CN111374810A

CN111374810A - Coated vascular stent with improved wall-adhering performance

Info

Publication number: CN111374810A
Application number: CN201910255852.8A
Authority: CN
Inventors: 李安伟; 孟维金; 王永胜
Original assignee: Hangzhou Weiqiang Medical Technology Co Ltd
Current assignee: Hangzhou Endonom Medtech Co Ltd
Priority date: 2018-12-29
Filing date: 2019-03-30
Publication date: 2020-07-07
Also published as: CN210301319U

Abstract

The invention provides a coated vascular stent with improved adherence performance, which comprises a coating and a main support frame arranged on the coating, and further comprises a support expansion positioning piece arranged at the near end and/or the far end of the coating, wherein after the coated vascular stent is radially extruded, the radial supporting force of the support expansion positioning piece can maintain the complete expansion of the near end and/or the far end of the coating, so that the coated vascular stent is in sealing fit with the inner wall of a blood vessel to avoid internal leakage.

Description

Coated vascular stent with improved wall-adhering performance

Technical Field

The invention relates to the technical field of implantable blood vessels, in particular to a coated vascular stent with improved adherence performance.

Background

At present, the vascular diseases can be treated by adopting minimally invasive intervention, and the method has small wound on patients, high safety and high effectiveness, so the method is determined by doctors and patients and becomes an important treatment method for the vascular diseases. The interventional therapy method is characterized in that a blood vessel stent is implanted into a diseased blood vessel section of a patient by using a conveying system, and the implanted blood vessel stent can support a blood vessel of a stenotic occlusion section or block a laceration of a blood vessel interlayer by expanding, so that the elastic retraction and the reshaping of the blood vessel are reduced, the blood flow of a lumen is kept smooth, and the effect of preventing restenosis is achieved.

The covered blood vessel stent is a blood vessel stent which is widely applied at present, and can isolate blood flow and blood vessels with pathological changes, thereby avoiding the fatal risk of blood vessel rupture. However, the existing covered stent has the defect of internal leakage, which is the phenomenon that after the covered stent is placed into a blood vessel, persistent blood flow appears outside the covered stent cavity and in the aneurysm cavity and the adjacent blood vessel cavity treated by the covered stent. The consequences of internal leakage: (1) the tumor lumen continues to enlarge, eventually promoting rupture of the aortic aneurysm or diversion to traditional surgery. (2) The thrombus in the tumor cavity is impacted into the normal blood flow to cause the embolism of the distal artery.

Endoleaks are classified into 4 types according to the source of the leakage: the inner leakage is formed because the covered blood vessel stent and the autologous blood vessel can not be tightly attached, and comprises a near end interface and a far end interface; the leakage of blood comes from the reflux of blood from collateral blood vessels, including lumbar artery, inferior mesenteric artery, sacral artery, internal iliac artery, etc.; the inner leakage is formed because the self interface of the covered blood vessel stent can not be tightly combined or the covered blood vessel stent is broken; leakage through the woven seam of the stent cover. Wherein the tectorial blood vessel stent and the autologous blood vessel can not be tightly attached to form the common reason of internal leakage: (1) vessel angulation: the constant expansion of the aneurysm, changes in arterial wall structure, and hemodynamic changes distort the blood vessels, often in the proximal neck vessels and iliac arteries of the aneurysm. When the stent anchoring site is in the proximal and distal vessel angulation regions, the vessel angulation may cause the stent to not fit snugly against the vessel after placement. Larger angulations are more prone to blood leakage. (2) Too short neck: the stent can not be tightly attached to the autologous blood vessel due to the short tumor neck at the near end is another important reason for causing the leakage of the near end. (3) Neck blood vessel morphology: the uniform thickness of the neck blood vessel at the near end is very important for the firm anchoring of the covered blood vessel bracket. (4) Calcification of blood vessels: calcification is a common pathological change of aneurysms, and when calcified plaques are located in anchoring areas of a stent of a covered blood vessel, the stent cannot be tightly attached to an autologous blood vessel. (5) The diameter of the covered vessel stent is selected wrongly: endoleaks can result when the stent diameter is selected to be too small at the proximal and distal anchoring sites. (6) And (3) plastic molding of the covered vascular stent: remodeling within a certain period of time after the placement of the covered vessel stent is an important factor for the occurrence of secondary endoleaks. Poor stability after the covered stent is placed due to insufficient anchoring parts of the covered stent is a main reason for internal leakage after plastic molding. The above factors often coexist. The current internal leakage treatment method generally adopts balloon dilatation or stent-attached blood vessel; however, the current treatment method still cannot completely eliminate the inner leakage.

Disclosure of Invention

The invention aims to provide a covered vessel stent which can improve the adherence performance to eliminate internal leakage.

In order to solve the technical problems, the invention provides a covered stent with improved adherence performance, which comprises a covering membrane, a main body support frame arranged on the covering membrane, and a support expansion positioning piece arranged at the near end and/or the far end of the covering membrane, wherein after the covered stent is radially extruded, the radial supporting force of the support expansion positioning piece can maintain the complete expansion of the near end and/or the far end of the covering membrane.

The stent graft provided by the invention is characterized in that the expansion positioning piece is arranged at the near end and/or the far end of the stent graft, and the expansion positioning piece has radial supporting force. Therefore, after the covered stent is expanded in an implanted blood vessel, the radial supporting force of the expanding positioning piece can expand the near end and/or the far end of the covered stent to be attached to the inner wall of the blood vessel so as to maintain the close attachment of the near end and/or the far end of the covered stent and the inner wall of the blood vessel, so that no gap exists between the covered stent and the inner wall of the blood vessel, and internal leakage is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a structural schematic diagram of a covered stent according to a first embodiment of the present invention.

Fig. 2 is an enlarged view of a portion II in fig. 1.

Fig. 3 is a structural schematic diagram of a covered stent according to a second embodiment of the invention.

Fig. 4 is a structural schematic diagram of a covered stent according to a third embodiment of the invention.

Fig. 5 is an enlarged view of a portion V in fig. 4.

Fig. 6 is an enlarged view of a VI portion in fig. 4.

Fig. 7 is a structural schematic diagram of a covered stent according to a fourth embodiment of the invention.

Fig. 8 is an enlarged view of a portion VIII in fig. 7.

Fig. 9 is a schematic structural diagram of a stent graft according to a fifth embodiment of the present invention.

Fig. 10 is a structural schematic view of a covered stent according to a sixth embodiment of the invention.

Fig. 11 is a structural schematic view of a stent graft according to a seventh embodiment of the present invention.

Fig. 12 is an enlarged view of XII in fig. 11.

Fig. 13 is a structural schematic view of a covered stent according to an eighth embodiment of the invention.

Fig. 14 is an enlarged view of the XIV portion in fig. 13.

Fig. 15 is a structural schematic view of a covered stent according to a ninth embodiment of the invention.

Fig. 16 is an enlarged view of a portion XVI in fig. 15.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

Furthermore, the following description of the various embodiments refers to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. Directional phrases used in this disclosure, such as, for example, "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "side," and the like, refer only to the orientation of the appended drawings and are, therefore, used herein for better and clearer illustration and understanding of the invention, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

In the description of the present invention, the "proximal end" of the present invention refers to the end near the heart site, and the "distal end" refers to the end away from the heart site. The high and low values in the present invention are defined as the end surface beyond the coating film is referred to as high and the end surface not beyond the coating film is referred to as low, and this definition is for convenience of description and should not be construed as limiting the present invention.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural view of a covered stent according to a first embodiment of the present invention; fig. 2 is an enlarged view of a portion II in fig. 1. The invention provides a coated blood vessel stent 100 with improved adherence performance, which comprises a tubular coated membrane 20, a main body support frame 40 arranged on the coated membrane 20, and a support expansion positioning part 60 arranged at the near end and/or the far end of the coated membrane 20. After the covered stent graft 100 is implanted into a blood vessel, namely, the covered stent graft 100 is radially extruded by expansion, the radial supporting force of the expanding positioning piece 60 can maintain the near end and/or the far end of the covered membrane 20 to be completely expanded, so that the covered membrane 20 is tightly attached to the inner wall of the blood vessel to avoid internal leakage. In this embodiment, the radial support force of the expanding positioning member 60 can maintain the proximal end and/or the distal end of the covering membrane 20 in a complete circular ring structure.

The expanding positioning piece 60 is a self-expanding annular positioning frame which can be radially expanded, and the coating 20 is fixed on the annular positioning frame. The annular spacer may be disposed at a proximal end and/or a distal end of the cover 20, the proximal end and/or the distal end of the cover 20 being secured to an outer surface and/or an inner surface of the annular spacer. In this embodiment, the expanding positioning member 60 is disposed at the proximal end of the covering membrane 20, and the proximal end surface of the covering membrane 20 extends to the expanding positioning member 60, that is, at least a portion of the proximal end of the covering membrane 20 overlaps with the expanding positioning member 60. Preferably, the proximal face of the cover 20 is flush with the proximal face of the expansion locator 60. Under the state that the covered stent 100 is unfolded, the radial supporting force of the expanding positioning piece 60 expands the covered membrane 20 to be attached to the inner wall of the blood vessel, so that the covered membrane 20 and the inner wall of the blood vessel are sealed to prevent internal leakage.

In other embodiments, the proximal end surface of the covering film 20 may be higher than the proximal end surface of the expanding positioning member 60, and the covering film 20 higher than the proximal end surface of the expanding positioning member 60 is turned inward or outward and then connected to the expanding positioning member 60.

According to the stent graft 100 provided by the invention, the expansion positioning piece 60 is arranged at the proximal end and/or the distal end of the stent graft 20, and the expansion positioning piece 60 has radial supporting force. Therefore, after the stent graft 100 is deployed in an implanted blood vessel, the radial supporting force of the expanding positioning member 60 can expand the proximal end and/or the distal end of the stent graft 20 to be attached to the inner wall of the blood vessel, so as to maintain the sealing attachment between the proximal end and/or the distal end of the stent graft 20 and the inner wall of the blood vessel, thereby avoiding inner leakage due to no gap between the stent graft 20 and the inner wall of the blood vessel.

The shape of the transverse end face of the covering membrane 20 is circular or oval matched with the blood vessel, and the covering membrane 20 is made of polyester fabric, polytetrafluoroethylene, polyester fiber or other medical high polymer materials.

The main body support frame 40 is a self-expanding support frame, the support frame may be an elastic metal support frame or an elastic nonmetal support frame such as an elastic ring or a polymer material, and the main body support frame 40 may also be restored to its original shape by mechanical expansion, for example, by balloon expansion. In this embodiment, the support frame is a nitinol stent, and when the support frame is delivered through a sheath, the diameter of the support frame may be contracted to a smaller state for delivery through the sheath; when the main body support 40 is released in the diseased vessel, the main body support 40 can automatically expand to the required shape and size, so that the main body support 40 can be supported on the inner wall of the diseased vessel, and the main body support 40 can radially support the inner wall of the vessel. In this embodiment, the main body support frame 40 is a bare support frame woven by metal wires.

The main body support frame 40 may be a radially compressed grid structure, a rod structure, a frame structure or a flexible foldable structure, or may be formed by cutting a metal tube into a grid or frame structure. The metal wire can be nickel-titanium alloy, cobalt-chromium alloy, stainless steel or other metal materials with good biocompatibility, preferably a superelastic shape memory alloy nickel-titanium wire, and the manufacturing process of the metal wire is the same as that of a traditional stent, and is not repeated herein.

As shown in fig. 1, the main body support frame 40 includes a plurality of Z-shaped or sine-wave shaped waveform support rods 42, the waveform support rods 42 are sewn by medical suture or attached to the inner surface or the outer surface of the covering membrane 20 by medical glue, or fixed between two layers of covering membranes 20 by hot pressing, and the waveform support rods 42 are arranged at intervals along the axial direction of the main body support frame 40. Each of the wave-shaped support rods 42 may be an equal-wave support rod or a high-low wave support rod, and the equal-wave support rods refer to that the heights of the wave crests and the heights of the wave troughs on the wave-shaped support rods 42 are the same, that is, the wave crests and the wave troughs are respectively on the same plane. The high-low wave supporting rods mean that the heights of all wave crests on the wave-shaped supporting rods 42 are different, and the heights of all wave troughs can also be different.

In this embodiment, the main body support frame 40 is formed by axially arranging a plurality of equal-wave support rods at intervals, the wave-shaped support rods 42 are woven by nickel-titanium wires with the diameter of 0.5mm, the number of the sine waves can be any number, and the vertical height of the wave-shaped support rods 42 can be any height. Each of the corrugated support rods 42 is sewn to the cover film 20 by a suture, which may follow the corrugated course of each of the corrugated support rods 42 along the entire body support 40, preferably a polymer suture, which may be a PTFE or PET suture.

Each of the wave-shaped supporting rods 42 is composed of a plurality of supporting units connected end to end, each of the supporting units includes a peak 421, a valley 423, and a wave rod 425 connected between the peak 421 and the valley 423. Each waveform supporting rod 42 can be formed by bending a super-elastic nickel-titanium wire, a connecting sleeve is arranged on each waveform supporting rod 42, the two opposite ends of the waveform supporting rod 42 are connected by the connecting sleeve, namely, the two opposite ends of the waveform supporting rod 42 are contained in the connecting sleeve, and then the two ends of the nickel-titanium wire are fixed in the connecting sleeve by mechanical pressing or welding.

In the present embodiment, the peak 421 between two adjacent waveform supporting rods 42 corresponds to the peak 421, and the valley 423 corresponds to the valley 423.

In other embodiments, the wave-shaped support rods 42 may be high and low wave support rods.

The expanding positioning element 60 in this embodiment is an annular woven mesh 62, the annular woven mesh 62 is disposed at the proximal end of the covering film 20, and the annular woven mesh 62 is woven by mutually interlaced warp yarn 621 and weft yarn 623; the annular knitted net 62 is knitted by memory alloy wires having elasticity, that is, the warp wires 621 and the weft wires 623 are knitted by memory alloy wires having elasticity. The annular knitted mesh 62 includes a proximal end surface 625 and a distal end surface 626, the cover 20 is fixed to the annular knitted mesh 62, and the proximal end surface of the cover 20 is located between the proximal end surface 625 and the distal end surface 626 of the annular knitted mesh 62. The annular mesh grid 62 may be woven by one elastic memory alloy wire, or may be woven by a plurality of elastic memory alloy wires, and the memory alloy wire is preferably a nickel-titanium wire. The wire diameter of the nickel-titanium wire is less than 0.1 mm.

The weaving mesh of the annular weaving net 62 can be in other shapes such as diamond, rectangle or polygon.

The annular woven mesh 62 can be connected to the inner surface or the outer surface of the covering membrane 20 by sewing, hot pressing or gluing, so that the annular woven mesh 62 and the covering membrane 20 can be tightly fixed.

In other embodiments, the proximal face of the cover membrane 20 may be flush with the proximal face of the annular mesh grid 62.

In other embodiments, the proximal end surface of the covering membrane 20 may be higher than the proximal end surface of the annular mesh grid 62, and the covering membrane 20 higher than the proximal end surface of the annular mesh grid 62 may be connected to the annular mesh grid 62 after being turned inward or outward.

In other embodiments, the proximal edge and/or the distal edge of the annular mesh grid 62 are provided with developing marks, which may be developing members such as developing filaments continuously or intermittently wound around the proximal edge and/or the distal edge of the annular mesh grid 62, or dot-type developing marks continuously or intermittently provided on the proximal edge and/or the distal edge of the annular mesh grid 62; the developing member material can be made of materials with good X-ray impermeability, strong corrosion resistance and good biocompatibility, and includes, but is not limited to, materials such as gold, platinum, tantalum, osmium, rhenium, tungsten, iridium, rhodium and the like or alloys or composites of these metals.

In other embodiments, the cover film 20 is provided with visualization marks on either the proximal or distal edges.

Referring to fig. 3, fig. 3 is a schematic structural view of a covered stent according to a second embodiment of the present invention. The structure of the stent graft provided by the second embodiment of the present invention is similar to that of the first embodiment, except that: in the second embodiment, the proximal end and the distal end of the covering membrane 20 are provided with the expanding positioning members 60, specifically, the proximal end and the distal end of the covering membrane 20 are respectively provided with the annular woven meshes 62, the proximal end of the covering membrane 20 is connected to the annular woven mesh 62 at the proximal end of the covering membrane 20, and the distal end of the covering membrane 20 is connected to the annular woven mesh 62 at the distal end of the covering membrane 20. The proximal face of the cover 20 is located between the proximal face 625 and the distal face 626 of the proximal annular mesh 62, preferably the proximal face of the cover 20 is flush with the proximal face 625 of the proximal annular mesh 62; the distal surface of the cover 20 is located between the proximal and

distal surfaces

625, 626 of the distal annular woven mesh 62, and preferably the distal surface of the cover 20 is flush with the distal surface 626 of the distal annular woven mesh 62.

In other embodiments, the proximal edge and/or the distal edge of the looped mesh grid 62 at the proximal end of the cover 20 is provided with visualization indicia; the proximal and/or distal edges of the looped woven mesh 62 at the distal end of the cover 20 may also be provided with visualization indicia.

Referring to fig. 4 to 6, a structure of a stent graft according to a third embodiment of the present invention is similar to that of the first embodiment, except that: in the third embodiment, the expanding positioning member 60 further includes an annular waveform expanding rod 65, the annular waveform expanding rod 65 includes a plurality of supporting units in a Z-shape or a sine waveform, which are connected end to end, and each of the supporting units includes a wave peak 651, a wave valley 653, and a wave rod 655 connected between the wave peak 651 and the wave valley 653. The annular waveform expansion rod 65 is formed by integrally cutting superelastic nickel titanium by laser. The wave trough 653 of the annular waveform expanding rod 65 is connected to the annular woven mesh 62, when the covered stent is implanted into a corresponding blood vessel and expanded, the annular waveform expanding rod 65 expands to drive the annular woven mesh 62 to expand the annular woven mesh 62 and the annular waveform expanding rod 65 together, and the covering membrane 20 is tightly attached to the inner wall of the blood vessel by the radial supporting force of the annular woven mesh 62 and the annular waveform expanding rod 65, so that the covering membrane 20 is tightly attached to the inner wall of the blood vessel in a sealing manner, and internal leakage is prevented; because the main body support frame 40, the annular woven mesh 62 and the annular waveform expansion support rod 65 have radial expansion force on the inner wall of the blood vessel after being unfolded, the covered blood vessel support can be stably positioned on the inner wall of the blood vessel, and the covered blood vessel support is prevented from displacing.

In this embodiment, the annular corrugated expansion rod 65 has 5 wave crests and wave troughs, the wall thickness of the annular corrugated expansion rod 65 is 0.4mm, and the width of the wave beam is 0.45mm, so that the annular corrugated expansion rod 65 has a greater radial support strength. The proximal edge of the ring-shaped woven mesh 62 is flush with the proximal edge of the covering membrane 20, and the valleys of the ring-shaped corrugated expansion struts 65 are connected to the proximal edge of the ring-shaped woven mesh 62. Because the annular mesh grid 62 itself has superelasticity and certain rigidity, in addition, the radial supporting force of the annular waveform expanding support rods 65 is uniformly applied to the near end of the covered membrane 20 as an intermediate through the annular mesh grid 62, so that the near end edge of the covered membrane 20 is completely attached to the vessel wall, the adherence performance of the covered stent 100 is greatly improved, and internal leakage is prevented.

As shown in fig. 5, the annular corrugated expansion bar 65 is connected to the annular mesh grid 62 by a suture of medical suture or medical glue. Specifically, the intersections of the wave troughs 653 of the annular waveform expansion rod 65 and the annular mesh grid 62 are spirally wound by a medical suture line with the wave troughs 653 as a path for one circle, and the suture line sews the covering film 20 and the annular mesh grid 62 on the sewing path together with the annular waveform expansion rod 65; or the wave troughs 653 of the annular corrugated expanding rod 65, the cover film 20 and the annular woven mesh 62 are glued into a whole by medical glue at the intersection of the wave troughs 653 of the annular corrugated expanding rod 65 and the annular woven mesh 62.

As shown in fig. 6, the annular waveform expanding rod 65 is provided with anchoring barbs 656, these anchoring barbs 656 are arranged at least one circle along the circumference of the annular waveform expanding rod 65, after the stent graft 100 is implanted, the anchoring barbs 656 can be penetrated into the inner wall of the blood vessel to further anchor the stent graft 100, and the anchoring stability is better by using the anchoring barbs 656, which can prevent the stent graft 100 from falling off.

In this embodiment, the anchoring barbs 656 are disposed on each peak 651 of the annular corrugated expanding rod 65, and two inner side surfaces of the peaks 651 opposite to each other extend an anchoring barb 656 obliquely toward the annular woven mesh 62.

In other embodiments, the wave bars 655 and/or the wave troughs 653 of the ring-shaped wave-shaped spreader bar 65 may each be provided with anchoring barbs 656.

In other embodiments, the annular corrugated expanding rods 65 and the annular mesh grid 62 may be provided with anchoring barbs.

In another embodiment, the annular mesh grid 62 and the annular corrugated expansion bar 65 may be provided together at the distal end of the cover 20. Specifically, each peak of the annular waveform expansion bar 65 is connected to the annular mesh grid 62, and the other part of the annular waveform expansion bar 65 except the peak is exposed out of the distal end surface of the cover film 20. The distal ring-shaped corrugated expansion bar 65 may also be provided with anchor barbs 656. The distal end face of the cover film 20 extends over the peaks of the distal ring-shaped undulating stent struts 65.

In other embodiments, at least one circle of development marks may be provided on the annular waveform expansion bar 65 in the circumferential direction.

Referring to fig. 7 and 8, a structure of a stent graft according to a fourth embodiment of the present invention is similar to that of the third embodiment, except that: in the fourth embodiment, the peaks 651 of the annular waveform expansion bar 65 are connected to the annular mesh grid 62 at the proximal end of the covering membrane 20, and preferably, the proximal end face 625 of the annular mesh grid 62 is flush with the peaks 651 of the annular waveform expansion bar 65. Specifically, the annular corrugated expansion struts 65 are lower than the proximal end surface of the annular mesh grid 62, that is, the annular corrugated expansion struts 65 do not expose the proximal end surface 625 of the annular mesh grid 62, so that the peaks 651 of the annular corrugated expansion struts 65 are connected to the annular mesh grid 62, and the proximal end surface of the covering membrane 20 extends over the annular mesh grid 62, preferably, the proximal end surface of the covering membrane 20 is flush with the proximal end surface of the annular mesh grid 62. In the state that the covered stent 100 is unfolded, the radial supporting force of the wave crest 651 of the annular waveform expanding rod 65 expands the annular mesh grid 62, and the proximal end of the covered membrane 20 is tightly attached to the inner wall of the blood vessel together with the annular mesh grid 62, so that the covered membrane 20 and the inner wall of the blood vessel are sealed to prevent internal leakage; the wave troughs 653 and the wave rods 655 of the annular corrugated expansion rod 65 can radially expand the coating 20, so that the coating 20 is attached to the inner wall of the blood vessel more tightly.

The annular waveform expanding rod 65 in this embodiment is also provided with an anchoring barb 656, and specifically, the anchoring barb 656 is provided at each peak 651 of the annular waveform expanding rod 65.

Referring to fig. 9, a structure of a stent graft according to a fifth embodiment of the present invention is similar to that of the third embodiment, except that: in the fifth embodiment, a branch stent 42 is connected to the distal end of the main body support frame 40, the outer diameter of the branch stent 42 is smaller than the outer diameter of the main body support frame 40, specifically, two branch stents 42 are arranged at the distal end of the main body support frame 40, and the structure of each branch stent 42 is similar to that of the main body support frame 40, that is, the branch stent comprises a tubular covering film and a plurality of Z-shaped or sine-wave shaped waveform support rods arranged on the covering film.

In other embodiments, the outer peripheral wall of the covering membrane 20 is provided with an opening, and the opening extends into the cavity of the main body support frame 40 to form an embedded branch.

Referring to fig. 10, a structure of a stent graft according to a sixth embodiment of the present invention is similar to that of the first embodiment, except that: in the sixth embodiment, the annular mesh grid 62 is provided with the anchoring barbs 627, specifically, the proximal edge of the annular mesh grid 62 is provided with a plurality of anchoring barbs 627 along the circumferential direction, and after the stent graft is implanted, the anchoring barbs 627 can pierce the inner wall of the blood vessel to further anchor the stent graft, so that the anchoring stability is better, and the stent graft is prevented from falling off.

In other embodiments, the anchoring barbs 627 may be provided at the middle or distal end of the looped mesh grid 62.

Referring to fig. 11 and 12 together, the structure of the stent graft according to the seventh embodiment of the present invention is similar to that of the third embodiment, except that: in the seventh embodiment, the annular positioning frame is a single annular positioning rod 64, and the annular positioning rod 64 is fixed to the outer surface or the inner surface of the proximal end or the distal end of the covering membrane 20. In this embodiment, the annular positioning rod 64 is fixed to the proximal end of the covering membrane 20, and the annular positioning rod 64 is made of nitinol wire with a diameter greater than 0.1 mm.

The annular positioning rod 64 is an expansion-type support ring made of elastic memory alloy, and preferably, the annular positioning rod 64 is a nickel-titanium alloy support ring. The annular positioning rod 64 may be woven from a memory alloy wire or may be integrally cut from a memory alloy wire by laser.

The annular positioning rod 64 may be connected to the covering membrane 20 by sewing, hot pressing or gluing, so that the annular positioning rod 64 and the covering membrane 20 can be tightly fixed, and the annular positioning rod 64 and the annular corrugated expanding rod 65 are also connected by sewing, hot pressing or gluing. After the covered stent 100 is implanted into a blood vessel, the annular waveform expanding rod 65 expands and expands the annular positioning rod 64 and expands the covered stent 20 through radial supporting force, so that the covered stent 20 is in sealing fit with the inner wall of the blood vessel 20 to avoid inner leakage.

In this embodiment, the annular positioning rod 64 and the annular waveform expansion rod 65 are both located at the proximal end of the covering film 20, the valleys 653 of the annular waveform expansion rod 65 are connected to the annular positioning rod 64, that is, the valleys 653 of the annular waveform expansion rod 65 are lower than the proximal end surface of the covering film 20, and the wave rods 655 and the wave peaks 651 of the annular waveform expansion rod 65 are exposed out of the proximal end surface of the covering film 20 except the valleys 653. The wave trough 653 of the annular wave-shaped expanding rod 65 is connected with the annular positioning rod 64 through a medical suture. The annular positioning rod 64 is provided with connecting arc rods 642 corresponding to the wave troughs 653 of the annular waveform expanding rod 65, the connecting arc rods 642 extend along the corresponding wave troughs 653 in a bending manner, and each wave trough 653 is connected to the corresponding connecting arc rod 642. Specifically, the annular positioning rod 64 is bent toward the distal end corresponding to each wave trough 653 of the annular expanding wave rod 65 to form an arc-shaped connecting arc rod 642, and the connecting arc rod 642 is bent along the corresponding wave trough 653. The medical suture between the wave trough 653 of the ring-shaped wave-shaped expanding rod 65 and the corresponding connecting arc rod 642 is along the wave-shaped trend of each wave trough 653 along the whole wave trough 653, and the medical suture is sutured on the corresponding covering film 20.

The annular positioning rod 64 may also be provided with an anchoring barb along its circumferential direction.

The annular positioning rod 64 is provided with the connecting arc rod 642 corresponding to the wave trough 653, so that the connecting length between the annular positioning rod 64 and the annular waveform expanding rod 65 can be increased, the connection between the annular positioning rod 64 and the annular waveform expanding rod 65 is firmer, and the annular waveform expanding rod 65 is convenient for transmitting the radial supporting force to the film 20 through the annular positioning rod 64.

In another embodiment, the distal end of the membrane 20 may be provided with an annular positioning rod 64 and an annular waveform expanding rod 65, a peak 651 of the annular waveform expanding rod 65 is connected to the annular positioning rod 64, that is, the peak 651 of the annular waveform expanding rod 65 is attached to the distal end of the membrane 20, and the annular waveform expanding rod 65 has a wave bar 655 and a wave trough 653 exposed on the distal end surface of the membrane 20 except the peak 651. The wave peak 651 of the annular waveform expanding rod 65 is connected with the annular positioning rod 64 through a medical suture. The annular positioning rod 64 is provided with a connecting arc rod corresponding to the wave peak 651 of the annular waveform expanding rod 65, the connecting arc rod extends along the corresponding wave peak 651 in a bending manner, and each wave peak 651 is connected to the corresponding connecting arc rod 642. Specifically, each peak 651 of the annular positioning rod 64 corresponding to the annular waveform expanding rod 65 is bent toward the proximal end to form an arc-shaped connecting arc rod, and the connecting arc rod is bent along the bending of the corresponding peak 651. The medical suture between the wave peak 651 of the annular waveform expanding rod 65 and the corresponding connecting arc rod follows the whole wave peak 651 along the waveform trend of each wave peak 651, and the medical suture is sutured with the corresponding covering film 20.

Referring to fig. 13 and 14 together, the structure of the stent graft according to the eighth embodiment of the present invention is similar to that of the seventh embodiment, except that: in the eighth embodiment, the peak 651 of the annular waveform dilating rod 65 is connected to the annular positioning rod 64 at the proximal end of the graft 20. Specifically, the annular positioning rod 64 and the annular waveform expansion rod 65 are both disposed at the proximal end of the membrane, the annular positioning rod 64 is closer to the proximal end surface of the membrane 20 than the annular waveform expansion rod 65, the annular waveform expansion rod 65 is lower than the proximal end surface of the annular mesh grid 62, that is, the annular waveform expansion rod 65 is not exposed out of the proximal end surface 625 of the annular mesh grid 62, and the annular waveform expansion rod 65 is closer to the distal end than the annular positioning rod 64. The annular positioning rod 64 is connected with the wave crest 651 of the annular waveform expansion rod 65, when the covered stent 100 is in an unfolded state, the radial supporting force of the wave crest 651 of the annular waveform expansion rod 65 expands the annular positioning rod 64, and the radial supporting force of the annular positioning rod 64 and the radial supporting force of the annular waveform expansion rod 65 expand the proximal end of the covered membrane 20, so that the covered membrane 20 and the inner wall of the blood vessel are sealed, and inner leakage is prevented; the wave troughs 653 and the wave rods 655 of the annular corrugated expansion rod 65 can radially expand the coating 20, so that the coating 20 is sealed and attached to the inner wall of the blood vessel.

The annular positioning rod 64 is provided with a connecting arc rod 645 corresponding to the wave peaks 651 of the annular waveform expanding brace 65, the connecting arc rod 645 extends along the corresponding wave peaks 651 in a bending manner, and each wave peak 651 is connected to the corresponding connecting arc rod 645. Specifically, the annular positioning rod 64 is bent toward the proximal end corresponding to each peak 651 of the annular waveform expanding brace 65 to form an arc-shaped connecting arc rod 645, and the connecting arc rod 645 is bent along the corresponding peak 651. The medical suture between the wave peak 651 of the annular waveform expansion bar 65 and the corresponding connecting arc bar 645 is along the waveform trend of each wave peak 651 along the whole wave peak 651, and the medical suture is sutured with the corresponding covering film 20.

Referring to fig. 15 and 16 together, the structure of the stent graft according to the ninth embodiment of the present invention is similar to that of the third embodiment, except that: in the ninth embodiment, the annular positioning frame is at least one annular connecting string 68, and the annular connecting string 68 is fixed on the outer surface or the inner surface of the covering film 20. Specifically, the looped connecting cord 68 is secured to the outer or inner surface of the proximal or distal end of the cover 20. In this embodiment, the annular connecting string 68 is fixed to the proximal end of the covering film 20, and specifically, the annular connecting string 68 is connected between the valley 653 of the annular waveform expanding lever 65 and the peak 421 of the proximal-most waveform supporting lever 42.

The annular connecting string 68 is an expanded support ring made of memory alloy having elasticity, and preferably, the annular connecting string 68 is a nickel titanium alloy support ring. The annular connecting rope 68 is woven from a memory alloy wire.

The annular connecting string 68 may be connected to the film 20 by sewing, heat pressing or gluing, so that the annular connecting string 68 and the film 20 can be tightly fixed, and the connection between the annular connecting string 68 and the annular corrugated expansion bar 65 is completed by the annular connecting string 68 winding around the valleys 653 of the annular corrugated expansion bar 65. After the covered stent 100 is implanted into a blood vessel, the annular positioning rod 64 and the annular waveform expansion supporting rod 65 radially expand the annular connecting rope 68 to drive the waveform supporting rod 42 at the nearest end to radially expand the covered stent 20 together, so that the covered stent 20 is in sealing fit with the inner wall of the blood vessel to prevent internal leakage; and the main body support frame 40, the annular connecting rope 68 and the annular waveform expansion support rod 65 have radial expansion force on the inner wall of the blood vessel after being unfolded, so that the covered blood vessel support can be stably positioned on the inner wall of the blood vessel, and the covered blood vessel support is prevented from displacing.

The looped connecting cord 68 is wound at least one time around each of the valleys 653 of the looped expanding wave stay 65, and in this embodiment, the looped connecting cord 68 is wound two times around each of the valleys 653 of the looped expanding wave stay 65.

In another embodiment, the distal end of the film 20 may be provided with a ring-shaped connecting string 68 and a ring-shaped expanding brace 65, the ring-shaped connecting string 68 is wound between the peak 651 of the ring-shaped expanding brace 65 and the valley of the most distal wave-shaped support rod 42, that is, the peak 651 of the ring-shaped expanding brace 65 is attached to the distal end of the film 20, and the wave rod 655 and the valley 653 of the ring-shaped expanding brace 65, except the peak 651, are exposed out of the distal end surface of the film 20. The annular connecting string 68 is wound between the wave peak 651 of the annular wave-shaped expanding rod 65 and the wave trough of the most distal wave-shaped supporting rod 42.

In other embodiments, the winding positions of the loop-shaped connecting string 68 and the wave troughs 653/wave peaks 651 of the loop-shaped expanding brace 65, and the winding positions of the loop-shaped connecting string 68 and the wave crests/wave troughs of the wave-shaped supporting bar 42 can be knotted and fixed.

In other embodiments, the looped connecting cord 68 may be replaced with a visualization wire containing a visualization material, preferably a nickel-titanium alloy wire containing tantalum.

The foregoing is illustrative of embodiments of the present invention, and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the embodiments of the present invention and are intended to be within the scope of the present invention.

Claims

1. The utility model provides an improve tectorial membrane intravascular stent of adherence performance, its include the tectorial membrane and set up in the main part support frame of tectorial membrane, its characterized in that, tectorial membrane intravascular stent still including set up in the expansion of the near-end and/or the distal end of tectorial membrane props the setting element tectorial membrane intravascular stent receives radial extrusion back, expand the radial supporting force of propping the setting element and can maintain the near-end and/or the distal end's of tectorial membrane complete expansion.

2. The stent graft as recited in claim 1, wherein said stent graft positioning member comprises an annular positioning frame, said annular positioning frame being radially expandable, said stent graft being secured to said annular positioning frame.

3. The covered stent-graft of claim 2, wherein the annular positioning frame is an annular mesh, an annular positioning rod or at least one annular connecting string.

4. The covered stent-graft of claim 3, wherein the loop-shaped mesh, the loop-shaped positioning rod or the at least one loop-shaped connecting rope is woven from elastic memory alloy wires.

5. The covered stent-graft of claim 3, wherein the annular mesh grid, the annular positioning rods or at least the annular connecting strings are fixed on the covering membrane by means of sewing, heat pressing or gluing.

6. The stent graft as claimed in claim 3, wherein the annular woven mesh is woven from warp and weft threads which are interlaced with each other.

7. The stent graft as claimed in claim 6, wherein the woven mesh of the circular woven mesh is diamond-shaped, rectangular or polygonal.

8. The covered stent-graft according to any one of claims 3 to 7, wherein the proximal end surface of the covering membrane is positioned between the proximal end surface and the distal end surface of the annular mesh grid at the proximal end; the far end surface of the covering film is positioned between the near end surface and the far end surface of the annular weaving net at the far end.

9. The covered stent-graft according to claim 8, wherein the stent-graft positioning member further comprises an annular corrugated stent-graft, the wave trough or wave crest of the annular corrugated stent-graft is connected to the annular positioning frame by suture of medical suture or medical glue, and the annular corrugated stent-graft and the annular positioning frame radially expand the covered membrane together after being unfolded, so that the covered membrane maintains a complete circular structure at the end.

10. The stent graft as claimed in claim 9, wherein the annular wave-shaped stent struts and/or the annular positioning frame are provided with anchoring barbs.

11. The stent-graft of claim 10, wherein the annular positioning frame and the annular waveform expansion bar are both located at the proximal end of the stent-graft, and the proximal end of the annular positioning frame is connected with the wave trough or wave crest of the annular waveform expansion bar; or the annular positioning frame and the annular waveform expanding support rod are both positioned at the far end of the covering film, and the far end of the annular positioning frame is connected with the wave crest or the wave trough of the annular waveform expanding support rod.

12. The stent-graft of claim 11, wherein the peaks of the annular wave-shaped struts are flush with the proximal face of the proximal annular spacer; the wave trough of the annular waveform expanding support rod is flush with the far end surface of the annular positioning frame at the far end.

13. The stent-graft according to claim 9, wherein the annular positioning frame is provided with a connecting arc rod corresponding to the wave crest or the wave trough of the annular expanding wave strut, and the annular expanding wave strut is connected to the connecting arc rod.

14. The stent graft as recited in claim 13, wherein each connecting arc rod extends along a corresponding peak or valley, and the connecting arc rods are connected to the peak or valley.

15. The stent-graft of claim 9, wherein the annular positioning frame is wound at least one turn at the peak or the valley of the annular corrugated expansion bar.

16. The covered stent-graft of claim 3, wherein the ring-shaped woven mesh, the ring-shaped positioning rod or at least one ring-shaped connecting rope is provided with a developing mark.