CN216676047U

CN216676047U - Support frame

Info

Publication number: CN216676047U
Application number: CN202023124232.8U
Authority: CN
Inventors: 张涵; �田�浩; 卢惠娜
Original assignee: Microport Neurotech Shanghai Co Ltd
Current assignee: Microport Neurotech Shanghai Co Ltd
Priority date: 2020-12-22
Filing date: 2020-12-22
Publication date: 2022-06-07
Anticipated expiration: 2030-12-22

Abstract

The utility model provides a stent which comprises an inner stent and an outer stent. The inner stent comprises a proximal portion, an intermediate portion and a distal portion which are connected in sequence. The outer layer bracket is sleeved on the outer wall of the middle part and covers at least part of the middle part; the distal portion is flared and connected to the intermediate portion at an obtuse angle. Wherein, the inner layer bracket and the outer layer bracket are both of a net structure. Therefore, the outer-layer bracket is covered on the middle part, so that the metal coverage rate is improved, the plugging effect is ensured, and the radial supporting force of the bracket is enhanced. Wherein, the flaring distal end portion can be opened and attached to the wall when the stent is pushed out for a short distance, and is not easy to displace, thereby having better anchoring effect. In addition, the metal coverage rates of the proximal part and the distal part are lower than the sum of the metal coverage rates of the middle part and the outer layer stent, so that the branch blood vessel is not easy to block, and the blood flow is ensured to be unblocked.

Description

Support frame

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a bracket.

Background

Intracranial aneurysms are mostly abnormal bulges on the wall of an intracranial artery, are the first causes of subarachnoid hemorrhage, and are second to cerebral thrombosis and hypertensive cerebral hemorrhage in cerebrovascular accidents and are the third cause.

Current treatment of intracranial aneurysms has focused primarily on surgical clipping and intratumoral interventional embolization. In interventional embolization, the mainstream approaches are spring coil embolization and covered stents. The spring ring has large occupying effect of embolism, the neck of the aneurysm is easy to remain, and the spring ring needs higher packing density for the giant aneurysm and obviously compresses the surrounding tissues. At present, a self-expanding covered stent is temporarily not available on the market, and the spherical expanding covered stent is a spherical expanding covered stent, but the flexibility of the spherical expanding covered stent is poorer than that of the self-expanding covered stent, the in-place capability is poor, and the far-end vascular lesion can not be treated. The dense mesh support is usually woven, so that the metal coverage rate is improved, the blood flow direction is changed, and the healing in the walking is effectively promoted. However, the existing dense net supports are all full-body dense nets, and have the following defects: (1) the blood vessel cover is easy to cover branch vessels besides the tumor neck, and ischemic complications are caused; (2) because the bracket is formed by weaving thin metal wires, the radial supporting force is lower than that of other intracranial brackets, and because the cerebrovascular condition is complex, the bracket can not be smoothly opened under the condition of tortuosity or the middle part can not be restored to the specified diameter to cause the problem of non-adherence; (3) the poor anchoring of the distal end during delivery through a microcatheter may cause problems with stent migration during release.

Therefore, there is a need for a new stent that addresses at least one of the problems described above to improve the effectiveness of stents in treating intracranial aneurysms.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a stent to solve at least one problem of poor anchoring force, insufficient radial supporting force, poor wall attaching capability and easy branch covering caused ischemic complications of the stent.

In order to solve the technical problem, the utility model provides a bracket, which comprises an inner bracket and an outer bracket; the inner stent comprises a proximal end part, an intermediate part and a distal end part which are connected in sequence; the outer layer bracket is sleeved on the outer wall of the middle part and covers at least part of the middle part; the distal end part is flared and is connected with the middle part at an obtuse angle; wherein, the first and the second end of the pipe are connected with each other,

the inner layer support and the outer layer support are both of net structures, and the metal coverage rates of the near end part and the far end part are both lower than the sum of the metal coverage rates of the middle part and the outer layer support.

Optionally, in the stent, the proximal portion is flared and connected to the intermediate portion at an obtuse angle.

Optionally, in the holder, the proximal portion is ramp-shaped, and a radial dimension of the proximal portion tapers in a direction away from the intermediate portion.

Optionally, in the stent, the middle portion and the outer stent are both tubular, and the outer diameter of the middle portion is equal to the inner diameter of the outer stent.

Optionally, in the stent, the inner stent and the outer stent may be compressed or self-expanded in the same proportion.

Optionally, in the stent, the stent has a first diameter and a second diameter after self-expansion; wherein the second diameter is greater than the first diameter; the first diameter ranges from: less than or equal to 0.029 inch; the second diameter is in the range of: greater than or equal to 2 mm and less than or equal to 7 mm.

Optionally, in the stent, the metal coverage of the outer stent is in the range of: greater than or equal to 20% and less than or equal to 40%;

the metal coverage range of the middle part is as follows: greater than or equal to 5% and less than or equal to 20%;

the proximal and distal end portions have a metal coverage range of: less than or equal to 10%.

Optionally, in the stent, the outer stent has two opposite end portions, and at least one end portion is fixedly connected with the middle portion.

Optionally, in the stent, the inner layer stent is a mesh structure formed by cutting a tube material or weaving at least one weaving wire, and the outer layer stent is a mesh structure formed by weaving at least one weaving wire.

Optionally, in the stent, the outer stent is coated with a drug and/or a visualization coating, and the proximal portion and the distal portion are each provided with at least one visualization mark.

In summary, the present invention provides a stent, which comprises an inner stent and an outer stent. The inner stent comprises a proximal portion, an intermediate portion and a distal portion which are connected in sequence. The outer layer bracket is sleeved on the outer wall of the middle part and covers at least part of the middle part; the distal portion is flared and connected to the intermediate portion at an obtuse angle. Wherein the inner stent and the outer stent are both of a mesh structure, and the metal coverage of the proximal portion and the distal portion is lower than the sum of the metal coverage of the intermediate portion and the outer stent. Therefore, the outer-layer bracket is covered on the middle part, so that the metal coverage rate is improved, the plugging effect is ensured, and the radial supporting force of the bracket is enhanced. Wherein, the flaring distal end portion can be opened and attached to the wall when the stent is pushed out for a short distance, and is not easy to displace, thereby having better anchoring effect. In addition, the metal coverage rate of the proximal part and the distal part is lower than the sum of the metal coverage rate of the middle part and the metal coverage rate of the outer layer stent, so that the branch blood vessel is not easy to block, and the blood flow is ensured to be smooth.

Drawings

FIG. 1 is a schematic structural view of a stent according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of an inner stent according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of an outer stent according to an embodiment of the present invention;

FIG. 4 is a schematic structural view of a stent according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a stent according to an embodiment of the present invention;

wherein the reference numbers indicate:

10-inner layer support; 101-a proximal portion; 102-an intermediate portion; 103-a distal portion; 104-development mark; 20-outer layer bracket.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the utility model will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently.

It should be further understood that the terms "first," "second," "third," and the like in the description are used for distinguishing between various components, elements, steps, and the like, and are not intended to imply a logical or sequential relationship between various components, elements, steps, or the like, unless otherwise indicated or indicated. The term "proximal" is usually the end near the operator, the term "distal" is usually the end near the patient, i.e. near the lesion, "end" and "other end" and "proximal" and "distal" are usually the corresponding two parts, which not only include the end points, but the terms "mounted", "connected" and "connected" are to be understood broadly, e.g. they may be fixed connections, detachable connections, or integrated; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention provides a stent, and referring to fig. 1-3, the stent includes an inner stent 10 and an outer stent 20. The inner stent 10 includes a proximal portion 101, an intermediate portion 102, and a distal portion 103 connected in this order. The outer bracket 20 is disposed on the outer wall of the middle portion 102 and covers at least a portion of the middle portion 102. The distal portion 103 is flared and connected to the intermediate portion 102 at an obtuse angle. Wherein, the inner stent 10 and the outer stent 20 are both of a mesh structure, and the metal coverage of the proximal portion 101 and the distal portion 103 are both lower than the sum of the metal coverage of the intermediate portion 102 and the outer stent 20.

Referring to fig. 1, the middle portion 102 and the outer stent 20 are both tubular, and the outer diameter of the middle portion 102 is equal to the inner diameter of the outer stent 20, i.e. the outer stent 20 is tightly attached to the outer wall of the middle portion 102 without a gap therebetween. The arrangement of the outer layer stent 20 reinforces the radial supporting force of the middle part 102 so as to improve the adherence of the stent, and the stent can be expanded to the diameter of a blood vessel even in a relatively curved blood vessel in the cranium, so that complications caused by unopened stent or untight adherence due to insufficient radial supporting force are avoided. Further, the outer bracket 20 has two opposite ends, and at least one end is fixedly connected to the middle portion 102, so as to ensure stable connection between the outer bracket 20 and the middle portion 102. That is, either one of both end portions of the outer stent 20 is connected to the intermediate portion 20, or both end portions of the outer stent 20 are connected to the intermediate portion 20. Wherein, the connection mode between the outer layer bracket 20 and the middle part 20 includes but is not limited to: welded, bonded, or otherwise wrapped around the intermediate portion 102 by braided wires of the outer stent 20.

With continued reference to fig. 1, in the present embodiment, the proximal portion 101 and the distal portion 102 are flared and connected to the intermediate portion 102 at an obtuse angle. In particular, the angle between the axial extension of the outer contours of the proximal and

distal portions

101, 103 and the central axis a-a' of the intermediate portion 102 is 10-40 degrees, preferably 30 degrees. The flaring design mode is favorable for opening the stent to adhere to the wall immediately when the stent is pushed out by a short distance, has good anchoring effect, and aims at the wide-diameter aneurysm, the stent is not easy to retract to the neck of the aneurysm when released, is not easy to shift, and simultaneously reduces the operation difficulty of a doctor. Further, at least one visualization mark 104 is provided on each of the proximal portion 101 and the distal portion 103, and optionally, on the tip of each of the proximal portion 101 and the distal portion 103. The visualization marker 104 is mainly used for helping a doctor to confirm the pushing position of the stent and the release amount of the stent in a visualization mode during the operation. The material of the development mark 104 includes opaque platinum, gold, and an alloy thereof, and the development mark 104 may be in a form of a spring or a circular tube, and is sleeved on the wires of the proximal portion 101 and the distal portion 103. The number of the development marks 104 is not limited in this embodiment, and may be 3, 4, 5, or 6.

Specifically, referring to fig. 2, the proximal portion 101 and the distal portion 102 are respectively disposed at two opposite ends of the middle portion 102, and are integrally formed or fixedly connected with the middle portion 102. Wherein the length of the proximal portion 101 and the distal portion 103 may optionally range from 1 mm to 3 mm, such as 2 mm, according to clinical validation. The length of the intermediate portion 102 may range from 10 mm to 75 mm, such as 60 mm. In some embodiments, the inner stent 10 is laser cut from tubing. Optionally, the material of the pipe is: one or more of nickel-titanium alloy, nitinol, stainless steel, cobalt-chromium alloy, and nickel-cobalt alloy having shape memory properties. The tubing has a wall thickness in the range of 50 microns to 100 microns, for example: 50 microns, 80 microns, or 100 microns. The width range of each wave rod formed after cutting is as follows: 50 microns to 100 microns, and can be, for example: 50 microns, 80 microns, or 100 microns. Further, after cutting, the proximal portion 101 and the distal portion 102 may optionally be petaloid in shape and expand in a direction away from the intermediate portion 102. In this embodiment, the number of petals is not limited, and may be 3, 4, 5, or 6. The intermediate portion 102 is formed by a plurality of open or closed pattern structures connected in an axial direction, wherein the formed pattern includes, but is not limited to: w-shaped, sine wave, cosine wave, V-shaped wave, and the like.

Referring to fig. 3, the outer layer stent 20 is woven by using a weaving yarn. Wherein the braided wire has a diameter of less than or equal to 0.002 inches. Optionally, the outer layer stent 20 is woven by an even number of woven filaments, for example: 48 braided wires with a diameter of 0.001-0.002 inch are braided into a plurality of rhombic latticed tubular structures. Wherein, in order to ensure a certain metal coverage rate, the axial diagonal length of the rhombic grid is preferably 0.1 mm to 0.5 mm. And the weaving silk can be selected from the following materials: nickel titanium alloys, cobalt based alloys, stainless steel or tantalum alloys, and the like. In some embodiments, the outer surface of the outer stent 20 is also coated with a drug for therapeutic purposes, such as anti-thrombosis, and/or a visualization coating to help the physician identify the location of the stent to be pushed and the amount of release of the stent. Optionally, the thickness range of the drug and/or developing coating is: 20 nm to 100 nm, preferably 60 nm.

Further, referring to fig. 1, the middle portion 102 of the inner stent 10 and the outer stent 20 can be compressed or self-expanded at the same rate, so that the stent can be compressed and pushed out synchronously without gap, thereby achieving better adherence. Thus, the stent has a first diameter in a compressed state and a second diameter that is self-expanding. Wherein the first diameter is in the range of: less than or equal to 0.029 inches, such that the stent can be delivered through a microcatheter of 0.029 inches and less. The second diameter is in the range of: greater than or equal to 2 mm and less than or equal to 7 mm, so that the stent can be suitable for lesions of the middle cerebral artery, the internal carotid artery and the posterior circulation.

In the stent provided in this embodiment, the metal coverage of the outer stent 20 is as follows: 20% or more and 40% or less, for example, 20% or 30% or more. The metal coverage range of the middle portion 102 is: greater than or equal to 5% and less than or equal to 20%, for example, 15% or 18%, etc. The metal coverage ranges of the proximal portion 101 and the distal portion 103 are: less than or equal to 10%, for example 5% or 8%, etc. Therefore, the metal coverage of the proximal portion 101 and the distal portion 103 is lower than the sum of the metal coverage of the intermediate portion 102 and the outer stent 20. The outer stent 20 is sleeved on the middle part 102, so that the metal coverage rates of the two are overlapped, thereby facilitating the sealing of the focus, such as the neck of a tumor, and playing a main treatment role. The metal coverage of the proximal part 101 and the distal part 103 is relatively low, so that the branch blood vessels are not easy to block, and the blood flow is ensured to be smooth. And complications caused by ischemia are avoided.

Referring to fig. 4, based on the shape and technical effects of the stent, optionally, the inner stent 10 in the stent may also be woven by a woven wire. The material of the braided wire includes but is not limited to nickel-titanium alloy, cobalt-based alloy, stainless steel, tantalum alloy and the like. The number range of the weaving silk is as follows: 12 to 36, preferably 24. The shape of the braid may be consistent with the outer stent 20, i.e.: a plurality of rhombic grid-shaped tubular structures. Since the metal coverage of the inner stent is slightly lower than that of the outer stent 20, for example, the metal coverage of the outer stent 20 is 30%, the metal coverage of the middle portion 102 of the inner stent 10 is 15%, and the metal coverage of the proximal portion 101 and the distal portion 103 of the inner stent 10 is 8%. The axial diagonal length of the rhombic cells ranges from 0.5 mm to 1 mm. Wherein the diameter of the wire braided into the inner stent is greater than 0.002 inches.

In some embodiments, at least one of the proximal portion 101 and the distal portion 103 of the inner stent 10 has a flared shape, i.e. the diameter of the proximal portion 101 and/or the distal portion 103 is larger than the diameter of the intermediate portion 102, and the proximal portion 101 and/or the distal portion 103 forms an angle of 10 degrees to 40 degrees, preferably 30 degrees, with the stent axis. The proximal portion 101 and the distal portion 103 of the inner stent 10 have a length of 1.5mm in the axial direction of the stent.

Referring to fig. 5, the proximal portion 101 of the inner stent may also be tapered for ease of delivery, and the proximal portion 101 may be tapered in radial dimension away from the intermediate portion 102 to facilitate electrical detachment by soldering the proximal portion 101 to a delivery guidewire.

In summary, in the stent provided by the present invention, the outer stent 20 covers the middle portion 102, which not only improves the metal coverage rate, ensures the plugging effect, but also enhances the radial supporting force of the stent. The flaring distal end 103 can be opened and attached to the wall when the stent is pushed out for a short distance, and is not easy to displace, thereby having good anchoring effect. In addition, the metal coverage of the proximal part 101 and the distal part 103 is lower than the sum of the metal coverage of the intermediate part 102 and the metal coverage of the outer stent 20, so that the branch blood vessels are not easy to block, and the blood flow is ensured to be smooth.

It should be understood, however, that the intention is not to limit the utility model to the particular embodiments described. It will be apparent to those skilled in the art that many changes and modifications can be made, or equivalents employed, to the presently disclosed embodiments without departing from the intended scope of the utility model. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the content of the technical solution of the present invention is departed from.

Claims

1. A stent, comprising an inner stent and an outer stent; the inner stent comprises a proximal end part, an intermediate part and a distal end part which are connected in sequence; the outer layer bracket is sleeved on the outer wall of the middle part and covers at least part of the middle part; the distal end part is flared and is connected with the middle part at an obtuse angle; wherein the content of the first and second substances,

the inner stent and the outer stent are both of a mesh structure, and the metal coverage of the proximal portion and the distal portion is lower than the sum of the metal coverage of the intermediate portion and the outer stent.

2. The stent of claim 1 wherein the proximal portion is flared and connects to the intermediate portion at an obtuse angle.

3. The stent of claim 1, wherein the proximal portion is ramped and tapers in radial dimension away from the intermediate portion.

4. The stent of claim 1, wherein the intermediate portion and the outer stent are both tubular and the intermediate portion has an outer diameter equal to an inner diameter of the outer stent.

5. The stent of claim 1 wherein the inner stent and the outer stent are compressible or self-expandable in equal proportions.

6. The stent of claim 5, wherein the stent has a first diameter and a second diameter after self-expansion; wherein the second diameter is greater than the first diameter; the first diameter ranges from: less than or equal to 0.029 inch; the second diameter is in the range of: greater than or equal to 2 millimeters and less than or equal to 7 millimeters.

7. The stent of claim 1 wherein the outer stent has a metal coverage in the range of: greater than or equal to 20% and less than or equal to 40%;

8. The stent of claim 1 wherein the outer stent has two opposing end portions and at least one end portion is fixedly attached to the intermediate portion.

9. The stent of claim 1, wherein the inner layer stent is a mesh structure cut from a tube material or woven from at least one woven wire, and the outer layer stent is a mesh structure woven from at least one woven wire.

10. The stent of claim 1 wherein the outer stent is coated with a drug and/or visualization coating and the proximal portion and the distal portion each have at least one visualization marker disposed thereon.