CN104287870B - Intraluminal stent - Google Patents

Abstract

The invention discloses a luminal stent, which comprises a bare stent segment and a covered stent segment connected with the bare stent segment, the bare stent segment includes at least two coaxial wave-shaped rings and rigid connectors, and the bare stent segment also includes Inelastic and arbitrarily bendable flexible connectors, at least two adjacent wave-shaped rings are connected by rigid connectors and flexible connectors, and the rigid connectors and soft connectors in the circumferential direction The connectors are arranged in a mixed manner, and the length of the flexible connector is slightly greater than the shortest distance between two wave-shaped rings. The invention provides a luminal stent capable of improving the flexibility of the stent and maintaining the axial connection strength of the stent.

Description

Endoluminal stent

technical field

The invention belongs to the technical field of medical devices, and relates to a stent in a lumen, in particular to a lumen stent used in the aorta.

Background technique

Aortic diseases mainly include aortic dissection and aortic aneurysm; aortic aneurysm is further divided into aortic true aneurysm and aortic pseudoaneurysm. Aortic aneurysm and aortic dissection are extremely dangerous diseases. The mortality rate within 48 hours after onset is greater than 50%, and the mortality rate within two weeks is greater than 85%, which has seriously threatened human health. With the arrival of China's aging trend, its incidence will continue to rise.

Among patients with aortic aneurysm, patients with abdominal aortic aneurysm account for 63% to 79% of the prevalence of aortic aneurysm, and most of them occur in the elderly population over 60 years old, with an incidence rate of 2% to 4%, and more men than women , ranking 13th among all causes of death. As shown in Figure 1a, 1b, most abdominal aortic aneurysms4 are caused by atherosclerosis, and are generally located at the distal end of the renal artery Arrows in Figures 1a and 1b), extending to the bifurcation of the abdominal aorta, often involving the iliac artery5, and occasionally above the renal artery2; once the abdominal aortic aneurysm4 ruptures, the mortality rate is as high as 50% to 80% , is a very dangerous disease, so it is of great significance to intervene before the rupture of the abdominal aorta.

In the process of minimally invasive interventional treatment of aortic disease, the principle of endovascular isolation is usually used, that is, endovascular aneurysm repair (EVAR), and a covered stent is used to isolate the blood flow from the aortic aneurysm or aortic dissection. At present, the aortic stent graft in the industry is mainly composed of a metal wire and a PET (polyethylene terephthalate resin) film or ePTFE (polytetrafluoroethylene) film covering it, and the metal wire is made into a cylindrical shape. Stent skeleton covered with PET film or ePTFE film.

Most luminal stents used to treat aortic aneurysms include a covered stent segment and a bare stent segment connected to the covered stent segment. The covered stent segment is used to isolate the blood flow from the aortic aneurysm or aortic dissection. The bare stent segment is used to improve the adherence of the proximal end of the stent and the support and anchoring performance of the proximal end of the aortic stent-graft, to prevent the displacement of the stent-graft segment and the type I endoleak of the proximal end of the stent during and after the operation. For stents used in the abdominal aorta, the bare stent segment also avoids cutting off blood flow into the renal artery.

As shown in Figures 1a and 1b, taking abdominal aortic aneurysm as an example, Figure 1a shows a situation with a better shape of the proximal anchoring area, and Figure 1b shows a situation with a poor shape of the proximal anchoring area. The shape of the region has certain requirements, and the length of the proximal aneurysm neck H (referring to the length of the normal aortic segment between the proximal end of the tumor and the proximal renal artery) is required to be ≥ 15mm. The length of the proximal aneurysm neck should be extended to H≥10mm; the angle α of the proximal suprarenal neck (referring to the angle between the central axis of the proximal aneurysmal neck and the central axis of the suprarenal abdominal aorta) should be ≤60°; The angle β (referring to the angle between the central axis of the proximal tumor neck and the central axis of the tumor cavity) should be ≤70°. The shorter the aneurysm neck, the smaller the area available for stent-graft anchoring, and the higher the probability of complications such as proximal type I endoleak and graft displacement during and after surgery. The greater the angle of the aneurysm neck, the more flexible the brace is required to accommodate it. At present, a technology to solve this problem in the industry is the proximal bare stent transrenal artery technology, which releases the proximal bare stent of the covered stent vessel across the renal artery. The applicable bare stents are divided into bare stents without anchors and anchors. There are two types of bare stents. Bare stents without anchors are mostly single-circle wave-shaped rings, which are cylindrical or bell-shaped. They are mainly used in clinical situations where the length of the proximal aneurysm neck is greater than 15 mm and the shape of the aneurysm neck is regular, which can provide a good landing area for it. , but this kind of bare stent has the disadvantage of poor anchoring because it only relies on circumferential force to adhere to the inner wall of the blood vessel, and it is still relatively prone to displacement during the operation or in the later stage of the operation.

For cases with short aneurysms (between 10mm<H<14mm), bare stents with anchors are usually used for suprarenal fixation. The anchor structures are inserted into the vessel wall, which can firmly fix the stent and prevent long-term failure of the stent. This design broadens the scope of application for endovascular treatment of abdominal aortic aneurysms compared with bare stents without anchors. Bare stents with anchors can be divided into single-loop structure and multi-loop structure according to their basic composition structure (currently, the industry generally has two loops). Due to the short axial length of the stent due to the complex and curved vessel anatomy, the anchor on one side of the bare stent will be excessively attached to the vessel wall, and the anchor on the other side will be separated from the vessel wall and hang in the air, which will affect its Anchoring performance.

The multi-turn structure with multi-turn wavy rings can avoid the above disadvantages, but the connection between adjacent wavy rings will bring new problems. Currently, the adjacent wavy rings are connected by rigid connectors Together, such as in adjacent wave-shaped rings, where the distal apex of one wave-shaped ring is connected to the proximal apex in the other wave-shaped ring, metal thin rods are connected. This rigid connection increases the bare stent The overall connection stiffness avoids the shortening of the stent, but it causes the problem of poor flexibility. It is difficult for the bare stent to adapt to changes in the angle of the blood vessel. probability of occurrence.

Contents of the invention

The technical problem to be solved by the present invention is to provide a lumen stent that can improve the flexibility of the stent and maintain the axial connection strength of the stent in view of the above-mentioned defects in the prior art.

The technical solution adopted by the present invention to solve the technical problem is: a lumen stent, including a bare stent segment and a covered stent segment connected to the bare stent segment, and the bare stent segment includes at least two coaxial corrugated Rings and rigid connectors, the bare stent segment also includes flexible connectors that are inelastic and can be bent arbitrarily, and each adjacent two of the at least two wave-shaped rings passes through the The rigid connector is connected to the flexible connector, and the rigid connector and the flexible connector are mixed in the circumferential direction, and the length of the flexible connector is slightly longer than the distance between the two wave-shaped rings. Minimum spacing.

Each of the wave-shaped rings includes a plurality of continuous end-to-end support portions that form waves. All the support portions are located on the same cylindrical surface and arranged symmetrically about the central axis. End apex and multiple distal apexes; a proximal apex of one undulating ring in two adjacent undulating rings is connected to a distal apex of the other undulating ring through a rigid connector or a flexible connection file connection.

The at least two wave-shaped rings include a near-end wave-shaped ring and a distal wave-shaped ring, and the waveform phases between adjacent near-end wave-shaped rings and distal wave-shaped rings are asynchronous; or the near-end The wave width of the wave-shaped ring is greater than the wave width of the distal wave-shaped ring.

The rigid connectors and the flexible connectors are alternately arranged.

The wave-shaped ring and the rigid connecting piece are integrally formed.

The rigid connectors are arranged obliquely with respect to the central axis of the bare stent segment and are located on the same cylindrical surface.

The included angle δ between the rigid connector and the circumferential line perpendicular to the central axis of the bare stent segment is 20°-45°.

Each wave-shaped ring is provided with a connecting hole for fixing the flexible connecting piece.

The flexible connector is a single thread with high tensile strength and compatible with the human body; or the flexible connector is a mixed thread in which one or more kinds of silk are blended in multiple strands.

The thread is made of polymer material, and the polymer material includes at least one of PE, PTFE, PET and PP.

The wave-shaped ring includes at least one set of suspended proximal vertices and/or at least one set of suspended distal vertices that are not connected to adjacent wave-shaped rings, and each set of suspended proximal vertices includes 1 suspended proximal apex or 2 suspended proximal vertices. adjacent suspended near-end vertices, and each set of suspended distal vertices includes one suspended distal vertex or two adjacent suspended distal vertices.

The rigid connectors are arranged helically or linearly in the axial direction of the bare stent segment; and/or the flexible connectors are arranged helically or linearly in the axial direction of the bare stent segment.

The top of the proximal end of the bare stent segment is provided with an anchor thorn, and the anchor thorn is directed towards the distal end of the bare stent segment.

In the endoluminal stent of the present invention, in addition to the connection between the adjacent wave-shaped rings of the bare stent segment through rigid connectors, flexible connectors are also used for connection. Since the flexible connector is inelastic and can be bent arbitrarily, and the rigid connection and soft connection coexist, on the basis of meeting the axial tensile strength of the luminal stent and preventing shortening, the use of the soft connector increases the risk of the luminal stent The bending compliance can also ensure the overall axial connection strength of the stent.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Figure 1a is a schematic diagram of an infrarenal abdominal aortic aneurysm with a standardized proximal anchoring area;

Figure 1b is a schematic diagram of an infrarenal abdominal aortic aneurysm with relatively irregular morphology of the proximal anchoring zone compared to Figure 1a;

Fig. 2 is a schematic diagram of the structure of the lumen stent of the present invention;

Fig. 3 is a schematic structural view of the first embodiment of the bare stent segment;

Fig. 4 is a plane expanded view of the bare stent section in Fig. 3;

Fig. 5a, 5b are partial schematic diagrams in Fig. 4;

Fig. 6 is a partial schematic diagram in Fig. 4;

FIG. 7 is a schematic diagram of the lumen stent in FIG. 2 after being released into the abdominal aorta;

Fig. 8 is a schematic structural diagram of a bare stent segment in a second embodiment;

Fig. 9 is a plane expanded view of the bare stent section in Fig. 8;

Fig. 10 is a partial schematic diagram in Fig. 9;

Figure 11 is a schematic diagram of the connection between the bare stent segment and the main body covered stent in Figure 9;

Fig. 12 is a schematic diagram of the lumen stent in Fig. 11 after being released into the abdominal aorta;

Fig. 13 is a schematic structural view of the third embodiment of the bare stent segment;

Fig. 14 is a plane expanded view of the bare stent of the embodiment in Fig. 13;

Fig. 15 is a schematic structural view of a fourth embodiment of a bare stent segment;

Fig. 16 is a plane development view of the bare stent of the embodiment in Fig. 15 .

detailed description

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation of the present invention will be described in detail by taking an abdominal aortic stent as an example with reference to the accompanying drawings. Those of ordinary skill in the art should know that the abdominal aortic stent is only used as an example and does not limit the present invention. The luminal stent of the present invention is any covered luminal stent with a bare stent, including but not limited to abdominal Aortic stents also include thoracic aortic stents, iliac artery stents, etc.

Position definition: the present invention defines the position according to the blood flow direction, that is, the blood flows from the proximal end to the distal end.

As shown in Figure 2, a kind of endoluminal stent comprises bare stent segment 10 and the membrane stent segment 20 that is connected with bare stent segment 10, and bare stent segment 10 comprises at least two coaxial corrugated rings 100 and rigid connection 130, the bare stent segment 10 also includes a soft connector 131 that is inelastic and can be bent arbitrarily, and each adjacent two wave-shaped rings 100 in at least two wave-shaped rings 100 pass through the rigid connector 130 and the soft connector 131. The connecting parts 131 are connected, and the rigid connecting parts 130 and the flexible connecting parts 131 are mixedly arranged in the circumferential direction.

As shown in Figure 2, the stent graft segment 20 in the endoluminal stent includes a membrane 201 and a metal skeleton 202, and the metal skeleton 202 can be made of a biocompatible SIM (stress-induced martensitic) alloy, such as a nickel-titanium alloy , its shape can also be a plurality of wave-shaped rings arranged in the axial direction, and the covering film 201 is connected with the metal skeleton 202 as a whole by heat treatment or sewing. The specific structure of the stent-graft segment 20 is the same as that of other stent-graft segments in the prior art, and will not be repeated here. In this embodiment, the metal skeleton 202 is a sinusoidal wave shape formed by braiding nickel-titanium wire or cutting and shaping the nickel-titanium tube, and is arranged axially. The covering film 201 is made of PFFE (Polytetrafluoroethylene) or PET (Polythylene terephthalate) material, and is connected with the metal frame 202 as a whole by heat treatment or sewing.

The bare stent segment 10 in the endoluminal stent is arranged at the proximal end of the stent-graft segment 20 , and the distal end of the bare stent segment 10 is sutured together with the membrane at the proximal end of the stent-graft segment 20 . The bare stent segment 10 includes at least two coaxial wave-shaped rings 100, wherein coaxial means that both the bare stent segment 10 and the covered stent segment 20 are arranged in the axial direction of the endoluminal stent, and the two have a common A central axis, about which at least two wave-shaped rings 100 of the bare stent segment 10 are arranged symmetrically. These wave-shaped rings 100 have the same or similar wave shapes, for example, the wave-shaped rings 100 may be Z-shaped waves, V-shaped waves, or sine waves. The wave-shaped ring 100 and the rigid connector 130 can be formed separately, and then connected together by welding, bonding, etc., or the wave-shaped ring 100 and the rigid connector 130 can be integrally formed to form the bare stent segment 10, For example, a nickel-titanium tube is integrally cut, and a bare stent segment 10 is formed through multi-step heat setting using a mold. The diameter of the nickel-titanium tube used can be determined according to the inner diameter of the blood vessel at the specific placement location, for example, the diameter of the nickel-titanium tube is 5 mm.

Each wave-shaped ring 100 includes a plurality of continuous end-to-end support portions 112 forming waves, and all the support portions 112 are located on the same cylindrical surface and arranged symmetrically about the central axis, that is, the wave-shaped ring 100 forms a cylindrical structure. . A plurality of proximal vertices and a plurality of distal vertices are formed at the end-to-end connections of the plurality of supporting parts 112; these proximal vertices are peaks in the entire waveform, and the distal vertices are troughs in the entire waveform. A proximal vertex of one wave-shaped ring 100 of two adjacent wave-shaped rings 100 is connected to a distal vertex of the other wave-shaped ring 100 through a rigid connector 130 or a flexible connector 131 . In the circumferential direction, the rigid connectors 130 and the flexible connectors 131 are arranged in a mixed manner, that is, the arrangement of the rigid connectors 130 and the flexible connectors 131 is not concentrated, and at a certain position the rigid connectors 130 and the flexible The connection of the connecting piece 131 is optional, that is, the position connected with the rigid connecting piece 130 will not be connected with the flexible connecting piece 131, and the rigid connecting piece 130 is selected for connection at different positions using the flexible connecting piece 131. In this way, the flexible connectors 131 are doped in the middle of the rigid connectors 130 in the circumferential direction, which can reduce the overall bending stiffness of the rigid connectors 130 and increase the flexibility of the lumen stent.

The rigid connector 130 refers to a connector with a certain hardness and bending compliance, and the rigid connector 130 has both a supporting function and a connecting function. The rigidity of the rigid connector 130 can avoid the shortening of the stent and provide the overall axial connection strength of the stent, while also ensuring a certain bending compliance of the stent as a whole. The flexible connector 131 is a connector that is inelastic, has no tensile deformation, and can be bent arbitrarily. Therefore, the flexible connector 131 mainly has a connection constraint function, that is, it plays a role in the near-end apex and the distal apex of the wave-shaped ring 100. The role of constraints, during the bending process of the endoluminal stent, since the length of the flexible connecting piece 131 is slightly greater than the shortest distance between the two wave-shaped rings 100, the flexible connecting piece 131 constrains the proximal apex of the wave-shaped ring 100 The apex of the apex of the proximal end and the apex of the distal end conform to the bending deformation along with the bending, which increases the flexibility of the whole lumen stent, so as to avoid the relatively sharp apex of the proximal end and the apex of the distal end from piercing into the vessel wall and causing damage to the vessel.

In the mixed arrangement of the rigid connectors 130 and the flexible connectors 131, the rigid connectors 130 and the flexible connectors 131 are preferably alternately arranged in the circumferential direction. The staggered arrangement refers to the regular doping of the flexible connectors 131 in the rigid connectors 130, for example, the flexible connectors 131 are provided at intervals of one or more rigid connectors 130 in the circumferential direction, and the flexible connectors 131 can be arranged continuously One or more, generally the number of continuous rigid connectors 130 and flexible connectors 131 is not more than three, so as to avoid too strong or too weak local rigidity.

The rigid connector 130 is a columnar or rod-shaped structure as a whole, and its shape can be various, such as straight line, arc, curve, etc., and its cross-sectional shape can be circular, oval, square after chamfering or other infinite shapes. The irregular shapes with sharp corners and the like have the same diameter or width as the support portion 112 . The rigid connector 130 is made of biocompatible metal, or other materials that can be used for lumen stents. Nickel-titanium alloy material is preferred in this embodiment.

The waveforms of the wave rings 100 can be the same or different, and the peak widths can be the same or different, so that the orientation of the rigid connector 130 is different relative to the central axis of the lumen stent, for example: parallel to the central axis , arranged obliquely with respect to the central axis, wherein some rigid connectors 130 are arranged obliquely with respect to the central axis of the bare stent segment 10 and are located on the same cylindrical surface. The inclination direction of the rigid connecting member 130 relative to the central axis is limited, and is limited to inclination on the same cylindrical surface, rather than inward or outward inclination. Preferably, the inclination angle of the rigid connector 130 is: the angle δ between the rigid connector 130 and the circumferential line perpendicular to the central axis of the bare stent segment 10 is 20°-45°. Compared with the rigid connector 130 arranged parallel to the central axis, the rigid connector 130 arranged obliquely is more flexible. For example, when the bracket is bent, if the rigid connecting rod is parallel to the central axis, the rigid connector 130 will be fully stressed. If it is relatively inclined, the force will only be applied near the bending deformation point; in addition, the oblique arrangement of the rigid connector 130 can cooperate to form a helical arrangement in the axial direction, further improving the overall bending compliance of the stent.

At the position where the flexible connecting piece 131 is used for connection, each wave-shaped ring 100 is provided with a connecting hole (such as connecting holes 116 and 123 ) for fixing the flexible connecting piece 131 . The location of the connection hole is at the proximal or distal apex of the wave-shaped ring 100 .

The flexible connector 131 can be a flexible cord, and the flexible connector 131 is a single thread with high tensile strength that is compatible with the human body; or the flexible connector 131 is one or more of the above-mentioned silk threads. A blend of strands. The above-mentioned thread can be made of polymer material, for example, the material of the flexible connector 131 is PE (polyethylene, polyethylene), PTFE (polytetrafluoroethylene, Polytetrafluoroethylene), PET (polyethylene terephthalate) with relatively high tensile strength. Ethylene glycol formate, Polythylene terephthalate), PP (polypropylene, Polypropylene) material sutures or other medical sutures and their combined sutures can be a single strand or a mixed strand of multiple strands of the same or different materials blended. It is preferred that the flexible connector 131 is a blended thread of multiple blends of various silk threads. It has been proved by experiments that the use of a blended thread has a more reliable connection and tensile strength than a single material, and is more suitable for the connection and connection of the bare stent segment 10. Tie a knot to secure. The flexible connector 131 used in this embodiment is composed of ultra-high molecular weight PE and PP sutures. PE and PP sutures adopt a braided structure. Compared with most other polyester fibers and polymer blends, this combination suture The body cross-section is flatter, smaller knots are easier to tie, and the knots are stronger, in addition to having higher tensile strength.

The top of the proximal end of the bare stent segment 10 is provided with anchor thorns 114 , and each of the anchor thorns 114 faces the distal end of the bare stent segment 10 . Specifically, an anchor thorn 114 is arranged on the proximal apex of the wave-shaped ring 100 at the proximal end of the bare stent segment 10. FIG. The anchor thorn 114 of the shape 110 is located above the renal artery 2, and its anchor thorn 114 penetrates into the aortic vessel wall to ensure reliable anchoring of the proximal end of the lumen stent; 120 across the renal artery to ensure the normal blood supply of the renal artery; the proximal end of the graft is located on the lower side of the renal artery.

As shown in FIGS. 3-16 , the wave-shaped ring 100 may include a proximal wave-shaped ring 110 and a distal wave-shaped ring 120, and between adjacent wave-shaped rings 110 at the proximal end and wave-shaped distal rings 120 The waveform phases between them are asynchronous; or the wave width of the proximal wave ring 110 is greater than that of the distal wave ring 120 . Such setting can facilitate the rigid connector 130 to be inclined (non-parallel) relative to the central axis, so that the overall bending compliance of the stent is improved, and it is also beneficial for the rigid connector 130 to cooperate in the axial direction to form a helical shape, further improving the overall bending compliance of the stent . Of course, the illustrated embodiment is only used as an example, and the wave widths of the proximal waveform ring 110 and the distal waveform ring 120 can be the same, and the waveform phases can be synchronized.

The implementation of a plurality of different bare stent segments 10 is described in detail below according to the arrangement of different wave-shaped rings 100:

The first embodiment: as shown in Figures 3-7, the bare stent segment 10 includes two wave-shaped rings 100, namely the proximal wave-shaped ring 110 and the distal wave-shaped ring 120, the wave-shaped ring 100 It can be a Z-shaped wave, a V-shaped wave or a sine wave, etc.

As shown in Figures 3-5, the support portion 112 of the near-end wave-shaped ring 110 is connected end to end to form a Z-shaped wave, the proximal apex 111a and the distal apex 111b, and the proximal apex 111a and the distal apex 111b respectively transition A circular arc 115a, 115b is formed, and a connection hole 116 is provided at the apex of the distal end. In this embodiment, six Z waveform units are formed, as shown in FIG. 5 a , and the waveform height h1 (the vertical distance between the proximal apex 111 a and the distal apex 111 b ) is 9 mm.

As shown in Figures 3, 4, 5a, and 5b, the proximal apex 111a extends toward the proximal direction with an anchor thorn post 113, and the anchor thorn post 113 is provided with an anchor thorn 114 integrally formed with the anchor thorn post 113, and the anchor thorn 114 is provided with It protrudes in the circumferential direction from the proximal end of the anchor thorn post 113, and extends toward the distal end, forming an angle γ with the surface of the anchor thorn post 113. As shown in Figure 5b, the included angle γ is between 20° and 60°, preferably between The angle γ is 45°, and the length of the anchor thorn 114 is between 2 mm and 5 mm, preferably 3 mm. When in use, the anchor thorn 114 can be inserted into the blood vessel, and the intima at the inserted position can be covered. In this way, the proximal end of the stent can be reliably fixed, and the intraoperative and long-term displacement of the stent can be avoided.

The distal wave-shaped ring 120 includes a proximal apex 121a, a distal apex 121b, and a support portion 112 between adjacent proximal apex 121a and distal apex 121b. The number of waveforms of the far-end waveform ring 120 is greater than that of the near-end waveform ring 110, which is 9 waveforms, but the circumference of the cylinder formed by the enclosure is basically equal, so the wave width is reduced, and the waveform height is the same as that of the near-end waveform. Ring 110 is equal, also 9mm. A connection hole 123 is provided at the proximal apex 121a.

The proximal wave-shaped ring 110 and the distal wave-shaped ring 120 are connected together by three inclined rigid connectors 130 and three flexible connectors 131, and a flexible connection is fixed between the connecting hole 116 and the connecting hole 123. Item 131. As shown in FIG. 6 , the angle δ between the rigid connector 130 and the circumferential line perpendicular to the central axis of the bare stent segment 10 is 20°-45°, and in this example it is 30°.

As shown in FIGS. 3 and 4 , a suture hole 124 is provided at the apex 121 b of the distal wave-shaped ring 120 to connect the bare stent with the proximal end of the endoluminal stent graft 201 .

As shown in Figure 2, the stent-graft segment 20 includes a membrane 201 and a metal skeleton 202, the metal skeleton 202 is a sinusoidal waveform braided by nickel-titanium wire, and the membrane 201 is PFFE (polytetrafluoroethylene, Polytetrafluoroethylene) or PET ( Polyethylene terephthalate (Polythylene terephthalate) material is connected as a whole by heat treatment or sewing.

FIG. 7 is a schematic diagram of the endoluminal stent released into the abdominal aorta 1. After the release, the proximal waveform ring 110 is located near the upper side of the renal artery 2, and its anchor 114 penetrates into the aortic vessel on the upper side of the renal artery 2. In the wall, ensure the reliable anchoring of the proximal end of the lumen stent; the proximal waveform ring 110 and the distal waveform ring 120 cross the renal artery to ensure the normal blood flow supply of the renal artery; the proximal end of the stent graft section 20 The end is located on the lower side of the renal artery.

The second embodiment of the bare stent segment 10 : the bare stent segment 10 adopts more than two wave-shaped rings 100 , that is, one proximal wave-shaped ring 110 and two or more distal wave-shaped rings 120 .

The structure of the near-end wave-shaped ring 110 is the same as that of the first embodiment, and will not be repeated here.

Compared with the first embodiment, the arrangement of multiple distal wave-shaped rings 120 increases the overall length-to-diameter ratio of the bare stent segment 10, resulting in better flexibility and compliance with more complex aneurysm neck angles, while being less The long length of the bare stent section can make the proximal wave-shaped ring 110 enter into the straight section of the suprarenal abdominal aorta, so that the adhesion to the wall is better and the proximal anchoring is more stable. The distal wave-shaped ring 120 at the most distal end is sutured together with the proximal end membrane 201 of the endoluminal stent. The proximal wave-shaped ring 110 can be arranged according to needs, for example, it can have the same structure as the proximal wave-shaped ring 110 in the first embodiment.

FIG. 9 is a schematic plan view of the bare stent segment 10 in the second embodiment. A plurality of distal wave-shaped rings 120 are arranged in parallel to the distal end of the proximal wave-shaped ring 110 along the axial direction, and the waveforms are in phase with each other and have equal wave widths. In this embodiment, six distal wave-shaped rings 120 are provided. , the adjacent distal wave-shaped rings 120 partially overlap in the axial direction and are arranged in a fish-scale shape, that is, the distance between the proximal vertices or the distal vertices of two adjacent wave-shaped rings 100 is smaller than the wave height. As shown in FIG. 10 , the overlapping distance d is preferably 1/3˜2/3 of the wave height, and in this embodiment, the overlapping distance d is 1/2 of the wave height. In this embodiment, each distal waveform ring 120 is composed of 9 Z-shaped waveforms. The height of each wave is 8.0 mm, and the overlapping distance between the front and rear two distal wave rings 120 is 4 mm. Two adjacent distal wave-shaped rings 120 in the distal wave-shaped rings 120 are connected together by three rigid connectors 130 and three flexible soft connectors 131 . The rigid connector 130 and the bracket are laser cut as a whole, the flexible flexible wire is a hybrid wire combined with PE+PP, and the flexible connector 131 is connected through a connection hole.

In this example, the rigid connectors 130 between the plurality of distal wave-shaped rings 120 are linearly arranged in the axial direction, that is, the rigid connectors 130 between adjacent distal-end wave-shaped rings 120 are parallel to the central axis, And the axially adjacent rigid connectors 130 are arranged on the same straight line. As shown in FIG. 9 , in this example, the flexible flexible connectors 131 between the wave-shaped rings 120 at the distal end are also arranged in a straight line. In the circumferential direction, the rigid connectors 130 and the flexible connectors 131 are alternately arranged, that is, a flexible connector 131 is provided between two rigid connectors 130 .

The connection mode of the near-end wave-shaped ring 110 and the first distal wave-shaped ring 120 at the proximal end, and the connection mode of the proximal-end wave-shaped ring 110 and the distal wave-shaped ring 120 in the first embodiment same. In order to ensure the axial connection strength between the proximal wave-shaped ring 110 and the distal wave-shaped ring 120, the distal wave-shaped ring 120 is provided with a proximal apex of a rigid connector 130 and a proximal wave-shaped ring 110. The distal vertices are connected together by an inclined rigid connector 130, which does not change the shape of the waveform of the proximal waveform ring 110, and ensures that the waveform of the proximal waveform ring 110 is evenly distributed along the circumferential direction. The rigid connector 130 and the bare stent The included angle between the central axes of the segments 10 is 30°.

As shown in FIGS. 8 , 9 , and 11 , the most distal wave-shaped ring 120 may be the same as the other distal wave-shaped rings 120 , or the number of waves may be the same, and the wave height may be slightly higher. In this embodiment, the waveform height of the most distal wave-shaped ring 120 is 9mm, and a suture hole 124 is set at the apex of the distal end of the most-distal wave-shaped ring 120 to connect the bare stent segment 10 to the tube. The proximal ends of the grafts 20 of the luminal stent are connected together.

Figure 12 is a schematic diagram of the endoluminal stent being released into the abdominal aorta 1. After the release, the proximal waveform ring 110 is located above the renal artery 2, and its anchor 214 penetrates into the aortic vessel wall to ensure that the endoluminal stent Reliable anchoring at the proximal end; the wave-shaped ring 120 at the distal end crosses the renal artery 2 to ensure the normal blood flow supply of the renal artery; the proximal end of the stent graft segment 20 is located at the lower side of the renal artery.

The third embodiment: as shown in Figures 13 and 14, the third embodiment is a deformation on the basis of the second embodiment, and the rigid connectors 130 between the multiple distal wave rings 120 and the soft The arrangement of the connectors 131 is changed. Each rigid connector 130 and flexible connector 131 are parallel to the central axis, and the rigid connector 130 is helical in the axial direction of the bare stent segment 10; Spiral upwards.

In this embodiment, adjacent distal wave-shaped rings 120 are connected together by three rigid connectors 130 and three flexible connectors 131 . In this example, the rigid connectors 130 between the distal wave-shaped rings 120 are spiral in the axial direction, and the two rigid connectors 130 in the axial direction are not on the same straight line, and are arranged at intervals of a wave distance in the circumferential direction. In such an arrangement, when the bare stent segment 10 at the proximal end is bent, the bending resistance on the same axis between two adjacent wave-shaped rings 100 is further reduced compared with the second embodiment, which can further improve the luminal stent. The flexibility can adapt to more complex aneurysm neck shapes; the flexible connecting piece 131 between the wave-shaped rings 120 at the distal end is also in a spiral shape. In the circumferential direction, the rigid connector 130 and the flexible connector 131 are also spaced apart by a waveform distance.

The structure of the near-end wave-shaped ring 110 may be the same as that of the first embodiment, and details will not be repeated here.

The fourth embodiment: as shown in FIGS. 15 and 16 , the proximal bare stent segment 10 in this embodiment includes a proximal wave-shaped ring 110 and two or more distal wave-shaped rings 120 . The structure of the near-end wave-shaped ring 110 is the same as that of the proximal-end wave-shaped ring 110 in the first embodiment.

As shown in Figure 16, the distal wave ring 120 is composed of 9 waves, and there are three uniformly distributed and inclined rigid connectors 130 in the circumferential direction between the two distal wave rings 120, and the inclined rigid connectors 130 The distal apex 121b of the first distal wave-shaped ring 120 is connected with the proximal apex 121a of the adjacent second distal wave-shaped ring 120 . In the circumferential direction, the two rigid connectors 130 are connected together by a flexible connector 131 . The proximal apex 121 a connected with the flexible connecting member 131 is provided with a connecting hole 116 , and the distal apex 121 b is provided with a connecting hole 123 for connecting and fixing the flexible connecting member 131 . The proximal and intermediate distal wave rings 120 have a wave height of 9 mm.

The far-end waveform ring 120 at the farthest end has the same number of waveforms as the proximal waveform ring 110, and the waveform height is slightly greater than the waveform height of the distal waveform ring 120, and the waveform height is 10mm. A suture hole 124 is provided at the apex of the distal end of the ring 120 to connect the bare stent and the stent graft segment together.

The connection mode between the proximal wave-shaped ring 110 and the distal wave-shaped ring 120 is the same as that between the adjacent distal wave-shaped rings 120, and only three oblique rigid connectors 130 are used for connection. , and the rigid connection piece 130 with the distal wave-shaped ring 120 forms a helical shape in the circumferential direction.

In this embodiment, the wave-shaped ring 100 includes at least one set of suspended near-end vertices 125 and/or at least one set of suspended distal-end vertices 126 that are not connected to adjacent wave-shaped rings 100, and each set of suspended near-end vertices 125 includes One suspended near-end apex or two adjacent suspended near-end apexes, and each set of suspended distal apexes 126 includes one suspended distal apex or two adjacent suspended distal apexes. These suspended distal apexes 126 and suspended proximal apexes 125 save a part of the rigid connector 130 in the bare stent segment 10, so that part of the distal apex and the proximal apex of the above-mentioned adjacent wave-shaped rings 100 are in a suspended state , can reduce the overall bending stiffness, and this part of the suspended distal apex 126 and the suspended proximal apex 125 can cling to the blood vessel wall or even slightly penetrate the blood vessel wall because they are not bound, which increases the anchoring of the lumen stent. At the same time, because the number of suspended vertices in each group of suspended far-end vertices or suspended near-end vertices does not exceed 2, there are rigid connectors and soft connectors on both sides of the circumference to constrain, so the above-mentioned suspended vertices The waveform will not be greatly reversed and go deep into the blood vessel wall to cause new damage to the blood vessel. The rest of the structure is the same as the first implementation mode, and will not be repeated here.

The second-fourth implementations are based on the first implementation and increase the number of distal waveform rings 120. The distal waveform rings 120 are located in the renal artery and near the lower side of the renal artery. For the shape of blood vessels with a large upper angle, in addition to avoiding cutting off the blood flow flowing into the renal artery and mesenteric artery, the distal wave-shaped ring 120 also needs to have good flexibility to conform to the blood vessel, so the inclination of the rigid connector 130 Both the setting and the flexible connector 131 increase the flexibility of the luminal stent, and at the same time, the overall length of the bare stent increases, so that the proximal ring can be located in the relatively straight arterial vessel above the renal artery, so that the structure of the anchor thorn 114 can It is completely inserted into the blood vessel, and has good wall-attachment and anti-displacement properties.

In order to adapt to patients with different sizes and positions of blood vessels, the present invention can be designed into different models and specifications according to the diameter of the abdominal aorta in adults. In each of the above embodiments, the diameters of each part are equal, or in the form of a bell mouth, with a diameter of 20mm to 36mm, such as preferably 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 33mm and 36mm, and a total length of 30 to 60mm.

Claims (10)

1. A luminal stent comprising a bare stent segment and a covered stent segment connected to the bare stent segment, the bare stent segment comprising at least two coaxial corrugated rings and rigid connectors, characterized in that , the bare stent segment also includes an inelastic and arbitrarily bendable flexible connector, and each adjacent two wave-shaped rings in the at least two coaxial wave-shaped rings pass through the rigid connector and The flexible connectors are connected, the rigid connectors and the flexible connectors are arranged in a mixed manner in the circumferential direction, and the length of the flexible connectors is slightly greater than the shortest distance between the two wave-shaped rings. 2. The endoluminal stent according to claim 1, wherein each of the wave-shaped rings comprises a plurality of continuous support portions connected end to end to form waves, and all support portions are located on the same cylindrical surface, about The central axis is axisymmetrically arranged, and the end-to-end connections of multiple supporting parts form multiple proximal vertices and multiple distal vertices; one of the proximal vertices of one of the two adjacent wave-shaped rings is connected to the other A distal apex of the wave-shaped ring is connected by a rigid connector or a soft connector. 3. The endoluminal stent according to claim 2, wherein the at least two coaxial wave rings comprise a proximal wave ring and a distal wave ring, and the adjacent proximal wave The waveform phases between the ring and the wave-shaped ring at the distal end are asynchronous; or the wave width of the wave-shaped ring at the proximal end is greater than that of the wave-shaped ring at the distal end. 4 . The endoluminal stent according to claim 1 , wherein the rigid connectors and the flexible connectors are alternately arranged in the circumferential direction. 5 . The endoluminal stent according to claim 1 , wherein the rigid connector is arranged obliquely with respect to the central axis of the bare stent segment and is located on the same cylindrical surface. 6 . 6 . The endoluminal stent according to claim 2 , wherein the included angle δ between the rigid connector and a circumferential line perpendicular to the central axis of the bare stent segment is 20°-45°. 7. The endoluminal stent according to claim 1, wherein the flexible connector is a single-strand silk thread with high tensile strength that is compatible with the human body; or the flexible connector is a Or a variety of silk yarns that have been blended in multiple strands. 8. The endoluminal stent according to claim 7, wherein the wire is made of a polymer material, and the polymer material includes at least one of PE, PTFE, PET and PP. 9. The endoluminal stent according to claim 2, wherein the wave-shaped ring comprises at least one set of suspended proximal vertices and/or at least one set of suspended distal ends that are not connected to adjacent wave-shaped rings Vertices, each group of suspended proximal vertices includes 1 suspended proximal vertex or 2 adjacent suspended proximal vertices, and each group of suspended distal vertices includes 1 suspended distal vertex or 2 adjacent suspended distal vertices. 10. The endoluminal stent according to claim 1, characterized in that, the rigid connectors are arranged helically or linearly in the axial direction of the bare stent segment; and/or the flexible connectors are arranged on the bare stent segment The segments are arranged in a spiral or straight line in the axial direction.