EP-4740914-A1 - VASCULAR STENT

EP4740914A1EP 4740914 A1EP4740914 A1EP 4740914A1EP-4740914-A1

Abstract

Disclosed in the present invention is a vascular stent. The vascular stent includes a main stent provided with a main lumen; the main stent includes a proximal section, a distal section, and a middle section located between the proximal section and the distal section and extending axially; a recessed portion is provided on the middle section; a supporting structure which protrudes outwards relative to the recessed portion is provided above the recessed portion; and at least part of the supporting structure is degradable. According to the vascular stent of the present invention, at least part of the supporting structure at the top of the vascular stent is configured to be degradable. In this way, the initial mechanical supporting effect of a recess section is guaranteed while retaining the overall structure. In a long term, the material of this part can be automatically absorbed after a certain time, thereby reducing the restraint and compression on a branch stent, reducing the occupation of the main lumen space, and reducing irritation to vascular wall.

Inventors

SHU, CHANG
DAI, Shuang
XIAO, Benhao
RUI, Shixuan

Assignees

Lifetech Scientific (Shenzhen) Co., Ltd.

Dates

Publication Date: 20260513
Application Date: 20240628

Claims (15)

A vascular stent, comprising a main stent provided with a main lumen, wherein the main stent comprises a proximal section, a distal section, and a middle section located between the proximal section and the distal section and extending axially; the middle section is provided with a recessed portion, above which a supporting structure is arranged; and at least part of the supporting structure is degradable.
The vascular stent according to claim 1, wherein the supporting structure is provided with a branch passage that radially penetrates through the supporting structure; the branch passage allows a branch stent to pass through; at least part of an edge of the branch passage is degradable, enabling the branch passage to be expanded upon at least partial degradation; and the expanded branch passage exerts reduced compression on the branch stent passing therethrough.
The vascular stent according to claim 2, wherein the branch passage comprises at least a right branch passage near a distal side of the supporting structure; and/or a left branch passage near a proximal side of the supporting structure.
The vascular stent according to claim 2, wherein the supporting structure comprises a mesh structure having a plurality of grids, and one or more of the grids form the branch passage.
The vascular stent according to claim 1, wherein the supporting structure comprises a main supporting layer that is at least partially degradable; the main supporting layer is formed by supporting filaments; and the supporting filaments comprise at least a degradable first supporting filament.
The vascular stent according to claim 5, wherein the degradable first supporting filament forms the main supporting layer.
The vascular stent according to claim 5, wherein the supporting filaments further comprise a non-degradable second supporting filament, and the degradable first supporting filament and the non-degradable second supporting filament jointly form the main supporting layer.
The vascular stent according to claim 7, wherein the first supporting filament forms a degradable layer, while the second supporting filament forms a non-degradable layer, and the degradable layer and the non-degradable layer are arranged opposite to each other within a same layer; or the first supporting filament forms a degradable layer, while the second supporting filament forms a non-degradable layer, and the degradable layer and the non-degradable layer are adjacent to and connected to each other at an adjacent position; or the first supporting filament and the second supporting filament are arranged in an interlaced manner within a same layer, such that the first supporting filament forms a plurality of degradable layers, while the second supporting filament forms a non-degradable layer, and the plurality of degradable layers are distributed in the non-degradable layer within the same layer.
The vascular stent according to any one of claims 6 to 8, wherein during the formation of the main supporting layer, the plurality of supporting filaments are intersected and form intersection points; and at the intersection points, the plurality of supporting filaments are interconnected, and/or overlapped, and/or hooked.
The vascular stent according to claim 9, wherein when the plurality of supporting filaments are overlapped at the intersection points, the plurality of supporting filaments at the intersection points may be connected via a fastener and the fastener is configured to radially restrain the plurality of supporting filaments to avoid radial separation from one another; and/or when the plurality of supporting filaments comprise the first supporting filament and the second supporting filament, and the first supporting filament and the second supporting filament are overlapped at the intersection points, the first supporting filament at the intersection points is located above the second supporting filament; and/or when the plurality of supporting filaments comprise the first supporting filament and the second supporting filament, and the first supporting filament and the second supporting filament are overlapped at the intersection point, a radial thickness of the first supporting filament at least at the intersection point is greater than a radial thickness of the second supporting filament, and a cross passage through which the second supporting filament passes is formed at the intersection point of the first supporting filament.
The vascular stent according to claim 10, wherein when the supporting filaments at the intersection points are connected with each other via the fastener, a first sliding passage extending in a first predetermined direction and a second sliding passage extending in a second predetermined direction are formed on the fastener; one of the supporting filaments slides relative to the fastener along the first predetermined direction, while the other supporting filament slides relative to the fastener along the second predetermined direction, and the first predetermined direction and the second predetermined direction are predetermined movement directions of the supporting filaments when the vascular stent is compressed or self-expands; and/or when the cross passage through which the second supporting filament passes is formed on the first supporting filament, the cross passage has a predetermined length along an extension direction of the first supporting filament.
The vascular stent according to claim 9, wherein when the plurality of supporting filaments are hooked, an elastic connecting member which extends axially is arranged between the supporting filaments at a hooking position; end portions of the elastic connecting member are respectively connected to hooked portions of the plurality of supporting filaments; and the elastic connecting member is configured to elastically pull the supporting filaments toward each other.
The vascular stent according to claim 6 or 7, wherein the supporting structure further comprises a non-degradable local supporting layer; the local supporting layer and the main supporting layer are stacked from inside to outside; and the local supporting layer is opposite to a degradable layer that is formed by the first supporting filament and that is located in the main supporting layer.
The vascular stent according to claim 5, wherein the main supporting layer comprises a mesh structure; in a naturally expanded state, the main supporting layer comprises, in a circumferential direction, a first mesh region and a second mesh region connected to the first mesh region; the first mesh region comprises a plurality of rows of intersection units which are formed by mutually overlapping a plurality of first-direction supporting filaments arranged at intervals and a plurality of second-direction supporting filaments arranged at intervals; the second mesh region comprises at least one row of hooking units, each row of hooking units comprises one or more axially arranged hooking units, and each hooking unit comprises a first hooking member and a second hooking member; and in at least part of the hooking units, the first hooking member and the second hooking member are substantially axially hooked, alternatively, in at least part of the hooking units, the first hooking member and the second hooking member are substantially axially separated to form a gap, alternatively, in at least part of the hooking units, the first hooking member and the second hooking member are abutted against each other in a non-hooking manner.
The vascular stent according to claim 5, wherein the degradable first supporting filament is either entirely degradable or partially degradable; and when the first supporting filament is partially degradable, the first supporting filament has a multi-layer structure arranged from inside to outside, and comprises a non-degradable inner core located at an innermost layer and a degradable covering layer located at an outermost layer.

Description

Technical Field The present invention relates to the technical field of interventional medical devices, and particularly, to a vascular stent. Background Art Aortic aneurysms and aortic dissections are severe life-threatening conditions. Without active treatment, aortic aneurysm sacs and aortic dissections will progressively enlarge and may eventually rupture, leading to severe complications and mortality. With the increasing prevalence of hypertension, hyperlipidemia, and hyperglycemia, the incidence of aortic aneurysms and aortic dissections has also risen significantly. Traditional open surgery for treating aortic aneurysms and aortic dissections is associated with a large surgical incision, elevated mortality rates, prolonged operation times, high postoperative complication rates, and considerable surgical difficulty. In contrast, endovascular treatment has become a preferred method due to its features of a minimal incision, fewer postoperative complications, shorter operation time, and reduced surgical complexity. The endovascular treatment involves implanting a covered stent within the aorta to isolate a diseased vascular segment outside the covered stent and direct blood flow through a lumen of the covered stent, thereby protecting the vessel. As shown in FIG. 1, a supporting corrugated ring of an existing aortic covered stent 100' is generally made of a memory metal alloy to facilitate the selection of the brachiocephalic artery, the left common carotid artery, and the left subclavian artery through an internal branch by using a guidewire during surgery. However, after being implanted, a branch stent will occupy corresponding main lumen space due to the restraint of the supporting corrugated ring, and the supporting corrugated ring exerts a negative compressive effect on the implanted branch stent. In particular, as indicated at position A' in FIG. 1, a branch stent 203' corresponding to the left subclavian artery is prone to restraint and compression by the supporting corrugated ring after being implanted, which may hinder blood flow through the left subclavian artery. Furthermore, the presence of the supporting corrugated rings may cause long-term irritation to the vascular wall or induce a retrograde tear in the vascular wall. Summary of the Invention In view of the above, the present invention provides a vascular stent to solve at least part of the aforementioned technical problems. To achieve this objective, the present invention adopts the following technical solutions. The present invention provides a vascular stent, including a main stent provided with a main lumen. The main stent includes a proximal section, a distal section, and a middle section located between the proximal section and distal section and extending axially. The middle section is provided with a recessed portion, above which a supporting structure is arranged. At least part of the supporting structure is degradable. In one embodiment, the supporting structure is provided with a branch passage that radially penetrates through the supporting structure. The branch passage allows a branch stent to pass through. At least part of an edge of the branch passage is degradable, enabling the branch passage to be expanded upon at least partial degradation. The expanded branch passage exerts reduced compression on the branch stent passing therethrough. In one embodiment, the branch passage includes at least a right branch passage near a distal side of the supporting structure; and/or a left branch passage near a proximal side of the supporting structure. In one embodiment, the supporting structure includes a mesh structure having a plurality of grids, and one or more of the grids form the branch passage. In one embodiment, the supporting structure includes a main supporting layer that is at least partially degradable. The main supporting layer is formed by supporting filaments, and the supporting filaments include at least a degradable first supporting filament. In one embodiment, the degradable first supporting filament is either entirely degradable or partially degradable. When the degradable first supporting filament is partially degradable, the first supporting filament has a multi-layer structure arranged from inside to outside, and includes a non-degradable inner core located at an innermost layer and a degradable covering layer located at an outermost layer. In one embodiment, the degradable first supporting filament forms the main supporting layer. In one embodiment, the supporting filaments further include a non-degradable second supporting filament, and the degradable first supporting filament and the non-degradable second supporting filament jointly form the main supporting layer. In one embodiment, the first supporting filament forms a degradable layer, while the second supporting filament forms a non-degradable layer, and the degradable layer and the non-degradable layer are arranged opposite to each other within a same laye