Cross-joint intravascular stent and preparation method thereof

Abstract

The invention relates to a cross-joint intravascular stent and a preparation method thereof. The cross-joint intravascular stent comprises a first part and a second part which are distributed in the axial direction of the cross-joint intravascular stent. The first part comprises a plurality of first stent rings which are arranged at intervals in the axial direction of the joint-crossing intravascular stent and are mutually independent, and a whole-surface covering film fixedly arranged on the first stent rings; from the proximal end to the distal end, the distance between every two adjacent first stent rings is gradually increased; the second part comprises a plurality of second stent rings which are arranged at intervals in the axial direction of the joint-crossing intravascular stent and are mutually independent, and a plurality of rows of connecting membrane groups which are sequentially arranged in the axial direction of the joint-crossing intravascular stent; each row of connecting membrane group comprises a plurality of connecting membranes which are uniformly distributed in the circumferential direction of the joint-crossing intravascular stent, and the two ends of each connecting membrane are fixedly connected with the two adjacent second stent rings respectively; the width of the rods forming the first stent ring is greater than the width of the rods forming the second stent ring.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a transarticular vascular stent and a preparation method thereof. BACKGROUND

[0002] This section is intended to provide background or context to the embodiments of the application. The description herein does not constitute admission of prior art.

[0003] Peripheral arterial disease (PAD) is a common cardiovascular disease, which often occurs in lower extremity arteries, and the femoro-popliteal artery (FPA) is the main affected site. FPA is a key pathway for blood supply to the lower extremities, and its anatomical structure includes branches such as common femoral artery, superficial femoral artery, adductor hiatus, popliteal artery, etc. FPA is responsible for supplying blood to the lower extremity tissues, but under pathological conditions (such as atherosclerosis), it is prone to chronic blood flow obstruction, leading to PAD.

[0004] The treatment methods for PAD include drug therapy, physical exercise and endovascular intervention. Among them, stent implantation is a minimally invasive endovascular treatment method, which implants a permanent stent (such as a metal mesh) into the blocked artery through balloon angioplasty to restore blood flow. Compared with traditional bypass surgery, stent implantation has the advantages of short recovery time and low invasiveness, so it is increasingly widely used in clinical practice.

[0005] However, the unique biomechanical environment of FPA poses a severe challenge to the durability of the stent. Lower extremity arteries undergo complex mechanical deformation during daily activities (such as walking, sitting, and squatting), including axial compression / stretching (axial compression / stretching rate of about 7%), torsion (angle up to 70°) and bending (angle up to 110°), especially in the adductor hiatus and popliteal artery regions. These deformations will cause the stent to bear periodic stress, leading to stent fracture, plastic deformation or in-stent restenosis (ISR). Clinical data shows that the incidence of ISR is high, and often requires repeated surgery, which is a major difficulty in the treatment of PAD.

[0006] Existing stent designs often cannot meet the differentiated needs of different regions of FPA. For example, the stent shown in FIG. 1A is a straight stent, which is not suitable for the complex mechanical deformation of FPA. The stent shown in FIG. 1B is a bifurcated stent, which is not suitable for the adductor hiatus region. The stent shown in FIG. 1C is a bifurcated stent with a twist, which is not suitable for the popliteal artery region. Figure 1As shown, different parts of the lower limb artery (such as A, B, C, D, D is divided into P1, P2, P3) have specific requirements for the performance of the stent: for example, part A requires accurate positioning, part B requires high radial support force, part C / P1 requires flexibility and anti-torsion, part P2 requires flexibility, and part P3 requires small diameter and low chronic outward force (COF). The existing stent usually only performs well in a single performance, but lacks comprehensive adaptability, leading to easy restenosis or fracture after long-term implantation.

[0007] Therefore, there is an urgent need in the art for a new FPA stent that can adapt to various mechanical deformations of the lower limb artery, maintain excellent compliance and fatigue resistance in bending, twisting, compression and other modes, while minimizing mechanical stress stimulation to the arterial wall and maximizing lumen maintenance. The present application is aimed at the above problems and proposes a cross-joint vascular stent to solve the shortcomings of the prior art. SUMMARY

[0008] The purpose of the present application is to provide a cross-joint vascular stent with a different structure and a preparation method thereof.

[0009] To achieve the above-mentioned purpose, the technical solution adopted by the present application is: The first aspect of the present application relates to a cross-joint vascular stent having an expanded state and a contracted state, the inner diameter of the cross-joint vascular stent in the expanded state being larger than the inner diameter of the cross-joint vascular stent in the contracted state; the cross-joint vascular stent comprises a first part and a second part distributed along the axial direction of the cross-joint vascular stent, wherein the first part is located at the proximal end and the second part is located at the distal end; The first part comprises a plurality of first stent rings arranged at intervals along the axial direction of the cross-joint vascular stent and independent of each other, and a full-surface covering film fixedly arranged on the plurality of first stent rings; wherein from the proximal end to the distal end, the distance between adjacent two first stent rings gradually increases; The second part comprises a plurality of second stent rings arranged at intervals along the axial direction of the cross-joint vascular stent and independent of each other, and a plurality of rows of connecting film groups arranged in sequence along the axial direction of the cross-joint vascular stent; each row of connecting film groups comprises a plurality of connecting films uniformly distributed along the circumferential direction of the cross-joint vascular stent, and both ends of each connecting film are fixedly connected with adjacent two second stent rings, respectively; The width of the rod forming the first stent ring is greater than the width of the rod forming the second stent ring.

[0010] According to some embodiments, the distance between any two adjacent first stent rings at the proximal end is 0.2-0.5mm, such as 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc., and the distance between any two adjacent first stent rings at the distal end is 1-3mm, such as 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, etc.

[0011] According to some embodiments, the distance between any two adjacent second stent rings is equal; the distance between any two adjacent first stent rings, the distance between any two adjacent first and second stent rings, and the distance between any two adjacent first stent rings at the distal end are equal.

[0012] According to some embodiments, the width of the rod of the first stent ring is 0.27-0.3mm, such as 0.27mm, 0.28mm, 0.29mm, 0.3mm, etc., and the width of the rod of the second stent ring is 0.2-0.24mm, such as 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, etc.

[0013] According to some embodiments, the transarticular vascular stent is made of absorbable material; the first stent ring and the second stent ring are respectively a braided ring or a cut ring.

[0014] According to some embodiments, the first stent ring and the second stent ring are respectively a braided ring or a cut ring.

[0015] According to some embodiments, the width of the connecting film is 0.3-0.64mm.

[0016] According to some embodiments, the number of connecting films in each row of connecting film groups is 2-3.

[0017] According to some embodiments, the connecting films in multiple rows of connecting film groups are arranged in multiple rows in the axial direction of the transarticular vascular stent, and each connecting film extends in the same clockwise direction.

[0018] According to some embodiments, each row of connecting film groups further comprises a stent ring film consistent with the shape of the second stent ring, and the stent ring film, the connecting film, and the covering film are integrally arranged.

[0019] According to some embodiments, the two ends of the connecting film are respectively fixedly connected with the nearest peak and valley in the two adjacent stent ring films.

[0020] Further, the stent ring film, the connecting film and the covering film are formed by electrospinning; and / or, the material of the stent ring film, the connecting film and the covering film is absorbable material.

[0021] Still further, the pore size of the film formed by electrospinning is below 5 microns.

[0022] Further, the surface of the stent ring film, the connecting film and the covering film is coated with a sustained-release drug coating.

[0023] According to some embodiments, the joint includes a knee joint or an elbow joint.

[0024] The second aspect of the present application provides a preparation method of the trans-joint vascular stent as described above, which includes the following steps: (1) preparing a first stent ring and a second stent ring; (2) preparing a film by electrospinning; (3) cutting the film to form the covering film and the plurality of connecting film groups; (4) fixedly connecting the cut film, the first stent ring and the second stent ring to obtain the trans-joint vascular stent.

[0025] The third aspect of the present application provides a preparation method of the trans-joint vascular stent as described above, which includes the following steps: (1) preparing a first stent ring and a second stent ring; (2) preparing a film by electrospinning; (3) fixedly connecting the film, the first stent ring and the second stent ring; (4) cutting the film at the corresponding position after the fixed connection to obtain the trans-joint vascular stent.

[0026] Due to the use of the above technical solutions, the present application has the following advantages compared with the prior art: The present application uses different design structures for different sections of the trans-joint vascular stent, so that the trans-joint vascular stent can adapt to various mechanical deformations of the trans-joint artery, maintain excellent compliance and fatigue resistance in bending, twisting, compression and other modes, minimize the mechanical stress stimulation to the arterial wall, and maximize the lumen maintenance, thereby effectively avoiding the occurrence of stent fracture, plastic deformation or in-stent restenosis, and reducing the probability of secondary surgery. BRIEF DESCRIPTION OF DRAWINGS

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram showing the different regions of the lower limb arteries; Figure 2 A three-dimensional view of a transarticular vascular stent; Figure 3 Front view of a cross-articular vascular stent; Figure 4 This is the front view of the braided loop; Figure 5 A three-dimensional diagram of a woven loop; Figure 6 Front view of the cutting ring with the developing ring; Figure 7 A three-dimensional view of the cutting ring without the developing ring; Figure 8 This is a diagram showing the unfolded state of the cut membrane. Figure 9 This is a front view of the cut membrane; Figure 10 This is a diagram showing the unfolded state of the stent annular membrane; Figure 11 A three-dimensional view of the membrane obtained by electrospinning; Figure 12 This is a perspective view of fixing a membrane obtained by electrospinning to a first support ring and a second support ring in one embodiment; Figure 13 This is a front view of a membrane obtained by electrospinning, fixed to a first support ring and a second support ring, according to one embodiment. Figure 14 A schematic diagram of a transarticular vascular stent in a blood vessel. Figure 1 ; Figure 15 A schematic diagram of a transarticular vascular stent in a blood vessel. Figure 2 . Detailed Implementation

[0029] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0030] In the description of the embodiments of the present application, it should be understood that the terms "proximal end" and "distal end" refer to the end closer to the heart as the proximal end and the end farther from the heart as the distal end in the blood vessel. The "axial direction of the vascular stent" refers to the linear dimension along the longitudinal axis of the stent, in which direction compression or stretching deformation can occur. The "circumferential direction of the vascular stent" refers to the annular dimension around the longitudinal axis of the stent, which is usually associated with the radial direction. The "full-surface covering film" refers to a complete film on which no holes are provided except for the micropores brought by the electrospinning process.

[0031] The orientation of the present application is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0032] In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0033] In the embodiments of the present application, unless otherwise specifically specified and limited, the first feature is "in" or "out" of the second feature, which can include the first and second features in direct contact, or the first and second features not in direct contact but in contact through another feature between them. Moreover, the first feature is "in" the second feature, which means that the first feature is closer to the center line than the second feature. The first feature is "out" of the second feature, which means that the first feature is farther away from the center line than the second feature.

[0034] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present application. In order to simplify the disclosure of the embodiments of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples and the purpose is not to limit the embodiments of the present application. In addition, reference numerals and / or reference letters can be repeated in different examples of the embodiments of the present application, and such repetition is for the purpose of simplification and clarity, and does not itself indicate a relationship between the various embodiments and / or arrangements discussed. In the present application, the features with the same name are the same in structural size unless otherwise specified.

[0035] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0036] Figures 2 to 15A transarticular vascular stent is shown, which has an expanded state and a contracted state, and the inner diameter of the transarticular vascular stent in the expanded state is larger than that in the contracted state. Wherein, Figure 2 and Figure 3 A schematic diagram of the transarticular vascular stent in the expanded state is shown. The transarticular vascular stent can be compressed in the delivery sheath by conventional methods and released by conventional methods, for example, the transarticular vascular stent can be a self-expanding stent, that is, the transarticular vascular stent can be inflated to the expanded state by itself as soon as it is released from the delivery sheath; or it can be a balloon-expandable stent, that is, the transarticular vascular stent is loaded on a balloon, and the transarticular vascular stent is forced to expand to the expanded state by expanding the balloon. Figure 14 and Figure 15 A schematic diagram of the transarticular vascular stent in the expanded state is shown. The transarticular vascular stent can be compressed in the delivery sheath by conventional methods and released by conventional methods, for example, the transarticular vascular stent can be a self-expanding stent, that is, the transarticular vascular stent can be inflated to the expanded state by itself as soon as it is released from the delivery sheath; or it can be a balloon-expandable stent, that is, the transarticular vascular stent is loaded on a balloon, and the transarticular vascular stent is forced to expand to the expanded state by expanding the balloon.

[0037] As shown in Figure 2 and Figure 3 The transarticular vascular stent includes a first part 1 and a second part 2 distributed along the axial direction of the transarticular vascular stent. Wherein, the first part 1 is located at the proximal end, and the second part 2 is located at the distal end.

[0038] The first part 1 includes a plurality of first stent rings 11 and a covering film 12. The plurality of first stent rings 11 are arranged along the axial direction of the transarticular vascular stent and are independent of each other. That is, the plurality of first stent rings 11 are separated from each other, and the relative fixation of the plurality of first stent rings 11 is achieved by the covering film 12, and there is no other connecting structure between the plurality of first stent rings 11 except the covering film 12. The covering film 12 is a whole dense film, and no large hole is provided on the covering film 12, so as to prevent cell ingrowth and avoid excessive proliferation of endothelial cells. The covering film 12 is fixedly arranged inside and / or outside the plurality of first stent rings 11, Figure 2 and Figure 3 The covering film 12 is fixedly arranged inside the plurality of first stent rings 11 as shown in

[0039] As shown in Figure 3 From the proximal end to the distal end, the distance between the adjacent two first stent rings 11 gradually increases. In some embodiments, the distance L1 between the adjacent two first stent rings 11 at the proximal end (i.e. the distance between the rightmost two first stent rings 11 in Figure 3 the first part 1) is 0.2-0.5mm, and the distance L2 between the adjacent two first stent rings 11 at the distal end (i.e. the distance between the leftmost two first stent rings 11 in Figure 3The distance between the two adjacent first stent rings 11 at the leftmost end of the first part 1 is 1-3 mm. The distance between the two adjacent first stent rings 11 refers to the distance between the valley bottom of the right stent ring and the peak top of the left stent ring. The gradual increase in the distance between the two adjacent first stent rings 11 can gradually increase the compliance of the first part 1 and provide a lower COF force. The width W1 of the rod of the first stent ring 11 is 0.27-0.3 mm. The control of the proximal end distance of the first stent ring 11 and the width of the rod of the first stent ring 11 can provide a higher radial support force to meet the support requirements of the proximal non-movement area of the artery, such as the support requirements of the proximal non-movement area of the superficial artery.

[0040] The second part 2 includes a plurality of second stent rings 21 and a plurality of rows of connecting membrane groups. The plurality of second stent rings 21 are arranged along the axial direction of the transarticular vascular stent and are independent of each other. That is, the plurality of second stent rings 21 are separated from each other, and the relative fixation of the plurality of second stent rings 21 is achieved by the connecting membrane groups, and there is no other connecting structure between the plurality of second stent rings 21. The plurality of rows of connecting membrane groups are arranged along the axial direction of the transarticular vascular stent in sequence, one row of connecting membrane groups is arranged between the two adjacent second stent rings 21, and one row of connecting membrane groups is also arranged between the adjacent second stent ring 21 and the first stent ring 11, that is, the adjacent second stent ring 21 and the first stent ring 11 are fixedly connected through the row of connecting membrane groups. Alternatively, the adjacent second stent ring 21 and the first stent ring 11 are fixedly connected through the covering film 12.

[0041] Each row of connecting membrane groups includes a plurality of connecting membranes 22 uniformly distributed along the circumferential direction of the transarticular vascular stent, and the two ends of each connecting membrane 22 are fixedly connected with the adjacent two second stent rings 21. The number of connecting membranes 22 in each row of connecting membrane groups is 2-3. The second stent ring 21 is connected by the plurality of connecting membranes 22, so that the second part 2 is designed to be hollow, providing excellent flexibility to meet the requirements of the movement area of the transarticular segment, and at the same time, there are many collateral branches around the transarticular artery. The hollow design can avoid collateral branch occlusion after long-term implantation. For example, the movement area from the proximal end of the femoral popliteal artery to the popliteal artery P3 segment through the knee joint has the largest arterial deformation during walking, sitting, and squatting, so the flexibility requirement of the stent is the highest. At the same time, there are many collateral branches around the transarticular artery. The hollow design can avoid collateral branch occlusion after long-term implantation. In some embodiments, the width W3 of the connecting membrane 22 is 0.3-0.64 mm, which can ensure the connecting strength and avoid fracture while minimizing the impact on the torsional performance of the second part 2.

[0042] As Figure 3As shown, the distance between any two adjacent second stent rings 21 is equal; the distance L3 between two adjacent second stent rings 21, the distance L4 between an adjacent first stent ring 11 and a second stent ring 21, and the distance L2 between two adjacent first stent rings 11 at the distal end are all equal. The width W1 of the strut forming the first stent ring 11 is greater than the width W2 of the strut forming the second stent ring 21. The width W2 of the strut of the second stent ring 21 is 0.2-0.24 mm. Thus, more appropriate support force and flexibility are provided.

[0043] The first stent ring 11 and the second stent ring 21 are respectively a woven ring or a cut ring. As shown in Figure 4 and Figure 5 the structure of the woven ring is shown, wherein Figure 6 and Figure 7 the structure of the cut ring is shown, wherein Figure 6 The cut ring is provided with a developing ring to facilitate identification of the position of the transarticular vascular stent in the blood vessel. Whether it is a woven ring or a cut ring, it contains periodically arranged peaks and valleys. As shown in Figure 3 the peaks of the plurality of first stent rings 11 and the peaks of the plurality of second stent rings 21 are aligned, and the valleys of the plurality of first stent rings 11 and the valleys of the plurality of second stent rings 21 are aligned.

[0044] The connecting membranes 22 in the plurality of rows of connecting membrane groups are arranged in multiple rows in the axial direction of the transarticular vascular stent, and each connecting membrane 22 extends in the same clockwise direction. The angle between the extension direction of the connecting membrane 22 and the axial direction of the transarticular vascular stent is an acute angle. As shown in Figure 3 each row of connecting membrane groups contains two connecting membranes 22, one connecting membrane 22 in each row of connecting membrane groups is aligned in the axial direction of the transarticular vascular stent, and the other connecting membrane 22 in each row of connecting membrane groups is also aligned in the axial direction of the transarticular vascular stent, thereby forming two rows, and the two rows of connecting membranes 22 are arranged on opposite sides of the transarticular vascular stent.

[0045] In some embodiments, as shown in Figure 8 and Figure 9 each row of connecting membrane groups further includes a stent ring membrane 23 consistent with the shape of the second stent ring 21. The stent ring membrane 23, the connecting membrane 22, and the covering membrane 12 are integrally arranged. The stent ring membrane 23 is consistent with the shape of the second stent ring 21, and therefore, the stent ring membrane 23 also contains periodically arranged peaks and valleys. The two ends of the connecting membrane 22 are respectively fixedly connected to the nearest peaks and valleys in the two adjacent stent ring membranes 23. By fixedly connecting the stent ring membrane 23 and the second stent ring 21, the connecting membrane group is fixedly connected to the second stent ring 21, which can further improve the firmness of the fixed connection between the connecting membrane 22 and the second stent ring 21, and avoid disconnection between the two.

[0046] In some embodiments, the stent ring membrane 23, the connecting membrane 22, and the covering membrane 12 are formed by electrospinning.Figure 11 The complete membrane formed by electrospinning is shown, and the pore size of the membrane formed by electrospinning is below 5 microns, Figure 10 The micropores on the stent ring membrane 23 and the connecting membrane 22 are shown. Due to electrospinning film forming, pores inevitably exist in the membrane, and the fiber filaments are as tightly packed as possible during electrospinning, and nanometer, micrometer, and submicron electrospinning is used for processing, so that the pore size on the membrane is controlled to be below 5 microns, and a dense membrane is prepared to prevent cell ingrowth and effectively improve the long-term patency rate. The membrane prepared in this way can achieve a thinner thickness and better radial and axial tensile properties compared to the ePTFE membrane, thereby facilitating the thinning of the transarticular vascular stent and increasing the inner diameter of the transarticular vascular stent.

[0047] In some embodiments, the transarticular vascular stent is made of absorbable materials, including but not limited to high molecular weight polylactic acid, absorbable magnesium alloy, etc. The materials of the stent ring membrane 23, the connecting membrane 22, and the covering membrane 12 are also absorbable materials, including but not limited to PLA, PDLA, PDO, PLGA, etc. so that the transarticular vascular stent can gradually degrade after the cell endothelialization is completed.

[0048] In some embodiments, the surface of the stent ring membrane 23, the connecting membrane 22, and the covering membrane 12 is coated with a sustained-release drug coating, and the active substances in the sustained-release drug coating include but are not limited to everolimus, paclitaxel, etc., and the sustained-release matrix includes but is not limited to PDLA, PDLLA, PLDA, PLGA, etc. The sustained-release drug coating can inhibit intimal hyperplasia and improve long-term patency.

[0049] Although the transarticular vascular stent is developed for lower extremity arteries, it is also applicable to upper extremity arteries. The joint includes a knee joint or an elbow joint, i.e., the transarticular vascular stent can be applied to a vascular artery across the knee joint position, or can be applied to a vascular artery across the elbow joint.

[0050] The transarticular vascular stent can be prepared by the following method: Method one: (1) The first stent ring 11 and the second stent ring 21 are prepared by a braiding machine or a laser cutting heat treatment polishing process; (2) The membrane is prepared by electrospinning; (3) The membrane is cut by a femtosecond laser cutting machine to form the covering membrane 12 and the multiple rows of connecting membrane groups; (4) The cut membrane is arranged inside or outside the first stent ring 11 and the second stent ring 21, and is fixed and connected by a hot melting or biological glue bonding method to obtain the transarticular vascular stent.

[0051] Method two: (1) The first stent ring 11 and the second stent ring 21 are prepared by a weaving machine or a laser cutting heat treatment polishing process; (2) The film is prepared by electrospinning; (3) The film is arranged inside the first stent ring 11 and the second stent ring 21, as shown in Figure 12 and 13 , and is fixed and connected by a hot melt or biological glue bonding method; (4) The film is cut by a femtosecond laser cutting machine at the corresponding position after the fixed connection in step 3, and a transarticular vascular stent is obtained.

[0052] The transarticular vascular stent is designed in a segmented manner, and specific designs are made for the two segments to meet the mechanical property changes of different regions of the transarticular vascular stent, to minimize the mechanical stress stimulation to the vascular intima, and to minimize the long-term restenosis rate. The fracture rate of the transarticular vascular stent of the present application is extremely low. After 4 billion times of in vitro fatigue pulsation cycles and 100 million times of bending and torsion experiments, the fracture rate is "0".

[0053] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A transarticular vascular stent having an extended state and a retracted state, wherein the inner diameter of the transarticular vascular stent in the extended state is larger than its inner diameter in the retracted state; characterized in that: The transarticular vascular stent includes a first portion (1) and a second portion (2) distributed along the axial direction of the transarticular vascular stent, wherein the first portion (1) is located at the proximal end and the second portion (2) is located at the distal end; The first part (1) includes a plurality of first stent rings (11) that are spaced apart and independent of each other along the axial direction of the transarticular vascular stent, and a whole-surface covering film (12) fixedly disposed on the plurality of first stent rings (11); wherein, from the proximal end to the distal end, the distance between two adjacent first stent rings (11) gradually increases; The second part (2) includes a plurality of second stent rings (21) that are spaced apart and independent of each other along the axial direction of the transarticular vascular stent, and a plurality of rows of connecting membrane groups arranged sequentially along the axial direction of the transarticular vascular stent; each row of connecting membrane groups includes a plurality of connecting membranes (22) that are evenly distributed along the circumference of the transarticular vascular stent, and the two ends of each connecting membrane (22) are fixedly connected to two adjacent second stent rings (21); The width of the rod forming the first support ring (11) is greater than the width of the rod forming the second support ring (21).

2. The transarticular vascular stent according to claim 1, characterized in that: The distance between two adjacent first stent rings (11) located at the proximal end is 0.2-0.5 mm, and the distance between two adjacent first stent rings (11) located at the distal end is 1-3 mm.

3. The transarticular vascular stent according to claim 1, characterized in that: The distance between any two adjacent second stent rings (21) is equal; the distance between two adjacent second stent rings (21), the distance between an adjacent first stent ring (11) and a second stent ring (21), and the distance between two adjacent first stent rings (11) located at the distal end are all equal.

4. The transarticular vascular stent according to claim 1, characterized in that: The width of the rod of the first support ring (11) is 0.27-0.3mm, and the width of the rod of the second support ring (21) is 0.2-0.24mm.

5. The transarticular vascular stent according to claim 1, characterized in that: The transarticular vascular stent is made of absorbable material; the first stent ring (11) and the second stent ring (21) are respectively braided rings or cut rings.

6. The transarticular vascular stent according to claim 1, characterized in that: The plurality of first stent rings (11) and the plurality of second stent rings (21) are all peak-to-peak aligned and valley-to-valley aligned; the angle between the extension direction of the connecting membrane (22) and the axial direction of the transarticular vascular stent is an acute angle.

7. The transarticular vascular stent according to claim 1, characterized in that: The width of the connecting membrane (22) is 0.3-0.64 mm.

8. The transarticular vascular stent according to claim 1, characterized in that: The number of connecting membranes (22) in each row of connecting membrane groups is 2 to 3.

9. The transarticular vascular stent according to claim 1, characterized in that: The connecting membranes (22) in the multi-row connecting modules are arranged in multiple rows along the axial direction of the transarticular vascular stent, and each connecting membrane (22) extends in the same clockwise direction.

10. The transarticular vascular stent according to claim 1, characterized in that: Each row of connecting membranes also includes a support ring membrane (23) with the same shape as the second support ring (21), and the support ring membrane (23), the connecting membrane (22) and the covering membrane (12) are integrally formed.

11. The transarticular vascular stent according to claim 10, characterized in that: The two ends of the connecting membrane (22) are fixedly connected to the closest peak and valley phases in the two adjacent support ring membranes (23), respectively.

12. The transarticular vascular stent according to claim 10, characterized in that: The stent ring membrane (23), the connecting membrane (22), and the covering membrane (12) are formed by electrospinning; and / or, the stent ring membrane (23), the connecting membrane (22), and the covering membrane (12) are made of absorbable material.

13. The transarticular vascular stent according to claim 12, characterized in that: The pore size of the membrane formed by electrospinning is less than 5 micrometers.

14. The transarticular vascular stent according to claim 10, characterized in that: The surfaces of the stent ring membrane (23), the connecting membrane (22), and the covering membrane (12) are coated with a sustained-release drug coating.

15. The transarticular vascular stent according to claim 1, characterized in that: The joints include the knee joint or the elbow joint.

16. A method for preparing a transarticular vascular stent as described in any one of claims 1 to 15, characterized in that: It includes the following steps: (1) Prepare the first stent ring (11) and the second stent ring (21); (2) Membranes were prepared by electrospinning; (3) The membrane is cut to form the coating (12) and the multi-row connecting membrane assembly; (4) The cut membrane, the first stent ring (11) and the second stent ring (21) are fixedly connected to obtain the cross-articular vascular stent.

17. A method for preparing a transarticular vascular stent as described in any one of claims 1 to 15, characterized in that: It includes the following steps: (1) Prepare the first stent ring (11) and the second stent ring (21); (2) Membranes were prepared by electrospinning; (3) The membrane, the first support ring (11) and the second support ring (21) are fixedly connected together; (4) Cut the membrane at the corresponding position after it is fixed and connected in step (3) to obtain the cross-articular vascular stent.

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