CN108938160B - Stent for near bifurcation lesions - Google Patents

Abstract

The invention discloses a bracket for lesions of a near bifurcation part, which is a tubular bracket formed by a plurality of wavy supporting pieces which are axially connected together, wherein the tubular bracket comprises a near-end supporting mechanism, a middle-area supporting mechanism and a far-end supporting mechanism which are sequentially connected; the middle area supporting mechanism and the far end supporting mechanism are respectively of annular structures; the near-end supporting mechanism comprises a circumferential supporting part connected with the middle-area supporting mechanism and an orientation supporting part arranged at the near end of the circumferential supporting part; the circumferential support part is of an annular structure; the directional support is a circumferentially open loop with a non-flush structure at its proximal end face to form a localized support in the circumferential direction. The invention provides a stent suitable for a vascular stenosis or occlusion lesion near a vascular bifurcation, which aims to solve the problem that the existing vascular stent cannot completely cover the lesion or protrudes into a main blood vessel to influence contralateral blood flow to cause complications after being implanted into a branch blood vessel.

Description

Stents for near-bifurcation lesions

Technical Field

The present invention belongs to the technical field of medical devices and relates to a vascular stent, and in particular to a vascular stent that can be used for interventional treatment of stenotic or occlusive lesions near a vascular bifurcation.

Background technique

With the rapid development of modern society, the aging of the population has intensified, people's work pressure has continued to increase, and their living habits are not healthy enough, resulting in frequent cardiovascular diseases in my country, which have become the number one disease endangering the health of the Chinese people. Its prevention and treatment has become the focus of attention of the medical community at home and abroad. Among them, efficient and minimally invasive interventional treatments such as implantation of vascular stents are currently the most important and effective cardiovascular disease diagnosis and treatment technologies. For vascular stenosis or occlusive lesions, vascular stents can be implanted to support and expand the diseased blood vessels, so that the blood flow of the diseased blood vessels can be restored.

Generally, diseased blood vessels are narrow, and a common vascular stent can be placed to prop up the blood vessels. However, in actual clinical practice, the vascular stenosis lesions of many patients are located near the bifurcation of the blood vessels (i.e., at the origin of the side branch extending from the main branch), and at this moment, the stent must completely cover the target injury, and in some cases, even should exceed the lesion segment to reach the adjacent lesion-free or almost lesion-free vascular region, so as to make full use of the potential of the stent for acute and subsequent vascular opening. Therefore, in the case of branches, the stent must cover the mouth of the side branch. The mouth of the side branch usually has a cross-sectional plane that is not perpendicular to the longitudinal axis of the side branch and extends, because the side branch can extend at an angle different from 90 °, for example, at an angle between 40 °-60 °. As shown in Figure 1A, common stents can not fully provide coverage of the lesion position in this case.

For example, in patients with iliac vein compression syndrome, the left common iliac vein is compressed by the right common iliac artery and the fifth lumbar vertebra. This continuous mechanical compression and arterial pulsation cause adhesion, intimal hyperplasia, and fibrosis in the venous cavity, causing stenosis and occlusion of the lumen, leading to venous reflux obstruction in the left lower limb. Therefore, the stent used here needs to have strong support force. However, there are few specialized venous stents on the market. Arterial stents are mainly used in clinical treatment of iliac vein stenosis, and the radial support force of arterial stents is weak and cannot meet the requirements. In addition, the iliac vein runs close to the pelvis and has physiological curvature, so it needs to have good flexibility. The most important thing is that the bilateral iliac veins flow upward into the inferior vena cava in an inverted "Y" shape. The right iliac vein runs steeper and straighter, forming an angle of about 20 degrees with the inferior vena cava, and the left iliac vein forms an angle of about 40 degrees with the inferior vena cava. Currently, the commonly used venous/peripheral arterial stents are mostly straight-tube stents. In addition, because the left common iliac vein is between the right iliac artery and the lumbar vertebrae, it is not easy to accurately position and release the stent during implantation, and the stent is very likely to jump forward into the inferior vena cava when released. In addition, if the iliac vein involves lesions of the inferior vena cava, the stent needs to be protruded into the inferior vena cava to completely expand the stenosis, but the protruding stent may affect the blood return of the contralateral iliac vein and even cause deep vein thrombosis on the contralateral side. It has been reported that unilateral stents entering the inferior vena cava account for 7-10%, resulting in a 15% incidence of contralateral iliac vein thrombosis. In addition, clinical cases have shown that the anterior wall of the iliac vein is often "funnel-shaped" due to the pulsation of the right iliac artery, the occlusion site, and the distal iliac vein. The tip of the stent enters the inferior vena cava too little, and the upper edge of the stent cannot completely cover the iliac vein lesions. The straight-tube stent is easily squeezed to the distal end of the iliac vein due to insufficient anchoring force, thus leading to treatment failure.

As shown in FIG1B , when the above-mentioned vascular stenosis lesion is located near the bifurcation of the blood vessel, because the angle of the blood vessel bifurcation is not a right angle, if the lesion position is to be completely covered, a stent will be placed in any bifurcated blood vessel, and a protruding portion of the stent will exist in the main blood vessel. The unilateral stent will be suspended in the main blood vessel and will be subjected to long-term erosion by the main blood flow or the contralateral branch blood flow, resulting in instability of the stent. In addition, as shown in FIG1C , when a straight tubular stent is used at the branch mouth, due to the large difference in diameter between the branch and the main blood vessel, a large bend will occur. Therefore, the use of a straight tube stent is very likely to increase the formation of thrombus in the stent due to poor wall adhesion or affecting the contralateral blood flow backflow to form turbulence or eddy currents.

Summary of the invention

The technical problem to be solved by the present invention is to provide a vascular stent for interventional treatment of stenosis or occlusive lesions near vascular bifurcations, in response to the defects of the prior art, so as to solve the problem that the existing vascular stents cannot completely cover the lesions after being implanted in branch vessels or penetrate into the main blood vessels, affecting the contralateral blood flow and causing complications.

The technical solution adopted by the present invention to solve the technical problem is:

A stent for lesions near bifurcation is a tubular stent formed by a plurality of wavy support members connected together axially, the tubular stent comprising a proximal support mechanism, a middle support mechanism and a distal support mechanism connected in sequence;

The middle area support mechanism and the distal end support mechanism are respectively annular structures;

The proximal support mechanism includes a circumferential support portion connected to the middle support mechanism, and a directional support portion arranged at the proximal end of the circumferential support portion;

The circumferential support portion is an annular structure;

The directional support portion is an open ring in the circumferential direction, and its proximal end surface is a non-flush structure to form local support in the circumferential direction.

Furthermore, in the stent for treating lesions near bifurcation, the proximal end surface of the directional support portion is preferably in an inclined plane, curved surface or wavy surface.

Furthermore, in the stent for lesions near the bifurcation, the proximal end face of the directional support portion is preferably an inclined plane, and the angle α between the proximal end face and the central axis of the stent satisfies: 90°＞α＞0°.

Furthermore, in the stent for near-bifurcation vascular lesions, the proximal support mechanism is preferably formed by axially connecting a plurality of wavy support members of the same wavelength, and the crest units and trough units of adjacent wavy support members are connected one-to-one to form a grid structure.

Furthermore, in the stent for near-bifurcation vascular lesions, the directional support portion is preferably a grid-like open-loop structure, and the number of grids decreases gradually from the distal end to the proximal end.

Furthermore, in the stent for near-bifurcation vascular lesions, it is preferred that the middle region support mechanism and the proximal support mechanism or/and the middle region support mechanism and the distal support mechanism are connected via circumferentially spaced connecting components, and the parts of the wavy support members that are not connected to the connecting components are suspended without connection.

Furthermore, in the stent for near-bifurcation vascular lesions, preferably, axially adjacent wavy support members in the middle zone support mechanism are connected by circumferentially spaced connection components, and parts of the wavy support members that are not connected to the connection components are suspended without connection.

Furthermore, in the stent for near-bifurcation vascular lesions, the wavy support member is preferably composed of support units connected end to end; each of the support units includes a crest unit, a trough unit, and a wave rod connected between the crest unit and the trough unit, and the connecting assembly includes at least one connecting rod, which is fixed between the crest unit or trough unit of a wavy support member and the wave rod of an adjacent wavy support member.

Furthermore, in the stent for near-bifurcation vascular lesions, preferably in the same connecting assembly, at least two connecting rods are included, and adjacent connecting rods are arranged in a figure-eight or inverted figure-eight shape.

Furthermore, in the stent for near-bifurcation vascular lesions, the projections of the connection components arranged between the three adjacent circles of corrugated support members in the axial direction preferably do not overlap or partially overlap.

Furthermore, in the stent for near-bifurcation vascular lesions, the connecting rod is preferably a straight rod, a special-shaped rod with a curved structure or an arc structure, or a combination thereof.

Furthermore, in the stent for proximal bifurcation vascular lesions, preferably, after expansion, in the proximal support mechanism, at least the directional support portion gradually extends outward from the distal end to the proximal end.

Furthermore, in the stent for near-bifurcation vascular lesions, preferably, at least the angle β between the longest axial section of the directional support portion and the central axis of the stent satisfies: 30°≥β＞0°.

Furthermore, in the stent for proximal bifurcation vascular lesions, preferably, after expansion, the outer diameter of the tubular stent gradually expands from the distal end to the proximal end to form a tapered structure.

Furthermore, in the stent for near-bifurcation vascular lesions, the distal support mechanism is preferably formed by axially connecting a plurality of wavy support members of the same wavelength, and the crest units and trough units of adjacent wavy support members are connected one-to-one to form a grid structure.

The proximal end face of the stent of the present invention is a non-flush structure suitable for the bifurcated blood vessel near the bifurcation site, forming a local support in the circumferential direction. The non-flush structure can set the inclination angle of the proximal end face of the stent according to the intersection of the bifurcated blood vessel near the bifurcation site, so that the proximal end of the stent and the lesion position at the intersection of the blood vessels are completely fitted and covered, avoiding the problem in the prior art that the vascular stent cannot completely cover the lesion after being implanted in the branch blood vessel or penetrates into the main blood vessel to affect the contralateral blood flow and cause complications.

The proximal support mechanism and the distal support mechanism of the stent of the present invention are the wave crest units and the wave trough units of the corrugated support members connected one by one, which can form a closed diamond grid structure. The wavelengths of adjacent corrugated support members are the same in size and evenly distributed, which can achieve a good support effect. The middle zone support mechanism adopts the connection assembly to be arranged at intervals. In the circumferential direction, the parts of the corrugated support members that are not connected to the connecting assembly are suspended in the air without connection, and the degree of freedom is relatively large, which can ensure the good flexibility of the stent.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

1A-1C are schematic diagrams of structures of prior art intravascular implantation;

FIG2 is a schematic diagram of the expanded structure of Example 1 of the present invention;

FIG3 is a schematic structural diagram of an implementation scheme of Example 1 of the present invention;

FIG4 is a schematic structural diagram of another implementation method of Example 1 of the present invention;

FIG5 is a schematic diagram of the expanded structure of Example 2 of the present invention;

FIG6 is a schematic diagram of the structure of Embodiment 3 of the present invention;

FIG7 is a schematic diagram of the expanded structure of Example 3 of the present invention;

FIG8 is a schematic diagram of the expanded structure of Example 4 of the present invention;

FIG. 9 shows the implantation of Embodiments 1-4 of the present invention into a blood vessel.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

Definition of orientation: The proximal end in the present invention refers to the end of the stent close to the heart after the stent is implanted in the blood vessel; the following structure refers to the structure of the stent after expansion. The axial direction refers to the central axis direction of the stent, and the direction perpendicular to the central axis is the radial direction. The inner side of the stent refers to the side close to the bifurcation of the bifurcated blood vessel when the stent is expanded.

Embodiment 1, as shown in Figures 2-4 and 9, a stent for lesions near the bifurcation is a tubular stent formed by a plurality of wavy support members 1111, 1121, 121, 131 connected axially together, the tubular stent comprising a proximal support mechanism 110, a middle region support mechanism 120 and a distal support mechanism 130 connected in sequence, a total of three parts; the middle region support mechanism 120 and the distal support mechanism 130 are respectively annular structures; the proximal support mechanism 110 comprises a circumferential support portion 111 connected to the middle region support mechanism 120, and a directional support portion 112 arranged at the proximal end of the circumferential support portion 111; the circumferential support portion 111 is an annular structure; the directional support portion 112 is a structure which is open in the circumferential direction and whose proximal end face is non-flush to form local support in the circumferential direction.

In the above structure, the circumferential support portion 111, the middle support mechanism 120 and the distal support mechanism 130 of the proximal support mechanism 110 are all annular structures, so that the stent forms a tubular structure body, and the directional support portion 112 arranged at the nearest end of the stent is an open ring structure. A plurality of wavy support members 1111 form the circumferential support portion 111, a plurality of wavy support members 121 form the middle support mechanism 120, and a plurality of wavy support members 131 form the distal support mechanism 130. The annular shape of the present invention refers to that the wavy support members 1111, 121, 131 are connected end to end to form a ring, and the open ring refers to that the wavy support members 1121 are separated end to end, and the wavy support members 1121 are adjacent to each other end to end or are spaced a certain distance apart, and form an approximately annular or C-shaped structure in the axial projection.

As shown in FIG. 9 , the proximal end face of the stent of the present invention is a non-flush structure suitable for bifurcated blood vessels, forming local support in the circumferential direction. The non-flush structure can set the inclination angle of the proximal end face of the stent according to the intersection of the bifurcated blood vessels, so that the proximal end of the stent and the intersection of the blood vessels are completely fitted and covered, which can cover the lesion site without protruding into the main blood vessel, thereby avoiding the problem in the prior art that the vascular stent cannot completely cover the lesion site after being implanted in the branch blood vessel or protrudes into the main blood vessel to affect the contralateral blood flow and cause complications.

The proximal support mechanism 110 includes two parts, one is a circumferential support part 111 connected to the middle support mechanism 120, and the other is a directional support part 112 arranged at the most proximal end. The two parts are respectively composed of a wavy support member 1121 and a wavy support member 1111.

The local support described in the directional support part 112 is due to the non-flush proximal end face, and the axial length of each position in the radial direction is different. The proximal end face refers to the side surface in the axial direction of the most proximal end of the stent. The stent is a tubular structure, and its end face is generally annular. Since the proximal end of the directional support part 112 is not flush, an inclined or serrated proximal end is formed. Corresponding to the shape of the blood vessel near the intersection of the bifurcated blood vessels, the proximal end of the present invention adopts an inclined structure, that is, the non-flush structure of the directional support part 112 has multiple implementation methods. After the stent is expanded, it is preferred that the proximal end face of the directional support part 112 is in an inclined plane, arc surface or wavy surface. That is, the directional support part 112 is gradually extended in length from one side to the other side of the circumferential support part 111 in the radial direction, and the equidistant extension forms an inclined plane, and the non-equidistant extension forms an arc surface or a wavy surface. Preferably, the equidistant extension is used, and the proximal end face of the directional support part is an inclined plane. The height difference between the outermost side and the innermost side is 1-30mm, preferably 5-20mm. The angle α between the inclined plane and the central axis of the stent satisfies: 90°＞α＞0°, preferably 60°＞α＞30°. The specific inclination angle is set according to the intersection angle and the diameter of the intersecting blood vessels, and is not limited here. The requirements of the present invention are met as long as it is within the above angle range.

The proximal support mechanism 110 is formed by axially connecting a plurality of wavy support members 1111, 1121 of the same wavelength, and the crest units and trough units of adjacent wavy support members 1111, 1121 are connected one-to-one to form a grid structure. The same wavelength means that the length of each waveform of the wavy support members 1111, 1121 is the same in the circumferential direction. Since the crest units and trough units of adjacent wavy support members 1111, 1121 are connected one-to-one to form a grid structure, in the wavy support members 1111, 1121 of the proximal support mechanism 110 of the present invention, the shapes of the wavy support members 1111, 1121 can be the same or different, that is, the waveform does not need to limit the axial amplitude, but only needs to limit the length of each circumferential waveform to satisfy the one-to-one connection of the crest units and trough units of adjacent wavy support members 1111, 1121 to form a grid structure. Preferably, adjacent wavy support members 1111 and 1121 have substantially the same waveform, ie, waveforms with the same wavelength and the same amplitude, forming a diamond grid structure.

The directional support portion 112 is a grid-like open-loop structure, and the number of grids gradually decreases from the distal end to the proximal end. That is, the grid-like structure is partially incomplete, that is, the wavy support members 1121 on the proximal end face have different circumferential lengths, resulting in the absence of other wavy support members 1121 at the corresponding positions of some wavy support members 1121, while retaining its wavy structure, that is, the proximal end face has a V-shaped and diamond-shaped structure. The wavy support members 1111 of the circumferential support portion 111 have the same circumferential length, which can achieve a one-to-one corresponding connection between the wave crest units and the wave trough units of the completely adjacent wavy support members 1111.

The distal support mechanism 130 is also formed by axially connecting a plurality of wavy support members 131 of the same wavelength, and the wave crest units and wave trough units of adjacent wavy support members 131 are connected one by one to form a grid structure. The grid structure of the distal support mechanism 130 is substantially the same or similar to the structure of the circumferential support portion 111 of the proximal support mechanism 110, and will not be described in detail here.

The wavy support members 1111, 1121, 121, 131 are all composed of support units 1210 connected end to end; each of the support units 1210 includes a crest unit 1211, a trough unit 1213, and a wave rod 1212 connected between the crest unit 1211 and the trough unit 1213, and the wave rod 1212 is in the shape of a straight rod, a special-shaped rod with a curved structure or an arc structure, or a combination thereof. The shape of the wave rod 1212 described here is the shape of the wavy support member when it is unfolded into a plane. The special-shaped rod means that the wave rod is not a straight rod, and the special-shaped rod with a curved structure means that the straight rod or the arc rod has a curved structure. The curved structure is a curved part on the wave rod 1212, and the curved part can enhance the bending or stretching performance of the wave rod 1212. The curved structure can be set at any position of the wave rod 1212, preferably in the middle of the wave rod 1212. Preferably, the special-shaped rod with a curved structure or an arc-shaped structure is an arc-shaped rod, a straight rod with an arc-shaped portion, a Z-shaped rod or an S-shaped rod.

In each support unit 1210, the wave rod 1212 is an integral structure or fixedly connected with the wave crest unit 1211 and the wave trough unit 1213. The entire wave-shaped support members 1111, 1121, 121, 131 can also be an integral structure or a fixed connection. The stent of the present invention is made by laser cutting and heat setting, and the material of the stent body can be selected from stainless steel, tantalum, cobalt-based alloy, platinum, nickel-titanium alloy and new titanium alloy, and the preferred material is nickel-titanium alloy.

A plurality of support points 1126 and/or developing points may be provided at the ends of the proximal support mechanism 110 and the distal support mechanism 130. The support point 1126 is a smooth raised structure provided on the crest unit 1211 of the corrugated support member 1121, and the raised structure may be a solid structure or a structure with a hole in the center. The number and interval of the settings are set according to actual needs and are not limited here. The developing point is used to develop the position of the stent in the blood vessel during surgery, and may be at the same position as the support point, or another developing point may be provided. In this embodiment, the developing point is a developing point formed by filling the developing material in the center hole of the support point.

The circumferential support portion 111, the middle support mechanism 120 and the distal support mechanism 130 can be directly connected, or can be connected through a connecting assembly 122. Preferably, the middle support mechanism 120 and the proximal support mechanism 110, or the middle support mechanism 120 and the distal support mechanism 130 are connected through a connecting assembly 122 arranged at circumferential intervals. The connecting assembly 122 can also be arranged between them at the same time. The parts of the wavy support members 1111, 121, 131 that are not connected to the connecting assembly 122 are suspended in the air without connection. That is, the wave crest units 1211 and the wave trough units 1213 of the axially adjacent support units 1210 that are not connected to the connecting assembly are suspended in the air without connection.

The axially adjacent corrugated support members 121 in the middle zone support mechanism 120 are connected via the connection components 122 arranged at intervals in the circumferential direction, and the parts of the two adjacent circles of corrugated support members 121 that are not connected to the connection components 122 are suspended in the air without connection. That is, the wave crest units 1211 and wave trough units 1213 of the axially adjacent support units 1210 that are not connected to the connection components 122 are suspended in the air without connection.

There is no connection between two adjacent groups of connecting components 122 of two axially adjacent wavy support members 1111, 121, 131. No connection means that there is no connection between the crest units of the wavy support members 1111, 121, 131 and the trough units at axially adjacent positions, so that there is a larger relative movement or bending space between the two in the radial and axial directions, thereby increasing the flexibility of the bracket.

The connection component 122 in the above-mentioned middle region support mechanism 120 may be the same as or different from the connection component 122 between the proximal support mechanism 110 and the middle region support mechanism 120 and the connection component 122 between the middle region support mechanism 120 and the distal support mechanism 130 .

The connecting assembly 122 includes at least one connecting rod 1221. There are many ways to fix the connecting rod 1221. The connecting rod 1221 can be set between axially adjacent wave crest units 1211 and wave trough units, or the connecting rod 1221 can be fixed between a wave crest unit 1211 or a wave trough unit 1213 of a wave-shaped support member and a wave rod 1212 of an adjacent wave-shaped support member. In this embodiment, the connecting assembly 122 is set between axially adjacent wave crest units 1211 and wave trough units 1213.

In this embodiment, as shown in FIG. 2 , a connecting rod 1221 is provided in the connecting assembly 122, and the connecting rod 1221 is an integral structure or fixedly connected to the support unit 1210. Among them, the integral molding is formed by laser cutting of a tube. The connecting rod 1221 is tilted between the peak unit 1211 and the trough unit 1213, that is, the two adjacent wavy support members 1121, 121, 131 are not synchronized, that is, the peak unit 1211 of one wavy support member 1121, 121, 131 is staggered with the trough unit 1213 of another wavy support member 1121, 121, 131 in the axial direction, and the circumferentially adjacent connecting rods 1221 can be arranged in parallel or non-parallel, even if the adjacent connecting rods 1221 are arranged in an eight-shaped or inverted eight-shaped shape. Similarly, the connecting rods 1221 in different axial rows can be parallel or non-parallel.

The connection components 122 are arranged between two adjacent circles of corrugated support members 1111, 121, 131, and all the connection components 122 are evenly spaced in a circle. In the circumferential direction, the connection rods 1221 are arranged in exactly the same manner or repeatedly arranged in a certain arrangement sequence.

The projections of all the connection components 122 between the corrugated support members in the axial direction do not overlap or partially overlap; or all the connection components 122 are arranged in a spiral shape or staggered in the axial direction. The connection rods 1221 are evenly distributed in groups along the circumference, and the connection rods 1221 of two adjacent circles are staggered in the axial direction, so that the connection components 122 can withstand greater local tension and pressure, and the bracket can deform evenly when it is stretched or bent.

The connecting rod 1221 is a straight rod, a special-shaped rod with a curved structure or an arc structure, or a combination thereof. In this embodiment, a straight rod is selected.

The stent of the present invention is tubular in shape. As shown in Figures 2-3, the stent of the present invention is a tubular stent extending in equal diameters. In another embodiment, the stent of the present invention can be a tubular stent extending in non-equal diameters. For example, as shown in Figure 4, the stent is a tapered tubular shape. In another embodiment, the stent can also be a variable diameter structure composed of a tapered tubular shape and a straight tubular shape. Preferably, after expansion, the outer diameter of the tubular stent gradually expands from the distal end to the proximal end to form a tapered structure.

Embodiment 2, as shown in FIG5 , is based on Embodiment 1 and has been partially improved.

A stent for lesions near a bifurcation site is a tubular stent formed by a plurality of wavy support members 1111, 1121, 121, 131 connected axially together. The tubular stent includes a proximal support mechanism 110, a middle support mechanism 120 and a distal support mechanism 130 connected in sequence, a total of three parts. The three parts themselves are the same as those in Example 1, and the difference lies in the structure of the connecting component 122.

A group of connection components 122 is provided with at least two connection rods 1221, and the connection rods 1221 are fixed between the wave crest unit 1211 or the wave trough unit 1213 of a wave-shaped support member 1121, 121, 131 and the wave rod 1212 of the adjacent wave-shaped support member 121, 121, 131. The connection rods 1221 in the same connection component 122 can be arranged in parallel, or can be arranged in an eight-shaped or inverted eight-shaped shape. Preferably, the connection rods 1221 are arranged in an eight-shaped or inverted eight-shaped shape, which can strengthen the supporting force and improve the radial supporting force with the same number of connection rods 1221. The connection rods 1221 of the central support mechanism 120 are distributed in pairs, forming a closed-loop connection unit with the connected wave-shaped support members 1111, 121, 131 and are evenly staggered, ensuring good flexibility, scalability and connection strength, and maintaining a good shape of the bracket and the waveform when bending or stretching. Since the wave crest units 1211 of the wave-shaped support members 1111, 121, 131 correspond to the wave crest units 1211 of the adjacent wave-shaped support members 1111, 121, 131 in the axial direction, the connecting rods 1221 are connected to the wave trough units 1213 of the proximal wave-shaped support member and the wave rods 1212 of the distal wave-shaped support member, and the connecting rods 1221 form an inclined structure, so that the two adjacent connecting rods 1221 form an eight-shaped or inverted eight-shaped arrangement. And the connecting rods 1221 in each group of connecting components 122 are symmetrically arranged.

The arrangement is completely the same means that the connecting rods 1221 are arranged in an eight-shaped or inverted eight-shaped shape. Preferably, the connecting components 122 arranged between the three adjacent circles of corrugated support members do not overlap or partially overlap in the axial direction. In this embodiment, the two connecting rods 1221 are arranged in an eight-shaped shape.

The remaining structures are the same as those in Embodiment 1 and will not be described in detail here.

Embodiment 3, as shown in Figures 6-7, this embodiment is based on Embodiment 1 or 2, with some improvements.

As shown in FIG6 , different from the first or second embodiment, the length of the wave rods 1212 of the corrugated support member 111 constituting the proximal support mechanism 110 is not uniform, the number of wave rods 1212 in one axial row of the proximal support mechanism 110 is the same, and the length of some inner wave rods 1212 gradually extends toward the proximal end along the axial direction, thereby forming an inclined surface structure of the proximal support mechanism 110. That is, due to the elongated waveform amplitude, the circumferential support portion 111 and the directional support portion 112 are formed.

The remaining structures are the same as those in Embodiment 1 or 2 and will not be described in detail here.

As shown in FIG6 , in order to further strengthen the fit between the stent and the inner wall of the blood vessel, in the proximal support mechanism 110 after expansion, at least the directional support portion 112 gradually expands outward from the distal end to the proximal end. That is, the directional support portion 112 extends from the circumferential support portion 111 in the axial direction toward the proximal end, and also gradually extends outward in the radial direction, forming an outward-turned trumpet-mouth structure. The degree of outward turn should not be too large. Preferably, at least the angle β between the longest axial section of the directional support portion 112 and the central axis of the stent satisfies: 30°≥β＞0°, that is, the directional support portion 112 is slightly outward-turned. As shown in FIG6 , in this embodiment, the proximal closed-loop area gradually expands radially outward from the distal end to the proximal end with an angle β of 20°. By expanding the tubular structure outward at a certain angle at the proximal end, it is more in line with the anatomy of the bifurcated blood vessels, so that the proximal end of the stent can achieve a good wall adhesion effect.

Different from Example 2, at least two wave crest units 1211 or two wave trough units 1213 are spaced between two connecting rods 1221 in the same group. The projections of the axially adjacent closed-loop connecting units formed by the connecting assembly 122 and the corrugated support member partially overlap in the axial direction, which can better ensure the scalability and connection strength of the stent, and keep the stent and the corrugated shape in good shape when bent or stretched.

Embodiment 4, as shown in FIG8 , is based on Embodiment 3 and has been partially improved.

Different from the embodiment 3, the proximal support mechanism 110 in this embodiment includes two parts: a circumferential support part 111 and a directional support part 112. The structure of this part is the same as that of the embodiment 1, and will not be described in detail here.

The proximal end face of the proximal support mechanism 110 is formed by increasing or decreasing the number of support units 1210. Compared with Example 3 in which the grid height is adjusted by the axial length of the wave rod 1212 of the support unit, this design has a grid of more uniform size and better radial and axial support strength.

In addition, in this embodiment, the proximal support mechanism 110 gradually expands radially outward at an angle β of 10° from the distal end to the proximal end. The tubular structure expands outward at a certain angle at the proximal end, which is more in line with the anatomy of the bifurcated blood vessels, so that the proximal end of the stent achieves a good wall adhesion effect.

Claims (20)

1. A stent for near bifurcation lesions, the stent being a tubular stent formed of a plurality of corrugated struts axially connected together, characterized in that: the tubular support comprises a proximal end supporting mechanism, a middle area supporting mechanism and a distal end supporting mechanism which are connected in sequence;

the middle area supporting mechanism and the far end supporting mechanism are respectively of annular structures;

the proximal end supporting mechanism is formed by axially connecting a plurality of wavy supporting pieces with the same wavelength and the same amplitude, and crest units and trough units of adjacent wavy supporting pieces are correspondingly connected one by one to form a diamond grid-shaped structure; the near-end supporting mechanism comprises a circumferential supporting part connected with the middle-area supporting mechanism and an orientation supporting part arranged at the near end of the circumferential supporting part;

The circumferential support part is of an annular structure;

the directional support part is an open loop in the circumferential direction, and the proximal end surface of the directional support part is of a non-flush structure so as to form a local support in the circumferential direction; the directional support part is of a grid-shaped open-loop structure, and the grid number of the directional support part is gradually reduced from the far end to the near end;

in the proximal support mechanism after inflation, at least the directional support portion extends gradually outwardly from the distal end to the proximal end;

at least the included angle beta between the axial longest section of the directional support part and the central axis of the bracket meets the following conditions: the angle beta is more than or equal to 30 degrees and more than 0 degrees.

2. The stent for near bifurcation lesions according to claim 1, wherein the proximal end face of the directional support is in an inclined plane or arc.

3. The stent for near bifurcation lesions according to claim 2, wherein the proximal end face of the directional support is an inclined plane having an angle α with the central axis of the stent that satisfies: 90 DEG > alpha > 0 deg.

4. The stent for near bifurcation lesions according to claim 1, wherein the proximal end face of the directional support is in an inclined plane or wavy plane.

5. The stent for near bifurcation lesions according to claim 4, wherein the proximal end face of the directional support is an inclined plane having an angle α with the central axis of the stent that satisfies: 90 DEG > alpha > 0 deg.

6. The stent for near bifurcation lesions according to claim 1, wherein the middle area support mechanism is connected to the proximal end support mechanism or/and the middle area support mechanism is/are connected to the distal end support mechanism by first connecting members arranged circumferentially at intervals, and the portions of the corrugated support not connected to the first connecting members are suspended and not connected.

7. The stent for near bifurcation lesions according to claim 1, wherein axially adjacent ones of the undulating struts in the mid-region support mechanism are connected by circumferentially spaced apart second connection assemblies and portions of the undulating struts not connected to the second connection assemblies are suspended and unconnected.

8. The stent for near bifurcation lesions according to claim 6, wherein said undulating struts of said mid-region support mechanism are comprised of support units connected end-to-end; each supporting unit comprises a wave crest unit, a wave trough unit and a wave rod connected between the wave crest unit and the wave trough unit; the first connection assembly includes at least one connection rod secured between a crest unit or a trough unit of one corrugated support and a wave rod of an adjacent corrugated support.

9. The stent for near bifurcation lesions according to claim 8, wherein the same first connecting assembly comprises at least two connecting rods, adjacent connecting rods being arranged in a splayed configuration.

10. The stent for near bifurcation lesions according to claim 8, wherein the same first connecting assembly comprises at least two connecting rods, adjacent connecting rods being arranged in an inverted splayed configuration.

11. The stent for near bifurcation lesions according to claim 8, wherein the connecting rod is a straight rod, a shaped rod with a curved structure, or a combination thereof.

12. The stent for near bifurcation lesions according to claim 8, wherein the connecting rod is a straight rod, a shaped rod with an arcuate structure, or a combination thereof.

13. The stent for near bifurcation lesions according to claim 7, wherein said undulating struts of said mid-region support mechanism are comprised of support units connected end-to-end; each supporting unit comprises a wave crest unit, a wave trough unit and a wave rod connected between the wave crest unit and the wave trough unit; the second connection assembly includes at least one connection rod fixed between the crest units or the trough units of one corrugated support and the wave rods of an adjacent corrugated support.

14. The stent for near bifurcation lesions according to claim 13, wherein the same second connecting assembly comprises at least two connecting rods, adjacent connecting rods being arranged in a splayed configuration.

15. The stent for near bifurcation lesions according to claim 13, wherein the same second connecting assembly comprises at least two connecting rods, adjacent connecting rods being arranged in an inverted splayed configuration.

16. The stent for near bifurcation lesions according to claim 13, wherein the projections of the second connecting assemblies disposed between adjacent three turns of the undulating struts of the mid-region support mechanism in the axial direction do not overlap or partially overlap.

17. The stent for near bifurcation lesions according to claim 13, wherein the connecting rod is a straight rod, a shaped rod with a curved structure, or a combination thereof.

18. The stent for near bifurcation lesions according to claim 13, wherein the connecting rod is a straight rod, a shaped rod with an arcuate structure, or a combination thereof.

19. The stent for near bifurcation lesions according to any of claims 1-7, wherein the outer diameter of the tubular stent gradually expands from distal end to proximal end after expansion, forming a tapered structure.

20. The stent for near bifurcation lesions according to any of claims 1-7, wherein the distal support means is formed by axially connecting a plurality of corrugated supports of the same wavelength, and the crest units and the trough units of adjacent corrugated supports of the distal support means are connected in one-to-one correspondence to form a grid-like structure.