CN114052982A

CN114052982A - Film-carrying support

Info

Publication number: CN114052982A
Application number: CN202010746438.XA
Authority: CN
Inventors: 高小龙
Original assignee: Shanghai Suchang Medical Technology Co ltd
Current assignee: Shanghai Suchang Medical Technology Co ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2022-02-18
Also published as: WO2022022143A1

Abstract

The invention relates to the field of medical apparatus and instruments, and discloses a membrane-carrying bracket, which comprises: the bracket main body is of a hollow latticed structure; a membrane structure disposed inside the stent body, a proximal end of the membrane structure being secured to the stent body. The invention fixes the near end of the membrane structure on the main body of the bracket, so that other parts of the membrane structure keep a free state on the main body of the bracket, thereby improving the compliance of the membrane-carrying bracket, simultaneously reducing the difficulty of the connection process of the membrane-carrying bracket, and being convenient for processing membrane structures with different shapes to adapt to blood vessels with different shapes.

Description

Film-carrying support

Technical Field

The invention relates to the field of medical instruments, in particular to a membrane-carrying bracket.

Background

Aneurysms are common cardiovascular and cerebrovascular diseases and are extremely lethal once ruptured. Larger aneurysms are more at risk of rupture, and even if the ruptured aneurysm is treated conservatively, the ruptured aneurysm is more at risk of rupture after stabilization, and the aneurysm usually has an acute onset and a short course of disease and is prone to poor prognosis. The causes of aneurysm formation are many, and are related to arteriosclerosis, hypertension, myofibrodysplasia, immune factors, genetic factors and the like, and the pathogenesis of the aneurysm is not completely clear at present. There is no fully unified understanding of the treatment of aneurysms, which is the basis for medical treatment, and the treatment of aneurysms mainly includes surgical clamping of the aneurysm and interventional intraluminal treatment. The surgical operation has higher risk, larger wound and more complications, and along with the development of interventional technology, the occurrence of the bracket greatly improves the curative effect of interventional therapy on intracranial aneurysm.

The current clinically major scaffolding technologies include: stent assisted spring coil embolization, blood flow guide placement, and covered stent placement. The stent-assisted spring ring embolism can change the hemodynamic state of the neck of the aneurysm, change the curvature of the parent artery and play a role of a scaffold for the growth of vascular endothelium. The blood flow guiding device can change the hemodynamic state in the artery to induce thrombosis in the aneurysm. The covered stent can isolate the blood flow in the aneurysm to induce the thrombosis in the aneurysm. However, the inventors have found that the prior art vascular stents still have some drawbacks.

In the process of interventional operation of stent-assisted spring coil embolism, the aneurysm cavity needs to be filled by passing through a stent mesh delivery spring coil through a microcatheter, the difficulty of passing through the stent gap by the microcatheter is high, the risk is high due to the fact that vascular tissues are easy to puncture during operation, and the cost is high. There is a risk of delayed occlusion, recurrence and rupture after aneurysm embolization. In the blood flow guiding device implantation, in order to change the blood flow in the artery to induce the thrombosis in the aneurysm, the stent is expected to have high metal coverage rate, and the metal coverage rate of the blood vessel stent refers to the proportion of the metal coverage area in the stent to the total area of the stent. At present, the Pipeline stent with the metal coverage rate of about 35 percent can be selected for interventional therapy clinically. However, too high metal coverage of the stent presents problems of high radial tension and poor compliance; may obstruct or even block the blood flow of the peripheral blood vessels, causing additional injury to the patient; the blood pressure at the proximal end of the aneurysm is high, the meshes of the stent are easy to rupture and bleed under the continuous scouring of blood flow, and the like.

The covered stent in the prior art can solve part of problems of the metal bare stent, but the inventor finds a new problem in the manufacturing and processing process, and mainly embodies the following aspects: firstly, the film covering processing difficulty on the metal stent is high; secondly, the film is thick and difficult to load and transport.

Disclosure of Invention

The invention aims to provide a membrane-carrying stent, which is suitable for a tortuous blood vessel, improves the overall compliance of the membrane-carrying stent, facilitates the loading and conveying of the membrane-carrying stent, and reduces the difficulty of the connection process of the membrane-carrying stent by only fixing a membrane structure at the near end.

The technical scheme provided by the invention is as follows:

a membrane-bearing stent comprising:

the bracket main body is of a hollow latticed structure;

a membrane structure disposed inside the stent body, a proximal end of the membrane structure being secured to the stent body.

In this scheme, fix on the support main part through the near-end with the membranous structure, reduced the processing degree of difficulty of year membrane support, can improve the holistic compliance of year membrane support simultaneously, be convenient for load and carry in the blood vessel to with membranous structure setting in the inside of support main part, the vascular wall is hugged closely under the erodeing of blood to the membranous structure of being convenient for, thereby forms the shutoff to aneurysm.

Further preferably, a portion or all of the membrane structure tapers axially in a direction from the proximal end to the distal end of the membrane structure.

In this scheme, through setting up some or all of membrane structure to the round platform shape, utilize the cross-section size to the influence of fluid pressure different, more be favorable to blood to flow from the near-end to the distal end, flow from the one end that the cross-section is big to the one end that the cross-section is little promptly, can prevent simultaneously that blood from flowing into the intermediate layer between membrane structure and the support main part.

Further preferably, the distal end of the membrane structure is fixed on the stent main body, and the part of the membrane structure between the proximal end and the distal end is kept in a free state on the stent main body, and preferably, the diameter of the distal end of the membrane structure is larger than that of the stent main body, so that the membrane structure is corrugated in the circumferential direction of the stent main body.

In this scheme, to the less in service behavior of blood pressure, can fix the distal end and the support main part of membranous structure, at this moment, the main part of membranous structure keeps the free state in the support main part, preferably, can also make the distal end diameter of membranous structure be greater than the diameter of support main part, when under blood stream washing, the distal end of membranous structure can hug closely in the support main part, and some is protruding to the net on the support main part, form wave fold, thereby effectively prevent blood and get into the intermediate layer between membranous structure and the support main part, and the fold part can be favorable to blood to form the thrombus, thereby form the shutoff to the aneurysm export.

Further preferably, the membrane structure is provided with a notch corresponding to the branch blood vessel, one end of the notch penetrates through the far end of the membrane structure, and the other end of the notch extends to the middle part of the membrane structure or penetrates through the near end of the membrane structure.

In this scheme, be provided with the breach corresponding with branch's blood vessel on the membrane structure, can make blood enter into branch's blood vessel through the breach, and can not cause the shutoff to branch's blood vessel, simultaneously, the one end of breach runs through the distal end of membrane structure, and the other end extends to the middle part of membrane structure or runs through the near-end of membrane structure, and this is decided according to the actual conditions of blood vessel.

Further preferably, the proximal end of the membrane structure and the stent main body are sewn through a suture, wherein the suture sews a part or all of the proximal end of the membrane structure to fix the proximal end of the membrane structure and the stent main body, and the suture is preferably made of a developing material.

In this scheme, can sew up through the stylolite between membrane structure's the near-end and the support main part to fix membrane structure's near-end and support main part, when fixed, can carry out circumference to membrane structure's near-end and fix, also can fix the near-end of membrane structure separately, simultaneously, the stylolite can adopt the development material preparation to form, can play the effect of the near-end of fixed membrane structure and support main part through the stylolite, and the effect of the near-end of demonstration membrane structure or the position of support main part.

Further preferably, the proximal end of the membrane structure is bonded to the stent body by an adhesive, and/or the proximal end of the membrane structure is made of a flocculent material and is wrapped around the stent body to fix the proximal end of the membrane structure to the stent body.

In this scheme, the near-end of membrane structure can bond with the support main part through the adhesive, can also adopt the flocculent material preparation with the near-end of membrane structure, like this, the near-end of membrane structure alright through the flocculent material winding in the support main part, can realize the fixed between the near-end of membrane structure and the support main part equally.

Further preferably, the membrane structure is made of a microporous membrane material, and the inner surface of the microporous membrane material is coated with a hydrophilic coating.

In this scheme, the membrane structure that forms through the preparation of micropore membrane material can conveniently carry out the medicine loading at the micropore on the membrane material, can reduce whole membrane-carrying support's material to a certain extent moreover, lets membrane-carrying support press more easily and hold the transport, and simultaneously, membrane material micropore has an important effect to membrane-carrying support's endothelialization process, and the hydrophilic coating can effectively reduce the interior thrombosis of membrane-carrying support, makes membrane-carrying support inside can form unobstructed blood flow channel.

Further preferably, a first developing mark for displaying the stent main body is arranged on the stent main body, and the first developing mark is distributed on the stent main body along the axial direction of the stent main body.

In the scheme, the first developing marks distributed along the axial direction of the stent main body are used for displaying the position and the total length of the stent main body in the blood vessel.

Further preferably, a second developing mark for displaying the membrane structure is arranged on the stent main body, and the second developing mark is distributed at the corresponding position of the stent main body and the membrane structure along the axial direction of the stent main body.

In the scheme, the second developing marks arranged at the positions, corresponding to the membrane structures, on the stent main body are used for indicating the positions of the membrane structures in the blood vessels and ensuring that the membrane structures at least cover the near ends of the aneurysms.

Further preferably, a third developing mark for displaying a notch in the film structure is arranged on the support main body, and the third developing mark is distributed at a position corresponding to the notch of the support main body along the axial direction of the support main body.

In the scheme, the third developing mark arranged at the position, corresponding to the notch, on the stent main body is used for indicating the position of the notch of the membrane structure in the blood vessel and ensuring that the notch of the membrane structure corresponds to the branch blood vessel.

The invention has the technical effects that:

according to the invention, the membrane structure is arranged on the stent main body, so that the density of grids on the stent main body can be reduced by utilizing the plugging effect of the membrane structure on the aneurysm, the metal coverage rate on the stent main body is reduced, the flexibility of the stent main body is improved, the radial tension and good wall adhesion performance of the stent main body can be ensured, and the loading and conveying of the membrane-carrying stent are facilitated; meanwhile, the membrane structure is only fixed on the support main body through the near end, and other parts of the support main body are kept in a free state on the support main body, so that the processing difficulty of the membrane-carrying support is reduced, meanwhile, membrane structures in different shapes can be conveniently manufactured to adapt to blood vessels in different shapes, the membrane structure and the support main body have certain mutual displacement, and the membrane-carrying support can still have certain compliance in some tortuous blood vessels.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic perspective view of a membrane-supporting scaffold according to the present invention;

FIG. 2 is a schematic view of a partial enlarged structure at the membrane structure of the present invention;

FIG. 3 is a schematic structural view of a microporous membrane material of the present invention;

FIG. 4 is an enlarged schematic view of the structure at A in FIG. 3;

FIG. 5 is a schematic view of a membrane structure of the present invention having one of the notch shapes disposed thereon;

FIG. 6 is a schematic view of a membrane structure of the present invention having an alternative notch configuration;

fig. 7 is a schematic structural view of the membrane structure of the present invention fabricated in a truncated cone shape.

The reference numbers illustrate:

1. the stent comprises a stent main body, 11 meshes, 12 openings, 2 membrane structures, 21 proximal ends, 22 distal ends, 23 gaps, 3 microporous membrane materials, 31 micropores, 4 first developing marks, 5 second developing marks, 6 third developing marks and 7 sutures.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

As a specific example, as shown in FIG. 1, a stent graft for use in a blood vessel containing an aneurysm structure comprises a stent body 1 and a membrane structure 2, wherein the stent body 1 is hollow inside, is hollow as a whole and has a circular cross section, and the stent body 1 has a lattice structure, and openings 12 are provided at both ends of the stent body 1. The stent body 1 includes an inflow section, an outflow section, and an intermediate section, the inflow section and the outflow section being supported on the blood vessel wall, the intermediate section corresponding to the position of the aneurysm. The membrane structure 2 is arranged inside the stent body 1, the proximal end 21 (referring to the end close to the heart) of the membrane structure 2 is fixed to the stent body 1, and the other parts of the membrane structure 2 remain free on the stent body 1 (see fig. 2), i.e. the other parts of the membrane structure 2 are not fixed to the stent body 1. Optionally, one end of the stent body 1 extends beyond the proximal end 21 of the membrane structure 2 and the other end extends beyond the distal end 22 of the membrane structure 2 (referring to the end away from the heart).

When the stent graft is released through a microcatheter to a site in a blood vessel where an aneurysm structure is present, the stent body 1 is expanded from a compressed state to conform to the blood vessel and is closely attached to the inner wall of the blood vessel, and blood flows through the inside of the stent graft (as shown by the direction of the arrow in fig. 1). The inflow and outflow sections of the stent body 1 will be correspondingly supported on the vessel wall. Under the scouring of the blood flow of certain blood pressure, the non-fixed part of the membrane structure 2 can be well attached to the inner wall of the stent main body 1, so that the effect of isolating the blood flow from entering the aneurysm neck inlet is realized. At this time, the part of the membrane structure 2 at the aneurysm opening can isolate the high-speed and high-pressure blood flow in the aorta from entering the false cavity where the aneurysm is located, so that the pressure in the false cavity is reduced, thrombus is formed, the aneurysm is filled, and the blood is prevented from entering the aneurysm to further increase the aneurysm. Meanwhile, the grid 11 on the stent main body 1 covers the tumor opening to change local blood flow, thereby promoting the blood flow in the tumor cavity to slow down and form thrombus, providing attachment points for the regeneration of blood vessel intima, and promoting the tumor neck remodeling and endothelialization of the aneurysm to achieve the healing effect.

Meanwhile, for the film-carrying stent for fixing the film structure 2 in the stent main body 1, the film structure 2 is not directly contacted with the conveying device, so that the clamping and releasing of the film-carrying stent are not influenced by large friction force formed on the surface of the film structure 2. After release of the stent graft into the vessel, a part of the blood will flow along the gap between the membrane structure 2 and the stent body 1 into the false lumen of the aneurysm at the distal end 22 of the membrane structure 2, since the membrane structure 2 is only fixed to the stent body 1 at the proximal end 21. For this portion of blood, the inventors have found that although there is a portion of blood flowing from the dissection between the distal end 22 of the membrane structure 2 and the stent body 1 into the false lumen of the aneurysm due to the distal end 22 of the membrane structure 2 being unsecured, this portion of blood does not adversely affect the aneurysm due to the proximity of the distal end 22 of the membrane structure 2 to the aneurysm outlet. This is because, when blood flows from the gap between the distal end 22 of the membrane structure 2 and the stent body 1 to the false lumen of the aneurysm, since the proximal end 21 of the membrane structure 2 is already blocked at the entrance of the aneurysm, no blood flow channel is formed at the entrance of the aneurysm, and the aneurysm does not further enlarge. Meanwhile, as the part of blood stays in the interlayer between the distal end 22 of the membrane structure 2 and the stent main body 1, the thrombus formation in the interlayer is promoted, which is beneficial to the healing of the aneurysm.

The whole of the tectorial membrane structure is fixed with the stent framework by the existing tectorial membrane stent, so that the aneurysm can be better blocked, but the inventor finds that the whole fixation of the tectorial membrane structure influences the compliance of the stent framework in the manufacturing and processing process, so that the compliance and the wandering capability of the existing tectorial membrane stent in the blood vessel are both poor. Therefore, in order to enable the membrane-carrying stent to still have good compliance and wandering capability in a tortuous blood vessel, the inventor fixes the membrane structure 2 by fixing the proximal end 21.

In this embodiment, the proximal end 21 of the membrane structure 2 is fixed to the stent body 1, so that other parts of the membrane structure 2 are kept in a free state on the stent body 1 (i.e. not fixed to the stent body 1), and thus, the membrane structure 2 and the stent body 1 have a certain degree of mutual displacement, so that the membrane-loaded stent has better compliance and the ability to wander in a blood vessel, and especially can still maintain a certain degree of compliance in some tortuous blood vessels, thereby increasing the adherence performance of the membrane-loaded stent.

Relative to the bare metal stent: the membrane-carrying support can reduce the metal coverage rate of the support, improve the overall compliance, reduce the pressure of the support main body 1 after carrying the membrane, improve the overall fatigue resistance, and avoid the damage of the support main body 1 and the rupture of the aneurysm. Through carrying the membrane on support subject 1, because membrane structure 2 compares in naked support has better shutoff effect, can play the effect that prevents blood entering aneurysm better, can reduce metal support's mesh density through membrane structure 2's shutoff effect to reduce metal support's metal coverage, make to carry the membrane support to have better compliance, can guarantee to carry the radial tension and the good adherence performance of membrane support simultaneously.

Simultaneously, compare in current tectorial membrane support: the film-carrying support in the embodiment is only fixed with the support main body 1 at the near end 21 of the film structure 2, so that the processing difficulty of the film-carrying support can be reduced, and the film structure 2 can be conveniently processed into different shapes. Because the current covered stent adopts the scheme of covering the stent framework and integrally fixing the covering film and the stent framework, the connection process difficulty of the covering film is large, and the film layer is often very thick, so that the pressing and holding difficulty of the covered stent is increased, the effect of plugging the aneurysm can be played, the processing is not convenient, and the manufacturing cost of the covered stent is difficult to reduce.

In conclusion, the membrane-loaded stent in the embodiment provides a fixing scheme completely different from that of the existing membrane-covered stent, so that the difficulty of the connection process between the membrane structure 2 and the stent main body 1 is reduced, the compliance of the membrane-loaded stent is improved, and the membrane-loaded stent can better adapt to tortuous blood vessels; and moreover, the membrane structure 2 with different shapes can be manufactured in practical use, for example, the membrane structure 2 with different shapes can reserve some vacant parts on the membrane structure 2, so that when the membrane-carrying stent is released into a blood vessel, the vacant parts on the membrane structure 2 can be opposite to the branch blood vessel, and blood flow can enter other peripheral blood vessels through the vacant parts.

In this embodiment, a part or all of the membrane structure 2 tapers axially in the direction from the proximal end 21 to the distal end 22 of the membrane structure 2. In this way, a part of the membrane structure 2 is given a certain taper, or the whole of the membrane structure 2 assumes a hollow structure of a truncated cone shape.

When incompressible fluid moves in a pipe, the cross sections of the pipe are designed to be different in size in order to maintain the flow stability, so that the flow velocity is large at the small cross section and small at the large cross section in the pipe. According to the bernoulli equation, an increase in flow velocity is accompanied by a decrease in fluid pressure, so that the pressure is small at the small cross-section and large at the large cross-section in the tube.

Based on the above principle, in the present embodiment, since the membrane structure 2 is fixedly connected only at the proximal end 21, the membrane structure 2 can be formed to have a tapered shape such that the cross-sectional area of the membrane structure 2 at the blood inflow section is larger than the cross-sectional area of the membrane structure 2 at the blood outflow section.

Therefore, the membrane structure 2 can play the effect of a membrane valve, and after the membrane-carrying stent is released into a blood vessel, the membrane valve is opened by utilizing the scouring of blood, so that the function of the covered stent can be realized, and the difficulty in the connection process of the covered stent can be reduced. As shown in fig. 6, this embodiment is more favorable for the flow of blood from the inflow section to the outflow section, while preventing the blood from flowing back into the dissection between the membrane structure 2 and the stent body 1 and into the false lumen of the aneurysm.

For example, by providing the membrane structure 2 near the distal end 22 as a truncated cone-shaped hollow structure, when blood flows to the membrane structure 2 near the distal end 22, the blood pressure at the distal end 22 of the membrane structure 2 is lower than that at other parts of the membrane structure 2 under the influence of the cross-sectional diameter, so as to facilitate the blood flowing out from the distal end 22 of the membrane structure 2.

Or for example, the whole membrane structure 2 is configured as a truncated cone-shaped hollow structure, the blood pressure at the distal end 22 of the membrane structure 2 is lower than the blood pressure at the proximal end 21 of the membrane structure 2 when the blood flows from the proximal end 21 to the distal end 22 of the membrane structure 2 due to the influence of the cross-sectional diameter of the membrane structure 2, so that the blood flow from the proximal end 21 to the distal end 22 of the membrane structure 2 is facilitated.

In order to prevent the distal end 22 of the membrane structure 2 from leaking inwards, the taper of the cavity wall of the membrane structure 2 is controlled, so that the edge of the distal end 22 of the membrane structure 2 is close to the inner surface of the stent main body 1, and the gap between the edge of the distal end 22 of the membrane structure 2 and the aneurysm cavity is controlled. At this point, although some blood may enter the aneurysm cavity from the gap, as described above, the aneurysm is not adversely affected because the distal end 22 of the membrane structure 2 has an edge corresponding to the aneurysm outlet.

For use with a low blood pressure, the distal end 22 of the membrane structure 2 may be fixed while the proximal end 21 is fixed, and only the main body portion is not fixed, and the portion of the membrane structure 2 located between the proximal end 21 and the distal end 22 remains free on the stent body 1.

In this embodiment, the diameter of the distal end 22 of the membrane structure 2 is larger than the diameter of the stent main body 1, so that the membrane structure 2 forms a corrugated shape in the circumferential direction of the stent main body 1, and the corrugated shape is formed by leaving a margin for the material at the distal end 22 of the membrane structure 2.

When the membrane structure 2 is fixed, part of the material of the far end 22 of the membrane structure 2 protrudes into the meshes of the stent main body 1 and bends, so that wave-shaped folds are formed at the far end 22 of the membrane structure 2, thereby preventing blood from entering the interlayer between the membrane structure 2 and the stent main body 1, and thrombus can be formed at the far end 22 of the membrane structure 2 through the folds, so as to plug the interlayer between the far end 22 of the membrane structure 2 and the stent main body 1, thereby effectively preventing the blood from leaking inwards.

In the case of a stent graft in which the proximal end 21 and the distal end 22 of the membrane structure 2 are fixed at the same time, the membrane structure 2 may be disposed outside the stent body 1 such that the membrane structure 2 covers the outer surface of the stent body 1, and after the stent graft is released into a blood vessel, the membrane structure 2 is tightly attached to the blood vessel wall, thereby achieving a good healing effect on aneurysm.

Relative to conventional stent grafts: the proximal end 21 of the membrane structure 2 in the membrane-carrying stent is fixed, and the main body part is not fixed, so that the membrane-carrying stent can be processed into different shapes easily and is suitable for different aneurysms. The membrane material can be a whole piece which is complete and regular, and can also be made into other irregular shapes according to the shape and the position of the aneurysm. If the aneurysm has no bifurcation blood vessel, the membrane structure 2 of the complete sleeve can be selected, and the sleeve can cover the aneurysm neck. If the aneurysm has a bifurcated vessel, as shown in fig. 5 and 6, a portion of the membrane material may be removed, or other shapes may be used depending on the anatomical structure.

As described above, since the membrane structure 2 is fixed to the stent body 1 in such a manner that the proximal end 21 of the membrane structure 2 is fixed to the stent body 1, the membrane structure 2 can be easily made into a special shape, i.e., the membrane structure 2 is provided with the gaps 23, and the gaps 23 can adapt to the blood circulation of the branch vessels. In particular, one of the shapes of the notch 23 is shown in fig. 5, one end of the notch 23 extending through the distal end 22 of the membrane structure 2 and the other end extending to the middle of the membrane structure 2. Fig. 6 shows another shape of the notch 23, where one end of the notch 23 extends through the proximal end 21 of the membrane structure 2 and the other end extends through the distal end 22 of the membrane structure 2, which allows a better adaptation to the blood flow of the branch vessel while forming a closure of the aneurysm.

It should be noted that the notch 23 may occupy a major arc or a minor arc in the radial cross section of the membrane structure 2, and since the proximal end 21 of the membrane structure 2 is already fixed to the stent body 1, after the stent graft is released into and adapted to the blood vessel, the membrane structure 2 and the stent body 1 are in a relatively fixed state, that is, the membrane structure 2 is stabilized on the stent body 1, thereby playing a role in blocking the aneurysm opening.

In addition, the density of the mesh 11 at the position corresponding to the notch 23 on the stent body 1 can be set smaller than the density of the mesh 11 at the position corresponding to the membrane structure 2 on the stent body 1, so that the mesh 11 on the stent body 1 has enough space to allow blood to pass through, and the blood can be blocked from flowing in the branch blood vessel while the aneurysm opening is blocked.

In this embodiment, the stent body 1 may be made of, for example, nitinol, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox/Elgiloy, platinum-chromium, or other biocompatible metals as known to those skilled in the art. Preferably, the stent body 1 is made of a shape memory alloy, but alternatively, may also comprise an elastically or plastically deformable material, such as a balloon expandable material. The grid 11 structure is arranged on the support main body 1, so that the radial tension and good wall adhesion performance of the support main body 1 can be guaranteed while the metal coverage rate is reduced as much as possible. The processing technology of the bracket main body 1 can be pipe laser cutting, silk thread weaving or welding, and the bracket main body 1 is formed by heat treatment and shaping, and is of a grid structure after heat shaping. The radial force of the stent body 1 can be adjusted by adjusting the thickness of the cut tube and the diameter of the thread for braiding. The compliance of the stent body 1 can be optimized by adjusting the density of the lattice-like structure of the stent body 1.

The stent main body 1 prepared by the shape memory alloy has good compressibility, and can reduce the diameter of the stent main body 1 to enter a blood vessel with smaller diameter, so that the stent-graft can be conveniently switched between a compression state during delivery and an expansion state during release.

When the membrane-carrying stent is conveyed to reach the focus part, the self-expansion release to the shape before the non-compression can be realized. Therefore, when the vascular reconstruction is carried out, the film-carrying stent with proper length and diameter is selected to be implanted into the arterial blood vessel according to the specific condition of the hemangioma to be treated, and the step of balloon dilatation is not needed after the stent reaches the focus position, so that the operation is convenient.

Further, the stent body 1 is preferably of a woven structure, and may be woven from 8 to 256 woven filaments, for example, with 12 to 64 woven filaments being preferred.

The stent body 1 may be a straight cylindrical shape, or may be a "dumbbell shape" in which the diameters of both end portions are larger than the diameter of the middle portion. The diameters of the two end parts of the dumbbell-shaped stent main body 1 are slightly larger than the diameter of the blood vessel, and after the stent main body 1 is released by self expansion, the two end parts of the stent main body 1 are completely attached to the blood vessel wall, so that the film-carrying stent can be tightly attached to the blood vessel wall.

Specifically, the diameters of the two end parts of the stent main body 1 are 2-6 mm, and the total length is 18-42 mm.

In the present embodiment, as shown in fig. 3, the membrane structure 2 is made of a microporous membrane material 3, and specifically, the membrane structure 2 is made of a membrane material having a low surface energy, for example, expanded polytetrafluoroethylene (ePTFE) which is a polymer membrane material and is made of polytetrafluoroethylene. The material is mainly composed of a plurality of nodes and limit positions emitted by the nodes, the nodes are mutually connected through criss-cross fibers, so that the material is beneficial to cell level and transmembrane migration, has good blood compatibility and tissue compatibility, has good fatigue resistance, wear resistance and extensibility, can tolerate most of hydrolytic enzymes in a body, and can reduce the coagulation of blood through passive anticoagulation. Meanwhile, as shown in fig. 4, the micropores 31 on the ePTFE membrane material can be used for carrying out drug loading by utilizing the micropores 31 on the membrane material, and on the other hand, the material of the whole membrane-carrying stent can be reduced to a certain extent, so that the membrane-carrying stent can be more easily squeezed and conveyed. Moreover, the micropores 31 of the membrane material are important factors influencing the endothelialization of the membrane-carrying stent, and the micropores 31 with a certain size play an important role in the endothelialization process of the membrane-carrying stent.

Meanwhile, the hydrophilic coating is coated on the inner surface of the microporous membrane material 3, so that thrombus formation in the membrane-carrying stent can be effectively reduced, and a smooth blood flow channel can be formed in the membrane-carrying stent, so that the incidence rate of stenosis of a lumen of the membrane-carrying stent is reduced.

In addition, the membrane material can be selected from non-degradable high molecules which are biologically modified or carry functional drugs and polymers thereof, such as polyvinyl chloride (PU), polyethylene terephthalate (PET), tetrafluoroethylene Polymer (PTFE) and the like; or degradable high molecular materials such as polylactic acid (PLLA or DLPLA), lactic-glycolic acid copolymer (PLGA), polyglycolic acid, polyglycolide, polylactide, polycaprolactone, polyglycolic acid, and the like; or related copolymers or natural polymers such as collagen, gelatin, chitosan, fibrinogen, and the like.

Specifically, the thickness of the film material is 0.5 to 50 μm.

In particular, the connection between the membrane structure 2 and the stent body 1 may be by sewing, gluing, winding or the like.

For example, the membrane structure 2 is only fixed to the stent body 1 at the proximal end 21 by means of stitching, and the stitching thread 7 may be made of a material such as polypropylene, polyester, nylon thread, etc. The sewing segments of the membrane structure 2 may be completely sewed in the circumferential direction, or may not be completely sewed, and only fixed at individual points, that is, the sewing thread 7 may sew a part of the proximal end 21 of the membrane structure 2, or sew the whole proximal end 21 of the membrane structure 2, so as to achieve the fixing effect between the proximal end 21 of the membrane structure 2 and the stent main body 1.

Further, if the suture 7 is made of a developable material, such as gold, platinum, PtW alloy, tantalum or PtIr alloy, the suture 7 can serve to fix the proximal end 21 of the membrane structure 2 and the stent body 1 and to indicate the position of the proximal end 21 of the membrane structure 2 or the stent body 1.

For another example, the membrane structure 2 is fixedly connected to the stent main body 1 only at the proximal end 21 by means of adhesion, and the connection may be achieved by means of medical adhesive, hot melt adhesion or electrostatic spinning.

Alternatively, for example, the membrane structure 2 may be fixedly connected to the stent body 1 only at the proximal end 21 by winding, for example, the proximal end 21 of the membrane structure 2 may be made of flocculent material and wound around the stent body 1.

In operation, a certain reference substance is needed to judge whether the membrane-carrying stent reaches the lesion site, and the release state of the stent is generally observed through development. Specifically, the development marks include a first development mark 4 for displaying the stent body 1 and a second development mark 5 for displaying the film structure 2. The first developing marks 4 are used for marking the position and the total length of the stent main body 1 in a blood vessel, are distributed on the stent main body 1 along the axial direction of the stent main body 1, and can be made of gold, platinum, PtW alloy, tantalum or PtIr alloy and the like, the first developing marks 4 can be made of alloy rings wrapping the stent main body 1, or can be made of alloy wires winding the stent main body 1 by weaving, and the embodiment is not limited in particular.

The second visualization mark 5 is used for indicating the position of the membrane structure 2 in the blood vessel, and ensuring that the membrane structure 2 can cover at least the proximal end of the aneurysm, so that it can be ensured that the membrane structure 2 can block most of the blood flow from entering the aneurysm, and at the same time, the membrane structure 2 is prevented from covering the branch blood vessels as much as possible.

Specifically, the second developing marks 5 are distributed at the corresponding positions of the stent main body 1 and the membrane structure 2 along the axial direction of the stent main body 1, and can be made of gold, platinum, PtW alloy, tantalum or PtIr alloy, and the second developing marks 5 are located at the boundary position of the membrane structure 2, and indicate the accurate position of the membrane structure 2 by winding the developing wire around the stent main body 1, or wrapping one or more sections of the stent main body 1 with the developing wire, or welding the developing ring on the stent main body 1.

Further, for the film carrier formed by the special-shaped film structure 2, that is, the film carrier provided with the notch 23 on the film structure 2, the developing marks further include a third developing mark 6 for displaying the notch 23 on the film structure 2, and the third developing mark 6 is distributed at the position of the support main body 1 corresponding to the notch 23 of the film structure 2 along the axial direction of the support main body 1. The third developing mark 6 can be made of gold, platinum, PtW alloy, tantalum or PtIr alloy, etc., the third developing mark 6 is located at the boundary position of the notch 23 on the membrane structure 2, and the accurate position of the notch 23 on the membrane structure 2 is indicated by winding the developing wire around the stent main body 1, or wrapping one or more sections of the stent main body 1 by the developing wire, or welding the developing ring on the stent main body 1.

The membrane-carrying stent in the embodiment can be compatible with a micro catheter, a micro guide wire, a push rod and the like and used in a matched manner. Before implantation, firstly carrying out radiography, determining the position, size, neck range and distribution condition of the aneurysm, selecting a bracket with proper specification, loading the bracket in place by a micro catheter, slowly releasing the bracket after observing the proper position of the developing point, simultaneously paying attention to fine adjustment of the position of the bracket to partially cover the aneurysm, keeping the branch blood vessel, carrying out radiography observation on the isolation effect and the unobstructed condition of the branch blood vessel after releasing, and withdrawing the surgical instrument.

In the membrane-carrying stent of the present invention, the membrane structure 2 is fixed to the stent body 1 only at the proximal end 21, which has the following advantages:

1. compared with a metal bare stent, after the part of the stent main body 1 carries the membrane, the pressure intensity of the stent main body 1 is reduced, the whole fatigue resistance of the implant is improved, and the damage of the stent main body 1 and the rupture of the aneurysm are avoided.

2. The implant film-carrying part can adopt the stent main body 1 with lower metal coverage rate, thereby improving the compliance of the implant.

3. Compared with the full-covered stent graft, the partial-covered stent graft has the advantages that the interference to other perforator arteries is reduced, and the application range is increased (compared with the full-covered stent graft, the partial-covered stent graft has the advantages of partial covering).

4. The membranous structure 2 of the stent-graft is fixed only at the proximal end 21 and can be easily processed into different shapes to adapt to different aneurysms.

5. As shown in fig. 7, the membrane structure 2 may be processed into a truncated cone shape, which facilitates the flow of blood from the inflow section to the outflow section, and simultaneously prevents the reverse flow of blood into the interlayer between the membrane structure 2 and the stent body 1.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A membrane-bearing stent characterized in that: the method comprises the following steps:

the bracket main body is of a hollow latticed structure;

2. A membrane-carrying stent according to claim 1, wherein:

a portion or all of the membrane structure tapers axially in a direction from the proximal end to the distal end of the membrane structure.

3. A membrane-carrying stent according to claim 1, wherein:

the distal end of the membrane structure is fixed on the stent main body, and the part of the membrane structure between the proximal end and the distal end is kept in a free state on the stent main body.

4. A membrane-carrying stent according to claim 1, wherein:

the membrane structure is provided with a notch corresponding to the branch blood vessel, one end of the notch penetrates through the far end of the membrane structure, and the other end of the notch extends to the middle part of the membrane structure or penetrates through the near end of the membrane structure.

5. A membrane-carrying stent according to claim 1, wherein:

the proximal end of the membrane structure and the stent main body are sewn through a suture line, wherein the suture line sews a part or all of the proximal end of the membrane structure to fix the proximal end of the membrane structure and the stent main body, and preferably, the suture line is made of developing materials.

6. A membrane-carrying stent according to claim 1, wherein:

the proximal end of the membrane structure is bonded to the stent body by an adhesive, and/or the proximal end of the membrane structure is made of a flocculent material and is wound around the stent body to secure the proximal end of the membrane structure to the stent body.

7. A membrane-carrying stent according to claim 1, wherein:

the membrane structure is made of a microporous membrane material, and the inner surface of the microporous membrane material is coated with a hydrophilic coating.

8. A membrane-carrying stent according to claim 1, wherein:

the bracket is characterized in that a first developing mark used for displaying the bracket main body is arranged on the bracket main body, and the first developing mark is distributed on the bracket main body along the axial direction of the bracket main body.

9. A membrane-carrying stent according to claim 1, wherein:

the support main body is provided with a second developing mark used for displaying the membrane structure, and the second developing mark is distributed at the corresponding position of the support main body and the membrane structure along the axial direction of the support main body.

10. A membrane-carrying stent according to claim 4, wherein:

the bracket main body is provided with a third developing mark for displaying a notch on the membrane structure, and the third developing mark is distributed along the axial direction of the bracket main body at the corresponding position of the bracket main body and the notch.