or more of polytetrafluoroethylene, polyvinylidene fluoride, polypropylene, polyethylene terephthalate and polyamide; the high molecular fluffy layer covers the synthetic rubber sub-fluffy layer or the synthetic rubber sub-compact layer, and exposes fluffy pores, has no rebound resilience or only extremely low rebound resilience, can be deformed randomly along with bending of a product, does not have traction characteristics and/or only has extremely small traction, and also provides a pore channel for fixing the tissue outside the blood vessel, so that the whole blood vessel axially slides to influence puncture when the puncture needle punctures, the higher porosity of the high molecular fluffy layer is beneficial to cell attachment, and the phenomenon that the cells are difficult to attach to fix the blood vessel due to low porosity of the sub-fluffy layer or the sub-compact layer, so that blood vessel sliding occurs in puncture, puncture is influenced, for example, the outer side of the artificial blood vessel wall is not provided with the high molecular fluffy layer, so that human cells are difficult to fix the surface of the blood vessel, the product moves along the puncture needle in the puncture process, and puncture difficulty is increased.

In the invention, the pipe wall of the multi-section wall surface area preferably comprises a synthetic rubber secondary compact layer and a synthetic rubber secondary fluffy layer at the same time, and more preferably comprises a polytetrafluoroethylene compact base layer, a synthetic rubber secondary compact layer, a high polymer bonding layer, a synthetic rubber secondary fluffy layer and a high polymer fluffy layer in sequence; the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer has rebound resilience for recovering an initial form, assists the puncture needle to puncture closure of a needle hole on the back wall surface, and has the characteristic of extruding and fixing the suture after the suture is penetrated through the suture needle.

In the invention, the deformation capacity of the polytetrafluoroethylene compact basal layer, the synthetic rubber sub-compact layer, the polymer bonding layer provided with the hard ring structure, the synthetic rubber sub-fluffy layer and the polymer fluffy layer is sequentially increased, because the compact basal layer is a blood vessel inner cavity, is closest to the central axis of the blood vessel, and the thickness can be increased along with the increase of the structural layer, after the artificial blood vessel is bent, the deformation amount of the layer far away from the axis is larger than that of the layer close to the axis, and if the artificial blood vessel is reversely designed, the blood vessel is not easy to bend or collapse if the artificial blood vessel is reversely designed.

The wall of the multi-section wall surface area is provided with a convex structure and a concave structure, so that the inner cavity change capacity of the pressed artificial blood vessel wall can be improved through the convex structure and the concave structure, and the potential crease of the artificial blood vessel is increased; folds in the present invention refer to bends at both sides of the rigid ring when the vascular prosthesis is inflated. The bend does not necessarily appear as a sharp-angled turn in the outer wall of the vessel. The height difference between the highest point of the convex structure and the lowest point of the concave structure is preferably 0.1-1.0 mm; in the invention, if the hard rings are arranged at the convex structure, as shown in fig. 4 and 17, the number of folds per unit length is more than or equal to 2, and the arrangement is between the two folds, so that the number of potential folds is more than or equal to 4, the blood vessel can be bent more easily by means of the existing folds, and the number of the deformable unit hard rings per unit length is reduced, thereby increasing the effective puncture area of the blood vessel, reducing the contact area between the puncture needle and the hard rings, reducing the self weight of the blood vessel, and reducing the foreign body sensation of the patient after implantation; when the hard ring structure is arranged at the convex structure, the polytetrafluoroethylene compact base layer corresponding to the hard ring structure is preferably provided with a structure which is convex towards the central line of the artificial blood vessel, so that stress concentration of the compact layer at the position can be avoided when the blood vessel is repeatedly expanded and contracted; referring to fig. 10, fig. 10 is a schematic structural diagram of an artificial vascular wall provided by the present invention, in the present invention, more preferably, a hard ring structure is disposed in a multi-segment wall area at a convex structure, the multi-segment wall area is divided into a hard ring area, a transition area and a non-hard ring area, wherein the hard ring area is an area where the hard ring structure is disposed or an area close to the hard ring, i.e. the convex structure is formed by taking the hard ring as an internal support, and the multi-segment wall area of the non-hard ring area is concave; referring to fig. 4 and 11, which are schematic structural views of a multi-segment wall area in an artificial blood vessel according to the present invention, wherein 15 is a non-rigid area, i.e. an area of the multi-segment wall area without a rigid ring structure, and 14 is a rigid ring area, i.e. an area of the multi-segment wall area with a rigid ring structure; preferably, the two adjacent hard rings are the same or different in distance (i.e., height) from the axis, and further preferably, the two hard ring structures have a height difference of less than 1 radial dimension of the hard rings, i.e., the thickness of the hard rings. When the section of the hard ring is of a flat structure, one side of the hard ring is the highest point of the convex structure; the diameter of the hard ring structure at the outer convex part can be set according to the diameter of a living blood vessel at the implantation part of the artificial blood vessel, the vertical distance between the inner wall of the concave structure and the axis and the vertical distance between the inner wall of the convex structure and the axis are preferably 0.1-1.0 mm, the difference value between the inner wall and the axis can be the outer wall, namely the vertical distance between the outer wall of the concave structure and the axis and the vertical distance between the outer wall of the convex structure and the axis are preferably 0.1-1.0 mm; when the number of the concave structures in the deformable unit is greater than or equal to 2, the inner wall of the concave structure refers to the inner wall of the concave structure closest to the axis.

The maximum relative inner diameter change rate of the multi-section wall surface area provided by the invention is preferably 0% -13%, more preferably 0.1% -5% in a pressurized state (the pressurized value is 7 kPa-24 kPa). Referring to fig. 12, fig. 12 is a schematic axial cross-sectional view of an artificial blood vessel according to the present invention deformed under low pressure and high pressure, wherein the left view is a low pressure state and the right view is a high pressure state. In the present invention, unless otherwise specified, the given schematic diagrams are all schematic diagrams in a low-pressure state. The partial enlarged view in fig. 12 shows two deformable elements, wherein the space between the two broken lines with smaller spacing represents the distribution area of the hard ring structure, and the product exists in the form of a left graph in the low pressure state because the left graph is the initial state structure of the product. Once the pressure rises, the high blood pressure presses the artificial vascular wall, so that the vascular wall has an expansion trend, and other areas except the hard ring area can be outwards deformed. Taking the blood pressure under a change period as an example (low pressure-high pressure-low pressure), a specific deformation process is described as follows: a. the wall surface of the product is shown in the left graph under low pressure; b. the inner cavity is pressurized by high pressure to start pressing the pipe wall, the pipe wall is firstly flattened, the local length is prolonged, and other non-deformed areas are pressed; c. because the two ends of the blood vessel are sewn and fixed, the whole lengthening trend is limited, the multi-section wall surface area of the local pipe wall starts to be outwards protruded, the length of the local area is recovered to be long, the compression on other areas is relieved, the original length of the other areas is recovered, and the final structure is as shown in the right graph (high-pressure state); d. b-c changes in other areas with high pressure conduction; e. the pressure of the inner cavity begins to drop, the wall surface begins to be flat because the material has a tendency of recovering the initial shape, the length of the local area begins to be long, and other deformed areas are extruded because the local area is limited and the two ends of the blood vessel are sewed and fixed, so that the lengths of the other deformed areas are slightly compressed; f. the pipe wall is restored to the left picture (low pressure state) structure of the upper picture due to elasticity, the length is restored to be long, and the extrusion of other deformation areas is relieved; g. other areas may also experience e-f changes with the transfer of low pressure.

According to the present invention, as an embodiment, the deformable unit further includes a smooth wall surface area; the length ratio of the multi-section wall surface area to the smooth wall surface area in the deformable unit is 1: and (0-2) when 0, the deformable unit has no smooth wall surface area. In practical use, the artificial blood vessel is likely to bend at 1 part or above, and the multi-section wall surface is required to bend at the bending part to strengthen the bending resistance, but the weight is relatively heavy in consideration of the fact that the multi-section wall surface has more smooth wall surfaces due to structural layers, and the product is required to be adjusted by embedding the smooth wall surface structure in consideration of the difference of the implantation area and the implantation time of a patient, so that the artificial blood vessel has multi-point bending to ensure smooth blood flow and properly reduce foreign body sensation caused by the weight of the product. In the invention, the smooth wall surface area and the multi-section wall surface area are integrally arranged; the smooth wall surface areas in the deformable unit can be positioned at two ends, the middle part of the deformable unit is provided with a plurality of sections of wall surface areas, the smooth wall surface areas and the plurality of sections of wall surface areas are alternately arranged, the deformable unit can also be provided with a structure with the smooth wall surface areas at the middle part of the two ends of the plurality of sections of wall surface areas, and the deformable unit is not particularly limited; the pipe wall of the smooth wall surface area comprises a polytetrafluoroethylene compact base layer, a synthetic rubber secondary fluffy layer and/or a secondary fluffy layer and a macromolecule fluffy layer which are sequentially arranged from inside to outside; the polytetrafluoroethylene compact base layer, the synthetic rubber secondary fluffy layer and/or the secondary fluffy layer and the macromolecule fluffy layer are the same as those described above, and are not repeated here; the layers are preferably integrated with the layers of the multi-section wall area; further preferably, the wall of the smooth wall area is the same as each layer of the wall of the multi-section wall area, but the wall of the smooth wall area is not provided with a convex structure and a concave structure, so that the surface of the smooth wall area is smooth, and therefore, a hard ring structure and a polymer bonding layer are not required to be arranged; the wall thickness of the smooth wall surface area is preferably 0.3-0.8 mm.

The wall of the multi-section wall surface area is provided with the convex structure and the concave structure, so that the area of the artificial blood vessel containing the smooth wall surface and the area of the multi-section wall surface can have different relative inner diameter change rates when the pressure is the same, and the change rate of the maximum relative inner diameter of the smooth wall surface area is preferably less than or equal to the change rate of the maximum relative inner diameter of the multi-section wall surface area. In the invention, the change rate of the maximum relative inner diameter of the smooth wall surface area is less than or equal to 1% in a pressurized state (the pressurized value is 7-24 kPa); the inner diameter of the smooth wall surface area is preferably 2.5-8.5 mm.

The number of the deformable units in the middle section of the artificial blood vessel provided by the invention can be one or more, and is not particularly limited, the deformable units are the minimum repeated deformable units of the artificial blood vessel provided by the invention, when the hard rings are of a parallel ring structure, the deformable units comprise at least one or more hard rings, the length of the deformable units is preferably controlled to be 1.0-10.0 mm, and the whole hard ring density of the unit length of the artificial blood vessel is low due to overlong deformable units, so that collapse easily occurs after bending; the deformation unit is too short, so that the density of the rigid ring in unit length is high, and the product is not easy to bend; when the intermediate section includes a plurality of deformable units, the structures of the different deformable units may be the same or different, and are not particularly limited; since the deformable units may include a multi-segment wall area and a smooth wall area, the plurality of deformable units may have the smooth wall area disposed only between some of the deformable units or only between two of the deformable units. When a plurality of deformable units form the middle section, adjacent deformable units can be connected through the concave structure, can be connected through the convex structure, can also be connected through the transition area between the convex structure and the concave structure, and is not particularly limited. Referring to fig. 13 to 16, fig. 13 to 16 are schematic structural views of the middle tube wall of the artificial blood vessel provided by the invention. In the intermediate section provided by the invention, the rigid ring structure is preferably a parallel ring structure or a spiral structure, and the spiral structure is preferably a structure of parallel spiral arrangement. When the hard rings are of parallel ring structure, as shown in fig. 13-15, one deformable unit comprises two hard rings, the distance between the central lines of the two hard rings is sequentially set to be f1 and f2 … …, the distance between the central lines of the nearest two hard rings of two adjacent deformable units connected with each other is sequentially set to be g1 and g2 … …, the lengths of the deformable units are sequentially set to be e1 and e2 … …, and the ranges of all f and g (f 1 and f2 … …; g1 and g2 … …) are all preferably 0.8-8.5 mm; if the spacing of the hard rings is uniformly changed, the variation ranges of the I f1-g 1I, the I g1-f 2I and the I f2-g 2I … … are all preferably 0.001~0.150 mm,e1-e … … =0; if the hard ring spacing is unevenly changed, the spacing value is two or more, and the changes are repeated, the ranges of the I f1-g 1I, the I g1-f 2I and the I f2-g 2I … … are all preferably 0.01-1.50 mm, and the ranges of the I e1-e 2I … … are preferably 0.01-1.50 mm. As other embodiments, when the hard rings are in a parallel ring structure, as shown in fig. 16, one deformable unit only includes one hard ring, the distances between two adjacent hard rings are g1 and g2 … … in sequence, the lengths of the deformable units are e1 and e2 … … in sequence, and the ranges of all g (g 1 and g2 … …) are preferably 0.8-8.5 mm; for uniformly changing hard ring spacing, the variation ranges of the I g1-g 2I and the I g2-g 3I … … are all preferably 0.001~0.150 mm,e1-e … … =0; if the hard ring spacing varies unevenly, the spacing value is two or more, and the range of I g1-g 2I and I g2-g 3I … … is preferably 0.01-1.50 mm, and the range of I e1-e 2I … … is preferably 0.01-1.50 mm.

When the hard ring structure is a parallel spiral structure, the spacing between the hard rings of the spiral structure is similar to that of the parallel ring structure, and the hard rings of the spiral structure are continuous structures on continuous deformable units of the middle section (not including smooth wall surface areas), namely, one or more integral structures. For example, if the number of the spiral hard rings is 2, similar to the case where two hard rings are included in one deformable unit, the arrangement of the spacing of the hard rings and the length of the deformable unit of 2 spirals is similar to the case where two hard rings in one deformable unit are included, fig. 13 to 15 may illustrate the case where the hard rings are spiral, that is, the hard rings on the left side of each continuous deformable unit in fig. 13 to 15 are hard rings of the same spiral structure, and the hard rings on the right side are hard rings of the same spiral structure; if the number of helical hard rings is 1 or more, similar to the case where 1 hard ring is contained in one deformable element, the spacing between the hard rings of the helical structure and the length of the deformable elements are set similar to the case where 1 hard ring is contained in one deformable element, fig. 16 may illustrate the case where the hard rings are helical, the hard rings contained in each continuous deformable element are the same, or the hard rings contained in each two continuous deformable elements are the same, or the hard rings contained in each other number of continuous deformable elements are the same.

Fig. 17 is a schematic cross-sectional view of a deformable unit in an artificial blood vessel according to the present invention, wherein 5 is a polymer fluffy layer, 6 is a synthetic rubber sub-fluffy layer, 7 is a polymer bonding layer, 8 is a synthetic rubber sub-dense layer, 9 is a polytetrafluoroethylene dense base layer, 10 is a hard ring structure, 11 is a convex structure, 12 is a first concave structure, and 13 is a second concave structure. The rigid ring section in the deformable unit provided in fig. 17 is in a small-cut circular shape, the convex structure is located at the upper part of one side of the rigid ring structure, the axial length of the rigid ring structure is r, the distance between the center of the section of the rigid ring structure and the boundary of one side of the deformable unit is c, c is less than or equal to 2r, the position of the convex structure 11 is at the upper part of the edge of one side of the rigid ring structure 10, one side of the convex structure 11 with the rigid ring structure 10 is provided with a second concave structure 13, the non-rigid ring area at the other side of the convex structure 11 is provided with a first concave structure 12, the height of the first concave structure 12 is lower than the height of the second concave structure 13, and each deformable unit comprises 2 rigid ring structures 10 and 2 convex structures 11.

In another embodiment of the present invention, a schematic diagram of the wall structure of the middle section is shown in fig. 18. In fig. 18, the cross section of the hard ring structure 10 is in a small cut circular shape, the outer convex structure 11 is positioned at the upper part of one side of the hard ring structure 10, each deformable unit comprises one hard ring structure 10 and one outer convex structure 11, and adjacent deformable units are connected through the inner concave structure 13; the axial length of the hard ring structure 10 is r, and the boundary distance between the center of the cross section of the hard ring structure 10 and the side of the deformable unit is c, wherein c is less than or equal to 2r.

In another embodiment of the present invention, a schematic diagram of the wall structure of the middle section is shown in fig. 19. In fig. 19, two deformable units are included, the cross section of the hard ring structure 10 is circular, the polymer bonding layer 7 wraps the hard ring structure 10, the convex structure 11 is positioned at the hard ring structure 10, the axial length of the hard ring structure 10 is r, the boundary distance between the center of the hard ring 10 and one side of the deformable units is c, c is less than or equal to 2r, the shape of the compact layer 9 at the bottom of the hard ring structure 10 is provided with a structure protruding inwards towards the center line of the artificial blood vessel, and the stress concentration of the compact layer 9 at the position can be avoided when the blood vessel repeatedly expands and contracts; each deformable element comprises 1 rigid ring structure 10 and 1 convex structure 11.

In another specific embodiment provided by the invention, a schematic diagram of the pipe wall structure of the middle section is shown in fig. 20. In fig. 20, adjacent deformable units are connected through one side of a convex structure 11, the cross section of the hard ring structure 10 is circular, the polymer bonding layer 7 wraps the hard ring structure 10, the convex structure 11 is located at one side or two sides close to the hard ring structure 10 and is not located right above, the axial length of the hard ring structure 10 is r, the boundary distance between the center of the hard ring structure 10 and one side of the deformable unit is c, c is less than or equal to 2r, the position of the convex structure 11 is at the upper part of one side edge of the hard ring structure 10, one side of the convex structure 11 without the hard ring structure 10 is provided with a second concave structure 13, the other side of the convex structure 11 with the hard ring structure 10 is provided with a first concave structure 12, the height of the first concave structure 12 is lower than the height of the second concave structure 13, and in each deformable unit, the 2 hard ring structures 10 and 2 convex structures 11 refer to the distance between the concave structures and the axis.

In another embodiment of the present invention, a schematic diagram of the wall structure of the middle section is shown in fig. 21. Fig. 21 includes two deformable units, the cross section of the hard ring structure 10 is circular, two sides of the hard ring structure 10 are respectively provided with a convex structure 11, each deformable unit includes 1 hard ring structure 10,2 convex structures 11,2 concave structures, and the hard ring structure 10 is only located in one concave structure. The hard ring structure 10 is located at a closer distance from the axis than the other concave structures.

After the inner cavity of the artificial blood vessel is pressed, the capacity of the inner cavity can be changed, and the change rate of the preferable cavity content is 6.0% -81.3%.

In order to further improve the anticoagulation performance of the artificial blood vessel, the inner wall of the artificial blood vessel is preferably also provided with an anticoagulation coating; the anticoagulation coating is a anticoagulation coating well known to those skilled in the art, and is not particularly limited, but a covalently bonded heparin coating is preferred in the present invention.

According to the invention, the vascular prosthesis preferably further comprises a first anastomosis segment and a second anastomosis segment for anastomosis with an autologous vessel; the first anastomosis section and the second anastomosis section are respectively positioned at two ends of the middle section. Referring to fig. 22 and 23, fig. 22 is a schematic structural view of an artificial blood vessel provided by the present invention, wherein the upper part is a schematic view of a parallel structure of a hard ring, the lower part is a schematic view of a spiral structure of a hard ring, and the lower part can be a schematic view of an inclined parallel structure, and fig. 23 is a three-dimensional partial cross-sectional view of the artificial blood vessel shown in fig. 8 or 16 in which the hard ring is spirally arranged; as a preferred embodiment, the stiff ring is in a parallel configuration substantially perpendicular to the axis of the vessel prosthesis or in a spiral configuration, substantially perpendicular meaning that the angle between the centerline of the stiff ring and the axis of the vessel prosthesis (i.e., the angle of inclination of the stiff ring in fig. 4) is 90 ° or approximately 90 °; when the hard rings are arranged in parallel in an inclined manner, the hard rings can generate a trend of changing from inclination to erection in the continuous contraction and expansion process of the blood vessel, and radial acting force is generated on the adjacent layers, so that the hard rings can be gradually separated from the adjacent layers, and the parallel rings in a basically vertical state, namely in a basically upright state, can avoid the trend; when a hard ring helix is provided, the radial forces may cancel each other out by the continuous helix. Wherein 1 is a deformable unit, 2 is an anastomosis segment, 3 is a parallel hard ring structure, and 4 is a spiral hard ring structure. The length of the anastomotic segment may be very short, as an embodiment the length of the anastomotic segment is greater than the length of a single deformable element. The first anastomosis section and the second anastomosis section are preferably integrally arranged with the middle section, and the thicknesses of the layers same as the middle section can be the same or different, and are not particularly limited; the tube walls of the first anastomosis segment and the second anastomosis segment preferably at least comprise polytetrafluoroethylene compact base layers; in a specific embodiment provided by the invention, the first anastomosis segment and the second anastomosis segment comprise a polytetrafluoroethylene dense base layer and a synthetic rubber secondary dense base layer; in a particular embodiment provided by the present invention, the first anastomosis segment and/or the second anastomosis segment preferably comprises a deformable element; the deformable unit is similar to the above, and is not described in detail herein, and the deformable unit includes a multi-section wall area, so that a relatively high change rate (radial elasticity) of the inner diameter of the anastomotic section can occur, thereby improving the change rate of the inner diameter of the implanted end of the living body blood vessel, reducing the difference of the change rate of the inner diameter of the living body blood vessel, and reducing the risk of occurrence of vascular stenosis at the anastomotic end.

As a preferable artificial blood vessel embodiment provided by the invention, the inner layer of the blood vessel is a polytetrafluoroethylene compact base layer with low elasticity, and is sequentially a synthetic rubber sub-compact layer which is slightly compact and has certain elasticity, a hard ring which is used for maintaining the shape of the blood vessel, a macromolecule bonding layer which is used for clamping the hard ring, a synthetic rubber sub-fluffy layer which is slightly loose and has obvious elasticity, and a low-elasticity macromolecule fluffy layer with high porosity. The polytetrafluoroethylene compact base layer is designed with a deformable unequal-height convex structure and a deformable unequal-height concave structure instead of a circular tube design, so that the polytetrafluoroethylene compact base layer deforms under radial pressure to increase the inner cavity capacity of a product, and meanwhile, the relative inner diameter change rate or the inner cavity volume change rate of the artificial blood vessel is adjusted by adjusting the structural shape material of the artificial blood vessel, for example, the relative inner diameter change rate or the inner cavity volume change rate which is close to that of a autologous blood vessel (namely a living blood vessel) is adjusted as required; the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer provide a closed hole effect after puncture and recovery elasticity after deformation; the high polymer bonding layer can ensure that the hard ring can be tightly bound on the surface of the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer, so that the sliding risk is reduced, and meanwhile, the high polymer bonding layer is used as a reinforcing material for the synthetic rubber secondary compact layer and the synthetic rubber secondary fluffy layer, so that the overall structural strength of the material is enhanced, and the falling risk of the material after repeated puncture for many times is reduced; the high molecular fluffy layer has no obvious elasticity, but has high porosity, is mainly used as a substrate for attaching human tissues, and can be well fixed in a body after being implanted, so that the situation that the product locally slides during puncturing can be reduced/eliminated, and the puncturing is more convenient.

The artificial blood vessel middle section provided by the invention has a convex structure and a concave structure with the blood vessel cavity content being pressed and adjustable, so that the low-elasticity material simulates the characteristic of high radial elasticity under the action of a rigid ring as a supporting framework, namely, the artificial blood vessel middle section has a certain relative inner diameter change rate or inner cavity volume change rate in a certain pressure range (the pressure of different patients or body parts implanted with artificial blood vessels possibly is different), thereby solving the problem that the blood flow dynamics is obviously changed due to the radial elasticity variation of the blood vessel wall after blood flows into the artificial blood vessel from the autologous blood vessel.

The invention also provides a preparation method of the artificial blood vessel, the artificial blood vessel prepared by the preparation method takes the hard ring as a supporting framework, and the non-hard ring area can expand and contract under the action of blood pressure; further, during expansion and contraction, the hard ring can be well maintained in its relative position in the elastomeric sub-dense layer or elastomeric sub-loft layer under the action of the polymeric bonding layer.

The invention provides an embodiment of a preparation method of an artificial blood vessel, which comprises the following steps: s1) forming a polytetrafluoroethylene compact base layer by shaping and heat treatment of a polytetrafluoroethylene material on a die; s2) smearing the synthetic rubber solution on a polytetrafluoroethylene compact base layer, and heating and shaping to form a synthetic rubber secondary compact layer or a synthetic rubber secondary fluffy layer; s3) winding a hard ring structure on the surface of the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer, then sleeving the raw material of the high polymer bonding layer on the outer side, and heating and shaping to form the high polymer bonding layer; s4) coating the synthetic rubber solution on the synthetic rubber sub-compact layer or the synthetic rubber sub-fluffy layer, and heating and shaping to form the synthetic rubber sub-fluffy layer or the synthetic rubber sub-compact layer; s5) coating the polymer solution on the surface of the synthetic rubber sub-fluffy layer or the synthetic rubber sub-compact layer, sleeving the polymer fluffy sleeve, and heating, drying and adhering to obtain the artificial blood vessel. Artificial blood vessels of the structures of fig. 4, 5, 6, 7, 18 can be obtained, but are not limited to.

As another embodiment of the preparation method, step S3 is changed to sleeving the polymer bonding layer outside the hard ring in advance, winding the hard ring on the surface of the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer, and then heating and shaping; the artificial blood vessel of the structure in fig. 1, 2 and 3 can be obtained but is not limited to.

As another embodiment of the preparation method, step S3 is changed to sleeving the polymer bonding layer outside the hard ring in advance, winding the hard ring on the surface of the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer, paving the polymer bonding layer between the hard rings, and then heating and shaping; an artificial blood vessel of the structure of fig. 8, 19, 20, 21 can be obtained, but is not limited to.

As another embodiment of the preparation method, step S3 is changed to sleeving the polymer bonding layer outside the hard ring in advance, winding the hard ring on the surface of the synthetic rubber sub-compact layer or the synthetic rubber sub-fluffy layer, paving the polymer bonding layer between the hard rings, heating and shaping, coating the synthetic rubber solution on the polymer bonding layer at the hard ring, heating and shaping, paving the polymer bonding layer on the coated synthetic rubber solution, and heating and shaping; an artificial blood vessel of the structure of fig. 9 and 10 can be obtained, but is not limited to.

The source of all the raw materials is not particularly limited, and the raw materials are commercially available.

Forming a polytetrafluoroethylene compact base layer by shaping and heat treatment of polytetrafluoroethylene materials on a die; the polytetrafluoroethylene material is a polytetrafluoroethylene material well known to those skilled in the art, and is not particularly limited, and is preferably a polytetrafluoroethylene tube or a polytetrafluoroethylene film in the present invention; the pipe wall thickness of the polytetrafluoroethylene pipe is preferably 0.1-0.32 mm; the thickness of the polytetrafluoroethylene film is preferably 0.012-0.032 mm, more preferably 0.015-0.025 mm, and still more preferably 0.02-mm; when the polytetrafluoroethylene material is a polytetrafluoroethylene film, the polytetrafluoroethylene film is preferably wound on a die for 3-27 circles, more preferably 5-20 circles, still more preferably 8-15 circles and most preferably 10 circles; the temperature of the heat treatment is preferably 320-395 ℃, more preferably 340-380 ℃, and the subsequent steps can be sequentially manufactured in a covering manner according to a multi-section structure.

Coating the synthetic rubber solution on a polytetrafluoroethylene compact base layer, and heating and shaping to form a synthetic rubber sub-compact layer or a synthetic rubber sub-fluffy layer; the synthetic rubber solution is preferably a silicone solution and/or a polyurethane solution; when the synthetic rubber secondary compact layer is prepared, the synthetic rubber solution is preferably 30% -100% of silicone solution and/or 30% -100% of polyurethane solution, more preferably 40% -80% of silicone solution and/or 40% -80% of polyurethane solution; when the synthetic rubber sub-fluffy layer is prepared, the synthetic rubber solution is preferably a silicone solution with the concentration of 25% -60% and/or a polyurethane solution with the concentration of 25% -60%, more preferably a silicone solution with the concentration of 25% -50% and/or a polyurethane solution with the concentration of 25% -50%; the temperature of the heating and shaping is preferably 100-155 ℃; when the prepared synthetic rubber secondary compact layer is prepared, the temperature for heating and shaping is preferably 100-155 ℃, more preferably 140-150 ℃; when the synthetic rubber secondary fluffy layer is prepared, the temperature for heating and shaping is preferably 100-155 ℃, more preferably 110-150 ℃.

Winding a hard ring structure on the surface of the synthetic rubber secondary compact layer or the synthetic rubber secondary fluffy layer, then sleeving the raw material of the high polymer bonding layer on the outer side, and heating and shaping to form the high polymer bonding layer; the temperature of the heat setting is preferably lower than the melting point of the polymer bonding layer raw material.

Coating the synthetic rubber solution on a polytetrafluoroethylene compact base layer, and heating and shaping to form a synthetic rubber sub-fluffy layer or a synthetic rubber sub-compact layer; the preparation method of the synthetic rubber sub-fluffy layer or the synthetic rubber sub-dense layer is the same as that described above, and is not repeated here.

Coating the polymer solution on the surface of the synthetic rubber sub-fluffy layer or the synthetic rubber sub-compact layer, sleeving the polymer fluffy sleeve, and heating, drying and adhering to obtain the artificial blood vessel; the mass concentration of the polymer solution is preferably 5% -35%, more preferably 10% -30%, and still more preferably 10% -20%; the macromolecule fluffy cover is of a macromolecule porous structure; the temperature for heating and drying is preferably 100-155 ℃, more preferably 100-110 ℃.

To further illustrate the present invention, the following describes in detail, with reference to examples, an artificial blood vessel with a pressure-adjustable lumen content.

In the following, the bonding layer mentioned is a polymer bonding layer, the dense layer or dense base layer is a polytetrafluoroethylene dense layer or polytetrafluoroethylene deadly base layer, the secondary dense layer is a synthetic rubber secondary dense layer, and the secondary fluffy layer is a synthetic rubber secondary fluffy layer.

The reagents used in the examples below are all commercially available.

The raw materials in the examples are as follows: (1) polytetrafluoroethylene tube: the thickness is 0.1-0.32 mm; (2) polytetrafluoroethylene film: the thickness is 0.020-0.025 mm; (3) silicone: the tensile rate is 300-400%, and the tearing strength is 10-15 kN/m; (4) polyurethane: tensile strength is 13.8-15.1 MPa, and tensile rate is 950-1050% (5) polyethylene hard ring: the diameter of the section of the ring material is 0.4-0.6 mm; (6) Polypropylene hard ring: the diameter of the section of the ring material is 0.1-0.3 mm; (7) polyethylene terephthalate sleeve: the thickness is 0.15-0.20 mm; (8) Polyamide bonding cuffs: the thickness is 0.20-0.25 mm; (9) polyethylene terephthalate fluffy cover: the thickness is 0.3-0.5 mm, and the diameter is 8-9 mm; (10) polytetrafluoroethylene porous sleeve: the thickness is 0.15-0.25 mm, and the diameter is 4.5-5.5 mm.

Example 1

Step 1: placing a polytetrafluoroethylene pipe sleeve (the pipe wall thickness range value is 0.1 mm-0.32 mm) on a die with the diameter of 8 mm, and carrying out indentation shaping heat treatment at 340 ℃ to form a compact base layer; (the purpose of physical indentation is to make a multi-segment structure with a flexible and pressure expandable base material, and subsequent steps can be made by covering the multi-segment structure in sequence).

Step 2: coating 60% silicone on the compact base layer, and shaping at 150deg.C to form a secondary compact layer; the step is to manufacture a secondary compact layer with a certain thickness, so that the problem that a puncture needle hole is difficult to close due to the fact that the secondary compact layer is too thin is avoided.

Step 3: winding two polyethylene hard rings on a secondary compact layer in a certain spiral form (double spiral), and controlling the interval between two adjacent hard rings in the deformable unit structure to be 8mm (the range value is 0.8-8.5 mm), wherein the interval between two pairs of hard rings in the two adjacent deformable unit structures is 2mm (the range value is 0.2-8 mm); this step is to allow the hard rings to be regularly distributed outside the secondary densification layer.

Step 4: sleeving a polyethylene terephthalate sleeve as a bonding layer on the outer side, and shaping at 105 ℃ (100 ℃ -110 ℃ highest temperature is lower than the melting point of polyethylene, and the processing temperature of the subsequent step is not higher than the temperature); the step is to make the hard ring fixed outside the secondary compact layer well, and keep the bonding layer tightly attached to the outer wall.

Step 5: coating 40% silicone on the outer side of the bonding layer, and shaping at 102 ℃ to form a secondary fluffy layer; the step is to manufacture a secondary fluffy layer with a certain thickness, embed a hard ring and a bonding layer, increase the overall thickness of the secondary compact layer and the secondary fluffy layer, and improve the overall elasticity.

Step 6: coating 15% silicone on the secondary fluffy layer, sleeving a polyethylene terephthalate fluffy sleeve, and drying and adhering at 102 ℃ to form an outermost fluffy layer; through the step, the fluffy layer can be attached to the outermost layer, so that the excessive exposure of the secondary fluffy layer is avoided, and the attaching probability of human tissues is reduced.

Step 7: uniformly covering the anticoagulation coating on the inner wall of the product to ensure that the product has a certain anticoagulation function; the anticoagulation of the inner wall of the artificial blood vessel can be further improved through the step.

Example 2

Step 1: winding a polytetrafluoroethylene film with the thickness of 0.020 and mm on a die with the diameter of 4mm for 10 circles, and carrying out indentation shaping heat treatment at 340 ℃ to form a compact base layer;

step 2: coating 40% silicone on the compact base layer, and shaping at 150deg.C to form a secondary compact layer;

step 3: a polyamide bonding sleeve containing a deformable unit structure with a polypropylene hard ring spacing (parallel ring structure perpendicular to the axis) of 3 mm and a polypropylene hard ring spacing variation of 0.3 mm in adjacent deformable units is sleeved outside as a bonding layer containing hard rings, and is shaped at 140 ℃.

Step 4: coating 25% silicone on the outer side of the bonding layer, and shaping at 140 ℃ to form a secondary fluffy layer;

Step 5: coating 10% silicone on the secondary fluffy layer, sleeving a polytetrafluoroethylene porous sleeve, and drying and adhering at 102 ℃ to form an outermost fluffy layer;

step 6: the anticoagulation coating is uniformly covered on the inner wall of the product, so that the product has a certain anticoagulation function.

Example 3

Step 1: winding a polytetrafluoroethylene film with the thickness of 0.016 and mm on a die with the diameter of 5mm for 10 circles, and carrying out indentation shaping heat treatment at 340 ℃ to form a compact base layer;

step 3: the polyamide is sleeved on a polypropylene hard ring, the spacing between the hard rings (parallel ring structures perpendicular to the axis) in the same deformable unit structure is 3.5mm, the spacing between the hard rings between two adjacent deformable units is 2.5 mm, and the polyamide-containing hard rings are shaped into a secondary compact layer at 140 ℃.

Step 4: coating a polypropylene hard ring containing a polyamide jacket with silicone with the concentration of 40%, and shaping at 140 ℃ to form a secondary compact layer;

step 5: coating 10% silicone on the secondary compact layer, sleeving a polytetrafluoroethylene porous sleeve, and drying and adhering at 102 ℃ to form an outermost fluffy layer;

Example 4

Step 1: sleeving a polytetrafluoroethylene tube with the wall thickness of 0.2mm on a die with the diameter of 7mm, and carrying out indentation shaping heat treatment at 345 ℃ to form a compact base layer;

step 2: coating 40% silicone on a compact base layer, placing polyethylene hard rings on the outer side, controlling the spacing between the hard rings (parallel ring structures perpendicular to the axis) in the same deformable unit structure to be 2.5mm, setting the nearest hard ring spacing between two adjacent deformable units to be 4.0mm, and forming a secondary compact layer at 150 ℃;

step 3: locally smearing 40% silicone on a polyethylene hard ring-free area, leaving a silicone-smeared concave area with the width of 1.5mm plus or minus 0.5mm, ensuring that the polyethylene hard surface exposed at the center of the concave area is not covered by silicone, and shaping at 150 ℃;

step 4: covering the bottom of a concave area containing the exposed surface of the polyethylene hard ring with a polyethylene terephthalate sleeve, then coating silicone with the concentration of 20% on the concave area, and shaping at 140 ℃ to form a secondary fluffy layer;

step 5: coating 10% silicone on the secondary compact layer and the secondary fluffy layer, sleeving a polyethylene terephthalate fluffy sleeve, and drying and adhering at 102 ℃ to form an outermost fluffy layer;

Example 5

Step 1: sleeving a polytetrafluoroethylene tube with the wall thickness of 0.25mm on a die with the diameter of 7mm, and carrying out indentation shaping heat treatment at 345 ℃ to form a compact base layer;

step 2: coating 40% silicone on a compact base layer, sleeving a polyamide bonding sleeve which comprises a deformable unit structure and has a polyethylene hard ring (parallel ring structure perpendicular to the axis) spacing of 3.6 mm and a polypropylene hard ring spacing of 3mm in adjacent deformable units on the outer side as a hard ring-containing bonding layer, shaping the secondary compact layer at 150 ℃, and simultaneously fixing the hard ring-containing bonding layer;

step 3: coating 25% silicone on the outer side of the bonding layer, and shaping at 140 ℃ to form a secondary fluffy layer;

step 4: coating 10% silicone on the secondary fluffy layer, sleeving a polyethylene terephthalate fluffy sleeve, and drying and adhering at 102 ℃ to form an outermost fluffy layer;

step 5: the anticoagulation coating is uniformly covered on the inner wall of the product, so that the product has a certain anticoagulation function.

Example 6

For the preparation of the secondary compact layer, the polyurethane solution with the concentration of 80% can be smeared on the compact base layer and dried, and the rest is the same as the steps except the step 2 in the embodiment 1/the embodiment 2.

Example 7

For the preparation of the secondary fluffy layer, 50% polyurethane solution can be coated on the bonding layer and dried, and the rest is the same as the other steps except for the step 5 in the embodiment 1 and the other steps except for the step 4 in the embodiment 2.

Example 8

For the hard ring, polyethylene, polypropylene, polyethylene terephthalate, polyvinylidene fluoride, and perfluoroethylene propylene copolymer are preferable. When two or more hard rings are regularly wound with each other, the same material or two or more materials may be used, or two or more materials may be wound with each other at intervals.

Example 9

The polymer bonding layer can be made of one, two or more than two materials selected from polypropylene, polyethylene terephthalate and polyamide.

Example 10

For the integral structure of the hard ring and the polymer bonding layer combined with each other: the hard ring is preferably made of one, two or more materials selected from polyethylene, polypropylene, polyethylene terephthalate, polyvinylidene fluoride and perfluoroethylene propylene copolymer; the polymer bonding layer is preferably made of one or two or more of polypropylene, polyethylene terephthalate and polyamide.

Example 11

The fluffy layer material can be prepared by blending one, two or more than two of polytetrafluoroethylene, polyvinylidene fluoride, polypropylene, polyethylene terephthalate and polyamide.

An embodiment of the artificial blood vessel comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer, wherein a synthetic rubber sub-compact layer and/or a synthetic rubber sub-fluffy layer is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; a hard ring structure is arranged between the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer; the pipe wall of the multi-section wall surface area is provided with a convex structure and a concave structure. Simultaneously, selecting the thickness, the material, the shape and the like of a proper polytetrafluoroethylene compact base layer, a high molecular fluffy layer and other layers; parameters such as structural shape, material and number of suitable hard rings, spacing, position in the deformable unit, etc.; the specific structure, position, number and other parameters of the proper convex structure and concave structure; suitable length of the deformable element. Meanwhile, whether the hard ring is wrapped with a high molecular bonding layer or not and the wrapping condition of the high molecular bonding layer are needed. According to the above arrangement, the maximum relative inner diameter change rate of the artificial blood vessel under pressure (the pressure range is 7 kPa to 24 kPa) is in the range of 0% to 13%, preferably 0.1% to 13%, and more preferably 0.1% to 5%.

As an embodiment, the structure in fig. 4 is used to prepare an artificial blood vessel, and the thickness, material, etc. of the polytetrafluoroethylene dense base layer, the polymer fluffy layer, the synthetic rubber secondary dense layer and the synthetic rubber secondary fluffy layer are selected appropriately; the structural parameters, materials, mutual distances, positions in the deformable unit, etc. of the suitable rigid ring; the structure parameters such as the specific height of the proper convex structure and the proper concave structure, and the positions and the number of the structure parameters; suitable length of the deformable element. 3 artificial blood vessel products (only including multi-section wall surface areas) with different inner diameters and 10mm lengths are selected, and deformation data characteristics shown in the following table can be realized under pressurization (the pressure range is 7 kPa-24 kPa), wherein the deformation data characteristics are shown in the following table:

wherein, the inner diameter at low pressure is the average inner diameter of the inner cavity of the product at low pressure, and d is expressed;

the inner diameter under high pressure is the average inner diameter of the inner cavity of the product under high pressure, and is expressed as D;

lumen volume v=3.14×d at low pressure ² /4×a，

a is a correction factor >1 under low pressure, and is related to a multi-section wall surface shape structure (comprising thickness and materials of each layer, the space between hard rings, the structure shape, the materials, the quantity and the positions of the space in a deformable unit, the space between the outer convex and the inner concave, the position, the quantity and the height difference and other parameters) \the length of the deformable unit\the average inner diameter of a product under low pressure;

Lumen volume v=3.14×d at high pressure ² /4×A，

A is a correction factor >1 under high pressure, and is related to the size of a pressure value born by a multi-section wall structure, the shape structure of the multi-section wall after being pressed (comprising thickness and materials of each layer, the spacing of hard rings, the structural shape, the materials, the number and the positions of the spacing in a deformable unit, the parameters such as the spacing between convex and concave, the position, the number and the height difference) and the length of the deformable unit, and the average inner diameter of a product under low pressure;

relative inner diameter change rate= (D-D)/d×100%;

lumen volume change rate= (V-V)/v×100%.

Claims

1. A vascular prosthesis with an adjustable volume of lumen content comprising: an intermediate section;

the number of the hard ring structures in the deformable unit is more than or equal to 1, and the hard ring structures are arranged at the convex structure and/or at one side edge of the convex structure and/or at two side edges of the convex structure;

the inner cavity change capacity of the artificial blood vessel wall after being pressed is improved through the convex structure and the concave structure;

the maximum inner diameter change rate of the multi-section wall surface area under the pressurized state is 0% -13%; the pressure value of the pressurized state is 7 kPa to 24kPa.

2. A vascular prosthesis with an adjustable volume of lumen content comprising: an intermediate section;

the hard ring structures are arranged on one side edge of the concave structure or on two side edges of the concave structure, the number of the concave structures in the deformable unit is more than or equal to 2, and the total number of the concave structures in the deformable unit is less than that of the concave structures in the deformable unit;

3. The vascular prosthesis of claim 1 or 2, wherein the stiff ring structure is disposed within the elastomeric sub-dense layer, within the elastomeric sub-loft layer, or between the elastomeric sub-dense layer and the elastomeric sub-loft layer.

4. The artificial blood vessel according to claim 3, wherein the polymer bonding layer has a whole layer structure and is disposed in the synthetic rubber compact layer or the synthetic rubber sub-bulk layer, and the synthetic rubber compact layer or the synthetic rubber sub-bulk layer is divided into two layers; or the polymer bonding layer is of a whole layer structure and is arranged between the synthetic rubber sub-compact layer and the synthetic rubber sub-fluffy layer.

5. The artificial blood vessel according to claim 1 or 2, wherein a synthetic rubber sub-dense layer is arranged between the polytetrafluoroethylene dense base layer and the polymer fluffy layer, the hard ring is arranged between the synthetic rubber sub-dense layer and the polymer fluffy layer, and a synthetic rubber sub-fluffy layer is arranged between the hard ring and the polymer fluffy layer;

6. The artificial blood vessel according to claim 1 or 2, wherein a synthetic rubber sub-compact layer and a synthetic rubber sub-fluffy layer are sequentially arranged between the polytetrafluoroethylene compact base layer and the polymer fluffy layer;

7. The artificial blood vessel according to claim 6, wherein the polymer bonding layer is a monolithic structure disposed between the elastomeric sub-dense layer and the elastomeric sub-fluffy layer;

8. The vascular prosthesis of claim 1 or 2, wherein the polymeric bonding layer has a thickness of 0.05 to 0.45 mm;

the macromolecule bonding layer is formed by one or more of polypropylene, polyethylene terephthalate and polyamide;

and/or the thickness of the synthetic rubber sub-fluffy layer is 0.05-0.60 mm.

9. The vascular prosthesis of claim 1 or 2, wherein the rigid ring structure has an axial length of 2 mm or less;

and/or, the ratio of the axial length to the thickness of the hard ring structure is greater than or equal to 1;

10. The vascular prosthesis of claim 1 or 2, wherein the rigid ring structure is arranged in a spiral structure in the deformable unit;

Or the artificial blood vessel comprises a plurality of hard rings, wherein the hard rings are of parallel ring structures; alternatively, the artificial blood vessel comprises a plurality of the hard rings, wherein the hard rings are parallel rings, and the parallel rings are perpendicular to the axis of the artificial blood vessel.

11. An artificial blood vessel according to claim 1 or 2, wherein,

12. The artificial blood vessel according to claim 1 or 2, wherein the hard ring structure is arranged at the outer convex structure, and the polytetrafluoroethylene compact base layer corresponding to the hard ring structure is provided with a structure protruding inwards towards the central line of the artificial blood vessel;

13. The artificial blood vessel according to claim 1 or 2, wherein the number of the convex structures and the number of the concave structures in the multi-segment wall surface area are each independently 1 or more, and when the number of the convex structures and/or the number of the concave structures are plural, the convex structures and the concave structures are arranged at intervals.

14. The vascular prosthesis of claim 1 or 2, wherein the deformable element further comprises a smooth wall area; the pipe wall of the smooth wall surface area comprises a polytetrafluoroethylene compact base layer and a macromolecule fluffy layer which are sequentially arranged from inside to outside; the polytetrafluoroethylene compact base layer and the macromolecule fluffy layer of the smooth wall area are provided with a synthetic rubber sub-compact layer and/or a synthetic rubber sub-fluffy layer.

15. The vascular prosthesis of claim 14, wherein the blood vessel is,

the length ratio of the multi-section wall surface area to the smooth wall surface area in the deformable unit is 1: (0-2);

and/or the wall thickness of the smooth wall surface area is 0.3-0.8 mm.

16. The vascular prosthesis of claim 1 or 2, wherein the deformable unit has a length of 1-10 mm; the intermediate section comprises a plurality of deformable elements;

the distance between two adjacent hard rings of adjacent deformable units is 0.8-8.5 mm.

17. The vascular prosthesis of claim 1 or 2, wherein the elastomeric sub-dense layer is formed of silicone and/or polyurethane;

and/or the number of the groups of groups,

the synthetic rubber secondary fluffy layer is formed by silicone and/or polyurethane;

and/or the number of the groups of groups,

the macromolecule fluffy layer is formed by one or more of polytetrafluoroethylene, polyvinylidene fluoride, polypropylene, polyethylene terephthalate and polyamide;

and/or the number of the groups of groups,

the porosity of the synthetic rubber secondary fluffy layer is 10% -90%; the porosity of the macromolecule fluffy layer is 35% -99%;

and/or the number of the groups of groups,

the synthetic rubber secondary fluffy layer has a porosity smaller than that of the polymer fluffy layer.