CN113367865A

CN113367865A - Medical support

Info

Publication number: CN113367865A
Application number: CN202010158767.2A
Authority: CN
Inventors: 苗琳莉; 张滢涛; 刘辰洋
Original assignee: Microport Neurotech Shanghai Co Ltd
Current assignee: Shentu medical technology (Shanghai) Co.,Ltd.
Priority date: 2020-03-09
Filing date: 2020-03-09
Publication date: 2021-09-10

Abstract

The invention relates to a medical stent which comprises a guide section and a support section, wherein the guide section comprises at least one layer of curved surface net-shaped structure and is provided with a proximal end and a distal end which are opposite, the support section is respectively arranged at the proximal end and the distal end, and the support section is of a net pipe-shaped structure. When the treatment device is used for treating bifurcation aneurysm, the guide section is arranged at the neck opening of the aneurysm, so that a branch blood vessel is not covered by the medical stent, and the branch blood vessel occlusion caused by the change of the blood flow dynamics flowing into the branch blood vessel is avoided.

Description

Medical support

Technical Field

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

Background

Intracranial aneurysm is usually abnormal bulging occurring on the wall of intracranial arterial blood vessel, and is the first cause of subarachnoid hemorrhage. At present, the treatment methods of intracranial aneurysms mainly include surgical clamping and intravascular interventional therapy, wherein the intravascular interventional therapy further comprises two modes of intratumoral spring coil embolization treatment and blood flow guiding device treatment. The intratumoral spring coil embolization treatment is to fill the spring coil in the aneurysm, so that the spring coil is filled in the aneurysm sac, the blood flow in the aneurysm sac disappears, and the risk of rupture and bleeding of the aneurysm is eliminated. The blood flow guiding device is used for treating the aneurysm by interfering the blood flow entering the aneurysm from the parent artery, so that the blood in the aneurysm is blocked and silted, and then thrombus is formed to promote the aneurysm to be completely closed.

Aneurysms can be classified into sidewall type aneurysms and bifurcation type aneurysms according to the location where the aneurysm grows. For bifurcation type aneurysm, when the intratumoral spring ring is used for embolization treatment, the spring ring is easy to fall into the parent artery, and when the blood flow guiding treatment is used, the risk of branch vessel occlusion is increased because the blood flow guiding device has higher metal coverage rate. In the prior art, the treatment of bifurcation aneurysms is usually performed by using a stent-assisted method, which includes an "ice cream technique", a "Y" type stent technique, an "X" type stent technique, a "T" type stent technique, a LIVS "brel" technique, etc., but these techniques still have the following disadvantages: (1) the recurrence rate is higher, particularly the recurrence rate of wide-neck aneurysm at the bifurcation part is higher; (2) the stent uses more metal materials, promotes the formation of thrombus and increases the risk of branch vessel occlusion.

Disclosure of Invention

The invention aims to provide a medical stent to reduce the recurrence rate of branched aneurysms and reduce the risk of branched vessel occlusion.

In order to achieve the above purpose, the medical stent provided by the invention comprises a guide section and a support section, wherein the guide section comprises at least one layer of curved net-shaped structure and has a proximal end and a distal end which are opposite, the proximal end and the distal end are respectively provided with the support section, and the support section is in a net-shaped structure.

Optionally, the guide section comprises a multi-layer curved mesh structure.

Optionally, the guide segment covers at least one tenth of a circumferential surface along a circumferential direction of the medical stent.

Optionally, the medical stent comprises a plurality of said guide segments.

Optionally, a plurality of said guide segments are disposed adjacently or with said support segment disposed between adjacent guide segments.

Optionally, adjacent guide segments have a predetermined included angle therebetween.

Optionally, the preset included angle is 0-180 °.

Optionally, the guide section has a length of 1-50 mm.

Optionally, at the guide section, the coverage of the braided filaments is 5% -50%.

Optionally, the support section connected to the proximal end of the guide section has a braided filament coverage of 5% -50%; and/or the presence of a gas in the gas,

the support section connected to the distal end of the guide section has a coverage of the woven filaments of 5-50%.

Optionally, the stent is a braided stent.

Optionally, the guide section and the support section are integrally woven.

Optionally, the number of the braided wires in the medical stent is 24-96.

Optionally, the medical stent is woven from metal wires; or the medical bracket is formed by mixed weaving of metal wires and non-metal wires.

Optionally, the wire diameter of the wire is 5-100 μm.

Optionally, in a transition region between the guide section and the support section, knitting filaments partially constituting the support section are reversely folded to axially opposite sides of the original extending direction to form the guide section.

Optionally, in the curved mesh structure of the guide section, when the knitting yarn is knitted to the boundary of the curved surface of the guide section, the knitting yarn is reversely folded to the opposite axial side of the original extending direction to continue knitting, and the knitting yarn is circularly reciprocated to form the curved mesh structure.

Optionally, at the transition area between the guide section and the support section, part of the weaving filaments stops reversing and continue weaving in the extension direction to form the support section.

Optionally, the medical stent is a cutting stent.

Optionally, the metal coverage of the guide segment is 5% -50%; and/or the support segment has a metal coverage of 5-30%.

Compared with the prior art, the medical bracket and the treatment device have the following advantages:

the medical stent comprises a guide section and a support section, wherein the guide section is of a curved net structure and is provided with a proximal end and a distal end which are opposite, the support section is arranged at the proximal end and the distal end respectively, and the support section is of a net pipe structure. That is, the guide section of the medical stent is not closed in the circumferential direction to form an opening, when the medical stent is used for treating an aneurysm, particularly a bifurcation aneurysm, two support sections are arranged on two sides of the aneurysm, the guide section is arranged at the neck opening of the aneurysm, and the opening is positioned on the opposite side (namely an arterial bifurcation) of the aneurysm, so that the medical stent does not influence the blood flow entering an arterial vessel while interfering the blood flow entering the aneurysm from a parent artery, and avoids causing arterial occlusion.

Secondly, the medical support can be a woven support, and the medical support can be integrally woven and formed, so that the production process of the support is simplified.

Drawings

FIG. 1 is a schematic representation of a medical stent according to an embodiment of the present invention, showing only one guide segment;

FIG. 2 is a schematic view of the medical stent of FIG. 1 applied to a bifurcated aneurysm;

fig. 3 is a schematic structural view of a medical stent according to an embodiment of the present invention, in which two guide segments are shown.

[ reference numerals are described below ]:

10-medical stent;

11-a guide segment;

12-a support section, 12 a-a proximal support section, 12 b-a distal support section;

13 a-a first side edge, 13 b-a second side edge;

20-aneurysm;

30-artery, 31-bifurcation site of artery.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a medical stent and a treatment device according to the present invention will be described in detail with reference to the accompanying drawings 1 to 3. 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.

As used in this specification, the singular forms "a", "an" and "the" include plural referents, and the plural forms "a plurality" includes more than two referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. 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 same or similar reference numbers in the drawings identify the same or similar elements.

As used herein, the terms "proximal" and "distal" refer to the relative orientation, relative position, and orientation of elements or actions with respect to one another from the perspective of a clinician using the medical device, and although "proximal" and "distal" are not intended to be limiting, the term "proximal" generally refers to the end of the medical device that is closer to the clinician during normal operation while the term "distal" generally refers to the end that is first introduced into a patient.

Fig. 1 shows a schematic structural diagram of a medical stent provided by the invention according to an embodiment. As shown in fig. 1, the medical stent 10 includes a guiding section 11 and a supporting section 12, the guiding section 11 includes at least one layer of curved net structure, in a first direction, the guiding section 11 has a proximal end and a distal end, the proximal end and the distal end are respectively provided with the supporting section 12, the supporting section 12 is a net pipe structure, and the supporting section 12 extends along the first direction. In other words, the guide segment 11 in this embodiment is not closed in the circumferential direction of the medical stent 10 and has an opening 13. In addition, the medical stent 10 has a generally cylindrical configuration, and the first direction is an axial direction of the medical stent 10.

The medical stent 10 is suitable for the treatment of aneurysms, particularly bifurcated aneurysms. As shown in fig. 2, an aneurysm 20 grows on an artery 30, and the aneurysm 20 is a bifurcation aneurysm, i.e., an arterial bifurcation site 31 is present near the aneurysm 20. The medical stent 10 may be provided with one guide section 11 and two support sections 12, hereinafter for convenience, the support section 12 connected to the proximal end of the guide section 11 is defined as a proximal support section 12a, and the support section 12 connected to the distal end of the guide section 11 is defined as a distal support section 12 b.

When the medical stent 10 is implanted into the artery 30, the guiding segment 11 is disposed at the neck of the aneurysm 20, the opening 13 faces the arterial bifurcation 31, the proximal supporting segment 12a and the distal supporting segment 12b are disposed on both sides of the aneurysm 20 (while the two supporting segments 12 are also disposed on both sides of the arterial bifurcation 31), and the two supporting segments 12 are closely attached to the wall of the artery 30. As such, the medical stent 10 is secured in the artery 30 by the proximal support section 12a and the distal support section 12 b. The guiding section 11 is used to alter the hemodynamics in the artery 30 and interfere with the flow of blood from the artery 30 or the arterial bifurcation 31 into the aneurysm 20 to embolize the aneurysm 20, while the intersection of the arterial bifurcation 31 and the artery 30 is not covered by the medical stent 10, so that the flow of blood in the artery remains open and does not cause occlusion of the arterial bifurcation 31 of the artery 30.

Along the circumferential direction of the medical stent 10, the curved mesh structure of the guide section 11, that is, the stent portion at the guide section 11, may cover at least one tenth of the circumference, and the specific value thereof may be set according to the size of the neck area of the aneurysm, for example, one quarter of the circumference, one half of the circumference, three quarters of the circumference, etc., but it should be ensured that the guide section 11 completely covers the neck opening of the aneurysm. The curved mesh structure of the guide section 11 can also be designed to match multiple specifications of aneurysms of different neck sizes in order to treat aneurysms of multiple neck sizes.

The length of the guide section 11 may be 1-50mm, specifically set according to the size of the neck of the tumor, and may be, for example, 5mm, 15mm, 36mm, 44mm, etc.

The guiding segment 11 may include a plurality of layers of curved mesh structures, for example, a plurality of layers of curved mesh structures woven by weaving silk, which are overlapped with each other to improve metal coverage and effectively block blood from entering into the aneurysm.

Generally, the medical stent 10 may be a cut stent made of nitinol or cobalt-chromium alloy, or the medical stent 10 may be a woven stent including nitinol or cobalt-chromium alloy wires, as long as the guide section 11 is formed on the medical stent 10 without being circumferentially closed. Regardless of the stent used, the metal coverage of the guide section 11 is preferably between 5% and 50%, so as to effectively interfere with the hemodynamics of the parent artery 30, reduce the exchange of blood flow between the aneurysm 20 and the parent artery 30, and promote embolization within the aneurysm 20.

The main function of the support section 12 in this embodiment is to position the medical stent 10 in the artery 30, and therefore there is no excessive requirement for the metal coverage of the support section 12. According to the actual situation, the metal coverage of any one of the support segments 12 may be greater than, equal to or less than the metal coverage of the guide segment 11, and the metal coverage of the two support segments 12 may be equal or unequal. For example, in one embodiment, the metal coverage of the proximal support section 12a may be between 10-30% and the metal coverage of the distal support section 12b may be between 10-30%. As understood by those skilled in the art, by "metal coverage" is meant the proportion of the area covered by the metal of any one segment to the area of the medical stent of the corresponding segment.

In an exemplary embodiment, the medical stent 10 is a woven stent, and the guide section 11 and the two support sections 12 are integrally woven.

In detail, the medical stent 10 is continuously woven from a plurality of filaments. For example, a plurality of the filaments are first interwoven to form the proximal support section 12a of a mesh tubular structure. The plurality of filaments are then continuously interwoven to form the guiding segment 11 of a curved mesh structure, the guiding segment 11 is not closed in the circumferential direction of the medical stent 10, and the guiding segment 11 has two opposite sides in a second direction, the two sides are connected to each other to enclose the opening 13, the second direction can be perpendicular to the first direction (taking the direction shown in fig. 1 as an example, the first direction is an X direction, the second direction is a Y direction, and the two sides are a first side P1 and a second side P2, respectively). Finally a plurality of said filaments are interwoven to form a mesh-like structure to form said distal support section 12 b. In this embodiment, the metal coverage of the proximal support section 12a and the distal support section 12b is smaller than the metal coverage of the guiding section 11. The metal coverage of the proximal support section 12a and the distal support section 12b may be equal. The number of wires in the woven stent may be between 48 and 64 in order to achieve a predetermined metal coverage of the medical stent 10.

In the case of integral knitting, the following knitting method may be used. In the transition area between the guiding segment 11 and the supporting segment 12, a part of the braiding filaments that should continue to spirally extend is folded back to the axial opposite side of the original extending direction for braiding, i.e. all braiding filaments are axially braided on one side of the medical stent, thereby forming the opening 13. The back-folded angle of the reversely folded braided filaments may be between 0 ° and 180 °. And may be reversed back and forth simultaneously by the two braided filaments to form said opening 13 between the two braided filaments. In the curved mesh structure of the guide segment 11, when the knitting yarn is knitted to the boundary of the curved surface of the guide segment 11 (the boundary of the opening 13 can also be understood), the knitting yarn is folded back to the opposite axial sides of the original extending direction to continue knitting, and the knitting yarn is circularly reciprocated to form the curved mesh structure. Upon return from the guide section to the support section, a portion of the braided filaments may no longer be turned back, but rather continue to be braided in the direction of extension, forming the support section 12. In this embodiment, the openings 13 may also be woven in alternative shapes, such as S-shaped or M-shaped or V-shaped, by selecting the area of the woven filaments to be reversed, which may be suitable for use in cases where there are multiple aneurysms in one artery. This can also be considered as a plurality of guide segments 11 arranged adjacently, and no transition between two adjacent guide segments 11 with supported segments 12 is required.

Further, the medical stent 10 may be formed by co-weaving metal wires and non-metal wires. The non-metallic wire can be made of biocompatible polymer materials such as polyethylene terephthalate (PET), polypropylene (PP), Polytetrafluoroethylene (PTFE) and the like. The wires may further be developable, thereby rendering the medical stent 10 developable. For such a co-woven medical stent 10, to achieve a predetermined blood flow guidance, at the guide section 11, the coverage of the woven wires (i.e., the metallic and non-metallic wires) may be between 20% and 50%, and at the support section 12 (including the proximal support section 11a and the distal support section 11b), the coverage of the woven wires may be between 10% and 30%, with the woven wires having a wire diameter in the range of 5-100 μm. In addition, the ratio of the metal wire to the non-metal wire may be set according to the strength actually required for the medical stent 10. The coverage rate of the braided wire is the ratio of the covered area of the braided wire of any section to the area of the medical stent of the corresponding section.

Of course, in other embodiments, the proximal support section 12a, the guiding section 11, and the distal support section 12b may be woven separately and then connected together. In this case, it is possible that the coverage of the braided wires of the various segments of the medical stent 10 is equal.

In addition, when an artery is formed with a plurality of aneurysms and the artery has a plurality of arterial bifurcations, for example, two aneurysms are grown at intervals on an arterial blood vessel having one arterial bifurcation on each of opposite sides of the two aneurysms. In this case, as shown in fig. 3, the medical stent 10 may further include two guide sections 11 and three support sections 12, and the support sections 12 and the guide sections 11 are alternately arranged from the proximal end to the distal end of the medical stent, i.e., the sections of the medical stent 10 are arranged in the order of the support section 12, the guide section 11, and the support section 12. According to specific needs, the two guide segments 11 may be aligned or staggered in the circumferential direction of the medical stent 10. The angle of the offset may be 0-180, such as 30, 45, 54, 90, 120, 160, etc.

Further, the medical stent may be applied to a treatment device for treating aneurysms, particularly bifurcated aneurysms. In some embodiments, the treatment device comprises the medical stent and a balloon catheter comprising a balloon over which the medical stent is crimped. In other embodiments, the medical stent is a self-expanding stent, and the treatment device comprises the medical stent and a push rod, the medical stent being disposed on the push rod.

The medical stent provided by the embodiment of the invention is provided with the guide section, the circumferential direction of the medical stent is not closed and the medical stent is provided with the opening, when the medical stent is applied to treatment of bifurcation-type aneurysm, the guide section is tightly attached to the neck of the aneurysm, and the opening is arranged at a branch blood vessel at the opposite side of the aneurysm, so that the medical stent interferes the hemodynamics of the parent artery to reduce the blood flow exchange between the parent artery and the aneurysm, further promotes the formation of embolism in the aneurysm, and simultaneously does not influence the blood flow entering the branch blood vessel, thereby not causing the occlusion of the branch blood vessel.

Although the present invention is disclosed above, it is not limited thereto. Various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The medical stent is characterized by comprising a guide section and a support section, wherein the guide section comprises at least one layer of curved net-shaped structure and is provided with a proximal end and a distal end which are opposite, the support section is respectively arranged at the proximal end and the distal end, and the support section is in a net-shaped structure.

2. The medical stent of claim 1, wherein the guide section comprises a multi-layer curved mesh structure.

3. The medical stent of claim 1, wherein the guide segment wraps around at least one tenth of a circumference along a circumference of the medical stent.

4. The medical stent of claim 1, wherein the medical stent comprises a plurality of the guide segments.

5. The medical stent of claim 4, wherein a plurality of the guide segments are disposed adjacently or the support segment is disposed between adjacent guide segments.

6. The medical stent of claim 4, wherein adjacent guide segments have a predetermined included angle therebetween.

7. The medical stent of claim 6, wherein the predetermined included angle is between 0 ° and 180 °.

8. The medical stent of claim 1, wherein the guide section has a length of 1-50 mm.

9. The medical stent of claim 1, wherein a coverage of braided filaments at the guide section is between 5% and 50%.

10. The medical stent of claim 1, wherein the support section connected to the proximal end of the guide section has a braided wire coverage of 5% to 50%; and/or the presence of a gas in the gas,

11. The medical stent of claim 1, wherein the stent is a braided stent.

12. The medical stent of claim 11, wherein the guide section and the support section are integrally woven.

13. The medical stent according to claim 11 or 12, wherein the number of the braided wires in the medical stent is 24 to 96.

14. The medical stent of claim 11 or 12, wherein the medical stent is woven from metal wires; or the medical bracket is formed by mixed weaving of metal wires and non-metal wires.

15. The medical stent of claim 14, wherein the wire diameter of the wire is 5-100 μm.

16. The medical stent of claim 13, wherein in the transition region between the guide section and the support section, the braided filaments partially constituting the support section are braided in a manner of being folded back to the axially opposite side of the original extending direction to form the guide section.

17. The medical stent of claim 13, wherein in the curved mesh structure of the guide section, the braided filaments are reversely folded to the opposite axial sides of the original extending direction when being braided to the boundary of the curved surface of the guide section, and are continuously braided in a circulating reciprocating manner to form the curved mesh structure.

18. The medical stent of claim 13, wherein at the transition region between the guide section and the support section, a portion of the braided filaments stops reversing direction and continues to braid in the direction of elongation to form the support section.

19. The medical stent of claim 1, wherein the medical stent is a cutting stent.

20. The medical stent of claim 19, wherein the metal coverage of the guide segment is 5% -50%; and/or the support segment has a metal coverage of 5-30%.