CN117414241A

CN117414241A - Intracranial vascular stent

Info

Publication number: CN117414241A
Application number: CN202311570408.8A
Authority: CN
Inventors: 顾兴中; 肖小康; 张玉成
Original assignee: Taizhou Institute Of Biomedicine And Medical Devices Southeast University
Current assignee: Taizhou Institute Of Biomedicine And Medical Devices Southeast University
Priority date: 2023-11-23
Filing date: 2023-11-23
Publication date: 2024-01-19

Abstract

The invention discloses an intracranial vascular stent, which comprises first waveform cells and second waveform cells, wherein the first waveform cells and the second waveform cells are used for forming the stent, every two groups of first waveform cells are symmetrically arranged along the circumferential direction of the vascular stent and are connected between waveform vertexes which are close to each other through first connecting rods to form a closed-loop stent unit, and the second waveform cells are positioned between the closed-loop stent units and are connected between adjacent first waveform cells through second connecting rods to form an open-loop stent unit; the first waveform cell and the second waveform cell of the vascular stent adopt the design of a large and small wave structure, and the symmetrical connecting rods are used, so that the uniformity of the large and small wave rings in the stent expanding process can be enhanced, the generation of dog bone effect is weakened, the symmetrical structures at two ends of the stent can enable the shapes and the stress conditions at two ends of the stent to be more uniform, the stent is favorable for adapting to the curvature and the diameter change of a blood vessel better, and the displacement risk of the stent in the blood vessel is reduced.

Description

Intracranial vascular stent

Technical Field

The invention relates to the technical field of vascular stents, in particular to an intracranial vascular stent.

Background

Intracranial stent technology is an important therapeutic tool in the interventional neurological field for the treatment of cerebrovascular diseases, in particular cerebral arterial stenosis, cerebral aneurysms, and hemangiomas. With the continuous progress of medical technology and the development of intracranial stents, significant progress and breakthrough has been made in this field. Prior art intracranial stents fall into three forms: 1. self-expanding stent: self-expanding stents are the most common type of intracranial stents. The device adopts a compressible support structure, is guided into a blood vessel through a guide wire, and is automatically unfolded and clung to the wall of the blood vessel after being released, so that stable support is provided. These stents are typically made of metal alloys with good visualization and biocompatibility; 2. a covered stent: the covered stent is additionally provided with a medicine covered film on the basis of the traditional self-expanding stent. The medicine can be released to inhibit restenosis of blood vessel or regeneration of tumor body, and reduce complications and recurrence risk after treatment; 3. double-deck support: the double-layer stent is a newer technology, and combines the advantages of the covered stent and the traditional stent. These stents generally have better flexibility and lower risk of secondary stenosis.

The problems are that: vascular injury: during intracranial stent placement, the vessel wall may sometimes be damaged, resulting in thrombosis or other complications. Improving the stent introduction and placement technique is critical to reduce vascular injury; secondary stenosis: after intracranial stent implantation, vascular stenosis may reoccur, especially in the case of treatment of cerebral arterial stenosis. Drug-coated and double-layered stent techniques are intended to solve this problem, but still require more research to improve the therapeutic effect; support stability: the stability of the stent is directly related to the therapeutic effect and patient recovery. How to ensure the stability and long-term effect of the stent inside the blood vessel is an aspect requiring continuous improvement; individualization treatment: due to the varying vascular anatomy and disease conditions of patients, a single standard stent may not be satisfactory in all cases. Thus, developing individually tailored scaffold technology is a challenge and direction of development.

Problems of the support structure: after the stent is implanted into a body, the shape of the two ends of the stent is unstable. It is known as the curved shape of dog bones when chewed. The dog bone effect is compromised: 1. the stability of the stent is reduced, and the stent may be displaced or distorted inside the blood vessel due to the instability of the shape of the stent, reducing the stability and durability of the stent. 2. Causing vascular damage, the unstable stent edges may cause friction or damage to the inner wall of the vessel, increasing the risk of vascular damage and thrombosis. 3. Causing obstruction of vascular flow, stent distortion may affect hemodynamics, resulting in local flow obstruction or vortex phenomena.

Disclosure of Invention

The technical purpose is that: aiming at the defects of the existing intracranial vascular stent, the invention discloses an intracranial vascular stent which can improve the uniformity of the stent in the expanding process, weaken the dog bone effect and adapt to the change of the curvature and the diameter of a blood vessel.

The technical scheme is as follows: in order to achieve the technical purpose, the invention adopts the following technical scheme:

an intracranial vascular stent comprises first waveform cells and second waveform cells, wherein the first waveform cells and the second waveform cells are used for forming the stent, every two groups of first waveform cells are symmetrically arranged along the length direction of the vascular stent and are connected between waveform vertexes which are close to each other through first connecting rods to form a closed-loop stent unit, and the second waveform cells are positioned between the closed-loop stent units and are connected between adjacent first waveform cells through second connecting rods to form an open-loop stent unit.

Preferably, the first connecting rod adopts a straight rod structure, and the second connecting rod adopts an S-shaped connecting rod which can axially stretch and deform the vascular stent.

Preferably, the second connecting rods of the present invention are arranged at intervals along the length direction of the second wave-shaped cells.

Preferably, the adjacent second connecting rods are arranged in a mirror image mode along the length direction of the vascular stent.

Preferably, the second connecting rods on two sides of the second waveform cell are alternately arranged along the length direction of the second waveform cell and are respectively connected at the peaks of waveforms at different positions of the second waveform cell.

Preferably, the wave number of the first waveform cell of the present invention is greater than the wave number of the second waveform cell.

Preferably, the waveform size of the first waveform cell of the present invention is larger than the waveform size of the second waveform cell.

Preferably, the first waveform cell of the present invention adopts nine-wave cells, and the second waveform cell adopts six-wave cells.

Preferably, the surface of the closed loop stent unit formed by the first waveform cell is provided with a drug film coating.

The beneficial effects are that: the intracranial vascular stent disclosed by the invention has the following beneficial effects:

1. the first waveform cell and the second waveform cell of the vascular stent adopt the design of a large and small wave structure, and the symmetrical connecting rods are used, so that the uniformity of the large and small wave rings in the stent expanding process can be enhanced, the generation of dog bone effect is weakened, the symmetrical structures at two ends of the stent can enable the shapes and the stress conditions at two ends of the stent to be more uniform, the stent is favorable for adapting to the curvature and the diameter change of a blood vessel better, and the displacement risk of the stent in the blood vessel is reduced.

2. The support structure of the invention combines the advantages and disadvantages of an open-loop support and a closed-loop support, and adopts an open-loop and closed-loop combined form; the function is to optimize the traditional intracranial stent structure, inherit the characteristics of weak supporting force of the open-loop structure while the compliance of the open-loop structure is strong, and the whole supporting force of the stent is enhanced by utilizing the closed-loop structure.

3. The first connecting rod of the closed-loop support unit adopts a straight rod, the second connecting rod of the open-loop support unit adopts an S-shaped connecting rod, every four waveforms adopt a connecting rod, and adjacent waveform connecting rods adopt mirror image S-shaped structures so as to offset the non-uniformity of the support during expanding and contracting, and due to the design of the multi-layer support structure, the stress at two ends of the support can be relatively uniformly distributed, and the form of opening and closing the loop is adopted, so that the form change of the support in the process from an open-loop state to a closed-loop state is more gentle in a layer-by-layer transition mode, the form distortion of the support during placement is reduced, and the effect of dog bones is obviously reduced; the S-shaped connecting ribs are adopted, so that the shrinkage ratio in the radial direction can be compensated to a certain extent, and the shrinkage ratio of the bracket when being unfolded is effectively reduced.

6. According to the invention, the closed loop structure covered by the medicine is combined with the open loop structure, so that the covered area of the medicine can be further enlarged, the curative effect of the medicine is enhanced, and the recurrence of stenosis or tumor is inhibited; the open loop structure has strong adaptability and can be suitable for complex vascular anatomy, and the stent stability of the closed loop structure enables the open loop structure to be suitable for simpler vascular lesions. The combination of the two structures can be widely applied to different types of cerebrovascular diseases, and provides more personalized and accurate treatment schemes.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a side expanded view of an intracranial stent structure according to the present invention;

FIG. 2 is a diagram showing the comparison of the structures of a first waveform cell and a second waveform cell according to the present invention;

FIG. 3 is a diagram showing the overall construction of an intracranial stent according to the invention;

wherein, 1-first wave form cell, 2-second wave form cell, 3-head rod, 4-closed loop support unit, 5-second connecting rod, 6-open loop support unit.

Description of the embodiments

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown, but in which the invention is not so limited.

As shown in fig. 1-3, the invention discloses an intracranial stent, which comprises a first waveform cell 1 and a second waveform cell 2 used for forming the stent, wherein each two groups of first waveform cells 1 are symmetrically arranged along the length direction of the stent and are connected between waveform vertexes which are close to each other through a first connecting rod 3 to form a closed-loop stent unit 4, and the second waveform cell 2 is positioned between the closed-loop stent units 4 and is connected between adjacent first waveform cells 1 through a second connecting rod 5 to form an open-loop stent unit 6.

The open loop and closed loop alternately arranged structure formed by the two waveform cells improves the support capability of the vascular stent while improving the compliance of the stent structure, and can carry out medicine coating on the closed loop stent unit 4, so that the stent can carry and release more medicines, and the curative effect of the medicines is enhanced.

In a specific embodiment, the first connecting rod 3 of the invention adopts a straight rod structure, the second connecting rods 5 adopt S-shaped connecting rods which can axially stretch and deform the vascular stent, the second connecting rods 5 are arranged at intervals along the length direction of the second waveform cell 2, the second connecting rods 5 at two sides of the second waveform cell 2 are alternately arranged along the length direction of the second waveform cell 2, and are respectively connected at the peaks of waveforms at different positions of the second waveform cell 2; the first connecting rod 3 is connected with the connected first waveform cell 1 to form a non-telescopic closed-loop structure, the axial expansion of the bracket is realized through the S-shaped connecting rod, and meanwhile, the waveform structures of the two waveform cells can be compressed and deformed, so that the bracket can realize radial diameter change in a certain range, and the radial diameter change and curvature change conditions under different conditions can be adapted.

Preferably, the adjacent second connecting rods 5 are arranged in a mirror image mode along the length direction of the vascular stent, so that when the stent is stressed and deformed, the non-uniformity of the stent during the stretching or shrinking is counteracted, the shape change of the stent in the process from an open-loop state to a closed-loop state is more gentle in a layer-by-layer transition mode, the shape distortion generated when the stent is placed is reduced, and the method plays an obvious role in reducing the dog bone effect.

The wave number of the first waveform cell 1 is larger than that of the second waveform cell 2; the waveform size of the first waveform cell 1 is larger than the waveform size of the second waveform cell 2, the small waveform and a plurality of modes can strengthen the axial strength of the stent, the problem that the strength is insufficient to support blood vessels is avoided, meanwhile, the large waveform can strengthen the radial strength of the stent through small deformation, the S-shaped connecting ribs are adopted in combination, the shrinkage of the stent in the radial direction can be compensated to a certain extent, the shrinkage of the stent when the stent is expanded is effectively reduced, and as shown in fig. 2, in the embodiment of the invention, the first waveform cell 1 adopts nine-wave cells, and the second waveform cell 2 adopts six-wave cells.

Meanwhile, as the surface of the closed-loop bracket unit 4 is relatively large, the closed-loop bracket unit is suitable for drug film coating, and more drugs can be released. By combining the closed loop structure covered by the medicine with the open loop structure, the covered area of the medicine can be further enlarged, the curative effect of the medicine is enhanced, and the recurrence of stenosis or tumor is inhibited; the open loop structure has strong adaptability and can be suitable for complex vascular anatomy, and the stent stability of the closed loop structure enables the open loop structure to be suitable for simpler vascular lesions. The combination of the two structures can be widely applied to different types of cerebrovascular diseases, and provides more personalized and accurate treatment schemes.

As shown in figure 3, the intracranial vascular stent provided by the invention can ensure uniformity of the stent, weaken generation of dog bone effect, ensure that the stent is stressed more uniformly by the mirror-image arrangement of the second connecting rods 5, can well adapt to curvature and diameter change of the vessel, reduce risk of shifting of the stent in the vessel, can enlarge coverage area of the drug by carrying the drug by the closed-loop stent unit 4, enhance curative effect of the drug and inhibit recurrence of stenosis or tumor.

The foregoing is only a preferred embodiment of the invention, it being noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.

Claims

1. The intracranial vascular stent is characterized by comprising first waveform cells (1) and second waveform cells (2) which are used for forming the stent, wherein every two groups of first waveform cells (1) are symmetrically arranged along the length direction of the vascular stent and are connected between waveform vertexes which are close to each other through first connecting rods (3) to form a closed-loop stent unit (4), and the second waveform cells (2) are positioned between the closed-loop stent units (4) and are connected between adjacent first waveform cells (1) through second connecting rods (5) to form an open-loop stent unit (6).

2. An intracranial stent according to claim 1, wherein the first connecting rod (3) is of a straight rod structure, and the second connecting rod (5) is of an S-shaped connecting rod which enables the stent to axially deform in a telescopic manner.

3. An intracranial vascular stent as claimed in claim 2, wherein the second connecting rods (5) are spaced apart along the length of the second wave shaped cells (2).

4. An intracranial stent as claimed in claim 2, characterised in that adjacent second connecting rods (5) are arranged in mirror image relationship to each other along the length of the stent.

5. An intracranial vascular stent according to claim 2 or 4, wherein the second connecting rods (5) on both sides of the second waveform cell (2) are alternately arranged along the length direction of the second waveform cell (2) and are respectively connected at the peaks of waveforms at different positions of the second waveform cell (2).

6. An intracranial stent as claimed in claim 1, characterised in that the wave number of the first waveform cell (1) is greater than the wave number of the second waveform cell (2).

7. An intracranial vascular stent as claimed in claim 1 or 6, wherein the waveform size of the first waveform cell (1) is greater than the waveform size of the second waveform cell (2).

8. An intracranial stent as claimed in claim 7, wherein the first waveform cell (1) is a nine-wave cell and the second waveform cell (2) is a six-wave cell.

9. An intracranial vascular stent as claimed in claim 1, wherein the closed-loop stent unit (4) formed by the first wave-shaped cells (1) is provided with a drug-coated coating on the surface.