CN110623780A - Sectional type tectorial membrane stent and preparation method thereof - Google Patents

Abstract

The invention provides a sectional type tectorial membrane stent, which comprises a tectorial membrane and a supporting framework fixed on the tectorial membrane, wherein the supporting framework comprises an annular structure and a spiral structure; the annular structure is formed by connecting a plurality of first waveform units end to end; the spiral structure is a tubular structure formed by a plurality of second waveform units which are connected end to end and are continuously and spirally arranged, and the whole extending direction of the spiral structure is parallel to the supporting framework. The invention also provides a preparation method of the sectional type covered stent. The annular structure in the sectional type covered stent provided by the invention has better radial supporting force to reduce the compression force, and the spiral structure has better flexibility, can adapt to the deformation of various bent and arched branch vessels, combines the annular structure and the spiral structure, and can adapt to different requirements of different branch vessels on the flexibility of the covered stent.

Description

Sectional type tectorial membrane stent and preparation method thereof

Technical Field

The invention relates to the field of medical instruments, in particular to a sectional type covered stent and a preparation method thereof.

Background

The middle layer of the normal human vascular artery wall is rich in elastic fibers, and can convey blood along with the relaxation of each heart beat. If the middle layer of the artery wall is damaged and the elastic fibers are broken and replaced by fibrous scar tissue, the artery wall loses elasticity and cannot resist the impact of blood flow, so that the blood vessel wall bulges or the intima tears to form an aortic aneurysm or a dissection. Aortic dissection is a disease of aorta with risk, rapid progression and high mortality, with an incidence of about 0.3%, untreated early mortality increasing by 1% per hour and more than 50% of patients dying within 1 week.

With the development of medical technology, more and more surgical methods such as open surgery, hybrid surgery or minimally invasive surgery are adopted to treat the inland aortic disease. The covered stent is placed at the position of a lesion by a minimally invasive method so as to isolate the lesion, effectively protect the wall of an aortic aneurysm from being pressed by the pressure of systemic artery, and further prevent the aortic aneurysm and the dissection from being broken.

Because of the small trauma and the definite therapeutic effect, aortic endoluminal repair has become an important treatment option for B-aortic dissection and infrarenal abdominal aortic aneurysm. However, for lesions adjacent to or involving major branch vessels that must be preserved, such as the a-dissect that involves the ascending aorta and aortic arch or abdominal aortic aneurysms that involve the renal arteries and more important branches, the conventional method is to replace the diseased arteries with artificial vessels by open surgery, which requires complete interruption of aortic blood flow for a certain period of time and to some extent, close cooperation of surgery, anesthesia, and extracorporeal circulation with the operating room, and only a few hospitals currently have the ability to perform aortic surgery, combined with prolonged extracorporeal circulation, myocardial interruption, and body temperature fluctuations of aortic surgery, so that the post-operative mortality and other systemic complications of aortic surgery occur at a significantly higher rate than other cardiac surgeries, especially those involving the aortic arch. On one hand, the A-type interlayer patient accounts for 80% of the interlayer cases, on the other hand, the open surgery has high difficulty and high postoperative complications and is difficult to develop in a large scale, and in recent years, new technologies are continuously proposed and applied to expand the application range of minimally invasive intraluminal repair, such as a branch covered stent, a windowing technology, a chimney technology, a periscope technology and a blood supply for reserving important branch blood vessels by diversion through hybridization surgery.

The stent with branches is formed integrally, so that the branch part is guided into the branch blood vessel to be released with great difficulty, only a single-branch stent which is successfully clinically applied at present by using a minimally invasive technology is used, the aortic arch part has three important branches, the spacing positions of the branches are greatly different, a multi-branch stent is reported to be clinically used in an open surgery at present, but the stent with three branches is guided into the corresponding branch blood vessel simultaneously and is also very difficult in the open surgery. The windowing technology is to remain the branched blood supply in the film-covered windowing hole at the opening of the branch blood vessel corresponding to the film-covered stent, and the windowing stent is arranged only by aligning the window hole to the branch blood vessel as far as possible, so that the operation is relatively simple, the windowing stent can be applied to the retention of multiple branches, but I-type internal leakage is easily generated. The chimney technology is similar to the periscope technology, a small covered stent for communicating a branch blood vessel with an aorta is placed outside the covered stent side by side, most of the technology is used for keeping a branch blood vessel at present, but the branch covered stent is easily blocked by the oppression of the aorta stent, and in addition, as the covered stent is placed side by side, I-type internal leakage is easily generated. Therefore, there is a clinical need to develop a stent graft more suitable for a branch vessel.

Disclosure of Invention

In view of the above, the present invention provides a segmented stent graft suitable for a branch vessel, and the specific technical solution is as follows.

A sectional type tectorial membrane stent comprises a tectorial membrane and a supporting framework fixed on the tectorial membrane, wherein the supporting framework comprises an annular structure and a spiral structure;

the annular structure is formed by connecting a plurality of first waveform units end to end; the spiral structure is a tubular structure formed by a plurality of second waveform units which are connected end to end and are continuously and spirally arranged, and the whole extending direction of the spiral structure is parallel to the supporting framework.

Preferably, the ring structures include a first ring structure and a second ring structure;

the support framework comprises a near-end annular support frame, a middle spiral support frame and a far-end annular support frame in sequence from a near end to a far end, the near-end annular support frame comprises a plurality of first annular structures which are parallel to each other, the middle spiral support frame is of a spiral structure, and the far-end annular support frame comprises a plurality of second annular structures which are parallel to each other.

Preferably, each first waveform unit consists of a first peak, a first wave bar and a first trough, and the first wave bar is connected with the first peak and the first trough; the first wave bars which are adjacent in the circumferential direction are connected to form a first wave crest near the proximal end, and the first wave bars which are adjacent in the circumferential direction are connected to form a first wave trough near the distal end; each second waveform unit consists of a second wave crest, a second wave rod and a second wave trough, and the second wave rod is connected with the second wave crest and the second wave trough; the circumferentially adjacent second wave bars meet near the proximal end to form a second wave crest, and the circumferentially adjacent second wave bars meet near the distal end to form a second wave trough.

Preferably, the first wave crest and the first wave trough of two axially adjacent circles of the first wave unit are located on the same axis.

Preferably, the first ring structure comprises a first start wave bar, a first end wave bar and a plurality of first waveform units connected between the first start wave bar and the first end wave bar, the first start wave bar is the first wave bar in one circle of the first ring structure, and the first end wave bar is the last first wave bar in one circle of the first ring structure; the first starting wave rod and the first terminal wave rod are connected in a winding, welding or steel sleeve fixing mode.

Preferably, the first end wave lever of the first ring structure comprises a first end extension section, the first end extension section extends to the starting position of the adjacent first ring structure, and the first end extension section forms a first starting wave lever of the adjacent first ring structure to connect the adjacent two first ring structures.

Preferably, the second ring structure includes a second start wave bar, a second end wave bar and a plurality of first waveform units connected between the second start wave bar and the second end wave bar, the second start wave bar is a first wave bar in one turn of the second ring structure, and the second end wave bar is a last first wave bar in one turn of the second ring structure; the second starting wave rod and the second terminal wave rod are connected in a winding, welding or steel sleeve fixing mode.

Preferably, the second end wave lever of the second ring structure includes a second end extending section, the second end extending section extends to the starting position of the adjacent second ring structure, and the second end extending section constitutes a second starting wave lever of the adjacent second ring structure to connect the adjacent two second ring structures.

Preferably, the middle spiral support frame includes a spiral starting wave rod, a spiral ending wave rod and a spiral part connected between the spiral starting wave rod and the spiral ending wave rod, the spiral starting wave rod is a first second wave rod of the middle spiral support frame, and the spiral ending wave rod is a last second wave rod extending along the spiral direction of the middle spiral support frame.

Preferably, the proximal end and/or the distal end of the middle helical support frame is connected with the annular structure by winding, welding or steel sleeve fixing.

Preferably, the helical start wave bar comprises a helical start extension connected to one of the first wave bars in the first loop formation to connect the proximal annular strut to the central helical strut.

Preferably, the "the helical start extension is connected to one of the first struts of the first loop formation" includes the helical start extension being connected to one of the first struts of the first loop formation closest to the central helical strut.

Preferably, the helical terminal wave rod comprises a helical terminal extension connected to one of the first wave rods in the second annular configuration to connect the central helical scaffold to the distal annular scaffold.

Preferably, the "the helical terminal extension is connected to one of the first wave bars in the second annular structure" comprises the helical terminal extension being connected to one of the first wave bars in the second annular structure closest to the central helical strut.

Preferably, the second wave crests of two axially adjacent second wave units are located on the same axis.

Preferably, the middle helical support frame extends from a proximal end to a distal end, and the middle helical support frame comprises a helical portion, the helical portion is composed of helical units, and the helical angle of each helical unit is 1-75 °.

Preferably, the support armature is woven from continuous filaments.

Preferably, the continuous filament is a single wire or a composite wire composed of a plurality of wires.

Preferably, the strength of the near-end annular support frame is greater than that of the middle spiral support frame.

Preferably, the wire diameter of the wire used for the proximal annular bracing frame is larger than the wire diameter of the wire used for the middle helical bracing frame and the distal annular bracing frame.

Preferably, the rigidity of the wire material used for the proximal annular stent is greater than the rigidity of the wire material used for the central helical stent.

Preferably, the supporting framework is of an equal-diameter straight pipe structure or a non-equal-diameter taper pipe structure.

Preferably, the distal annular bracing frame comprises a transitional second annular structure disposed on a side of the transitional second annular structure distal to the proximal annular bracing frame; the second annular transition structure forms a horn shape, and the second annular transition structure gradually increases in diameter from the proximal end to the distal end.

Preferably, the tectorial membrane includes inlayer tectorial membrane and outer tectorial membrane, support the skeleton and locate between inlayer tectorial membrane and the outer tectorial membrane, just the inlayer tectorial membrane is located support the skeleton inboard, the outer tectorial membrane is located support the skeleton outside.

Preferably, the segmented stent graft further comprises at least one visualization point.

The invention also provides a preparation method of the sectional type covered stent, which comprises the following steps:

winding the inner layer film on the film-coating mold rod;

sleeving a support framework on the inner-layer coating film, wherein the support framework is tightly connected with the layer coating film;

and wrapping the supporting framework with an outer-layer covering film.

The invention has the beneficial effects that: the annular structure in the sectional type covered stent provided by the invention has better radial supporting force to reduce the compression force, and the spiral structure has better flexibility and can adapt to the deformation of various bent and arched branch vessels; the annular structure and the spiral structure are combined, so that different requirements of different branch vessels on the flexibility of the covered stent can be met.

Drawings

FIG. 1 is a schematic structural view of a segmented stent graft according to the present invention.

FIG. 2 is a schematic structural diagram of a first waveform unit in a segmented stent graft provided in the present invention.

FIG. 3 is a schematic structural diagram of a second waveform unit in a segmented stent graft provided in the present invention.

FIG. 4 is a schematic structural diagram of a supporting framework in a segmented stent graft according to the present invention.

FIG. 5 is a schematic structural view of a segmented stent graft according to the present invention, in which the ring structures are connected by steel sleeves.

FIG. 6 is a schematic structural view showing the interconnection between the supporting frames of a segmented stent graft according to the present invention.

Fig. 7 is a schematic structural view illustrating that a spiral initial extension section and a first wave rod in a segmented stent graft provided by the invention are connected and fixed through a steel sleeve.

FIG. 8 is a schematic structural view of a connection between a helical start extension and a first start wave rod in a segmented stent graft according to the present invention.

FIG. 9 is a schematic structural view of a segmented stent graft according to the present invention, wherein the diameter of the proximal annular scaffold is larger than the diameter of the distal annular scaffold.

FIG. 10 is a schematic structural view of a segmented stent graft provided in the present invention, wherein the supporting framework is a straight tube with equal diameter.

FIG. 11 is a schematic view of a segmented stent graft according to the present invention in use with an aortic stent graft.

FIG. 12 is a schematic view of another segmented stent graft according to the present invention in use with an aortic stent graft.

FIG. 13 is a schematic structural view of a segmented stent graft including an inner cover and an outer cover according to the present invention.

FIG. 14 is a flow chart of a method for preparing a segmented stent graft according to the present invention.

FIG. 15 is a schematic view of the present invention providing a segmented stent-graft.

Detailed Description

While the following is a description of the preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Referring to fig. 1, the present invention provides a segmented stent graft 100, wherein the segmented stent graft 100 comprises a stent graft 120 and a supporting framework 110 fixed on the stent graft 120, and the supporting framework 110 comprises a ring structure 1200 and a spiral structure 1300. The ring structure 1200 is a ring structure formed by connecting a plurality of first waveform units 1100 (see fig. 2) end to end. Gaps are formed between adjacent ring structures 1200. The spiral structure 1300 is a tubular structure formed by a plurality of second waveform units 1400 (see fig. 3) which are connected end to end and continuously and spirally arranged, and the overall extending direction of the spiral structure 1300 is parallel to the supporting framework 110. The annular structure 1200 has better radial supporting force and can reduce the compression of other stents, the spiral structure 1300 has better flexibility, can adapt to the deformation of various bent and arched branch vessels, and the annular structure 1200 and the spiral structure 1300 are combined to adapt to different requirements of different branch vessels on the flexibility of the covered stent.

In a further embodiment, the ring structure 1200 includes a first ring structure 1210 and a second ring structure 1220. The support framework 110 comprises a proximal annular support frame 111, a middle spiral support frame 112 and a distal annular support frame 113 in sequence from a proximal end a to a distal end B, wherein the proximal annular support frame 111 comprises a plurality of mutually parallel first annular structures 1210, the middle spiral support frame 112 is a spiral structure 1300, and the distal annular support frame 113 comprises a plurality of mutually parallel second annular structures 1220. In this embodiment, the middle spiral support frame 112 has a spiral structure 1300, which has excellent flexibility and can adapt to the deformation of various curved and arched branch vessels, and the proximal annular support frame 111 and the distal annular support frame 113 have annular structures 1200, so that the whole support framework 110 has good radial support force at both ends, thereby achieving the effect of stably supporting the framework 110.

Referring to fig. 2, in a further embodiment, in the proximal or distal ring structure, each of the first waveform units 1100 is composed of a first peak 1112, a first wave rod 1111 and a first wave trough 1113, and the first wave rod 1111 connects the first peak 1112 and the first wave trough 1113. Circumferentially adjacent first wave bars 1111 meet near proximal end a to form first wave crests 1112, and circumferentially adjacent first wave bars 1111 meet near distal end B to form first wave troughs 1113. It is understood that the heights of the circumferentially adjacent first peaks 1112 may be uniform or non-uniform, and may be spaced at intervals. Similarly, the heights of the circumferentially adjacent first wave troughs 1113 may be uniform or nonuniform, and may be arranged at intervals. It is understood that the first waveform unit 1100 is configured to include one or more of a U-shaped wave, a V-shaped wave, and an S-shaped wave. It is understood that the first wave unit 1100 in the first and second annular structures 1210 and 1220 may be the same or may be adapted in size.

In a further embodiment, the first wave rods 1111 of the first wave unit 1100 have a length of 3-10mm, the extension lines of two adjacent first wave rods 1111 form an included angle of 30-150 degrees, and the height of the first wave unit is 3-10 mm. In a further embodiment, the first wave crests 1112 and the first wave troughs 1113 of two axially adjacent turns of the first wave unit 1100 are located on the same axis in the proximal or distal ring structure. Such as the peak 1112a and the valley 1113 in fig. 2, are located on the same axis L1. With the axis L1 oriented parallel to the support frame. As shown in fig. 2, the first wave peak 1112a and the first wave trough 1113 are located on the same axis L1, that is, the wave peak is opposite to the wave trough (the distance is shortest) between two axially adjacent circles of annular structures, that is, the distance between the first wave peak 1112a and the first wave trough 1113 is smallest, so that the near-diamond-shaped unit structures 1114 are formed between the axially adjacent first wave-shaped units 1100, so as to enhance the radial supporting force of the proximal annular supporting frame 111 and the distal annular supporting frame 113 formed by the first wave-shaped units 1100.

Referring to fig. 3, in the middle spiral structure, each of the second wave units 1400 is composed of a second peak 1412, a second wave bar 1411 and a second wave trough 1413, and the second wave bar 1411 connects the second peak 1412 and the second wave trough 1413. Circumferentially adjacent second wave bars 1411 meet near the proximal end a to form second wave crests 1412, and circumferentially adjacent second wave bars 1411 meet near the distal end B to form second wave troughs 1413. It is understood that the heights of the circumferentially adjacent second wave crests 1412 may or may not be uniform and may be spaced at high and low intervals. Likewise, the heights of the circumferentially adjacent second troughs 1413 may or may not be uniform, and may be arranged at high-low intervals. It is understood that the second waveform unit 1400 is configured to include one or more of a U-shaped wave, a V-shaped wave, and an S-shaped wave.

In a further embodiment, the length of the second wave bar 1411 in the second wave unit 1400 is 3-10mm, the included angle formed by the extension lines of two adjacent second wave bars 1411 is 30-150 degrees, and the height of the second wave unit is 3-10 mm.

In a further embodiment, the second peaks 1412 of two axially adjacent second wave shaped elements 1400 are located on the same axis in the central spiral structure. Second wave peak 1412 and an axially adjacent second wave peak 1412a as shown in fig. 3 are located on the same axis L2. It will be appreciated that the direction of the axis L2 is parallel to the support frame. That is, the second wave crests 1412 of two second waveform elements 1400 axially adjacent in the middle spiral support frame 112 correspond. The second wave crests 1412 and axially adjacent second wave crests 1412a as shown in fig. 3 correspond such that there is more space for the relative movement between the second wave crests 1412 and the axially adjacent second wave crests 1412a to ensure the compliance of the structure of the helical structure 1300.

Referring to fig. 4, in a further embodiment, the first ring structure 1210 includes a first start wave rod 1211, a first end wave rod 1212, and a plurality of first waveform units connected between the first start wave rod 1211 and the first end wave rod 1212. The first start wave bar 1211 is the first wave bar in one turn of the first ring structure 1210, and the first end wave bar 1212 is the last first wave bar in one turn of the first ring structure 1210. The first start wave rod 1211 and the first end wave rod 1212 are connected by winding, welding or steel sleeve fixing. In fig. 4, the first start wave bar 1211 is connected to the end wave bar 1212. Referring to fig. 5, in fig. 5, the first end wave rod 1212 and the first start wave rod 1211 are connected and fixed by the steel sleeve 150.

Referring to fig. 6, in a further embodiment, the first end node 1212 of the first ring structure 1210 includes a first end node extension 1213, the first end node extension 1213 extends to the start position of the adjacent first ring structure 1210a, and the first end node extension 1213 forms a first start node 1211a of the adjacent first ring structure 1210a to connect the first ring structure 1210 with the adjacent first ring structure 1210 a. So that the connection between the first ring structures 1210 is more stable.

Referring to fig. 4, in a further embodiment, the second ring structure 1220 includes a second start wave bar 1221, a second end wave bar 1222, and a plurality of first waveform units connected between the second start wave bar 1221 and the second end wave bar 1222. The second start beam 1221 is the first beam in one turn of the second loop 1220, and the second end beam 1222 is the last first beam in one turn of the second loop 1220. The second start wave rod 1221 and the second end wave rod 1222 are connected by winding, welding, or steel sleeve fixing. In fig. 4, the second start wave bar 1221 is wound with the second end wave bar 1222. In fig. 5, the second end wave rod 1222 and the second start wave rod 1221 are connected and fixed by a steel sleeve 150.

Referring to fig. 6, in a further embodiment, the second end wave bar 1222 of the second ring structure 1220 includes a second end extending section 1223, the second end extending section 1223 extends to the start position of the adjacent second ring structure 1220a, and the second end extending section 1223 forms a second start wave bar 1221a of the adjacent second ring structure 1220a, so as to connect the second ring structure 1220 and the adjacent second ring structure 1220 a. So that the connection between the second ring structures 1220 is more firmly and stably.

Referring to fig. 4, in a further embodiment, the middle spiral support frame 112 includes a spiral start wave rod 1121, a spiral end wave rod 1122, and a spiral portion 1124 connected between the spiral start wave rod 1121 and the spiral end wave rod 1122, the spiral start wave rod 1121 is a first second wave rod of the middle spiral support frame 112, and the spiral end wave rod 1122 is a last second wave rod of the middle spiral support frame 112 extending along a spiral direction. Wherein the helical start wave rod 1121 is disposed adjacent to the proximal annular support shelf 111 as compared to the helical end wave rod 1122. The helical portion 1124 is connected by a plurality of helical elements 1125 and extends helically from the proximal end a to the distal end B. Wherein the overall helical direction of the central helical support frame 112 refers to the direction in which both the proximal end a points towards the distal end B.

In further embodiments, the proximal and/or distal ends of the central helical strut 112 are connected to the ring structure 1200 by winding, welding, or steel sleeve fixation.

Referring to fig. 6, in a further embodiment, the spiral start wave rod 1121 includes a spiral start extension 1123, and the spiral start extension 1123 is connected to one of the first wave rods 1111a of the first ring structure 1210a in the proximal annular support frame 111 to connect the proximal annular support frame 111 to the middle spiral support frame 112. Wherein the helical start extension 1123 is connected to one of the first wave rods 1111a of the first ring structure 1210a by winding, welding or steel sleeve fixation. In fig. 6, a spiral start extension 1123 is wound on the first wave rod 1111 a. Referring to fig. 7, in fig. 7, the spiral start extension 1123 and the first wave rod 1111a are fixed by the steel sleeve 150.

It is understood that referring to fig. 8, the connection of the helical start extension 1123 to one of the first wave rods 1111a of the first ring structure 1210a of the proximal ring support 111 comprises the connection of the helical start extension 1123 to the first start wave rod 1211a of the first ring structure 1210a of the proximal ring support 111. In fig. 8 a steel sleeve 150 is used for the connection.

Referring again to fig. 6, in a further embodiment, the connection of the helical start extension 1123 to one of the first wave rods 1111a of the first loop structure 1210a in the proximal loop support 111 includes the connection of the helical start extension 1123 to one of the first wave rods 1111a of the first loop structure 1210a closest to the central helical support 112. Wherein the first loop 1210a closest to the central helical support frame 112 is shown as the first loop 1210a in figure 6.

It will be appreciated that the first wave bar in the first annular structure 1210, including the helical start extension 1123, may be connected anywhere in the proximal annular scaffold 111. Namely, the spiral start wave rod 1121 of the middle spiral support frame 112 can be extended into the proximal annular support frame 111, so as to further improve the stability of the overall structure of the stent.

The helical terminal wave rod 1122 includes a helical terminal extension 1126, the helical terminal extension 1126 connecting with one of the first wave rods 1111b in the second loop configuration 1220b to connect the middle helical strut 112 with the distal ring strut 113. Wherein the helical terminus extension 1126 is attached to one of the first wave rods 1111b of the second ring structure 1220b by wrapping, welding, or steel sleeve attachment. In FIG. 6, a helical wave rod 1111b is wound around a helical terminus extension 1126.

It will be appreciated that the "helical terminus extension 1126 connects to one of the first wave bars 1111b in the second annular structure 1220 b" includes the helical terminus extension 1126 connecting to the second terminus wave bar 1222b in the second annular structure 1220.

In a further embodiment, the "helical terminus extension 1126 connects to one of the first wave bars 1111b of the second ring structure 1220 b" includes the helical terminus extension 1126 connecting to one of the first wave bars 1111b of the second ring structure 1220b closest to the central helical strut 112. Wherein the second annular structure 1220b closest to the central helical strut 112 is shown as the second annular structure 1220b in figure 6.

It will be appreciated that the helical terminus extension 1126 may also be connected to the first wave bar in the second annular structure 1220 anywhere in the distal annular scaffold 113. Namely, the spiral terminal wave rod 1122 of the middle spiral support frame 112 can be extended into the distal annular support frame 113, so as to further improve the stability of the overall structure of the stent.

The near end and the far end of the middle spiral support frame 112 are respectively connected to the annular structure, the support frameworks 110 are integrally connected together and mutually constrained, and the radial stability and the axial stability of the support frameworks 110 are stronger.

Referring to fig. 4, in a further embodiment, the distal annular support 113 includes a transitional second annular structure 1220b, and the second annular structure 1220 is disposed on a side of the transitional second annular structure 1220b away from the proximal annular support 111. The transition second annular structure 1220B is flared, and the diameter of the transition second annular structure 1220B gradually increases from the proximal end a to the distal end B. When the distal annular scaffold 113 enters a branch vessel, the larger diameter increases its adherence and reduces the incidence of endoleaks. The transitional second annular structure 1220b may better engage the second annular structure 1220 in the middle helical support frame 112 and the distal annular support frame 113, further improving the overall stability of the segmented stent graft 100.

It will be appreciated that the transition second loop 1220B has a minimum diameter near the proximal end a that is equal to the diameter of the central helical strut 112, and the transition second loop 1220B has a maximum diameter near the distal end B that is equal to the diameter of the second loop 1220. To better engage the second annular structure 1220 in the central helical support frame 112 and the distal annular support frame 113.

In a further embodiment, the axial length of the proximal annular cage 111 is 5-50 mm.

In a further embodiment, the central helical support 112 extends from a proximal end a to a distal end B, the central helical support 112 comprises a helix 1124, the helix 1124 is made up of helical elements 1125, each helical element 1125 has a helix angle of 1-75 °. Preferably, the spiral angle of the spiral unit 1125 is 5-45 °. Within the above-mentioned helical angle range, the middle helical scaffold 112 has excellent flexibility and can be bent at will to adapt to different curved or arched blood vessels.

Referring to fig. 9, it will be appreciated that in other embodiments, the diameter of the proximal annular shelf 111 may be greater than the diameter of the distal annular shelf 113. For vessels having a larger diameter at the proximal end a and a smaller diameter at the distal end B.

Referring to fig. 10, it will be appreciated that in other embodiments, the diameter of the proximal annular shelf 111 may be equal to the diameter of the distal annular shelf 113. The entire support frame 111 is a straight tubular stent extending in equal diameters.

In a further embodiment, support armature 110 is woven from a continuous filament. The continuous filament may be a single strand or a multi-strand composite filament, and the material of the filament may be selected from a metallic material selected from stainless steel, cobalt alloy, tantalum, nickel titanium alloy, or other biocompatible metals; preferably of memory alloy, the plurality of composite wires may be twisted or braided from a plurality of wires, which may be of the same or different materials.

In a further embodiment, the continuous wire is a single wire or a composite wire of multiple wires, such as stainless steel, cobalt alloy, tantalum, nickel titanium alloy, or other biocompatible metal; preferably a memory alloy, more preferably a nickel titanium alloy. The support frame 110 is formed by weaving continuous metal wires, so that the stability of the support frame can be improved.

Referring to fig. 11, when the segmented stent graft 100 is used in conjunction with the aortic stent graft 200, the proximal stent graft 111 is squeezed by the aortic stent graft 200, and requires a large radial supporting force; on the other hand, as shown in fig. 12 (the specific structure of the circular stent and the helical stent is not explicitly shown in the figure), in some multi-branch vessels, several branch stents need to be used simultaneously, and in this case, the proximal ends of the branch stents are also squeezed by the adjacent branch stents. Thus, in a further embodiment, the strength of the proximal annular strut 111 is greater than the strength of the central helical strut 112; to this effect, the rigidity of the wire material used for the proximal annular support 111 is greater than that of the wire material used for the central helical support 112, or the wire diameter of the wire used for the proximal annular support 111 is greater than that of the wire used for the central helical support 112. So as to ensure that the near-end annular support frame 111 has good radial supporting force and can be firmly connected with other branch stents in the blood vessel. Preferably, the wire used for the proximal annular strut 111 has a wire diameter of 0.3 mm.

In a further embodiment, the wire diameter of the wire used for the central helical scaffolding 112 is smaller than the wire diameter of the distal annular scaffolding 112. To ensure good compliance of the central screw support frame 112. Preferably, the wire diameter of the wire used for the middle helical support frame 112 is 0.25 mm.

Referring to fig. 13 again, in a further embodiment, the coating 120 further includes an inner coating 121 and an outer coating 122, the supporting framework 110 is disposed between the inner coating 121 and the outer coating 122, the inner coating 121 is located on the inner side of the supporting framework 110, and the outer coating 122 is located on the outer side of the supporting framework 110. The materials of the inner layer coating 121 and the outer layer coating 122 may be independently selected from polymer materials with excellent biocompatibility, such as expanded polytetrafluoroethylene, PET, dacron, polyurethane, silicone, ultra-high molecular weight polyethylene or other suitable materials, and preferably, the inner layer coating 121 and the outer layer coating 122 are made of expanded polytetrafluoroethylene materials. The expanded PTFE provides a good barrier to fluid permeation and enhances the radial support of the segmented stent graft 100.

In a further embodiment, the inner and outer cover films 121 and 122 are each a unitary structure.

In a further embodiment, both the inner and outer cover films 121, 122 are a unitary structure. To make the segmented stent graft 100 more robust. It is understood that the inner layer cover film 121 and the outer layer cover film 122 may be formed into an integral structure by heat sealing.

In further embodiments, the segmented stent graft 100 further comprises at least one visualization point 130, wherein the visualization point 130 may be configured as a ring or figure 8 and may be fixed to the proximal and distal ends of the support scaffold 110 by sewing or welding, and the visualization point may be made of a material selected from gold, platinum-tungsten, palladium, platinum-iridium, rhodium, tantalum, or alloys or composites of these metals. Preferably, there are two developing points 130, and the two developing points 130 are symmetrically distributed on the supporting frame 110. Further, the developing points 130 are respectively located on the first peak of the proximal annular support frame 111 and the first valley of the distal annular support frame 112. To ensure that the segmented stent graft 100 as a whole can be effectively monitored.

Referring to FIGS. 14 and 15, the present invention further provides a method for preparing a segmented stent graft, wherein the method for preparing the segmented stent graft 100 comprises the steps S100, S200 and S300. The detailed procedure is as follows.

In step S100, the inner layer coating film 121 is wound on the coating film die bar 123.

Step S200, the supporting framework 110 is sleeved on the inner coating 121, and the supporting framework 110 is tightly connected with the inner coating 121. Wherein the supporting framework 110 adopts the supporting framework in any of the above embodiments.

Step S300, wrapping the outer layer film 122 around the supporting framework 110.

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

Claims (26)

1. A sectional type tectorial membrane support is characterized in that the sectional type tectorial membrane support comprises a tectorial membrane and a supporting framework fixed on the tectorial membrane, wherein the supporting framework comprises an annular structure and a spiral structure;

the annular structure is formed by connecting a plurality of first waveform units end to end; the spiral structure is a tubular structure formed by a plurality of second waveform units which are connected end to end and are continuously and spirally arranged, and the whole extending direction of the spiral structure is parallel to the supporting framework.

2. The segmented stent graft of claim 1, wherein the ring structure comprises a first ring structure and a second ring structure;

the support framework comprises a near-end annular support frame, a middle spiral support frame and a far-end annular support frame in sequence from a near end to a far end, the near-end annular support frame comprises a plurality of first annular structures which are parallel to each other, the middle spiral support frame is of a spiral structure, and the far-end annular support frame comprises a plurality of second annular structures which are parallel to each other.

3. The segmented stent-graft of claim 2, wherein each of the first wave-shaped units is comprised of a first peak, a first wave-bar and a first trough, the first wave-bar connecting the first peak and the first trough; the first wave bars which are adjacent in the circumferential direction are connected to form a first wave crest near the proximal end, and the first wave bars which are adjacent in the circumferential direction are connected to form a first wave trough near the distal end; each second waveform unit consists of a second wave crest, a second wave rod and a second wave trough, and the second wave rod is connected with the second wave crest and the second wave trough; the circumferentially adjacent second wave bars meet near the proximal end to form a second wave crest, and the circumferentially adjacent second wave bars meet near the distal end to form a second wave trough.

4. The segmented stent graft of claim 3, wherein the first peaks and the first troughs of two axially adjacent turns of the first waveform element are on the same axis.

5. The segmented stent graft of claim 3, wherein the first ring structure comprises a first start wave bar, a first end wave bar, and a plurality of first wave units connected between the first start wave bar and the first end wave bar, the first start wave bar being a first wave bar in one turn of the first ring structure, the first end wave bar being a last first wave bar in one turn of the first ring structure; the first starting wave rod and the first terminal wave rod are connected in a winding, welding or steel sleeve fixing mode.

6. The segmented stent graft of claim 5, wherein the first terminal wave bar of a first loop structure comprises a first terminal extension that extends to a starting location of an adjacent first loop structure, the first terminal extension constituting a first starting wave bar of the adjacent first loop structure to connect two adjacent first loop structures.

7. The segmented stent graft of claim 5, wherein the second ring structure comprises a second start wave bar, a second end wave bar, and a plurality of first wave units connected between the second start wave bar and the second end wave bar, the second start wave bar being a first wave bar in one turn of the second ring structure, the second end wave bar being a last first wave bar in one turn of the second ring structure; the second starting wave rod and the second terminal wave rod are connected in a winding, welding or steel sleeve fixing mode.

8. The segmented stent graft of claim 7, wherein the second terminal wave bar of a second ring structure comprises a second terminal extension that extends to a location where the adjacent second ring structure begins, the second terminal extension constituting a second start wave bar of the adjacent second ring structure to connect two adjacent second ring structures.

9. The segmented stent graft of claim 7, wherein the middle helical strut comprises a helical start wave rod, a helical end wave rod, and a helical portion connected between the helical start wave rod and the helical end wave rod, the helical start wave rod being a first second wave rod of the middle helical strut, the helical end wave rod being a last second wave rod of the middle helical strut extending in a helical direction.

10. The segmented stent graft of claim 9, wherein the proximal and/or distal ends of the middle helical scaffold are attached to the ring structure by winding, welding or steel sleeve fixation.

11. The segmented stent graft of claim 10, wherein the helical start wave rod comprises a helical start extension connected to one of the first wave rods in the first loop structure to connect the proximal annular scaffold to the central helical scaffold.

12. The segmented stent graft of claim 11, wherein the connection of the helical start extension to one of the first struts of the first loop structure comprises the connection of the helical start extension to one of the first struts of the first loop structure closest to the central helical scaffold.

13. The segmented stent graft of claim 10, wherein the helical terminal wave rod comprises a helical terminal extension connected to one of the first wave rods in the second annular structure to connect the central helical scaffold to the distal annular scaffold.

14. The segmented stent graft of claim 13, wherein the connection of the helical terminus extension to one of the first struts in the second annular structure comprises the connection of the helical terminus extension to one of the first struts in the second annular structure closest to the central helical scaffold.

15. The segmented stent graft of claim 3, wherein the second peaks of two axially adjacent second waveform elements lie on the same axis.

16. The segmented stent-graft of claim 2, wherein the middle helical strut extends from a proximal end to a distal end, the middle helical strut comprising a helix comprised of helical elements, each helical element having a helix angle of 1-75 °.

17. The segmented stent-graft of claim 2, wherein the support scaffold is woven from a continuous filament.

18. The segmented stent graft of claim 17, wherein the continuous wire is a single wire or a composite wire of multiple wires.

19. The segmented stent graft of claim 18, wherein the strength of the proximal annular scaffold is greater than the strength of the central helical scaffold.

20. The segmented stent graft of claim 19, wherein the wire diameter of the wire used for the proximal annular scaffolding is larger than the wire diameter of the wire used for the central helical scaffolding and the distal annular scaffolding.

21. The segmented stent graft of claim 19, wherein the proximal annular scaffolding is formed from a wire material having a stiffness greater than the stiffness of the central helical scaffolding.

22. The segmented stent graft of claim 1, wherein the support scaffold is in a straight, constant diameter tubular configuration or a non-constant diameter conical tubular configuration.

23. The segmented membrane stent of claim 2, wherein the distal annular support frame comprises a transitional second annular structure disposed on a side of the transitional second annular structure distal from the proximal annular support frame; the second annular transition structure forms a horn shape, and the second annular transition structure gradually increases in diameter from the proximal end to the distal end.

24. The segmented stent graft of claim 1, wherein the cover comprises an inner cover and an outer cover, the support scaffold is disposed between the inner and outer covers, and the inner cover is disposed inside the support scaffold and the outer cover is disposed outside the support scaffold.

25. The segmented stent graft of claim 2, wherein the segmented stent graft further comprises at least one visualization point.

26. A method for preparing a segmented stent graft, comprising:

winding the inner layer film on the film-coating mold rod;

sleeving a support framework on the inner-layer coating film, wherein the support framework is tightly connected with the layer coating film;

and wrapping the supporting framework with an outer-layer covering film.