CN110420074B

CN110420074B - Covered stent

Info

Publication number: CN110420074B
Application number: CN201910569085.8A
Authority: CN
Inventors: 肖本好; 刘彩萍
Original assignee: Shenzhen Xianjian Changtong Medical Co ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2019-06-27
Filing date: 2019-06-27
Publication date: 2022-04-05
Anticipated expiration: 2039-06-27
Also published as: CN110420074A

Abstract

The invention discloses a covered stent, which comprises a hollow tubular main body and a window arranged on the side wall of the tubular main body, wherein an elastic supporting piece is arranged on the periphery of the window, a developing piece is arranged on the elastic supporting piece, and at least one part of the developing piece is movably connected with the elastic supporting piece. The invention has the following effective effects: because the developing part and the elastic supporting part are both positioned at the periphery of the window, the developing part and the elastic supporting part can ensure that the periphery of the window has good developing property and supporting property at the same time.

Description

Covered stent

Technical Field

The invention relates to the technical field of interventional medical instruments, in particular to a covered stent.

Background

In more than ten years, aorta covered stent endoluminal isolation has been widely applied to lesions such as thoracic and abdominal aortic aneurysms and arterial dissections, has definite curative effect, small wound, quick recovery and few complications, and becomes a first-line treatment method. During operation, under the X-ray fluoroscopy monitoring, the covered stent is conveyed to the pathological change position through the corresponding conveying system, the covered stent isolates blood flow from the pathological change position, and the influence of blood pressure on the pathological change position is eliminated, so that the purpose of curing is achieved. Due to the complex structure of the blood vessels of the human body and the more arterial branch blood vessels, the use of the covered stent can influence the blood supply of the arterial branch blood vessels for special diseased parts such as the aortic arch part, the celiac trunk, the bilateral renal arteries or the superior mesenteric artery and the like. In response to this situation, it is necessary to provide a desired hole in the stent graft and establish a guide wire track from the hole of the stent graft to the arterial branch vessel, which requires good visualization and support of the edge of the hole to ensure that the guide wire can pass through the hole smoothly, thereby establishing the guide wire track.

However, the existing covered stent generally has 4 developing points arranged at the edge of the hole, i.e. one each of the developing points is arranged up, down, left and right, and the developing points are less distributed, so that the position of the edge of the hole is not easy to accurately judge when a guide wire track is established, the guide wire cannot pass through the hole smoothly, and the operation time is prolonged.

Disclosure of Invention

The present invention is directed to provide a stent graft, which addresses the above-mentioned shortcomings in the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the utility model provides a covered stent, includes hollow tubular main part, and sets up window on the lateral wall of tubular main part, the periphery of window is provided with elastic support spare, be provided with the development piece on the elastic support spare, at least a part of development piece with elastic support spare swing joint.

In the stent graft of the present invention, the developing member is spirally wound around the outer surface of the elastic support member.

In the covered stent, the developing part comprises a plurality of spiral units wound on the elastic supporting part, each spiral unit comprises two connected connecting parts, and an included angle between a tangent line corresponding to the intersection point of each connecting part and the elastic supporting part and a central line of each connecting part is 75-90 degrees.

In the stent graft of the present invention, the elastic support member has an open loop structure, and in a natural state, both end portions of the elastic support member at least partially overlap.

In the stent graft of the present invention, the overlapping portion of the both end portions of the elastic support member is located in the middle region of the elastic support member.

In the covered stent, the elastic supporting piece and the developing piece are coated with the wrapping pieces.

In the stent graft of the present invention, a spacer is provided between the elastic support member and the stent graft.

In the covered film bracket, the elastic supporting piece is provided with an installation groove, and the developing piece is movably connected in the installation groove; or, the development piece includes a plurality of annular development units that are, development unit mobilizable cover is in outside the elastic support piece.

In the stent graft of the present invention, the developing member includes at least one developing section, and the developing section includes a movable portion movably connected to the elastic support member, and a fixed portion fixedly connected to the elastic support member, the fixed portion being located outside a proximal end region and a distal end region of the elastic support member.

In the stent graft provided by the invention, the developing part comprises two developing sections, the two developing sections are symmetrically arranged along a connecting line of the near end and the far end of the elastic supporting part, the developing sections are spirally wound on the outer surface of the elastic supporting part, and the developing sections are wholly positioned outside the near end area and the far end area of the elastic supporting part.

In summary, the stent graft of the present invention has the following effects: because the developing part and the elastic supporting part are both positioned at the periphery of the window, the developing part and the elastic supporting part can ensure that the periphery of the window has good developing property and supporting property at the same time. And, because the development piece and elastic support piece swing joint, when taking place bending deformation, development piece and elastic support piece can move relatively, make development piece remove from the big region of elastic support piece's deflection, avoid development piece to take place obvious bending.

Drawings

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

FIG. 1 is a schematic view of a stent graft provided in accordance with one embodiment of the present invention;

FIG. 2 is a schematic view of the development member and the resilient support member around the window of the stent graft of FIG. 1;

FIG. 3 is a schematic view of the resilient support member of FIG. 2 in an open loop configuration;

FIGS. 4a and 4b are schematic views of a spiral unit of the developing device shown in FIG. 2;

FIGS. 5a and 5b are comparative views of the spiral unit of the developing member shown in FIG. 2;

FIG. 6 is a schematic view of the resilient support of FIG. 2 in a closed loop configuration;

FIG. 7a is a schematic view of the end of the resilient support of FIG. 2 provided with a spherical portion;

FIG. 7b is a schematic view of the end of the resilient support of FIG. 2 provided with a ring-like structure;

FIG. 8 is a schematic view of the developing member and the elastic supporting member around the window of the film-coating support according to the second embodiment of the present invention;

FIG. 9 is a schematic view of a developing member and an elastic supporting member around a window of a film frame according to a third embodiment of the present invention;

FIG. 10 is a schematic view of the developing member and the elastic supporting member around the window of the film-coating support according to the fourth embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the field of interventional medicine, it is commonly defined that a stent graft is proximal at the end proximal to the heart and distal at the end distal to the heart after release.

Referring to FIG. 1, one embodiment of the present application provides a stent graft 100, which includes a hollow tubular body 10 and a window 20 disposed on a sidewall of the tubular body 10, wherein a lumen of the tubular body 10 forms a blood flow path.

The tubular body 10 includes a bare stent 101, and a covering film 102 attached to the bare stent 101. The bare stent 101 is made of a material with good biocompatibility, such as nickel titanium, stainless steel, etc. The bare stent 101 comprises a plurality of circles of wavy rings 1011, and the plurality of circles of wavy rings 1011 are sequentially arranged at intervals from the proximal end to the distal end or are connected into a grid-like structure. The covering membrane 102 is made of a polymer material with good biocompatibility, such as PTFE, FEP, PET, and the like.

Referring to fig. 1 and 2, an elastic supporting member 30 is disposed around the window 20, a developing member 40 is disposed on the elastic supporting member 30, and the developing member 40 is movably connected to the elastic supporting member 30. When the stent graft 100 is compressed into the sheath, the elastic support member 30 is radially compressed, and significant bending deformation of the elastic support member 30, particularly at the proximal and distal regions thereof, occurs. Since the developing member 40 is movably connected to the elastic supporting member 30, when the developing member 40 and the elastic supporting member 30 are bent and deformed, the developing member 40 and the elastic supporting member 30 can move relatively, so that the developing member 40 is moved away from the area with a large deformation amount of the elastic supporting member 30, and the developing member 40 is prevented from being bent significantly. Moreover, since the developing member 40 and the elastic supporting member 30 are both located at the periphery of the window 20, the developing member 40 and the elastic supporting member 30 can make the periphery of the window 20 have both good developing property and good supporting property.

The elastic support member 30 is made of a material with a large elastic modulus, such as nitinol, so that the periphery of the window 20 has good compression and rebound characteristics. The developing member 40 is made of a material having X-ray opaque property and good biocompatibility such as gold, tantalum-niobium alloy, platinum-iridium alloy, etc. to provide good developing property to the periphery of the window 20, but the elastic modulus of such a material is small, resulting in that the elastic modulus of the developing member 40 is smaller than that of the elastic support member 30. Since the elastic modulus of the developing member 40 is relatively small, when the developing member 40 is deformed, the developing member 40 is easily plastically deformed, so that the resilience of the elastic supporting member 30 connected thereto is limited, the window 20 cannot be completely opened, the size of the opening of the window 20 is reduced, and the establishment of the guide wire track is affected. Because the developing member 40 is movably connected with the elastic supporting member 30, when the developing member 40 deforms, the developing member 40 can move on the elastic supporting member 30 and move to a position where the deformation amount of the elastic supporting member 30 is small, so that the developing member 40 is prevented from being plastically deformed.

Referring to fig. 3, the elastic supporting member 30 is an open-loop structure, and when it is in a natural state, two ends of the elastic supporting member 30 are at least partially overlapped. At this time, the elastic support 30 covers the entire circumference of the window 20, and can completely support the shape of the window 20. Since the elastic supporting member 30 has an open loop structure, when elastic deformation occurs, both end portions of the elastic supporting member 30 may move relatively, facilitating radial compression and resilient deformation of the elastic supporting member 30.

Since the proximal and distal end regions of the elastic support member 30 are deformed by a large amount, if the overlapping portions of the two end portions of the elastic support member 30 are located at or near the proximal and distal end regions of the elastic support member 30, when the deformation occurs, the end portions of the elastic support member 30 easily protrude from the spiral gap of the developing section 44, thereby affecting the subsequent relative movement of the two. Therefore, in order to avoid that the relative movement between both end portions thereof is affected by the bending deformation, the overlapping portion of both end portions of the elastic support member 30 is located at the middle region of the elastic support member 30. It should be noted that the "central region of the elastic support member" herein refers to a region covered by a point of the elastic support member 30 having a vertical distance of 2mm or more from the proximal and distal ends thereof.

The elastic support 30 is oval with a major axis m generally parallel to the generatrix of the stent graft 100 and a minor axis n generally perpendicular to the generatrix of the stent graft 100. Because of the relatively small dimension of the minor axis n, the elastic support 30 is more easily radially compressed when the stent graft 100 is compressed into the sheath, and the resilience generated within the sheath is less, which also helps to reduce the resistance to release. In the embodiment, the ratio of the long axis m to the short axis n of the elastic support member 30 satisfies 3/2 ≤ m/n ≤ 3, so as to facilitate radial compression and rebound deformation of the elastic support member 30.

Referring to fig. 2 again, the developing member 40 is spirally wound on the entire outer surface of the elastic supporting member 30, the inner diameter of the spiral structure surrounded by the developing member 40 is larger than the outer diameter of the elastic supporting member 30, so that the developing member 40 is movably sleeved outside the elastic supporting member 30, and when the elastic supporting member 30 is elastically deformed, two end portions of the elastic supporting member 30 are always located in the spiral structure surrounded by the developing member 40. The diameter of the inscribed circle of the cross section of the developing wire constituting the developing member 40 is 0.1mm or more, preferably 0.1mm to 0.5mm, to ensure good developability of the developing member 40. It is understood that in other embodiments, the developing member 40 may be wound around only a portion of the outer surface of the elastic support member 30.

Referring to fig. 4a and 4b, the developing member 40 includes a plurality of spiral units 41 wound on the elastic supporting member 30, and each spiral unit 41 includes two connecting portions 410, namely a first connecting portion 410a and a second connecting portion 410 b. Wherein, the included angle between the tangent b corresponding to the intersection point of the connecting part 410 and the elastic supporting part 30 and the central line a of the connecting part 410 is alpha, and alpha is more than or equal to 75 degrees and less than or equal to 90 degrees. Referring to fig. 5a and 5b, if the included angle α between the tangent line b corresponding to the intersection point of the connection portion 410 and the elastic supporting member 30 and the center line a of the connection portion 410 is small, when the elastic supporting member 30 bends and deforms, the connection portion 410 easily bends and deforms along with the elastic supporting member 30, thereby affecting the relative movement between the developing member 40 and the elastic supporting member 30. Also, since the elastic modulus of the developing member 40 is relatively small, when deformation occurs, the developing member 40 is easily plastically deformed, affecting the rebound of the elastic supporting member 30. Therefore, in the present invention, the above-mentioned included angle α is set within a range of 75 ° to 90 °, so that the relative movement between the developing member 40 and the elastic supporting member 30 is not affected by the bending deformation, and the plastic deformation of the developing member 40 is prevented.

It should be understood that the present application is not limited to the specific structure of the elastic support 30, and in other embodiments, the elastic support 30 may also be a closed-loop structure or a circular ring structure, so long as the elastic support 30 is movably connected to the developing member 40. For example, in the embodiment shown in FIG. 6, the resilient support 30 is an elliptical closed loop structure. Alternatively, in the embodiment shown in fig. 7a and 7b, the elastic supporting member 30 is an elliptical open-loop structure, in a natural state, two ends of the elastic supporting member 30 are at least partially overlapped, two ends of the elastic supporting member 30 are provided with spherical portions 31 or ring structures 32, and the developing member 40 is spirally wound on an outer surface of the elastic supporting member 30. The radial dimension of the spherical portion 31 and the annular structure 32 is larger than the gap between two adjacent first connecting portions 410a (or second connecting portions 410b), so as to prevent the end of the elastic supporting member 30 from passing through the gap of the developing member 40 when the developing member 40 and the elastic supporting member 30 move relatively, and ensure that the two ends of the elastic supporting member 30 are always located in the spiral structure surrounded by the developing member 30.

Since the elastic supporting member 30 and the developing member 40 are made of metal material, there is a potential difference between them, if they are directly contacted with blood, electrochemical corrosion and chemical corrosion are easily generated, which results in the breakage of the elastic supporting member 30 and the developing member 40, and the broken elastic supporting member 30 or the developing member 40 entering into the body circulation can cause serious injury to the patient. Therefore, in assembly, the elastic support member 30 to which the developing member 40 is attached may be put into a hollow wrapping member (not shown), and then the wrapping member may be fixed to the periphery of the window 20.

The wrapping member is of an annular structure and is made of a high polymer material with good biocompatibility, and blood-impermeable PTFE, ePTFE and the like are preferred. The elastic supporting member 30 is movably disposed in the wrapping member, and the wrapping member does not affect the movable connection between the elastic supporting member 30 and the developing member 40. Because the wrapping piece is wrapped outside the elastic supporting piece 30 and the developing piece 40, even if the elastic supporting piece 30 or the developing piece 40 is broken, the broken structure cannot enter the human body to cause injury to the patient.

In actual manufacturing, after the window 20 is opened on the covering film 102, the elastic supporting member 30 connected with the developing member 40 is placed on the periphery of the window 20, then the covering film 102 on the periphery of the window 20 is turned over toward one side of the elastic supporting member 30, the elastic supporting member 30 is wrapped in the covering film 102, and finally the covering films 102 on the inner side and the outer side of the elastic supporting member 30 are fixedly connected. That is, the wrapping member of the present embodiment is formed by folding back the coating film 102 around the window 20. It should be understood that the present embodiment does not limit the specific structure of the wrapping member, as long as the wrapping member can wrap the elastic supporting member 30 and the developing member 40 without affecting the movable connection therebetween. For example, in other embodiments, the wrapper and the cover 102 are separate pieces, and the wrapper is secured to the periphery of the window 20 by stitching.

Further, since the developing member 40 is movably wound around the elastic supporting member 30, when the developing member 40 and the elastic supporting member 30 are relatively moved, the elastic supporting member 30 or the developing member 40 is easily broken due to a friction force between the developing member 40 and the elastic supporting member 30. Therefore, a spacer (not shown) is disposed between the elastic support 30 and the developing member 40, and the spacer is made of a material having good biocompatibility, such as PTFE, FEP, PET, etc. The elastic supporting member 30 is isolated from the developing member 40 by the isolating member, so that not only friction caused by direct contact between the elastic supporting member and the developing member can be avoided, but also electrochemical corrosion and chemical corrosion can be avoided.

In this embodiment, the partition is covered on the whole outer surface of the elastic supporting member 30 by sewing or heat treatment, and the developing member 40 is movably sleeved outside the partition. It is understood that the position of the spacer on the elastic supporting member 30 is not limited in this embodiment, for example, in other embodiments, the spacer may be only covered outside two ends of the elastic supporting member 30, since the elastic supporting member 30 is an open loop structure and the relative friction between the two ends is relatively large, and the spacer is covered outside the two ends of the elastic supporting member 30, the two ends of the elastic supporting member 30 can be effectively prevented from being broken.

Referring to fig. 8, a stent graft according to a second preferred embodiment of the present invention is different from the first embodiment in that an installation groove 35 is formed on an elastic supporting member 30, and a developing member 40 is movably connected in the installation groove 35.

The developing member 40 includes a plurality of first developing units 45 having a spherical shape, and the first developing units 45 can roll in the mounting groove 35. When the bending deformation occurs, the developing member 40 and the elastic supporting member 30 can move relatively, so that the developing member 40 is moved away from the region with a large deformation amount of the elastic supporting member 30, and the influence of the developing member 40 on the pressing and rebound deformation of the elastic supporting member 30 is avoided.

Referring to fig. 9, a stent graft according to a third preferred embodiment of the present application is different from the first preferred embodiment in that the developing member 40 includes a plurality of annular second developing units 46, and each of the second developing units 46 is movably sleeved on the elastic support 30. When the bending deformation occurs, the second developing unit 46 can be moved away from the region where the deformation amount of the elastic support member 30 is large, avoiding the developing member 40 from affecting the pressing and resilient deformation of the elastic support member 30.

Referring to FIG. 10, the fourth preferred embodiment of the present application provides a stent graft, which is different from the first preferred embodiment in that the developing member 40 includes two developing segments 44 arranged at intervals, and the two developing segments 44 are symmetrically arranged along a connecting line r between the proximal end and the distal end of the elastic supporting member 30 and are located outside the proximal end region and the distal end region of the elastic supporting member 30. It should be noted that the term "proximal region and distal region of the elastic support member 30" herein refers to a region covered by a point of the elastic support member 30 having a vertical distance of 0.5mm or less from the proximal end and the distal end thereof.

The developing section 44 is spirally wound on the outer surface of the elastic supporting member 30, the developing section 44 includes a movable portion 441 movably connected to the elastic supporting member 30, and a fixing portion 442 fixedly connected to the elastic supporting member 30, and the fixing portion 442 is fixed to the elastic supporting member 30 by bonding, welding, or the like. The fixed portion 442 is located at both ends of the developing stage 44, and the movable portion 441 is located between both ends of the developing stage 44.

When the deformation occurs, the movable portion 441 and the elastic supporting member 30 can move relatively, so that the movable portion 441 is moved away from the region of the elastic supporting member 30 where the deformation amount is large, and the development section 44 is prevented from being plastically deformed. Since both ends of the developing section 44 are fixed, even if the movable portion 441 and the elastic supporting member 30 move relatively, the position of the developing section 44 on the elastic supporting member 30 as a whole is not affected, that is, the position of the developing section 44 on the elastic supporting member 30 as a whole is fixed, and the window 20 can be well developed and positioned. In the present embodiment, the entire developing section 44 is located outside the proximal end region and the distal end region of the elastic support 30, so that the entire developing section 44 can avoid the region of the elastic support 30 where the deformation amount is large, and the developing section 44 can be further prevented from being plastically deformed.

It is understood that the present embodiment does not limit the specific number and location of the developing segments 44, the developing segments 44 may further include one or more, and the developing segments 44 may also be located in the proximal and distal end regions of the elastic support 30 as long as the fixing portions 442 of the developing segments 44 are located outside the proximal and distal end regions of the elastic support 30.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides a covered stent, includes hollow tubular main part, and sets up window on the lateral wall of tubular main part, the periphery of window is provided with elastic support spare, its characterized in that, be provided with the development piece on the elastic support spare, at least partly of development piece with elastic support spare swing joint, when taking place bending deformation, the development piece with elastic support spare can relative movement, makes the development piece follow the regional removal that elastic support spare's deflection is big avoids the development piece takes place obvious bending.

2. The stent graft of claim 1, wherein the visualization element is helically wound around the outer surface of the elastic support element.

3. The stent graft as recited in claim 2, wherein the developing member comprises a plurality of spiral units wound on the elastic support member, the spiral units comprise two connected connecting portions, and an included angle between a tangent line corresponding to an intersection point of the connecting portion and the elastic support member and a center line of the connecting portion is 75 ° to 90 °.

4. The stent graft as recited in claim 1, wherein the elastic support member is an open loop structure, and in a natural state, the two ends of the elastic support member at least partially overlap.

5. The stent graft of claim 3, wherein the overlapping portions of the two ends of the elastic support are located in a middle region of the elastic support.

6. The stent graft of claim 1, wherein said elastic support member and said developer member are externally coated with a wrapping member.

7. The stent graft of claim 1, wherein a spacer is disposed between the elastic support member and the development member.

8. The film covering bracket as claimed in claim 1, wherein the elastic supporting member is provided with a mounting groove, and the developing member is movably connected in the mounting groove; or, the development piece includes a plurality of annular development units that are, development unit mobilizable cover is in outside the elastic support piece.

9. The stent graft as recited in claim 1, wherein the developing member comprises at least one developing section, the developing section comprising a movable portion movably connected with the elastic support member, and a fixed portion fixedly connected with the elastic support member, the fixed portion being located outside of the proximal and distal end regions of the elastic support member.

10. The stent graft as recited in claim 9, wherein the developing member comprises two developing segments symmetrically disposed along a line connecting the proximal end and the distal end of the elastic support member, the developing segments being spirally wound around the outer surface of the elastic support member, the developing segments being entirely located outside the proximal region and the distal region of the elastic support member.