CN114432001A - stent graft - Google Patents

Abstract

The invention provides a covered stent, which comprises a stent body and a covering film, wherein the covering film is arranged on the surface of the stent body, the stent body comprises a main stent part and two branch stent parts, the two branch stent parts and the main stent part are fixedly connected with the covering film and form a Y-shaped structure, the stent body comprises a plurality of annular stent sections which are sequentially arranged at intervals in the axial direction, and the main stent part comprises a near-end sealing area, a main body area and a transition area which are sequentially arranged from a near end to a far end; the outer diameter of the transition region is sequentially reduced from the near end to the far end; the body regions have the same outer diameter; the outer diameter of the proximal end of the transition region is the same as the outer diameter of the main body region; the proximal sealing zone comprises a proximal sealing stent section, the transition zone comprises a transition stent section, and the body zone comprises a body stent section; the maximum length of the wave rod of the near-end sealing support section is smaller than that of the wave rod of the main body support section; so configured, improve the compliance of tectorial membrane support to reduce interior hourglass and the risk of aversion.

Description

stent graft

This application is a divisional application with application number 202111487656.7.

technical field

The invention belongs to the technical field of medical devices, and particularly relates to a covered stent.

Background technique

Vascular interventional therapy, as a minimally invasive treatment, improves the survival probability for patients with vascular disease who cannot tolerate surgery. There are many vascular bifurcation points in the human body, and some lesions of aneurysm or dissection will involve the vascular bifurcation points and their branches. Taking the abdominal aorta as an example, the distal end of the abdominal aorta bifurcates into the iliac arteries on both sides. For cases of abdominal aortic aneurysm or dissection, conventional vascular interventional surgery will use the main stent (placed at the abdominal aorta lesion) and the branch stent (placed at the bilateral iliac artery lesion) in the lesion area to splicing in vivo. This method is more effective when the iliac artery is involved in the reconstruction of blood flow. Most of the main stents are designed with barbs, and the barbs puncture the blood vessels for anchoring. However, this treatment method requires 3 independently formed stents, which increases the operation cost, and the splicing between the stents also increases the risk of endoleak at the splicing. Risk, but also prolong the operation time, which is not good for the patient. At present, there are also a very small number of integrated stent products, but these products adopt a braided structure as a whole, with large crimping size, poor flexibility, high risk of endoleak, and long-term displacement.

Therefore, it is necessary to provide a new type of stent-graft to overcome the problems of existing stents for treating diseased areas involving vascular bifurcations and branches.

SUMMARY OF THE INVENTION

In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a stent-graft, which can improve the flexibility of the stent-graft with branches, and can also reduce the size of the pressure-grip of the stent-graft, and at the same time The risk of endoleak and long-term displacement is reduced.

In order to achieve the above object and other related objects, the present invention provides a stent-graft, including a stent body and a membrane, the membrane is arranged on the surface of the stent body, and the stent body includes a main body support part and a branch support two of the branch support parts and one of the main body support parts are fixedly connected with the covering film and form a Y-shaped structure, and the support body includes a plurality of annular support segments arranged at intervals in the axial direction;

The main body support part includes a proximal sealing area, a main body area and a transition area arranged in sequence from the proximal end to the distal end; the main body area has the same outer diameter; the outer diameter of the transition area is from the proximal end to the distal end decrease in sequence; the outer diameter of the proximal end of the transition zone is the same as the outer diameter of the main body zone;

The stent segment includes a proximal sealing stent segment, a transition stent segment, a main body stent segment and a branch stent segment; the proximal sealing region includes the proximal sealing stent segment, the transition region includes the transition stent segment, and the the body region includes the body support segment;

The maximum length of the stem of the proximal seal stent segment is less than the length of the stem of the body stent segment.

Optionally, the covered stent further includes a reinforcing rib, which is fixedly connected with the covering film, the reinforcing rib is arranged along the axial extension of the main body support part; the proximal end of the reinforcing rib is arranged on the main body In the area, the distal end of the reinforcing rib is disposed at the proximal end of the transition area, and the reinforcing rib can limit the axial retraction of the main body support portion.

Optionally, the length of the reinforcing rib is 1% to 80% of the axial length of the main body region.

Optionally, the distal end of the reinforcing rib is arranged on the wave crest of the first transition bracket segment at the proximal end of the transition area, and/or the proximal end of the reinforcing rib is arranged in the main body area. The proximal end of the first of the body stent segments.

Optionally, the proximal sealing area includes at least one heightened proximal sealing stent segment and at least one equal-height proximal sealing stent segment; the at least one heightened proximal sealing stent segment and the at least one equal-height proximal sealing stent segment. The end seal bracket segments are arranged at intervals in the axial direction of the main body bracket portion, and are aligned in the circumferential direction of the main body bracket portion; the at least one raised proximal end seal bracket segment is provided on the proximal end seal region. The most proximal end; at least one high wave trough is arranged between any two adjacent low wave troughs in the at least one heightened proximal end sealing stent segment.

Optionally, the main body support part further includes a bare segment, the bare segment includes an annular support segment, the distal end of the bare segment is fixedly connected to the covering film, and the proximal end of the bare segment extends axially upward. After the membrane is pulled out, the bare segment is configured to adhere to the vessel wall for anchoring after expansion, and a post-release structure is provided on the bare segment for cooperating with the delivery device to realize post-release of the stent-graft.

Optionally, a groove structure is provided on the bare segment, and a developing component is provided in the groove structure.

Optionally, the groove structure includes a first groove structure and a second groove structure, the length of the first groove structure is greater than the length of the second groove structure, the first groove structure and The second groove structure is arranged on different wave rods of the bare segment, and the lower edge of the first groove structure is flush with the lower edge of the second groove structure, so that the developing component The lower edge of the membrane coincides with the proximal edge of the membrane.

Optionally, the length of the first groove structure is 1.5 times to 3 times the length of the second groove structure.

Optionally, the proximal sealing area includes a heightened proximal sealing stent segment and at least one equal-height proximal sealing stent segment, and the one heightened proximal sealing stent segment and the proximal-most equal-height proximal end. The sealing bracket segments are arranged in an overlapping manner in the axial direction of the main body bracket portion, and are arranged staggered in the circumferential direction of the main body bracket portion; the at least one heightened proximal sealing bracket segment is arranged at the nearest end of the proximal sealing region. At least one high wave crest is arranged between any two adjacent short wave crests in the at least one heightened proximal sealing stent segment.

Optionally, the proximal end of the high crest of the most proximal-higher proximal-end sealing stent segment extends axially from the membrane to form a protruding segment, and the protruding segment is configured to adhere to the blood vessel wall after expansion. The protruding section is provided with a post-release structure for cooperating with the delivery device to realize post-release of the stent-graft.

Optionally, the length of the protruding section is 1.5mm˜5.0mm.

Optionally, the cross-sectional shape of the main body area is circular, the cross-sectional shape of the proximal end of the transition area is circular, and the cross-sectional shape of the distal end of the transition area is elliptical.

Optionally, the stent-graft further includes a branch binding coil configured to bind each stent segment of the branch stent part on the same side, and each stent segment of the branch stent part on the same side is composed of at least two said stents. Branch tying coils for tying.

In the above-mentioned stent-grafts, the annular stent segments are connected by a membrane to form an integrated Y-shaped stent-graft, which greatly reduces the operation cost and reduces the cost of splicing between traditional surgical stents. The risk of endoleak is also reduced while the operation time is reduced. In addition, the distal end of the stent graft of the main body "rides" on the bifurcation point of the blood vessel after the release, this fixing method conforms to the natural trend of human blood vessels, and the bifurcation point of the stent will not shift. In addition, the annular stent segments have a smaller crimping size and a smaller introduction path, and the annular stent segments are flexibly connected by a membrane, which increases the flexibility of the stent compared to the braided structure and can better connect with the human body. Tortuous vessels are matched. Furthermore, the main body stent part also includes a transition area, and the outer diameter of the transition area gradually decreases from the proximal end to the distal end, so that it can fit better with the covering film, and is more in line with the natural changes in the diameter of human blood vessels. trend to further reduce the risk of endoleak. Thirdly, the main body stent portion further includes a proximal sealing area, the proximal sealing area includes at least one heightened proximal sealing stent segment, and the at least one heightened proximal sealing stent segment enables the stent to have a better proximal end. End roundness and greater radial support force can effectively prevent type I endoleak caused by poor adhesion between the proximal end of the stent and the blood vessel. At the same time, the structural design of the first section of the proximal end to become higher can also be released after cooperation. Make the bracket release more precise and further improve the release accuracy.

In the above-mentioned stent-graft, reinforcing ribs are used to limit the retraction of the main body stent portion in the axial direction, which effectively reduces the risk of proximal displacement of the stent and makes the release position more accurate without affecting the flexibility of the stent.

In the above-mentioned stent-graft, the main body stent part further includes a bare segment or a protruding segment, and the bare segment or the protruding segment is preferably provided with a post-release structure, which can be matched with the conveyor to realize the post-release function. The rear release can effectively reduce the forward and backward jumps during the bracket release process, making the release position more accurate. At the same time, with the "straddle-type positioning" and the setting of reinforcing ribs, the positioning effect is better, and no barbs are required for the bare or protruding sections, which can anchor the stent at the proximal end without damaging the blood vessel.

In the above-mentioned stent-grafts, branch binding coils such as butterfly coils can be used to bind the branch stent parts on the same side, which can effectively avoid the problem that the stent cannot be opened due to the wire node being stuck during release, and reduces the operation time. Difficulty, further shortening the operation time

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a stent graft according to a preferred embodiment 1 of the present invention.

FIG. 2 is a partial structural schematic diagram of the bare segment of the preferred embodiment 1 of the present invention.

FIG. 3 is a schematic structural diagram of a reinforcing rib according to a preferred embodiment 1 of the present invention.

FIG. 4 is a schematic structural diagram of the bracket portion of the main body of the dental floss binding according to the first preferred embodiment of the present invention.

5 is a schematic structural diagram of a branch support portion on the same side of the branch binding coil binding in the preferred embodiment 1 of the present invention.

FIG. 6 is a schematic structural diagram of the stent graft according to the second preferred embodiment of the present invention.

Fig. 7a is a schematic structural diagram of the heightened proximal sealing stent segment according to the second preferred embodiment of the present invention.

Fig. 7b is a schematic structural diagram of a proximal sealing stent segment of equal height according to the second preferred embodiment of the present invention.

Fig. 7c is a schematic diagram of the same-height proximal sealing stent segment and the heightened proximal sealing stent segment overlapping in the axial direction and staggered in the circumferential direction according to the second preferred embodiment of the present invention.

Detailed ways

In order to make the content of the present invention clearer and easier to understand, the present invention will be further described below with reference to the accompanying drawings. Of course, the present invention is not limited to this specific embodiment, and general substitutions known to those skilled in the art are also covered within the protection scope of the present invention. The following embodiments and features in the embodiments may complement each other or be combined with each other without conflict.

The terms used in this application are for the purpose of describing particular embodiments only and are not intended to limit the application. As used in this application, the singular forms "a," "the," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should be understood that words like "a" or "an" do not denote a quantitative limitation, but rather denote that there is at least one; "a plurality" denotes a quantity of two or more. Words like "include" or "include" mean that the elements or items appearing before "including" or "including" cover the elements or items listed after "including" or "including" and their equivalents, and do not exclude other elements or objects. Next, the present invention is described in detail by using schematic diagrams, but these schematic diagrams are only for the convenience of describing the examples of the present invention in detail, and should not be regarded as a limitation of the present invention. As used herein, "proximal" refers to the end close to the heart; "distal" refers to the end close to the operator, that is, the end away from the heart; "axial" refers to the direction parallel to the axis; "radial" refers to the direction perpendicular to the axis; "circumferential" refers to the direction around the axis. As used herein, the "wave rod" refers to the stent rib, and the "wave rod length" refers to the dimension of the stent rib in the extending direction thereof.

<Example 1>

As shown in FIG. 1 , the present embodiment provides a stent-graft 100 with an integrated stent structure, that is, the stent-graft 100 is not formed by splicing a plurality of independent stents in vivo, but is fabricated in vitro A scaffold structure with branches is formed. The stent-graft 100 is suitable for the case where the lesion area of aneurysm or dissection involves the bifurcation point and its branches, including but not limited to the abdominal aorta. In the following description, the abdominal aorta and its branches are mainly involved in the lesion area as a schematic illustration, but it does not constitute a limitation of the present invention.

Specifically, the stent-graft 100 includes a stent body, and the stent body includes a main stent portion 110 and two branch stent portions 120 , and the stent-graft 100 further includes a membrane 130 . The two branch stent parts 120 and the one main body stent part 110 are both fixedly connected with the covering film 130 , so as to be integrally connected to form a Y-shaped stent covering 100 . It should be understood that the stent body and the covering film may be an integral structure or a separate structure, and a fixed connection between the stent body and the covering film can be achieved regardless of the separate body and the covering film. Herein, the two branch support parts 120 respectively constitute a branch support on the same side and a branch support on the opposite side, and for the convenience of explanation, the two branch support parts 120 are defined as a first branch support part 121 and a second branch support part 122 , the first branch support part 121 constitutes a branch support on the same side, and the second branch support part 122 constitutes a branch support on the opposite side. The outer diameter of the branch stent part 120 may be small at the proximal end and large at the distal end, or the outer diameter of the branch stent part 120 may remain unchanged.

Both the main body bracket part 110 and the branch bracket part 120 are hollow tubular structures, and the inner cavity of the main body bracket part 110 communicates with the inner cavity of the two branch bracket parts 120 . The main body support portion 110 and the branch support portion 120 both include a plurality of annular support segments (referred to as support segments) that are arranged in sequence in the axial direction, the annular support segments are of a wave-shaped structure, and the annular support segments are flexibly connected by a covering film 130, or Except for the reinforcing ribs 105 , the stent segments are only flexibly connected by the covering film 130 . Here, "flexible connection" can be understood as the annular stent segments are only fixedly connected with the covering film 130, and there is no rigid connection between any two adjacent annular stent segments in the axial direction. As shown in FIG. 1 , in a preferred case, there is no rigid connection between the annular stent segments except for the reinforcing ribs 105 , that is, the annular stent segments are only connected by the covering film 130 , and the covering film 130 is relatively soft to realize a flexible connection . It should be understood that "rigid connection" means that when the stent-graft is displaced or subjected to force, there is no relative displacement or deformation between the annular stent segments in the stent-graft; "flexible connection" means that the stent-graft produces displacement or deformation. When subjected to force, relative displacement or deformation may occur between the annular stent segments in the covered stent, and at this time, the flexibility is good.

The present application does not limit the shape of the waveform on the annular support segment, which can be a zigzag shape or an arc shape or other suitable shapes. The application does not specifically limit the metal material for making the stent body, as long as it is a medical metal material with good biocompatibility, such as 316 stainless steel, cobalt-chromium alloy or nickel-titanium alloy and other medical metal materials. The covering film 130 is a polymer soft material with good biocompatibility, which enables the stent body to form a closed cavity in the axial direction, and the covering film 130 can be arranged on the inner surface or the outer surface of the stent body.

Compared with the prior art, the stent-graft 100 of the present invention not only avoids the risk of endoleak caused by splicing multiple independent stents in the body, but also shortens the operation time and greatly reduces the operation cost. In particular, the distal end of the main body stent portion 110 is positioned on the bifurcation point of the abdominal aorta in a "riding" manner. This fixing method conforms to the natural trend of human blood vessels, and the bifurcation point of the stent graft 100 will not be displaced. , which can effectively reduce the risk of stent graft displacement. In addition, the stent-graft 100 is different from the overall braided stent structure, and the wave-shaped annular stent segment has a smaller crimping size, which means a smaller introduction path and less damage to the patient. Moreover, there is no rigid connection between the wave-shaped annular stent segments or no rigid connection except for the reinforcing ribs. Compared with the overall braided structure, the flexibility of the stent is increased, which can better match the tortuous blood vessels of the human body, and the therapeutic effect is better. it is good.

Continuing to refer to FIG. 1 , the main body stent portion 110 preferably includes a bare segment 101 , a proximal sealing area 102 and a main body area 103 arranged in sequence from the proximal end to the distal end, all of which are fixedly connected to the covering film 130 , such as suturing and suturing with the covering film 130 . / Hot melt fixed connection. Specifically, the annular stent segment includes a bare segment 101, a proximal sealing stent segment a2 and a main body stent segment a3; the bare segment 101 can also be understood to include an annular stent segment; the proximal sealing region 102 includes several proximal stent segments The specific number of the end sealing bracket segments a2 is not limited; the main body region 103 includes several main body bracket segments a3, and the specific number is also not limited. It should be understood that the coating film 130 is not covered on the bare segment 101 , and the coating film 130 is provided on both the proximal sealing region 102 and the main body region 103 . It should also be understood that the annular support segment further includes a branch support segment, and each of the branch support portions includes a branch support segment.

As shown in FIG. 2 , a bare segment 101 can be made by a cutting process. The bare segment 101 is a wavy annular stent segment. The distal end of the bare segment 101 is fixedly connected to the covering film 130 . The cover film 130 protrudes upward. The bare segment 101 is configured to adhere to the vessel wall for anchoring after expansion, so that the anchoring area at the proximal end of the stent portion 110 of the main body can be extended, and the bare segment 101 has no barbs, so that the stent can be anchored at the proximal end without being damaged. damage blood vessels. Preferably, the bare segment 101 is provided with a post-release structure for cooperating with the delivery device to realize post-release of the stent graft. The post-release can effectively reduce the forward and backward jumps during the stent release process, so that the release position is more precise and the treatment effect is better. This application does not limit the manner of post-release. In one embodiment, as shown in FIG. 2 , the post-release structure includes a hole structure 1011 , and a hole structure 1011 is provided on at least part of the crest of the bare section 101 , and the hole structure 1011 is used for matching with the conveyor to realize film coating Rear release of the stand.

Preferably, a developing member (not shown) is provided on the bare segment 101, and the developing member is made of a metal developing material, so as to identify the position and shape of the stent graft 100 according to the developing performance of the developing member under X-ray. Further, the wave bar 1012 of the bare segment 101 is provided with a groove structure, and the groove structure is used for fixing the developing component. The groove structure may include several first groove structures 1013 and several second groove structures 1014, the first groove structures 1013 may fix the first developing member, and the second groove structures 1014 may fix the second developing member. The first groove structure 1013 and the second groove structure 1014 are arranged on the surface of the wave rod 1012 of the bare section 101 , and the first groove structure 1013 and the second groove structure 1014 are arranged on different wave rods of the bare section 101 1012 on. Preferably, the surface of the wave rod 1012 of the bare segment 101 is convex, so that a groove structure is formed between the projections, thereby ensuring the strength of the bare segment 101 . The length of the first groove structure 1013 is greater than the length of the second groove structure 1014, therefore, the length of the first developing member is greater than the length of the second developing member. It should be understood that the length of the groove structure is the dimension along the extending direction of the wave rod 1012 . Preferably, the lower edge of the first groove structure 1013 is flush with the lower edge of the second groove structure 1014, so as to ensure that the lower edge of the developing component and the edge of the covering film 130 overlap, which is more convenient to identify the position and location of the proximal end of the stent graft. form. The lower edge of the groove structure refers to the distal edge of the groove structure. Optionally, the length of the second groove structure 1014 may be 1 mm˜3 mm, and the length of the first groove structure 1013 may be 2 mm˜6 mm. Further, the length of the first groove structure 1013 is 1.5 to 3 times the length of the second groove structure 1014, which ensures that the position and shape of the proximal end of the stent covering can be identified under X-rays. In this embodiment, a first groove structure 1013 is set on the opposite side of the bracket to fix the first developing member, and a second groove structure 1014 is set in other directions according to requirements to fix the second developing member, so as to be used in X-ray Identify the orientation and shape of the stent.

Referring to FIG. 1 , the proximal sealing region 102 includes at least one elevated proximal sealing stent segment 1021 and at least one equal-height proximal sealing stent segment 1022 . The depths of the troughs in the heightened proximal sealing stent segment 1021 are different, and at least one high trough is disposed between any two adjacent short troughs in the at least one heightened proximal sealing stent segment 1021 . The depths of the troughs in the iso-height proximal seal stent segments 1022 are all the same. "Depth of trough" refers to the vertical distance between adjacent peaks to troughs. At least one raised proximal sealing stent segment 1021 is disposed at the proximal-most end of the proximal sealing region 102 . The number of iso-height sealing stent segments 1022 in the proximal sealing region 102 is not limited, and can be one or more. Similarly, the number of the heightened proximal sealing stent segments 1021 may be one or more. At least one heightened proximal sealing stent segment 1021 and at least one equal-height proximal sealing stent segment 1022 are spaced apart in the axial direction of the main body bracket portion 110 and aligned in the circumferential direction of the main body bracket portion 110 .

In the embodiment shown in FIG. 1 , the number of heightened proximal sealing stent segments 1021 is 1, the number of equal-height proximal sealing stent segments 1022 is 3, one heightened proximal sealing stent segment 1021 and three The contour sealing stent segments 1022 are sequentially spaced from the proximal end to the distal end along the axial direction of the main body stent part 110 , and the heightened proximal sealing stent segments 1021 and the contour sealing stent segments 1022 are aligned in the circumferential direction of the main body stent part 110 layout. Here, "alignment" means, as shown in FIG. 1 , on a projection plane parallel to the axis of the main body stent portion, the projection of the peak of the heightened proximal sealing stent segment 1021 and the peak of the sealing stent segment 1022 of equal height The line connecting the projections is parallel to the axis of the main body support part, and similarly, the line connecting the projection of the trough of the heightened proximal seal support segment 1021 and the projection of the trough of the equal height seal support segment 1022 is parallel to the axis of the body support part. It should be understood that by adopting a combination of two heights of stent segments, the heightened and the same height, the proximal end of the stent-graft 100 can be more closely attached to the blood vessel, thereby effectively preventing the proximal end of the stent-graft 100 from being attached to the blood vessel. Type Ia endoleaks produced by not tightening.

In addition, the maximum length of the wave rod of the proximal sealing stent segment a2 is smaller than that of the main body stent segment a3. For example, the wave rod length of the proximal sealing stent segment a2 is 4 mm to 14 mm, and the wave rod length of the main body stent 16mm to 24mm. Therefore, the waveform of the proximal sealing region 102 is denser than that of the main body region 103, and the fitting effect with the blood vessel is better.

Continuing to refer to FIG. 1 , the main body area 103 includes a plurality of main body stent segments a3 arranged in sequence in the axial direction, and the number of the main body stent segments a3 is set according to the length of the lesion area. The heights of the wave crests of the main body support sections a3 constituting the main body region 103 are the same. The function of the main body region 103 is to support the blood flow channel and make the stent graft 100 adhere to the wall. Both the proximal sealing region 102 and the body region 103 are generally cylindrical in shape with the same outer diameter.

The main body stent part 110 preferably further includes a transition area 104 , and the bare section 101 , the proximal end sealing area 102 , the main body area 103 and the transition area 104 are sequentially arranged from the proximal end to the distal end, so that the main body area 103 and the branch stent part 120 are arranged in sequence from the proximal end to the distal end. A transition area 104 is provided in between. The outer diameter of the transition region 104 decreases sequentially from the proximal end to the distal end, and the outer diameter of the proximal end of the transition region 104 is the same as the outer diameter of the main body region 103 , and the main body region 103 has the same outer diameter. In addition, the annular support segment further includes a transition support segment a4, and the transition region 104 includes several transition support segments a4. Preferably, the cross-sectional shape of the main body region 103 is circular; preferably, the cross-sectional shape of the proximal end of the transition region 104 is circular, and the cross-sectional shape of the distal end of the transition region 104 is elliptical, and the long axis of the ellipse is elliptical. and the short axis decrease in turn. The number of the transition support sections a4 forming the transition area 104 is not limited, including but not limited to one transition support section a4, usually one transition support section a4 is sufficient. Therefore, in a preferred case, the proximal cross-section of the main body stent portion 110 is circular, and the distal cross-section is oval. The function of the transition area 104 is to make the transition between the main body support part 110 and the two branch support parts 120 smooth, so as to conform to the anatomical structure of human blood vessels, and the fitting effect is good. In addition, the transition area 104 adopts a variable diameter structure, which can better fit with the variable diameter section of the covering film 130, and is also more in line with the natural change trend of the diameter of the blood vessels of the human body. Therefore, compared with the traditional equal-diameter structure, the provision of the transition region 104 can make the stent-graft have better lumen retention, and effectively avoid the problem of occlusion of the branches of the stent along with the tortuosity of the blood vessel.

The stent-graft 100 preferably further includes a reinforcing rib 105 fixedly connected to the covering film 130, and the reinforcing rib 105 is configured to limit the retraction of the main body stent portion 110 in the axial direction. After the reinforcing ribs 105 are used, on the basis of retaining the compliance performance of the stent graft 100 as much as possible, the axial shortening of the stent graft 100 can be effectively prevented, and the risk of proximal displacement of the stent graft 100 can be effectively reduced. Preferably, the material of the reinforcing rib 105 is a metal material with good biodescription, including but not limited to nickel titanium, cobalt chromium alloy or 316 stainless steel.

Please refer to FIG. 3 , in conjunction with FIG. 1 , the reinforcing rib 105 is an elongated rod-shaped structure extending along the axial direction of the main body support portion 110 , and the proximal end and the distal end of the reinforcing rib 105 are fixedly connected to the covering film 130 , Such as stitching and/or hot melt joining. The proximal end of the reinforcing rib 105 is arranged on the main body region 103 , and the distal end is arranged at the proximal end of the transition region 104 to limit the axial shortening of the main body region 103 . Here, it should be understood that the reinforcing rib 105 is actually fixedly connected to the film 130, but the fixed position of the reinforcing rib 105 and the film 130 needs to ensure that the distal end of the reinforcing rib 105 is at the proximal end of the transition area 104, and the proximal end of the reinforcing rib 105 on the main body area 103 . Preferably, the proximal end of the reinforcing rib 105 is disposed on the first main body support section a3 at the proximal end of the main body area 103 , such as a crest, a wave trough or a wave crest of the first main body support section a3 at the proximal end of the main body area 103 . and the position between the troughs.

The number of reinforcing ribs 105 is preferably one to ensure the flexibility of the stent graft. Preferably, the distal end of the reinforcing rib 105 is arranged on the first transition bracket section a4 at the proximal end of the transition area 104 , and more preferably, the distal end of the reinforcing rib 105 is arranged on the first transition bracket at the proximal end of the transition area 104 . on the crest of segment a4. The present application does not specifically limit the length of the reinforcing rib 105 , and specifically determines the length of the reinforcing rib 105 according to the specification of the main body bracket portion 110 . For example, in a specific embodiment, the length of the reinforcing rib 105 is 1% to 80% of the axial length of the main body region 103 .

Further, as shown in FIG. 3 , both ends of the reinforcing rib 105 may be provided with fixing holes 1051 , and the reinforcing rib 105 is sewed and/or thermally connected to the film 130 through the fixing holes 1051 at both ends. The setting of the fixing holes 1051 can ensure that the two ends of the reinforcing rib 105 are firmly fixed to the covering film 130 and are not easily slipped off. The positioning method of the stent-graft 100 is that the stent bifurcation point "rides" on the bifurcation point of the abdominal aorta, and with the reinforcing ribs 105, it can effectively prevent the stent-graft from shortening in the tortuous abdominal aorta and ensure accurate positioning. sex. It should also be understood that, herein, the annular stent segments that bulge toward the proximal end are referred to as "peaks", and vice versa.

Referring back to FIG. 1 , the stent-graft 100 preferably further includes a dental floss 140, which is made of a soft polymer material with good biocompatibility such as PTFE, PET, or ultra-high molecular weight polyethylene. The proximal end of the dental floss 140 is fixedly connected to the membrane 130 and is used to bind each annular bracket segment of the main body bracket portion 110 to reduce the size of the bracket and facilitate the position adjustment of the bracket in vivo.

Referring to FIG. 1 , the dental floss 140 is knotted, and a plurality of main body binding coils 141 are formed at the knots. The number and positions of the main body binding coils 141 correspond to the number and positions of the annular bracket segments on the main body bracket portion 110 to be bound in a one-to-one manner. When tying, as shown in FIG. 4 , preferably the main body restraining coil 141 passes through the restraining coil 106 at the corresponding position on the stent segment, which can restrain the diameter of the main body stent portion 110 to a minimum, about 10%-20% of the nominal diameter of the stent. The binding coil 106 plays a role in limiting the position of the binding coil 141 of the main body, and the binding is more reliable and firm. The number and location of the restraint coils 106 can be set as desired. This binding structure is reliable and high strength. The structure of the restraint coil 106 is not limited, and the restraint coil 106 may be formed by additional suturing on the stent.

Referring to FIG. 1 , the stent-graft 100 may further include a branched confinement coil 150, which is made of a soft polymer material with good biocompatibility, such as PTFE, PET, or ultra-high molecular weight polyethylene. Optionally, the branch binding coil 150 is a butterfly-shaped coil, that is, an "8"-shaped coil. Wherein, each annular support segment of the first branch support portion 121 is provided with at least two branch restraint coils 150, and at least two branch restraint coils 150 of each ring support segment are preferably fixed in the same circumferential direction of the support segment, At least two branch restraint coils 150 respectively surround the stent segment from both sides. Due to the use of a mountain-turning operation, the second branch support portion 122 on the opposite side does not need to bind the branch restraint coil 150 . The operation method of "climbing the mountain" here is a well-known technique in the art, that is, it can be understood that the abdominal aorta and the bilateral iliac arteries are in an inverted Y-shaped structure, and the iliac artery on one side is using a guide wire catheter to climb the mountain. Consumables are used to establish bilateral iliac artery access, which is like turning over a mountain.

Please refer to FIG. 5 , the branch restraint coil 150 adopts the method of wrapping the first branch support part 121 on both sides, that is, two branch restraint coils 150 starting from the same point hug the first branch support part 121 ″ from both sides ”, in order to achieve the effect of binding and restraint. The structure is simple, the operation is easy, and the binding effect is reliable. By adopting this binding structure, the first branch support portion 121 can be released by pulling the binding guide wire, which can effectively avoid the failure of the support to pop open due to the wire node being stuck during release. Similarly, the branch restraint coil 150 can be used in conjunction with the restraint coil 106 (not shown in FIG. 5 ) on the bracket section of the first branch support part 121 , and the restraint coil 106 plays a role in limiting the position of the branch restraint coil 150 , and the binding is more reliable .

The size and distribution characteristics of human blood vessels vary greatly among individuals. Therefore, the size of the stent graft 100 can be selected according to the size of the blood vessels of the patient. In an exemplary embodiment, as shown in FIG. 1 , the length L1 of the main body bracket portion 110 is 30 mm˜130 mm, the diameter D1 of the main body bracket portion 110 is 16 mm˜34 mm, and the length L2 of the first branch bracket portion 121 is 20 mm˜20 mm. 80 mm, the length L3 of the second branch support part 122 is 20 mm to 80 mm, the diameter D2 of the first branch support part 121 is 8 mm to 24 mm, and the diameter D3 of the second branch support part 122 is 8 mm to 24 mm. Different from the traditional stent-graft, when the patient's iliac artery lesion has a large blood vessel diameter, the size of the branch stent portion 120 can still be adjusted according to the patient's special condition, and finally an integrated stent-graft 100 is made. That is, the sum of the diameters of the two branch support parts 120 may be greater than the diameter of the main body support part 110 , and certainly may be smaller than or equal to the diameter of the main body support part 110 .

<Example 2>

Please refer to FIG. 6 , FIG. 7 a , FIG. 7 b and FIG. 7 c , in another embodiment of the present invention, a stent-graft 100 ′ is also provided. The stent-graft 100 ′ cancels the bare segment, while the main stent The proximal end of the portion 110 is directly configured with the proximal sealing region 102', that is, the main body stent portion 110 of the stent-graft 100' of this embodiment includes the proximal sealing region 102', the main body and the zone 103 and transition zone 104. Another difference is that the relative positions of the heightened proximal sealing stent segment 121 and the equal-height proximal sealing stent segment 122 in the proximal sealing region 102' are adjusted.

Specifically, in the present embodiment, the proximal sealing region 102' includes one proximal sealing stent segment 1021 with heightened height and at least one proximal sealing stent segment 1022 of equal height. A heightened proximal sealing stent segment 1021 and a proximal sealing stent segment 1022 of the same height at the proximal end are overlapped and arranged in the axial direction of the main body bracket portion 110, and are arranged staggered in the circumferential direction of the main body bracket portion 110, so that the proximal end The proximal-most end of the sealing region 102 forms a stent segment that overlaps with heightened and equal heights. At least one high wave crest is set between any two adjacent short wave crests in the annular support segments formed by overlapping. Wherein the lower apex of the taller crest is aligned and on the same circumference as the lower apex of the short crest. Therefore, the lower vertices of the ring-shaped stent segments formed after overlapping are aligned, and the upper vertices exhibit height changes. It should also be understood that the "overlapping in the axial direction" refers to that a heightened proximal sealing stent segment 1021 and at least one proximal sealing stent segment 1022 of equal height are in the same circumferential direction; "circumferentially staggered arrangement" refers to Yes, one variable-height proximal sealing stent segment 1021 and at least one equal-height proximal sealing stent segment 1022 are staggered but not overlapped between the wave crests in the same circumferential direction, see Fig. 7c for details. In this solution, at least one heightened proximal sealing stent segment 1021 is disposed at the proximal end of the proximal sealing region 102', and at least one heightened proximal sealing stent segment 1021 is provided between any two adjacent short wave peaks. crest.

At this time, the staggered structure design of the height and the same height at the proximal end of the main body stent portion 110 can make the proximal end of the stent closely fit the blood vessel, and can effectively prevent the type Ia caused by the loose fitting between the proximal end of the stent and the blood vessel. At the same time, it can also make the stent have better roundness at the proximal end and greater radial support force, which can effectively prevent the type I endoleak caused by the poor adhesion between the proximal end of the stent and the blood vessel. The structural design of the heightened head section can also be matched with the rear release to make the stent release accurately.

As shown in FIG. 6 , the protruding section is formed by the proximal end of the high crest of the proximal-most heightened proximal sealing stent segment 1021 protruding from the covering film 130 in the axial direction to form a protruding section, at this time, the length of the protruding section is preferably 1.5 mm ~5mm, the number of high peaks in the heightened proximal sealing stent segment 1021 is about 3-6, and a hole structure can be set on the high peak to cooperate with the conveyor to achieve the function of post-release, which can effectively reduce the stent release process. The forward and backward jumps make the release position more accurate. And this structure is convenient to use with the cylindrical support (CUFF). Use with regular CUFF to increase the length of the treatment area. When used in conjunction with various fenestrated CUFFs, fenestrated CUFF can reconstruct the blood flow channels of branch vessels in the proximal visceral region. The usage and size are very flexible.

The rest of the structure of the stent graft 100' shown in this embodiment is basically the same as the structure of the stent graft 100 in the first embodiment, and the same parts will not be described in detail. For details, refer to the above-mentioned first embodiment.

It should be understood that after the stent-graft of the present invention is released, the bifurcation point of the stent-graft coincides with the bifurcation point of the human iliac artery, that is, the distal end of the stent part of the stent body rides on the bifurcation point of the iliac artery. This fixation method conforms to the natural trend of human blood vessels, and the stent bifurcation point will not be displaced. Especially when the reinforcing ribs are used, the distal end of the reinforcing ribs is set at the proximal end of the transition area, which effectively reduces the risk of stent shortening and proximal displacement. . At the same time, the barb-free design of the bare segment or the extended segment avoids the damage of the barb to the blood vessel on the one hand, and on the other hand extends the anchoring area of the proximal end of the stent, thereby broadening the scope of use of the stent, and also enabling the proximal end of the stent to Well anchored to blood vessels. In addition, the special structural design of the proximal sealing area and the transition area can make the main body stent fit closely with the blood vessel, which greatly reduces the risk of type Ia endoleak. Since the distal end of the human abdominal aorta bifurcates into the iliac arteries on both sides, the stent-graft of the present invention is particularly suitable for the abdominal aorta, and at the same time, the risk of endoleak and long-term displacement of the present application is low, effectively making up for the existing There are disadvantages of stent grafts.

The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by those of ordinary skill in the field of the present invention based on the above disclosure all belong to the protection scope of the present invention.

Claims (10)

1. A covered stent is characterized in that the covered stent is of an integrated stent structure and comprises a stent body, reinforcing ribs and a covered membrane; the covering film is arranged on the surface of the stent body; the bracket body comprises a main bracket part and a branch bracket part; the two branch support parts and the main body support part are fixedly connected with the film and integrally connected to form a Y-shaped structure; and the bifurcation point of the stent graft is used for adapting to the vessel bifurcation point so that the stent graft can straddle the vessel bifurcation point;

the bracket body comprises a plurality of annular bracket sections which are sequentially arranged at intervals in the axial direction;

the main body support part comprises a near end sealing area, a main body area and a transition area which are sequentially arranged from a near end to a far end; the body regions have the same outer diameter; the outer diameter of the transition area is sequentially reduced from the near end to the far end; the outer diameter of the proximal end of the transition region is the same as the outer diameter of the body region;

the bracket section comprises a near-end sealing bracket section, a transition bracket section, a main bracket section and a branch bracket section; the proximal sealing zone comprises the proximal sealing stent segment, the transition zone comprises the transition stent segment, and the body zone comprises the body stent segment;

the maximum length of the wave bars of the proximal seal carrier section is less than the length of the wave bars of the main body carrier section.

The number of the reinforcing ribs is one, the reinforcing ribs are fixedly connected with the film, and the reinforcing ribs extend along the axial direction of the main body support part; the near end of strengthening rib set up in on the main part district, the distal end of strengthening rib set up in the near end of transition district, the strengthening rib can restrict main part support portion is upwards retracted in the axial.

2. The stent-graft of claim 1, wherein the length of the ribs is between 1% and 80% of the axial length of the body region.

3. The stent graft of claim 1, wherein the distal ends of said ribs are disposed on the peaks of a first of said transition stent segments proximal to said transition region and/or the proximal ends of said ribs are disposed on a first of said main stent segments proximal to said main body region.

4. The stent-graft of claim 1, wherein the proximal seal zone comprises at least one high proximal seal stent segment and at least one contoured proximal seal stent segment; the at least one high-proximal end sealing support section and the at least one high-proximal end sealing support section are arranged at intervals in the axial direction of the main body support part and are arranged in an aligned mode in the circumferential direction of the main body support part; said at least one heightened proximal seal holder section is disposed at a proximal-most end of said proximal seal zone; at least one high wave trough is arranged between any two adjacent low wave troughs in the at least one high-proximal sealing bracket section.

5. The stent graft of claim 4, wherein the main body stent portion further comprises a bare section, the bare section comprises an annular stent section, the distal end of the bare section is fixedly connected with the stent graft, the proximal end of the bare section axially extends out of the stent graft, the bare section is configured to be expanded and then attached to a vessel wall for anchoring, and a rear release structure is disposed on the bare section for cooperating with a delivery device to effect rear release of the stent graft.

6. The stent graft of claim 5, wherein the bare segment has a groove structure disposed thereon, the groove structure having a development component disposed therein; the groove structure comprises a first groove structure and a second groove structure, the length of the first groove structure is larger than that of the second groove structure, the first groove structure and the second groove structure are arranged on different wave bars of the naked section, and the lower edge of the first groove structure is flush with the lower edge of the second groove structure, so that the lower edge of the developing component is coincident with the near-end edge of the film.

7. The stent graft of claim 6, wherein the length of the first groove structure is between 1.5 and 3 times the length of the second groove structure.

8. The stent graft of claim 1, wherein the cross-sectional shape of the body region is circular, the cross-sectional shape of the proximal end of the transition region is circular, and the cross-sectional shape of the distal end of the transition region is elliptical.

9. The stent-graft of claim 1, further comprising a branch tie coil configured for tying each stent segment of the branch stent portions on the same side, each stent segment of the branch stent portions on the same side being tied by at least two of the branch tie coils.

10. The stent-graft of claim 1, wherein the length of the branch stent part is 20mm to 80mm, and/or the outer diameter of the branch stent part is small at the proximal end and large at the distal end.

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