Covered stent and knotting method of covered stent

Abstract

This invention provides a laminated support structure, comprising a laminate, a first high-low wave annular support rod, a second high-low wave annular support rod, and a third high-low wave annular support rod. The laminate has a notch. The first high-low wave annular support rod is fixed to the distal end of the laminate, and includes a first high-wave unit, the crest of which protrudes beyond the distal edge of the laminate. The second high-low wave annular support rod is fixed to the proximal end of the laminate, the trough of which does not protrude beyond the proximal edge of the laminate, and the notch in the laminate is located at the end of the laminate near the second high-low wave annular support rod. The third high-low wave annular support rod is located between the first and second high-low wave annular support rods and is fixed to the laminate. This invention also provides a knotting method for the laminated support structure.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, and particularly relates to a covered stent and a knotting method for the covered stent. Background Technology

[0002] Existing covered stents have several structural design flaws. The graft, sutured onto the stent using conventional methods, often exhibits unstable fixation, leading to frequent detachment. When the covered stent is compressed, it experiences significant radial force, causing the stent's crests and / or troughs to protrude beyond the graft's edge, resulting in stent deformation and detachment. During stent release, the detached graft exposes the stent surface directly to the blood vessel wall, potentially causing secondary damage such as re-tears and bleeding, ultimately leading to surgical failure. Summary of the Invention

[0003] The present invention aims to provide a covered stent and a knotting method for the covered stent, so as to solve the technical problem of unstable fixation between the covered stent and the stent.

[0004] To address the aforementioned technical problems, the present invention provides a film-coated support structure, comprising a film, a first high-low wave annular support rod, a second high-low wave annular support rod, and a third high-low wave annular support rod. The film has a notch. The first high-low wave annular support rod is fixed to the distal end of the film, and includes a first high-waveform unit, the crest of which protrudes beyond the distal edge of the film. The second high-low wave annular support rod is fixed to the proximal end of the film, the trough of which does not protrude beyond the proximal edge of the film, and the notch is located at the end of the film near the second high-low wave annular support rod. The third high-low wave annular support rod is located between the first and second high-low wave annular support rods and is fixed to the film.

[0005] In some embodiments, the cut is formed by cutting the film along the shape of the second high-low wave annular support rod.

[0006] In some embodiments, a positioning film is provided at the trough of the second high waveform unit of the second high waveform unit, and the trough of the second high waveform unit is located between the covering film and the positioning film.

[0007] In some embodiments, the distance by which the peak of the first high-waveform unit protrudes beyond the distal edge of the coating is less than or equal to 1.5 mm.

[0008] In some embodiments, the first high-low wave annular support rod is symmetrical about the axial center line of the first high wave unit.

[0009] In some embodiments, the first high-low wave annular support rod further includes a first low wave unit, which is connected end-to-end with the first low wave unit or the first high wave unit that is circumferentially adjacent to it.

[0010] In some embodiments, the first high and low wave annular support rod is fixed to the covering film by needle and thread stitching, and the distance between each two adjacent stitching coils on the trough of the first high wave unit is less than the distance between each two adjacent stitching coils on the wave rod of the first high wave unit; the distance between each two adjacent stitching coils on the peak and trough of the first low wave unit is less than the distance between each two adjacent stitching coils on the wave rod of the first low wave unit.

[0011] In some embodiments, in the same suture loop, the distance between the center of the needle hole through which the suture enters the covering and the center of the needle hole through which the suture exits the covering is between 0.2 mm and 0.5 mm.

[0012] In some embodiments, the second high-low wave annular support rod includes a second high wave unit, wherein the distance between the trough of the second high wave unit and the proximal edge of the covering film ranges from 1.5 mm to 2 mm.

[0013] In some embodiments, the second high-low wave annular support rod further includes a plurality of second low wave units. Along the circumferential direction of the second high-low wave annular support rod, at least one second low wave unit is arranged between two adjacent second high wave units, and the second low wave units are connected end to end with the circumferentially adjacent second low wave units or second high wave units.

[0014] In some embodiments, the second high-low wave annular support rod is fixed to the covering film by needle and thread stitching, and the distance between each two adjacent stitching loops on the crest and trough of the second high wave unit and the second low wave unit is less than the distance between each two adjacent stitching loops on the wave rod of the second low wave unit.

[0015] In some embodiments, the covered support includes at least two third high-low wave annular support rods, the distance between any two adjacent third high-low wave annular support rods is in the range of 2mm to 3mm; the distance between the first high-low wave annular support rod and the adjacent third high-low wave annular support rod is in the range of 2mm to 3mm; and the distance between the second high-low wave annular support rod and the adjacent third high-low wave annular support rod is in the range of 2mm to 3mm.

[0016] In some embodiments, the third high-low wave annular support rod includes a plurality of third high wave units and a plurality of third low wave units. The third high wave units and the third low wave units are respectively arranged in a concentrated manner in the circumferential direction of the third high-low wave annular support rod. The third high wave units are connected end-to-end with the third high wave units or the third low wave units that are circumferentially adjacent to each other.

[0017] In some embodiments, the third high-low wave annular support rod is fixed to the covering film by stitching. The distance between two adjacent stitching coils on the crest and trough of the third high wave unit is less than the distance between every two adjacent stitching coils on the wave rod of the third high wave unit. The distance between every two adjacent stitching coils on the crest and trough of the second low wave unit is less than the distance between every two adjacent stitching coils on the wave rod of the third low wave unit.

[0018] In some embodiments, the crests and troughs of the first high-low wave annular support rod correspond one-to-one with the crests and troughs of the third high-low wave annular support rod in the axial direction; the crests and troughs of the second high-low wave annular support rod correspond one-to-one with the troughs and crests of the third high-low wave annular support rod in the axial direction.

[0019] The present invention also provides a knotting method for a covered support, which can be applied to any of the above embodiments. The first high-low wave annular support rod, the second high-low wave annular support rod, and the third high-low wave annular support rod are fixed to the covered membrane by needle stitching. The knotting method is used to tie the suture at the beginning and / or end of the stitching. The suture includes an insert section and an exit section that are connected end to end. The knotting method includes the following steps: inserting the suture into the covered membrane from one edge near the support rod and exiting the covered membrane from the opposite edge near the support rod, so that the exit section intersects with the insert section; wrapping the exit section around the insert section; and tightening the exit section and the insert section so that the exit section forms a knot on the insert section.

[0020] In some embodiments, the exit segment wraps around the inlet segment at least two turns. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a three-dimensional structural schematic diagram of the film-coated support provided by the present invention;

[0023] Figure 2 yes Figure 1 Enlarged view of Part II;

[0024] Figure 3 yes Figure 1 A three-dimensional structural diagram of the covered scaffold from another perspective;

[0025] Figure 4 yes Figure 1 Side view of the covered stent in the middle;

[0026] Figure 5 yes Figure 4 Enlarged view of the middle V section;

[0027] Figure 6 yes Figure 5 A schematic diagram of the unfolded planar structure of the membrane-covered scaffold;

[0028] Figures 7 to 8 yes Figure 1 A schematic diagram of the stitching process of the first high-low wave annular support rod of the covered scaffold;

[0029] Figure 9 This is a schematic diagram of the first knotting method of the film-coated stent provided by the present invention;

[0030] Figure 10 This is a schematic diagram of the second knotting method of the film-coated stent provided by the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Furthermore, the following descriptions of the embodiments are made with reference to the accompanying illustrations to illustrate specific embodiments in which the invention can be implemented. Directional terms used in this invention, such as "up," "down," "front," "rear," "left," "right," "inner," "outer," and "side," are merely directional references to the accompanying illustrations. Therefore, the directional terms used are for better and clearer explanation and understanding of the invention, and are not intended to indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set on" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. In the field of interventional medical devices, the proximal end refers to the end of the stent closest to the human heart after interventional treatment, and the distal end refers to the end of the stent furthest from the human heart after interventional treatment; the axial direction refers to the direction parallel to the line connecting the center of the distal end and the center of the proximal end of the medical device. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0034] In all embodiments of the present invention, the crests of the first high-low wave annular support rod 20, the second high-low wave annular support rod 30, and the third high-low wave annular support rod 40 face the distal end of the covered bracket 100, and the troughs of the first high-low wave annular support rod 20, the second high-low wave annular support rod 30, and the third high-low wave annular support rod 40 face the proximal end of the covered bracket 100.

[0035] Please see Figures 1 to 6 This invention provides a covered stent 100, which can be used to repair or support damaged blood vessels in interventional surgery. The covered stent 100 includes a cover 10, a first high-low wave annular support rod 20, a second high-low wave annular support rod 30, and a third high-low wave annular support rod 40. The first high-low wave annular support rod 20, the second high-low wave annular support rod 30, and the third high-low wave annular support rod 40 are arranged axially spaced along the cover 10 and do not contact each other. Specifically, the first high-low wave annular support rod 20 is sutured and fixed to the distal end of the cover 10, the second high-low wave annular support rod 30 is sutured and fixed to the proximal end of the cover 10, and the third high-low wave annular support rod 40 is sutured and fixed to the cover 10 and located between the first high-low wave annular support rod 20 and the second high-low wave annular support rod 30.

[0036] In this embodiment, the axial distance between the nearest point of the first high-low wave annular support rod 20 near the proximal end of the covering bracket 100 and the nearest point of the third high-low wave annular support rod 40 near the distal end of the covering bracket 100 is 2 mm. That is, the axial distance between the trough of the first high-low wave annular support rod 20 and the crest of the adjacent third high-low wave annular support rod 40 is 2 mm. The axial distance between the nearest point of the second high-low wave annular support rod 30 near the distal end of the covering bracket 100 and the nearest point of the third high-low wave annular support rod 40 near the proximal end of the covering bracket 100 is 2 mm; that is, the axial distance between the crest of the second high-low wave annular support rod 30 and the trough of the third high-low wave annular support rod 40 is 2 mm.

[0037] like Figure 2 and Figure 6 As shown, the first high-low wave annular support rod 20 includes multiple first high wave units 21 and multiple first low wave units 22. In the circumferential direction of the first high-low wave annular support rod 20, at least one first low wave unit 22 is provided between two adjacent first high wave units 21. The first high wave unit 21 is circumferentially connected to the circumferentially adjacent first high wave unit 21 or first low wave unit 22. The number of first low wave units 22 arranged on both sides of any first high wave unit 21 in the first high-low wave annular support rod 20 is equal, meaning the first high-low wave annular support rod 20 is symmetrical about the axial centerline of any first high wave unit 21. The first high wave unit 21 includes a wave crest 211, two wave troughs 215, and two wave rods 213 connecting the wave crest 211 and the two wave troughs 215. The first low-wave unit 22 includes a peak 221, two troughs 225, and two wave rods 223 connecting the peak 221 and the two troughs 225. The trough 215 of the first high-wave unit 21 is connected to the trough 225 of the adjacent first low-wave unit 22. Because the distal end of the coating support 100 needs to be fixed to the conveyor (not shown in the figure), in order to reserve assembly space for the coating support 100, the peak 211 of the first high-wave unit 21 of the first high-wave unit 20 protrudes beyond the distal edge of the coating 10, and the distance between the peak 221 of the first high-wave unit 21 and the distal edge of the coating 10 is less than or equal to 1.5 mm; preferably, the distance between the peak 211 of the first high-wave unit 21 and the distal edge of the coating 10 is 1.5 mm. The peak 221 of the first low waveform unit 22 of the first high and low waveform ring support rod 20 does not protrude beyond the distal edge of the film 10. Preferably, the distance between the peak 221 of the first low waveform unit 22 and the distal edge of the film 10 is 1.5 mm.

[0038] In this embodiment, the number of the first high-low wave annular support rods 20 of the covered support 100 is one. In other embodiments, the number of the first high-low wave annular support rods 20 may be two or more, and the two or more first high-low wave annular support rods 20 are arranged at intervals along the axial direction.

[0039] In this embodiment, the number of first high-waveform units 21 in the first high-low wave annular support rod 20 is two. In other embodiments, the number of first high-waveform units 21 may be three or more.

[0040] Before the first high-low wave annular support rod 20 is sewn and fixed onto the covering film 10, the first high-low wave annular support rod 20 is first fitted onto the covering film 10, and the suture needs to be tied with a knot at one end. The knot can be tied using existing knot-tying methods. The needle 50 is inserted starting from the wave rod 213 of one of the first high wave unit 21 of the first high wave annular support rod 20 (e.g., Figure 7 The stitching can begin at any point on the wave rod 213 of the first high-waveform unit 21. Preferably, the stitching begins at the midpoint of the wave rod 213 of the first high-waveform unit 21, that is, the distance from the starting point of the stitching to the wave crest 211 of the first high-waveform unit 21 in the axial direction is equal to the distance from the wave trough 215 of the first high-waveform unit 21 in the axial direction. The first suture is inserted into the outer surface of the covering membrane 10 near the first high-low wave annular support rod 20 and exits from the inner surface of the covering membrane 10. During the suturing process, it is necessary to ensure that the suture needle passes through the covering membrane 10 and ties the first high-low wave annular support rod 20 to the covering membrane 10. Then, the suture needle is inserted into the covering membrane 10 with one side close to the first high-low wave annular support rod 20 and exits the covering membrane 10 with the other side close to the first high-low wave annular support rod 20. The suture thread is repeatedly inserted into and exited from the covering membrane 10 around the first high-low wave annular support rod 20. The suture thread must be tightened after each insertion and exit of the suture needle to ensure that the first high-low wave annular support rod 20 can be firmly fixed to the covering membrane 10. Each time the suture needle enters and exits the covering membrane 10, a suture loop is formed. In the same suture loop, the distance between the center of the needle hole through which the suture enters the covering membrane 10 and the center of the needle hole through which the suture exits the covering membrane 10 ranges from 0.2 mm to 0.5 mm.

[0041] In this embodiment, the first high-low wave annular support rod 20 is fixed to the outer surface of the coating 10. In other embodiments, the first high-low wave annular support rod 20 may also be fixed to the inner surface of the coating 10.

[0042] Please see Figures 1 to 7During the process of sewing the first high-low wave ring support rod 20, continuous and dense sewing is required at both the beginning and end of the sewing. That is, the sewing loops at the beginning and end of the sewing are arranged closely to make the connection between the first high-low wave ring support rod 20 and the covering film 10 more stable at the beginning and end of the sewing. In this embodiment, two stitches are sewn at both the beginning and end of the sewing. When stitching the first high-wave unit 21, continuous and dense stitching is used on the trough 215 and the wave rod 213 of the first high-wave unit 21. That is, the stitching loops on the trough 215 and the wave rod 213 of the first high-wave unit 21 are closely arranged to increase the stability of the first high-low wave annular support rod 20 on the film 10. This ensures that when the film support 100 is subjected to radial force, the first high-low wave annular support rod 20, which is compressed and tends to move axially, will not push out of the film 10 or even fall off the film 10. The distance between any two adjacent stitching loops on the trough 215 of the first high-wave unit 21 is smaller than the distance between any two adjacent stitching loops on the wave rod 213 of the first high-wave unit 21. When stitching the first low-waveform unit 22, continuous and dense stitching is used on both the peaks 221 and troughs 225 of the first low-waveform unit 22. That is, the stitching loops on the troughs 225 and the wave rods 223 of the first low-waveform unit 22 are closely arranged to increase the stability of the first high-low wave annular support rod 20 on the covering film 10. This ensures that when the covering support 100 is subjected to radial force, the first high-low wave annular support rod 20, which is compressed and tends to move axially, will not move along the axial direction of the covering film 10. Specifically, the first high-low wave annular support rod 20 will not push out of the covering film 10 or even fall off the covering film 10, nor will it slide towards the proximal end of the covering film 10. Preferably, the distance between any two adjacent stitching loops on the peaks 221 and troughs 225 of the first low-waveform unit 22 is smaller than the distance between any two adjacent stitching loops on the wave rods 223 of the first low-waveform unit 22. In this embodiment, 7 to 8 stitches are sewn on the peaks 221 and troughs 225 of the first low waveform unit 22. The stitching loops are evenly and tightly distributed on the peaks 221 and troughs 225 of the first low waveform unit 22. The stitching loops on the wave rod 223 of the first low waveform unit 22 are evenly distributed. The distance between each two adjacent stitching loops on the wave rod 223 of the first low waveform unit 22 is about 1 mm.

[0043] Please refer to the following: Figures 7 to 9 The knotting method at the beginning and end of the stitching of the first high-low wave ring support rod 20 adopts the first knotting method. Before knotting using the first knotting method, the suture can be divided into an insert segment A and an exit segment B, with the insert segment A and the exit segment B connected end to end. The main steps of the first knotting method include:

[0044] Step 1: Insert the suture into the covering film 10 from one edge near the first high-low wave annular support rod 20, and exit the covering film from the opposite edge near the first high-low wave annular support rod 20, so that the exiting segment B intersects with the inserting segment A, and the exiting segment B is located above the inserting segment A.

[0045] Step 2: Wrap the exiting section B around the entering section A at least two times;

[0046] Step 3: Tighten the insertion section A and the exit section B so that the insertion section A and the exit section B are in close contact with the first high and low wave ring support rod 20, and the exit section B forms a knot on the insertion section A.

[0047] like Figure 9 As shown, in this embodiment, in the first knotting method, the number of turns of the through-segment B around the through-segment A is two.

[0048] In this embodiment, the knotting method at the beginning and end of the stitching of the second high-low wave annular support rod 30 and the third high-low wave annular support rod 40 can both adopt the first knotting method.

[0049] like Figure 2 and Figure 10 As shown, the knots at the wave rod 213 of the first high wave unit 21 and the wave rod 223 of the first low wave unit 22 of the first high and low wave ring support rod 20 are tied using a second knotting method. The second knotting method is similar to the first knotting method, but the difference between the second knotting method and the first knotting method is that in the second knotting method, the number of turns of the thread through section B wrapped around the thread through section A is one.

[0050] In this embodiment, the knotting method at the wave rod of both the second high-low wave annular support rod 30 and the third high-low wave annular support rod 40 can adopt the second knotting method.

[0051] like Figures 3 to 6As shown, the second high-low wave annular support rod 30 includes a second high wave unit 31 and a second low wave unit 32. Along the circumferential direction of the second high-low wave annular support rod 30, at least one second low wave unit 32 is provided between two adjacent second high wave units 31. The second high wave unit 31 is connected circumferentially to either the second high wave unit 31 or the second low wave unit 32 adjacent to it. At least one second low wave unit 32 is arranged between any two adjacent second high wave units 31. The second high wave unit 31 includes a wave crest 311, a wave trough 315, and a wave rod 313 connecting the wave crest 311 and the wave trough 315. The second low wave unit 32 includes a wave crest 321, a wave trough 325, and a wave rod 323 connecting the wave crest 321 and the wave trough 325. The trough 315 of the second high waveform unit 31 does not protrude from the proximal edge of the covering film 10. The distance between the trough 315 of the second high waveform unit 31 and the proximal edge of the covering film 10 ranges from 1.5mm to 2mm. The purpose is to reserve space for suturing and fixing the second high and low waveform support rod 30 on the covering film 10.

[0052] In this embodiment, the number of the second high-low wave annular support rods 30 in the covered support 100 is one. In other embodiments, the number of the second high-low wave annular support rods 30 may be two or more, and the two or more second high-low wave annular support rods 30 are arranged at intervals along the axial direction.

[0053] In this embodiment, the number of second high-waveform units 31 in the second high-low wave annular support rod 30 is three. In other embodiments, the number of second high-waveform units 31 may be two or more.

[0054] During the process of suturing and fixing the second high-low wave annular support rod 30 to the covering film 10, a separate suture is used; that is, the suture used for the second high-low wave annular support rod 30 is not the same as the suture used for the first high-low wave annular support rod 20. The suturing begins on the second high wave unit 31, and continuous and dense suturing is performed at both the beginning and end of the suturing, meaning the suture loops are tightly arranged to ensure a more stable connection between the second high-low wave annular support rod 30 and the covering film 10 at both ends. The first stitch enters from the outer surface of the covering film 10 and exits from the inner surface. The suture repeatedly enters and exits the covering film 10 around the second high-low wave annular support rod 30, fixing the second high-low wave annular support rod 30 to the covering film 10. For the second high-waveform unit 31, continuous and dense stitching is used on the peaks 311, troughs 315, and wave rods 313 of the second high-waveform unit 31. That is, the stitching loops on the peaks 311, troughs 315, and wave rods 313 of the second high-waveform unit 31 are tightly arranged to ensure that the second high-low wave annular support rod 30 will not be pushed out of the covering film 10 due to the release force when the covering support 100 is released. At the same time, the stitches at any position on the wave rod 313 of each second high-waveform unit 31 need to be knotted but not cut. In this embodiment, a second knotting method is used to knot the stitches at a position on the wave rod 313 corresponding to a peak 311 of the second high-waveform unit 31 with an axial distance of 3.5mm. For the second low-waveform unit 32, continuous and dense stitching is used on both the peaks 321 and troughs 325 of the second low-waveform unit 32. That is, the stitching loops on the peaks 321 and troughs 325 of the second low-waveform unit 32 are closely arranged to ensure that the second high-low wave annular support rod 30 will not be pushed out of the covering film 10 when the covering support 100 is released. The distance between any two adjacent stitching loops on the wave rod 323 of the second low-waveform unit 32 is greater than the distance between any two adjacent stitching loops on the peaks 311 and troughs 315 of the second high-waveform unit 31 and the peaks 321 and troughs 325 of the second low-waveform unit 32. In this embodiment, 7 to 8 stitches are sewn on the peaks 321 and troughs 325 of the second low waveform unit 32. The stitching loops are evenly and tightly distributed on the peaks 321 and troughs 325 of the second low waveform unit 32. The stitching loops on the wave rod 323 of the second low waveform unit 32 are evenly distributed. The distance between each two adjacent stitching loops on the wave rod 323 of the second low waveform unit 32 is about 1 mm.

[0055] In this embodiment, the second high-low wave annular support rod 30 is fixed to the inner surface of the coating 10. In other embodiments, the second high-low wave annular support rod 30 may also be fixed to the outer surface of the coating 10.

[0056] like Figure 4The covered stent 10 has a cut 11 at the end near the second high-low wave annular support rod 30, and the cut 11 is cut according to the shape of the second high-low wave annular support rod 30. In this embodiment, the cut 11 is formed by multiple V-shaped connections along the circumference to ensure that the covered stent 10 has good adhesion to the wall during the release process, is not prone to wrinkling, and is less likely to cause thrombosis.

[0057] like Figures 3-5 As shown, the covered support 100 also includes a positioning membrane 50, which is located at the trough of the second high-waveform unit 31 of the second high-waveform annular support rod 30. The trough of the second high-waveform unit 31 is located between the covered support 10 and the positioning membrane 50 to ensure that the second high-waveform annular support rod 30 will not be pushed out of the covered support 10 due to the release force when the covered support 100 is released. The shape and area of ​​the positioning membrane 50 are similar to the shape and area of ​​the trough of the second high-waveform unit 31. In this embodiment, the positioning membrane 50 is triangular. The positioning membrane 50 is fixed to the covered support 10 by stitching with a needle 60. A circle is stitched around the edge of the positioning membrane 50, and the suture is tied with a knot at the end of the stitch. After cutting the suture, the end of the suture is burned off with a soldering iron.

[0058] like Figures 4-6 As shown, the third high-low wave annular support rod 40 includes multiple third high wave units 41 and multiple third low wave units 42. The multiple third high wave units 41 and multiple third low wave units 42 are connected along the circumference of the third high-low wave annular support rod 40. The multiple third high wave units 41 and multiple third low wave units 42 are concentratedly arranged in the circumference of the third high-low wave annular support rod 40, that is, in the circumference of the third high-low wave annular support rod 40, all the third high wave units 41 are connected along the circumference of the third high-low wave annular support rod 40. All the third low-wave units 42 are connected circumferentially along the third high-low wave annular support rod 40. The two third high-wave units 41 at both ends of the plurality of third high-wave units 41 are respectively connected to the two third low-wave units 42 at both ends of the plurality of third low-wave units 42. A certain axial distance exists between the third high-low wave annular support rod 40 and the second high-low wave annular support rod 30 to ensure that the film-coated bracket 100 will not be unable to complete assembly due to insufficient assembly distance caused by compression during assembly. In this embodiment, the minimum axial distance between the third high-low wave annular support rods 40 is 2mm to 3mm, the minimum axial distance between the third high-low wave annular support rod 40 and the first high-low wave annular support rod 20 is 2mm to 3mm, and the minimum axial distance between the third high-low wave annular support rod 40 and the second high-low wave annular support rod 30 is 2mm to 3mm.

[0059] In this embodiment, the number of third high-low wave annular support rods 40 in the covered stent 100 is two. In other embodiments, the number of third high-low wave annular support rods 40 may be one or more.

[0060] like Figure 5 As shown, the third high-waveform unit 41 includes a peak 411, a trough 415, and a wave rod 413 connecting the peak 411 and the trough 415; the third low-waveform unit 42 includes a peak 421, a trough 225, and a wave rod 423 connecting the peak 421 and the trough 425. During the process of suturing and fixing the third high-low wave annular support rod 40 to the covering film 10, the same suture thread as the first high-low wave annular support rod 20 can be used. The first stitch enters from the outer surface of the covering film 10 and exits from the inner surface of the covering film 10. The suture thread repeatedly enters and exits the covering film 10 around the third high-low wave annular support rod 40 to fix the third high-low wave annular support rod 40 to the covering film 10. The stitching can begin at any point on the wave bar 413 of the third high waveform unit 41; preferably, the stitching can begin at the midpoint of the wave bar 413 of the third high waveform unit 41, that is, the distance between the stitching starting point and the wave crest 411 of the third high waveform unit 41 in the axial direction is equal to the distance between the stitching starting point and the wave trough 415 of the third high waveform unit 41 in the axial direction. For the third high waveform unit 41, continuous and dense stitching is used on the peaks 411 and troughs 415, and for the third low waveform unit 42, continuous and dense stitching is used on the peaks 421 and troughs 425, to ensure that when the covered support 100 is released, the third high and low waveform annular support rod 40 will not be pushed out of the covered support 10 due to the release force. The distance between each two adjacent stitching coils on the peaks 411 and troughs 415 of the third high waveform unit 41 is less than the distance between each two adjacent stitching coils on the wave rod 413, and the distance between each two adjacent stitching coils on the peaks 421 and troughs 425 of the third low waveform unit 42 is less than the distance between each two adjacent stitching coils on the wave rod 415. In this embodiment, 7 to 8 stitches are sewn on the crests 411, 421 and troughs 415, 425. The stitching loops are evenly and tightly distributed on the crests 411, 421 and troughs 415, 425. The stitching loops on the wave rods 413, 423 are evenly distributed. The distance between each pair of adjacent stitching loops on the wave rods 413, 423 is about 1 mm.

[0061] In this embodiment, the third high-low wave annular support rod 40 is fixed to the outer surface of the coating 10. In other embodiments, the third high-low wave annular support rod 40 may also be fixed to the inner surface of the coating 10.

[0062] like Figure 2 , Figure 5 and Figure 6As shown, in this embodiment, the first high-low wave annular support rod 20, the second high-low wave annular support rod 30, and the third high-low wave annular support rod 40 are arranged on the coating in a certain regular pattern. Specifically, the wave peaks 211, 221 and wave troughs 215, 225 of the first high-low wave annular support rod 20 are axially aligned with the wave peaks 411, 421 and wave troughs 415, 425 of the third high-low wave annular support rod 40; the wave peaks 211, 221 and wave troughs 215, 225 of the first high-low wave annular support rod 20 are axially aligned with the wave troughs 315, 325 and wave peaks 311, 321 of the second high-low wave annular support rod 3 ... second high-low wave annular support rod 30 are axially aligned with the wave troughs 315, 325 and wave peaks 311, 321 of the second high-low wave annular support rod 30; the wave peaks 211, 221 and wave troughs 215, 225 of the first high-low wave annular support rod 20 are axially aligned with the wave troughs 315, 325 and wave peaks 311, The peaks 311 and 321 and the troughs 315 and 325 are axially aligned with the troughs 415 and 425 and the peaks 411 and 421 of the third high-low wave annular support rod 40, respectively. The peaks 411 and 421 of one third high-low wave annular support rod 40 are axially aligned with the peaks 411 and 421 of the adjacent third high-low wave annular support rod 40. The troughs 415 and 425 of one third high-low wave annular support rod 40 are axially aligned with each other.

[0063] In other embodiments, the crests and troughs of the first high-low wave annular support rod 20, the second high-low wave annular support rod 30, and the third high-low wave annular support rod 40 do not necessarily need to be directly opposite each other in the axial direction.

[0064] The above are the embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the embodiments of the present invention, and these improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A covered stent, characterized in that, The covered stent includes: A film is applied, the film having slits; A first high-low wave annular support rod is fixed to the distal end of the covering film. The first high-low wave annular support rod includes a first high wave unit, the peak of which protrudes from the distal edge of the covering film. A second high-low wave annular support rod is fixed to the proximal end of the covering film. The troughs and crests of the second high-low wave annular support rod do not protrude beyond the proximal edge of the covering film. The cut is located at the end of the covering film near the second high-low wave annular support rod, and the cut is formed by cutting the covering film along the shape of the second high-low wave annular support rod. The third high-low wave annular support rod is located between the first high-low wave annular support rod and the second high-low wave annular support rod, and the third high-low wave annular support rod is fixed to the film. The second high-low wave annular support rod includes a second high wave unit. A positioning membrane is provided at the trough of the second high wave unit. The trough of the second high wave unit is located between the covering film and the positioning membrane to ensure that the second high-low wave annular support rod will not be pushed out of the covering film due to the release force when the covering film bracket is released. The shape of the positioning membrane is similar to the shape of the trough of the second high wave unit.

2. The covered stent according to claim 1, characterized in that, The distance by which the peak of the first high-waveform unit protrudes beyond the distal edge of the coating is less than or equal to 1.5 mm.

3. The covered stent according to claim 1, characterized in that, The first high-low wave annular support rod is symmetrical about the axial center line of the first high wave unit.

4. The covered stent according to claim 1, characterized in that, The first high and low wave annular support rod also includes a plurality of first low wave units, which are connected end to end with the first low wave units or the first high wave units that are circumferentially adjacent to each other.

5. The covered stent according to claim 4, characterized in that, The first high and low wave annular support rod is fixed to the film by needle and thread stitching. The distance between each two adjacent stitching loops on the trough of the first high wave unit is smaller than the distance between each two adjacent stitching loops on the wave rod of the first high wave unit. The distance between any two adjacent stitching coils on the peaks and troughs of the first low waveform unit is less than the distance between any two adjacent stitching coils on the wave bar of the first low waveform unit.

6. The covered stent according to claim 5, characterized in that, In the same suture loop, the distance between the center of the needle hole through which the suture enters the covering film and the center of the needle hole through which the suture exits the covering film is between 0.2 mm and 0.5 mm.

7. The covered stent according to claim 1, characterized in that, The distance between the trough of the second high-waveform unit and the near edge of the coating ranges from 1.5 mm to 2 mm.

8. The covered stent according to claim 7, characterized in that, The second high-low wave annular support rod also includes a plurality of second low wave units. Along the circumference of the second high-low wave annular support rod, at least one second low wave unit is arranged between two adjacent second high wave units. The second low wave units are connected end to end with the second low wave units or the second high wave units that are circumferentially adjacent.

9. The covered stent according to claim 8, characterized in that, The second high-low wave annular support rod is fixed to the covering film by needle and thread stitching. The distance between each two adjacent stitching loops on the peaks and troughs of the second high wave unit and the second low wave unit is less than the distance between each two adjacent stitching loops on the wave rod of the second low wave unit.

10. The covered stent according to claim 1, characterized in that, The film-coated support includes at least two third high-low wave annular support rods, and the distance between any two adjacent third high-low wave annular support rods is in the range of 2mm to 3mm; the distance between the first high-low wave annular support rod and the adjacent third high-low wave annular support rod is in the range of 2mm to 3mm; the distance between the second high-low wave annular support rod and the adjacent third high-low wave annular support rod is in the range of 2mm to 3mm.

11. The covered stent according to claim 8, characterized in that, The third high-low wave annular support rod includes a plurality of third high wave units and a plurality of third low wave units. The third high wave units and the third low wave units are respectively arranged in a concentrated manner in the circumferential direction of the third high-low wave annular support rod. The third high wave units are connected end to end with the third high wave units or the third low wave units that are circumferentially adjacent to them.

12. The covered stent according to claim 11, characterized in that, The third high-low wave annular support rod is fixed to the covering film by stitching. The distance between two adjacent stitching coils on the peak and trough of the third high wave unit is less than the distance between two adjacent stitching coils on the wave rod of the third high wave unit. The distance between two adjacent stitching coils on the peak and trough of the second low wave unit is less than the distance between two adjacent stitching coils on the wave rod of the third low wave unit.

13. The covered stent according to claim 1, characterized in that, The crests and troughs of the first high-low wave annular support rod correspond one-to-one with the crests and troughs of the third high-low wave annular support rod in the axial direction; the crests and troughs of the second high-low wave annular support rod correspond one-to-one with the troughs and crests of the third high-low wave annular support rod in the axial direction.

14. A knotting method for a covered scaffold, characterized in that, The knotting method of the covered stent is applied to the covered stent as described in any one of claims 1 to 13. The first high-low wave annular support rod, the second high-low wave annular support rod, and the third high-low wave annular support rod are fixed to the covered stent by needle stitching. The knotting method is used to tie the suture at the start and / or end of the suture. The suture includes an insert section and an exit section that are connected end to end. The knotting method includes the following steps: The suture is inserted into the covering film from one edge near the support rod and exits from the opposite edge near the support rod, such that the exiting section intersects the inserting section; Wrap the protruding section around the inserting section; Tighten the through section and the in section so that the through section forms a knot on the in section.

15. The knotting method for the covered stent according to claim 14, characterized in that, The exiting section wraps around the entering section at least two times.

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