Absorbable vascular stent

Abstract

The present invention relates to the field of medical devices, and specifically discloses an absorbable vascular stent, including at least one stent unit; the stent unit includes an upper deformation ring, a lower deformation ring and a plurality of first connecting ribs; the upper deformation ring is connected in sequence along the circumferential direction by a plurality of upper deformation blocks to form a wavy annular structure, the lower deformation ring is connected in sequence along the circumferential direction by a plurality of lower deformation blocks to form a wavy annular structure, and the upper deformation blocks and the lower deformation blocks are arranged in a staggered manner of wave crests and wave troughs, the upper end of the first connecting rib is fixedly connected to the bottom of the wave trough of the upper deformation ring, and the lower end is fixedly connected to the top of the wave crest of the corresponding lower deformation ring; the stent unit also includes a plurality of upper limit ribs and lower limit ribs arranged along its axial direction, the upper end of the upper limit rib is fixedly connected to the bottom of the wave crest of the upper deformation ring, and the lower end of the lower limit rib is fixedly connected to the top of the wave trough of the corresponding lower deformation ring. The present invention provides an absorbable vascular stent with sufficient expansion force.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an absorbable vascular stent. Background Art

[0002] Absorbable vascular stents are also called degradable vascular stents. Due to their excellent flexibility, biocompatibility, moderate degradability and mechanical support, they have become a very promising treatment for coronary artery stenosis. In addition, they can slowly degrade into safe and non-toxic small molecules while the blood vessels are repaired and healed, and are excreted from the body along with metabolic wastes. They have the potential to solve the long-term restenosis problem after permanent metal stent implantation. The materials of absorbable vascular stents are mostly high molecular polymers, including polyurethane, polylactic acid, polyglycolide, polylactide, polydioxanone, polycaprolactone, etc. These materials gradually degrade in the body and are excreted from the body after participating in the body's metabolism.

[0003] Existing absorbable vascular stents and vascular stent systems are shown in patent CN112399832 A (absorbable intravascular device that shortens during expansion to create space for vascular movement).

[0004] In cardiac surgery, emergency surgery when early aortic dissection causes multi-organ malperfusion is extremely risky and has a very high mortality rate. The best way is to open the true lumen, temporarily restore blood supply to the organs, and then perform surgery after the organ function is restored. The currently used interventional covered stents are difficult to remove during surgery and have extremely high surgical complications. Using absorbable vascular stents is a better way, but the existing absorbable vascular stents do not have self-expanding properties, and their expansion force is insufficient to fully expand the true lumen. Even if they are expanded by a balloon, they will gradually shrink after the balloon is detached.

[0005] Therefore, in order to solve the above problems, an absorbable vascular stent with sufficient expansion force is needed. Summary of the invention

[0006] In view of this, an object of the present invention is to provide an absorbable vascular stent with sufficient expansion force.

[0007] To achieve the above-mentioned object, the present invention provides an absorbable blood vessel stent, comprising at least one stent unit, wherein the stent unit comprises an upper deformable ring, a lower deformable ring arranged below the upper deformable ring, and a plurality of first connecting ribs for connecting the upper deformable ring and the lower deformable ring in the axial direction; the upper deformable ring is formed by a plurality of upper deformable blocks connected in sequence along the circumferential direction to form a wavy annular structure, the lower deformable ring is formed by a plurality of lower deformable blocks connected in sequence along the circumferential direction to form a wavy annular structure, and the upper deformable blocks and the lower deformable blocks are arranged in a manner of staggered wave crests and wave troughs, the upper end of the first connecting rib is fixedly connected to the bottom of the wave trough of the upper deformable ring, and the lower end is fixedly connected to the top of the wave crest of the corresponding lower deformable ring;

[0008] The bracket unit also includes a plurality of upper limit ribs and lower limit ribs arranged along its axial direction, the upper end of the upper limit rib is fixedly connected to the bottom of the wave peak of the upper deformation ring, and the lower end of the lower limit rib is fixedly connected to the top of the wave valley of the corresponding lower deformation ring; when the upper deformation ring and the lower deformation ring are deformed synchronously and cause the bracket unit to expand and shorten, the upper limit rib and the corresponding lower limit rib are locked with each other through the locking structure and prevent the bracket unit from retracting.

[0009] As a further improvement to the technical solution of the present invention, when the upper deformation ring and the lower deformation ring are asynchronously deformed to a set state, the locking structure between the upper limit rib and the corresponding lower limit rib is released and the restriction on the retraction of the bracket unit is released.

[0010] As a further improvement of the technical solution of the present invention, there is a gap between the upper limit rib and the corresponding lower limit rib; the locking structure includes a locking block and a plurality of locking grooves for the locking block to be inserted into; a locking block is protruding from one side of the lower limit rib, and a plurality of stop blocks are protruding from the side of the upper limit rib opposite to the lower limit rib, and a locking groove is formed between adjacent stop blocks; when the upper deformation ring and the lower deformation ring are deformed synchronously and cause the bracket unit to expand and shorten, the locking block moves and crosses the stop block into the locking groove; when the upper deformation ring and the lower deformation ring are deformed asynchronously, the upper limit rib and the lower limit rib gradually move away from each other and cause the locking block to escape from the locking groove.

[0011] As a further improvement to the technical solution of the present invention, the blocks on the same lower limit rib are evenly distributed along the length direction of the lower limit rib, the block is wedge-shaped and its inclined surface is set downward, and the locking block is provided with an arc surface on the side facing the inclined surface of the block.

[0012] As a further improvement to the technical solution of the present invention, the upper limit rib and the corresponding lower limit rib are both in the shape of a straight plate or a straight rod.

[0013] As a further improvement to the technical solution of the present invention, the upper limit rib is located outside the corresponding lower limit rib.

[0014] As a further improvement to the technical solution of the present invention, the absorbable vascular stent includes two or more stent units, and the upper and lower adjacent stent units are connected by a second connecting rib.

[0015] As a further improvement to the technical solution of the present invention, the upper end of the second connecting rib is fixedly connected to the bottom of the trough of the lower deformation ring of the upper bracket unit, and the lower end is fixedly connected to the top of the peak of the corresponding upper deformation ring of the adjacent next bracket unit.

[0016] As a further improvement to the technical solution of the present invention, the upper deformation block and the lower deformation block are both in a "V" shape or a "U" shape.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The present invention provides an absorbable vascular stent. When the upper deformation ring and the lower deformation ring are deformed synchronously, the upper limit rib and the corresponding lower limit rib maintain a specific matching relationship. When the stent unit expands and shortens, the upper limit rib and the corresponding lower limit rib continue to approach each other, the degree of overlap between the two gradually increases, and finally they are locked together through a locking structure. This locking is unidirectional, so that even if the external force disappears, the stent unit cannot retract, thereby allowing the vascular stent to have sufficient expansion force.

[0019] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are used to explain the present invention but do not constitute a limitation of the present invention.

[0021] Figure 1 This is a structural expansion diagram of an absorbable vascular stent in Example 1 of the present invention;

[0022] Figure 2 for Figure 1 Middle A-direction view;

[0023] Figure 3 It is a structural expansion diagram of an absorbable vascular stent in the second embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments; of course, the accompanying drawings are simplified schematic diagrams, and their proportional sizes do not constitute a limitation on the patented product.

[0025] Embodiment 1

[0026] like Figure 1 and Figure 2 As shown: An absorbable vascular stent provided in this embodiment includes a stent unit 1, wherein the stent unit 1 includes an upper deformable ring 101, a lower deformable ring 102 arranged below the upper deformable ring 101, and a plurality of first connecting ribs 103 for axially connecting the upper deformable ring 101 and the lower deformable ring 102; the upper deformable ring 101 is connected in sequence along the circumferential direction by a plurality of upper deformable blocks 104 to form a wavy annular structure, the lower deformable ring 102 is connected in sequence along the circumferential direction by a plurality of lower deformable blocks 105 to form a wavy annular structure, and the upper deformable blocks 104 and the lower deformable blocks 105 are arranged in a manner where the crests and troughs are staggered, and the upper end of the first connecting rib 103 is fixedly connected to the bottom of the trough of the upper deformable ring 101, and the lower end is fixedly connected to the top of the crest of the corresponding lower deformable ring 102.

[0027] "Up" and "Down" Figure 1 Directions shown shall prevail.

[0028] The vascular stent is made of biodegradable materials as a whole, such as polyurethane, polylactic acid, polyglycolide, polylactide, polydioxanone, polycaprolactone, etc.; the vascular stent has the function of expanding and supporting blood vessels. After fully exerting its function, the vascular stent can gradually degrade in the patient's body and eventually degrade into non-toxic products (such as water and carbon dioxide) that can be absorbed by the human body, so that the blood vessels can return to their natural state after the stent disappears.

[0029] The stent unit 1 is a basic unit for forming a vascular stent, and a single stent unit 1 can also be used as a medical device for dilating blood vessels. The upper deformation ring 101 and the lower deformation ring 102 are connected by the first connecting rib 103 to form the stent unit 1; the upper deformation block 104 and the lower deformation block 105 have the same structure, and can be in a "V" shape (including an "inverted V" shape), or can also be in a "U" shape (including an "inverted U" shape); the number of upper deformation blocks 104 in the upper deformation ring 101 and the number of lower deformation blocks 105 in the lower deformation ring 102 can be determined according to needs, and are not limited here. The upper deformation block 104 and the lower deformation block 105 are arranged in a staggered manner, that is, the crest of the upper deformation block 104 is opposite to the trough of the corresponding lower deformation block 105, and the trough of the upper deformation block 104 is opposite to the crest of the corresponding lower deformation block 105, that is, the upper deformation block 104 and the corresponding lower deformation block 105 are symmetrical based on the transverse midline of the stent unit 1. The first connecting ribs 103 may be in the shape of a straight plate, a straight rod, or a curved plate or a curved rod. In one bracket unit 1 , the number of the first connecting ribs 103 is the same as the number of the upper deformation blocks 104 and the lower deformation blocks 105 .

[0030] The upper deformation block 104 and the lower deformation block 105 can expand outward and stretch and shorten when subjected to radial force, so that the upper deformation ring 101 and the lower deformation ring 102 can also expand outward and stretch and shorten. At this time, the stent unit 1 as a whole also expands and shortens; when the radial force disappears, the stent unit 1 gradually compresses and stretches or even returns to its original state, which is the retraction of the stent unit 1; it is precisely because of the existence of the retraction effect that the expansion force of the existing vascular stent is insufficient.

[0031] The absorbable vascular stent provided in this embodiment has the following major improvements: the stent unit 1 also includes a plurality of upper limit ribs 106 and lower limit ribs 107 arranged along its axial direction, the upper end of the upper limit rib 106 is fixedly connected to the bottom of the wave crest of the upper deformation ring 101, and the lower end of the lower limit rib 107 is fixedly connected to the top of the wave trough of the corresponding lower deformation ring 102; when the upper deformation ring 101 and the lower deformation ring 102 are deformed synchronously and cause the stent unit 1 to expand and shorten, the upper limit rib 106 and the corresponding lower limit rib 107 are locked with each other through the locking structure and prevent the stent unit 1 from retracting.

[0032] The upper limit rib 106 and the lower limit rib 107 are arranged in the area formed by the upper deformation block 104, the corresponding lower deformation block 105 and the two adjacent first connecting ribs 103; the lower end of the upper limit rib 106 is a free end, and the upper end of the lower limit rib 107 is a free end; the upper limit rib 106 and the corresponding lower limit rib 107 are both in the shape of a straight plate or a straight rod; the axis of the upper limit rib 106 coincides with or is parallel to the axis of the upper deformation block 104, and the axis of the lower limit rib 107 coincides with or is parallel to the axis of the lower deformation block 105, so that the upper limit rib 106 can move downward and outward ("outward" is the direction away from the axis of the bracket unit 1, and "inward" is the direction close to the axis of the bracket unit 1) with the expansion of the upper deformation block 104, and the upper limit rib 106 moves upward and outward with the expansion of the lower deformation block 105, and the opposite is true when the upper deformation block 104 and the lower deformation block 105 contract.

[0033] When the upper deformation ring 101 and the lower deformation ring 102 are deformed synchronously (i.e., the expansion and contraction degrees are the same), the upper limit rib 106 and the corresponding lower limit rib 107 maintain a specific matching relationship. When the stent unit 1 expands and shortens (its inner diameter expands and its length shortens), the upper limit rib 106 and the corresponding lower limit rib 107 continue to approach each other, and the overlap between the two gradually increases, and finally they are locked together through the locking structure. This locking is unidirectional, so that even if the external force disappears, the stent unit 1 cannot retract, so that the blood vessel stent has sufficient expansion force. At this time, the external force that causes the deformation of the stent unit 1 can come from an existing balloon, such as the balloon shown in patent CN112399832 A.

[0034] Another key improvement of the absorbable vascular stent provided in this embodiment is that when the upper deformable ring 101 and the lower deformable ring 102 are asynchronously deformed to a set state, the locking structure between the upper limit rib 106 and the corresponding lower limit rib 107 is released and the restriction on the retraction of the stent unit 1 is released.

[0035] Asynchronous deformation means that the upper deformation ring 101 and the lower deformation ring 102 have different expansion and contraction degrees. For example, the upper deformation ring 101 expands, while the lower deformation ring 102 remains unchanged or contracts or expands (due to the connection function of the first connecting rib 103, the lower deformation ring 102 may expand in actual operation, but the expansion degree is not as good as the upper deformation ring 101). In this embodiment, after the upper deformation ring 101 and the lower deformation ring 102 expand to a certain and the same degree, they cannot retract due to the locking of the locking structure. At this time, when the upper deformation ring 101 continues to expand by controlling the balloon alone, the locking structure can be unlocked. After unlocking and removing the external force, the upper deformation ring 101 and the lower deformation ring 102 retract to a state where they can remain free, and the stent unit 1 can be expanded again by the balloon.

[0036] With this structure, it is possible to remedy the vascular stent that has deviations in expansion degree or placement position. Otherwise, if it is only locked in one direction, the stent has a low error tolerance rate, and once a deviation occurs, the consequences are difficult to make up for. In existing medical operations, this deviation often occurs, causing medical staff to spend more time on making up for the error.

[0037] In terms of specific structure, there is a gap between the upper limit rib 106 and the corresponding lower limit rib 107; the locking structure includes a locking block 108 and a plurality of locking grooves 109 for the locking block 108 to be inserted into; a locking block 108 is protruded from one side of the lower limit rib 107, and a plurality of stoppers 110 are protruded from the side of the upper limit rib 106 opposite to the lower limit rib 107, and locking grooves 109 are formed between adjacent stoppers 110; when the upper deforming ring 101 and the lower deforming ring 102 are deformed synchronously and cause the bracket unit 1 to expand and shorten, the locking block 108 moves and crosses the stopper 110 to enter the locking groove 109; when the upper deforming ring 101 and the lower deforming ring 102 are deformed asynchronously, the upper limit rib 106 and the lower limit rib 107 gradually move away from each other and cause the locking block 108 to escape from the locking groove 109.

[0038] The locking block 108 can be inserted into different locking grooves 109, and once it enters the locking groove 109, it cannot be withdrawn when the upper deformation ring 101 and the lower deformation ring 102 are deformed synchronously, and can only continue to move upward, that is, the bracket unit 1 can only continue to expand and shorten. At this time, as a preference, the blocks 110 on the same lower limit rib 107 are evenly distributed along the length direction of the lower limit rib 107, the blocks 110 are wedge-shaped and their inclined surfaces are set downward, and the locking block 108 is provided with an arc surface on the side facing the inclined surface of the block 110, and the arc surface of the locking block 108 can reduce the resistance of its movement on the inclined surface of the block 110, and once it crosses the inclined surface of the block 110, it enters the locking groove 109. The locking block 108 can be arranged at the top of the lower limiting rib 107 or near the top; the number of the blocking blocks 110 can be determined according to the needs, and the multiple locking grooves 109 formed by the multiple blocking blocks 110 make the locking structure have a multi-level locking function and can be used according to the needs.

[0039] The upper limit rib 106 is opposite to the corresponding lower limit rib 107 but is not located on the same straight line. Preferably, the upper limit rib 106 is located outside the corresponding lower limit rib 107. Therefore, when the upper limit rib 106 moves outward alone, the distance between the locking groove 109 and the locking block 108 increases continuously until the distance is greater than the lateral width of the locking block 108, and the locking structure can be unlocked.

[0040] Embodiment 2

[0041] like Figure 3 As shown, an absorbable vascular stent provided in this embodiment includes two stent units 1, and the upper and lower adjacent stent units 1 are connected by a second connecting rib 2. The structure of the stent unit 1 is the same as that shown in Example 1. Through the axial connection of the stent unit 1, the length of the vascular stent can be extended according to medical needs; of course, similarly, three, four or even more axial stent units 1 can be connected, and the vascular stent as a whole is a straight structure and is not bent.

[0042] The upper end of the second connecting rib 2 is fixedly connected to the bottom of the trough of the lower deformation ring 102 of the upper bracket unit 1 , and the lower end is fixedly connected to the top of the peak of the corresponding upper deformation ring 101 of the adjacent next bracket unit 1 .

[0043] In the case of multiple stent units 1, the existing longer balloon (the length is adapted to the length of the vascular stent) can also be used to expand the vascular stent; and when the locking structure needs to be unlocked, the vascular stent can be expanded to a certain extent first, and then multiple shorter balloons (the length is adapted to the length of the upper deformable ring 101) can be sent to the position of the upper deformable ring 101 of each stent unit 1 respectively, and then expanded to the same extent. After unlocking, the longer balloon can be used for expansion.

[0044] Finally, it should be noted that this article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only to help understand the core idea of ​​the present invention. Without departing from the principles of the present invention, the present invention may also be improved and modified, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. An absorbable vascular stent, comprising at least one stent unit; The bracket unit comprises an upper deformation ring, a lower deformation ring arranged below the upper deformation ring, and a plurality of first connecting ribs for connecting the upper deformation ring and the lower deformation ring axially; the upper deformation ring is connected in sequence along the circumferential direction by a plurality of upper deformation blocks to form a wavy annular structure, the lower deformation ring is connected in sequence along the circumferential direction by a plurality of lower deformation blocks to form a wavy annular structure, and the upper deformation blocks and the lower deformation blocks are arranged in a manner of staggered wave crests and wave troughs, the upper end of the first connecting rib is fixedly connected to the bottom of the wave trough of the upper deformation ring, and the lower end is fixedly connected to the top of the wave crest of the corresponding lower deformation ring; Features: The bracket unit also includes a plurality of upper limit ribs and lower limit ribs arranged along its axial direction, the upper end of the upper limit rib is fixedly connected to the bottom of the wave crest of the upper deformation ring, and the lower end of the lower limit rib is fixedly connected to the top of the wave trough of the corresponding lower deformation ring; when the upper deformation ring and the lower deformation ring are deformed synchronously and cause the bracket unit to expand and shorten, the upper limit rib and the corresponding lower limit rib are locked with each other through the locking structure and prevent the bracket unit from retracting; When the upper deformation ring and the lower deformation ring are asynchronously deformed to a set state, the locking structure between the upper limit rib and the corresponding lower limit rib is unlocked and the restriction on the retraction of the bracket unit is released; There is a gap between the upper limit rib and the corresponding lower limit rib; the locking structure includes a locking block and a plurality of locking grooves for the locking block to be inserted into; a locking block is protruded from one side of the lower limit rib, and a plurality of stoppers are protruded from the side opposite to the lower limit rib on the upper limit rib, and a locking groove is formed between adjacent stoppers; when the upper deformation ring and the lower deformation ring are deformed synchronously and cause the bracket unit to expand and shorten, the locking block moves and crosses the stopper to enter the locking groove; when the upper deformation ring and the lower deformation ring are deformed asynchronously, the upper limit rib and the lower limit rib gradually move away from each other and cause the locking block to escape from the locking groove; The blocks on the same lower limit rib are evenly distributed along the length direction of the lower limit rib, the blocks are wedge-shaped and their inclined surfaces are arranged downward, and the locking block is provided with an arc surface on one side facing the inclined surface of the block; The upper limit rib and the corresponding lower limit rib are both in the shape of a straight plate or a straight rod.

2. The absorbable vascular stent according to claim 1, Features: The upper limit rib is located outside the corresponding lower limit rib.

3. An absorbable vascular stent according to claim 1 or 2, Features: The absorbable blood vessel stent comprises two or more stent units, and the upper and lower adjacent stent units are connected via a second connecting rib.

4. The absorbable vascular stent according to claim 3, Features: The upper end of the second connecting rib is fixedly connected to the bottom of the trough of the lower deformation ring of the upper bracket unit, and the lower end is fixedly connected to the top of the peak of the corresponding upper deformation ring of the adjacent next bracket unit.

5. The absorbable vascular stent according to claim 1 or 2, Features: The upper deformation block and the lower deformation block are both in a "V" shape or a "U" shape.

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