CN212037829U - Covered stent - Google Patents

Abstract

The utility model relates to a covered stent, including main part support and branch's support, branch's support has relative near-end opening and distal end opening, and one of them is located in near-end opening and distal end opening the lateral wall of main part support, and the lumen of branch's support is linked together with the lumen of main part support, covered stent still includes and wears to locate preset the seal wire in the inner chamber of branch's support, and can be to getting into preset the seal wire of branch's support carries out spacing limit structure, and limit structure is located the outer wall or the inner wall of main part support, and limit structure is close to branch's support opening. The utility model discloses a tectorial membrane support is equipped with limit structure on the main part support, and limit structure sets up in the position relative with the distal end opening of branch's support, utilizes limit structure to the radial spacing of presetting the seal wire to make and preset the seal wire and can not take place the deflection and be difficult to the propelling movement, with the propelling movement smooth and easy nature of effective improvement preset seal wire, reduce the propelling movement degree of difficulty.

Description

Covered stent

Technical Field

The utility model relates to the technical field of medical equipment, especially, relate to a tectorial membrane support.

Background

The thoraco-abdominal aortic aneurysm refers to abdominal aortic aneurysm affecting abdominal trunk, superior mesenteric artery and renal artery, and is one of the difficulties in vascular surgical treatment due to high mortality and great operation difficulty, and the current methods for treating thoraco-abdominal aortic aneurysm mainly include: 1) traditional surgical procedures; 2) performing hybridization operation; 3) and (4) performing intracavity treatment. Compared with the traditional surgical operation and the hybrid operation, the intracavity treatment of the thoraco-abdominal aortic aneurysm becomes one of the hot points of interventional therapy development due to the advantages of small wound, few postoperative complications and the like.

The fenestration stent technology and the branch stent technology are main means for treating thoracoabdominal aortic aneurysm in the current cavity, wherein the fenestration stent has high requirement on stent positioning, the anchoring areas of the branch covered stent and the main stent are shorter, and the incidence probability of endoleak is higher. The branch type bracket has a lower incidence rate of internal leakage and lower positioning difficulty than a windowing bracket because the main body bracket and the branch bracket anchoring area are long. However, when the branch stent is connected with the branch covered stent, in order to establish a path between the main stent and the branch artery, the guide catheter needs to pass through the stent branch and then is selected into the branch artery cavity, and for complicated and distorted aneurysms, the difficulty of the guide wire passing through the stent branch is high, so the preset guide wire technology is widely adopted in the branch stent at present, the preset guide wire is preset in the branch, the preset guide wire is caught through the upper limb artery access, the guide catheter is sent into the branch artery along the preset guide wire, and then the implantation of the branch stent is completed.

However, during pre-guidewire capture, the pre-guidewire needs to be advanced a distance toward the distal end of the conveyor so that the distal end of the pre-guidewire passes through the end of the stent and away from the stent and the conveyor for capture. When the preset guide wire is pushed towards the far end, the far end of the preset guide wire is easy to block, and when the far end resistance of the preset guide wire is too large, the preset guide wire is easy to deviate from the pushing direction to be deflected, so that the pushing is difficult, and even the preset guide wire slides out of the branch.

SUMMERY OF THE UTILITY MODEL

Based on this, the utility model provides a covered stent can produce good spacing and direction effect to presetting the seal wire to the solution presets the technical problem of seal wire propelling movement difficulty.

The utility model provides a covered stent, includes main part support and branch support, branch support has relative near-end opening and distal end opening, near-end opening with one of them is located in the distal end opening the lateral wall of main part support, just the lumen of branch support with the lumen of main part support is linked together, covered stent is still including presetting the seal wire, it wears to locate to preset the seal wire in the lumen of branch support, covered stent still includes limit structure, limit structure can be to getting into branch support's the seal wire that presets carries on spacingly, limit structure is located on the outer wall or the inner wall of main part support, just limit structure is close to branch support's opening.

In an embodiment, the limiting structure includes at least one limiting member, and the limiting member and the surface of the main body bracket enclose to form a through hole, and the preset guide wire axially passes through the through hole.

In an embodiment, the limiting structure includes 2 or more than 2 limiting members, and the 2 or more than 2 limiting members are arranged along an axis of the branch support or arranged in a curve.

In an embodiment, the limiting member includes a wire, and both ends of the wire are fixed to the outer wall of the main body bracket to form the through hole in an enclosing manner.

In an embodiment, the 2 or more than 2 limiting members are distributed in a staggered manner in the axial direction of the main body stent, and the staggered portions of the 2 or more than 2 limiting members jointly enclose a channel for the preset guide wire to pass through.

In one embodiment, the axial distance between two adjacent limiting members is 5 mm-20 mm.

In one embodiment, the axial distance between the position limiting member closest to the end opening of the branch support and the end opening of the branch support is 5 mm-20 mm.

In an embodiment, the retaining member includes a sheet fixed on the main body frame and forming a channel for the preset guide wire to pass through with a surface of the main body frame.

In an embodiment, the axial length of the position-limiting member ranges from 10mm to 40mm, and the through hole surrounded by the position-limiting member has an outlet end, and the outlet end is opposite to the end opening of the branch bracket.

In one embodiment, the outlet end is axially spaced from the end opening of the branch stent by 5mm to 25 mm.

The utility model provides a be equipped with limit structure on tectorial membrane support's the main part support, limit structure sets up in the position relative with the tip opening of branch's support, utilizes limit structure to the radial spacing of presetting the seal wire to make and preset the seal wire and can not take place the deflection and be difficult to the propelling movement, with the propelling movement smooth and easy nature of presetting the seal wire effectively improves, reduces the propelling movement degree of difficulty.

Drawings

FIG. 1 is a schematic structural view of a stent graft;

FIG. 2 is a schematic view of the pre-positioned guidewire being blocked from radial deflection during advancement of the pre-positioned guidewire in the stent graft shown in FIG. 1;

fig. 3(a) to 3(b) are schematic structural diagrams of a stent graft according to embodiment 1 of the present invention, wherein fig. 3(a) shows that the inner branch and the outer branch of the stent graft are respectively provided with corresponding preset guide wires, fig. 3(b) shows a cross section of the preset guide wires and the preset guide wires pass through the through holes defined by the limiting members, and fig. 3(c) shows that the preset guide wires pass through the overlapping region of the regions defined by the two limiting members;

FIG. 3(d) is a schematic view showing the stent graft of example 1 after it has been released from the sheath portion of the delivery device;

FIG. 4(a) is a schematic structural view of the stent graft of example 2;

FIG. 4(b) is a schematic view showing the stent graft of example 2 after it has been released from the sheath section of the delivery device;

FIG. 4(c) is a schematic view showing the arrangement of the limiting members in the stent graft of example 2;

FIG. 5(a) is a schematic structural view of the stent graft of example 3;

FIG. 5(b) is a schematic view showing the stent graft of example 3 in a state released from the sheath portion of the delivery device.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

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

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

In the field of interventional medicine, for implants such as stents, the direction of blood inflow is defined as the "proximal end" and the direction of blood outflow is defined as the "distal end"; for the delivery device, the end closer to the operator is defined as the "proximal end", the end farther from the operator is defined as the "distal end", and the "proximal end" and the "distal end" of any part of the implant and the delivery device are defined according to this principle. "axial" generally refers to the length of the implant and carrier components, and "radial" generally refers to the direction perpendicular to the "axial" direction, and defines both "axial" and "radial" directions for either component of the implant and carrier in accordance with this principle.

FIG. 1 illustrates a stent graft 10, the stent graft 10 being a branched stent graft.

Specifically, the stent graft 10 includes a main body stent 11 and a branch stent, the main body stent 11 is tubular, the branch stent is hollow inside and open at both ends, and specifically, the branch stent has opposite proximal and distal openings. One of the proximal opening and the distal opening is connected to the side wall of the main body stent 11, and the lumen of the branch stent communicates with the lumen of the main body stent 11.

The stent graft may include an inner branch 12 or an outer branch 13, or the stent graft 10 may include a stent graft having both an inner branch 12 and an outer branch 13. The number of the branch stents may be 1-4, and the type and number of the branch stents of the stent graft 10 are not limited herein.

It should be noted that the inner branch 12, i.e. the branch support, is located inside the main body support 11, and a distal opening 12b is formed on the side wall of the main body support 11, i.e. the distal opening 12b of the inner branch 12 is connected with and penetrates through the side wall of the main body support 11. For example, in the stent graft 10 shown in FIG. 1, the main body stent 11 includes a tapered portion 111, and the inner branch 12 is disposed behind the main body stent 11 and connected to the tapered portion 111 at its distal end, that is, the distal end opening 12b of the inner branch 12 is formed in the tapered portion 111 of the main body stent 11, and then the distal end opening 12b of the inner branch 12 is elliptical in shape with respect to the inner branch 12 having a substantially circular tube shape. Accordingly, the outer branch 13, i.e., the branch stent, is located outside the main body stent 11, and the proximal opening 13a of the outer branch 13 is formed in the sidewall of the main body stent 11 to communicate with the lumen of the main body stent 11, i.e., the proximal opening 13a of the outer branch 13 is connected to and penetrates through the sidewall of the main body stent 11.

With continued reference to fig. 1, the lumens of the inner branch 12 and the outer branch 13 may be separately fed with a guidewire 20, and when establishing the branch artery path, a capture device may be introduced into the upper extremity artery access to the descending aorta to push the guidewire 20 proximally from the delivery device for capture.

As shown in fig. 2, the inventor found that when the resistance of the distal end 20a of the guide wire 20 is too high, the guide wire 20 is difficult to push, and even slides out of the corresponding branch and into the tumor, thereby losing the function of the guide wire 20.

Taking the preset guide wire 20 corresponding to the pushing inner branch 12 as an example, the preset guide wire 20 moves towards the distal end under the pushing of the conveyor located at the proximal end, because the distal end 20a of the preset guide wire 20 needs to enter the inner cavity of the main body support 11 through the distal end 12b of the inner branch 12 and finally pass through the proximal end 11a of the main body support 11, during this process, the distal end 20a of the preset guide wire 20 will receive a certain resistance F, and when the resistance F received by the distal end 20a of the preset guide wire 20 is too large, the preset guide wire 20 will be forced to be pushed, so that the preset guide wire 20 is bent to deviate from the pushing direction, and further the preset guide wire 20 is difficult to continue to be pushed, and even will slide out of the corresponding inner branch 12 and enter a tumor body, so that the function of the preset guide wire. To this end, the inventor improves the structure of the stent graft 10, so that the stent graft 10 can provide a better guiding effect for the preset guide wire 20, which is beneficial to improving the pushing smoothness of the preset guide wire 20, and the preset guide wire 20 is prevented from deviating from the pushing direction and easily sliding out from the branch stent.

Specifically, the outer wall of the stent graft 10 shown in fig. 1 is provided with a limiting structure, and the limiting structure is arranged on the outer wall of the main stent and close to the distal opening of the branch stent, so as to limit the radial deviation amplitude of the preset guide wire 20 by using the limiting structure, that is, the preset guide wire 20 has a good guiding effect when being pushed along the axial direction, thereby preventing the preset guide wire 20 from deviating too much in the pushing direction and being easily bent, effectively improving the pushing smoothness of the preset guide wire 20, and reducing the pushing difficulty. It will be appreciated that the retention structure may also be disposed on the main body support or the inner wall adjacent to the proximal opening of the branch supports. That is, the stopper structure may be provided on the inner wall or the outer wall of the main body bracket, and close to the end opening of the branch bracket.

Example 1

The stent graft 10 may be provided with 1, 2, or 2 or more, and the type of the stent graft may be an inner stent graft 12 or an outer stent graft 13. When more than 2 branched stents are provided on the stent graft 10, some of the branched stents may be the inner branch 12 and the other branched stents may be the outer branch 13. Therefore, when the stent graft 10 is provided with the limiting structure, the limiting structure can be arranged at the corresponding position of the main stent 11 according to actual needs, so as to limit and guide the preset guide wire 20 corresponding to the corresponding branch stent.

For example, as shown in connection with FIG. 3(a), in some embodiments, the stent graft 10 comprises 2 branch stents, one of which is the inner branch 12 and the other of which is the outer branch 13. When the preset guide wire 20 preset in the inner branch 12 needs to be limited and guided, a limit structure corresponding to the inner branch 12 can be arranged at a corresponding position of the main body support 11. Correspondingly, a limiting structure corresponding to the outer branch 13 may be disposed at a corresponding position of the main body support 11, so as to realize limiting and guiding the preset guide wire 20 that needs to pass through the outer branch 13, improve the smoothness of the preset guide wire 20 when the corresponding branch support is pushed, reduce the pushing difficulty, and avoid the phenomenon that the preset guide wire 20 deviates from the pushing direction and cannot be pushed continuously.

As shown in fig. 3(a), the position and number of the position-limiting structures on the main body support 11 can be configured according to actual needs.

For example, the position-limiting structure corresponding to the inner branch 12 has an effect of limiting and guiding the preset guide wire 20 passing through the inner branch 12, so that the position-limiting structure only needs to be arranged at a position of the main body support 11 opposite to the distal end opening 12b of the inner branch 12, and specifically, the position-limiting structure can be arranged at a position close to the distal end opening of the inner branch on the outer wall of the main body support. Specifically, the guidewire 20 is advanced from the stop structure through the distal opening 12b of the inner branch 12 and into the lumen of the inner branch 12, such that as the guidewire 20 is advanced toward the distal end of the carrier, the distal end 20a of the guidewire 20 will exit the proximal opening 12a of the inner branch 12 and ultimately exit the proximal end of the main body stent 11 for capture by a capture device. Because the preset guide wire 20 penetrates through the limiting structure, the limiting structure is utilized to achieve a good radial limiting effect on the preset guide wire 20, the preset guide wire 20 is stably pushed in the axial direction, and the influence on the pushing smoothness caused by deflection when the resistance F is too large in the pushing process of the preset guide wire 20 is further prevented. Therefore, by adopting the stopper structure provided at the position of the main body frame 11 opposite to the proximal end opening 12a of the inner branch 12, the difficulty of pushing the pre-set guide wire 20 at the corresponding inner branch 12 can be reduced.

It will be appreciated that in other embodiments, the stop structure may be disposed on the inner wall of the main body support adjacent to the proximal openings of the legs. Accordingly, the direction of advancement of the pre-guidewire may be advanced from the proximal end of the stent toward the distal end.

Correspondingly, the arrangement mode of the limiting structure corresponding to the outer branch 13 may refer to the limiting structure corresponding to the inner branch 12, specifically, the limiting structure which performs limiting and guiding on the preset guide wire 20 passing through the outer branch 13 is arranged at the position of the main body support 11 corresponding to the distal end opening 13b of the outer branch 13, and the limiting structure can also perform the limiting and guiding function on the preset guide wire 20 located in the outer branch 13, which is not described herein again.

It should be noted that the limiting structure corresponding to the inner branch 12 and the limiting structure corresponding to the outer branch 13 may be the same in structural form or may take different structural forms, and only the corresponding limiting structure may play a limiting and guiding effect on the preset guide wire 20 of the inner branch 12 or the outer branch 13.

The limiting structure provided on the main stent 11 of the stent graft 10 will be further described below by taking the limiting structure corresponding to the inner branch 12 as an example.

Referring to fig. 3(a), in some embodiments, the limiting structure includes at least one limiting member 112. For the stent graft 10, the main body stent 11 is of a tubular structure and includes a graft. The stopper 112 may be provided on the main body frame 11 so as to be fixed to the coating film, or may be directly fixed to the main body frame 11. For example, the stopper 112 is fixed to the film, and the stopper 112 may be connected to the film by heat sealing, bonding, fastening, sewing, or the like. Since the limiting member 112 is suitable for suturing when a wire is used, in some embodiments, the wire is integrally connected with the covering film in a suturing manner to form the limiting member, so that when the covering film is fixed to the main body stent 11, the limiting member 112 is fixed to a position of the main body stent 11 corresponding to the corresponding branch stent, so as to achieve a limiting and guiding effect on the preset guide wire 20 in the corresponding branch stent, thereby improving the smoothness of pushing the preset guide wire 20 and reducing the difficulty of pushing.

In some embodiments, the limiting structure includes 2 or more than 2 limiting members 112, and the arrangement direction of the limiting members 112 is consistent with the axial direction of the corresponding branch support.

Specifically, referring to fig. 3(a), the arrangement direction of the position-limiting members 112 corresponding to the inner branch 12 is aligned with the axial direction of the inner branch 12, so as to better exert a position-limiting guiding effect on the preset guide wire 20 passing through the inner branch 12. Accordingly, the arrangement direction of the position-limiting members 112 corresponding to the outer branch 13 is consistent with the axial direction of the outer branch 13, so as to better provide the position-limiting and guiding effect for the preset guide wire 20 passing through the outer branch 13.

As shown in fig. 3(b), the limiting member 112 comprises a wire made of a biocompatible material such as PTFE, dacron, and polypropylene, preferably a polyester suture.

After the limiting member 112 is connected to the main body frame 11, two ends 112a, 112b of the limiting member 112 are fixed on the main body frame 11 to form a through hole 113, specifically, the area enclosed by the limiting member 112 is the through hole 113. The preset guide wire 20 penetrates through the through hole 113, the limit part 112 limits the preset guide wire 20 in the through hole 113 in the radial direction, and then the limit part 112 can play a good guiding effect when the preset guide wire 20 is pushed along the axial direction, so that the pushing smoothness of the preset guide wire 20 is effectively improved, the preset guide wire 20 is prevented from bending and deviating from the pushing direction, and the pushing difficulty of the preset guide wire 20 is effectively reduced. The section of the through hole is similar to a semicircle, so that the preset guide wire can be more attached to the main body bracket.

In some embodiments, the diameter of the guide wire 20 may range from 0.1mm to 1.0mm, and the size of the through hole 113 is adapted to the diameter of the guide wire 20, specifically, the size of the through hole 113 is slightly larger than the diameter of the guide wire 20, so that the guide wire 20 can axially move through the through hole 113 of the position-limiting member 112.

In some embodiments, the area of the limiting member 112 on the main body support 11, i.e. the through hole 113, the orthographic projection area S of the cross section perpendicular to the axis of the main body support 11 satisfies the condition of S1 ≦ S ≦ 2S1, wherein S1 is the sectional area of the preset guide wire 20. With such a structure, the limiting member 112 can not only maintain the guiding effect on the preset guide wire 20, but also prevent the preset guide wire 20 from being easily swung in the circumferential direction when pushed due to an excessively large through hole 113 surrounded by the limiting member 112, which is not beneficial to capture.

In other embodiments, the through hole 113 for the preset guide wire 20 to pass through and having the radial limiting effect on the preset guide wire 20 is not defined by one limiting member 112, but is formed by two limiting members 112 that are distributed in a staggered manner in the circumferential direction of the main body support 11 and jointly defined.

Specifically, as shown in fig. 3(c), the 2 position-limiting members 112 are distributed in a staggered manner in the axial direction of the main body frame 11, and an orthogonal projection of a region surrounded by the 2 position-limiting members 112 on a cross section perpendicular to the axis of the main body frame 11 has an overlapping region 114, an area S2 corresponding to the overlapping region 114 is also a cross section area corresponding to a wall of the through hole 113 formed by the 2 position-limiting members 112, so that an area S2 corresponding to the overlapping region 114 also meets the following condition: s1 is not less than S2 is not less than 2S1, wherein S1 is the cross-sectional area of the preset guide wire 20. With this structure, the preformed guide wire 20 will pass through the overlapping region 114, that is, simultaneously pass through the region surrounded by the 2 limiting members 112, and then the wall of the through hole 113 formed by the surrounding of the 2 limiting members 112 will perform the radial limiting function on the preformed guide wire 20. The limiting parts are arranged in a staggered mode, the size of a space enclosed between a specific single limiting part and the outer surface of the main body support does not need to be considered, the limiting of the preset guide wire can be achieved by limiting the crossed overlapped area between 2 adjacent limiting parts, and the difficulty of the manufacturing process is reduced.

In some embodiments, the 2 limiting members 112 are distributed in a staggered manner in the circumferential direction of the main body support 11 to form through holes 113 which are commonly surrounded, and the preset guide wire 20 with a wire diameter of 0.35mm can pass through the through holes.

In some embodiments, as shown in fig. 3(a), when the limiting structure includes 2 or more than 2 limiting members 112, the axial distance d1 between two adjacent limiting members 112 ranges from 5mm to 20mm, for example, may be selected from 5mm, 10mm, 15mm, or 20 mm. Controlling the axial arrangement between the limiting members 112 within this distance range can prevent the axial distance between the limiting members 112 from being too large, and can also prevent the axial distance between the limiting members 112 from being too small. When the axial distance between the limiting members 112 is too large, the preset guide wire 20 is easy to slip out from between the limiting members 112, and the situation that when the distance is too small, the limiting members 112 are too dense and unnecessary materials are increased is prevented. The axial distance between the stop 112 closest to the distal opening of the branch support and the distal opening of the branch support may range from 5mm to 20mm, for example 5mm, 10mm, 15mm or 20 mm.

Referring to fig. 3(a), taking the limiting structure corresponding to the inner branch 12 as an example, the axial distance d2 between the limiting member 112 closest to the inner branch 12 and the distal opening 12b of the inner branch 12 has a value ranging from 5mm to 20mm, and in this distance range, the distance between the limiting member 112 and the distal opening of the inner and outer branches 13 is prevented from being too large, so that the preset guide wire 20 is prevented from slipping out from the distance between the limiting member 112 and the distal opening.

Referring to fig. 3(d), for example, when the stent graft 10 is not yet completely released from the sheath 30 of the delivery device, the preformed guide wire 20 is pushed such that the preformed guide wire 20 enters the distal opening 12b of the inner branch 12 corresponding to the limiting member 112 under the radial limitation of the limiting member 112, and finally exits from the proximal end 11a of the main stent 11, so that the preformed guide wire 20 is caught by a catcher (not shown) to establish a branch entry path.

Example 2

Referring to fig. 4(a), the same or similar parts of the stent graft 10 of embodiment 2 and the stent graft 10 of embodiment 1 are not repeated herein, but the main difference between the two parts is that in the stent graft 10 of embodiment 2, in the limiting structure corresponding to the distal opening of the branch stent, the limiting members 112 are not arranged along the axis of the branch stent, but arranged in a curve.

Taking the limiting structure corresponding to the inner branch 12 as an example, the limiting members 112 are distributed in a curved line at the position of the main body bracket 11 opposite to the distal end opening 12b of the inner branch 12. A through hole 113 surrounded by the limiting member 112 after being connected to the main body bracket 11 can allow the preset guide wire 20 to pass through, which is specifically referred to embodiment 1 and will not be described herein.

As shown in fig. 4(b), when the aneurysm neck angle is large, and the stent graft 10 is implanted into the target position of the blood vessel, the stent graft 10 may be distorted, so as to distribute a plurality of limiting members 112 in the main body stent 11 in a curved manner, and adapt to the requirement of pushing and guiding the preset guide wire 20 after the stent graft 10 is distorted, so that the preset guide wire 20 is pushed more stably.

It should be noted that the preset guide wire 20 path may be set according to the opening direction of the inner branch 12 and the position of the conveyor sheath 30, and the plurality of stoppers 112 may be arranged along the preset guide wire 20 path.

As shown in FIG. 4(b), after the stent graft 10 is partially advanced from the delivery sheath 30 and implanted into the blood vessel, the centerline L1 of the lumen of the inner branch 12 is angled with respect to the centerline L2 of the delivery sheath 30, i.e., the stent graft 10 is twisted.

For ease of understanding, the curved arrangement of the plurality of limit stops 112 is described further below in terms of only one possible twisting configuration of the stent graft 10.

Referring to FIGS. 4(b) and 4(c), L1 and L2 are projected onto the center plane of the stent graft 10, which is defined as a plane passing through the center axis of the main stent graft 11 and perpendicular to the plane defined by the center axes of the main stent graft 11 and the inner stent graft 12. Making an arc L3 tangent to both L1 and L2, the tangent points being p0 and p1, the radius of arc L3 being in the range 10mm < r < 100mm, the central angle a of the arc being in the range 0 < a < 90 °, and the curve passing through arc segment L3 and extending along L1 at tangent point p1 and extending along L2 at tangent point p2 being referred to as L0, where, the position-limiting members 112 are arranged on the main body frame 11 according to the curve L0 such that the projection of the plurality of position-limiting members 112 on the central plane is located on the curve L0, and then when the guidewire 20 is advanced, under the radial constraint of the plurality of stoppers 112, the guidewire 20 will move along the path generally constructed by the curve L0, therefore, in the process of pushing the preset guide wire 20, the pushing direction of each section is basically consistent with the axial direction of each section, and then in the process of pushing, the preset guide wire 20 is not deflected in the radial direction, so that the preset guide wire can be pushed to the inner branch 12 more smoothly.

In this embodiment, the limiting member 112 adopts such a curved distribution manner, even when the neck of the aneurysm is twisted, when the preset guide wire 20 is pushed to capture, since the preset guide wire 20 is constrained by the limiting member 112, the pushing path is smoother, and the pushing force applied to the preset guide wire 20 is substantially consistent with the axial direction of the preset guide wire 20, so that the preset guide wire 20 is pushed more stably and smoothly.

Example 3

The stent graft 10 of example 3 is identical to or similar to the stent graft 10 of examples 1 and 2, and is not repeated herein, except that the structure of the position limiting member 112 of the position limiting structure is different in the stent graft 10 of example 3.

Specifically, as shown in fig. 5(a), the limiting member 112 includes a sheet material, and after the sheet material is fixed to the main body support 11, a through hole 113 for the preset guide wire 20 to pass through is formed to extend a certain length along the axial direction, so as to form a structural form similar to a channel. For example, the axial length of the stop 112 may be selected to range from 10mm to 40mm, i.e., to form a channel of 10mm to 40mm in length. Therefore, the preset guide wire 20 can be continuously limited in the radial direction in the pushing process, so that a better axial guiding effect is obtained and the preset guide wire 20 is prevented from deviating from the pushing direction.

In this embodiment, the limiting member 112 may also be directly fixed on the main body support 11, or may also be fixed on a covering film of the main body support 11. For the fixing manner of the limiting member 112, reference may be made to embodiment 1, and details are not described herein.

The limiting member 112 may also be made of a biocompatible material such as PTFE, dacron, or polypropylene.

For convenience of description, one end of the preset guide wire 20, which is similar to the channel formed by the limiting member 112, is used as an outlet end 1121, the outlet end 1121 is opposite to the distal end opening of the branch stent, after the preset guide wire 20 passes through the limiting member 112, the preset guide wire 20 enters the distal end opening of the corresponding branch stent from the outlet end 1121, and then when the preset guide wire 20 is pushed, the preset guide wire 20 enters the lumen of the branch stent from the distal end opening of the branch stent. The section of the through hole is similar to a semicircle, so that the preset guide wire can be more attached to the main body bracket

As shown in fig. 5(a), the axial distance d3 between the outlet end 1121 of the limiting member 112 and the distal opening of the corresponding branch support may be in a range of 5 mm-25 mm, for example, 5mm, 10mm, 15mm, 20mm or 25 mm. The axial distance between the outlet end 1121 of the limiting member 112 and the distal end opening of the branch bracket is controlled within this range, so that the built-in guide wire can be prevented from slipping out from between the outlet end 1121 of the limiting member 112 and the distal end opening of the branch bracket, and the material consumption of the limiting member 112 can be reduced as much as possible, thereby saving the cost.

As shown in FIG. 5(b), when the stent graft 10 is not yet fully released, the proximal end 11a of the main stent graft 11 is pushed out from the delivery sheath 30, and the distal end of the stent graft 10 is still accommodated in the delivery sheath 30, at this time, the stent graft 10 may be twisted due to the included angle between the delivery sheath 30 and the axis of the stent graft 10. In the stent graft 10 of the embodiment, the material of the limiting member 112 can adapt to the bending requirement, that is, the limiting member 112 has flexibility, and then in the process of pushing the preset guide wire 20 to capture and establish a branch access, even if the stent graft 10 is twisted, the limiting member 112 can also conform to the bending requirement, thereby always having an axial guiding effect on the preset guide wire 20, so that the preset guide wire 20 can be pushed in the axial direction to prevent the radial deflection of the preset guide wire 20, thereby reducing the pushing difficulty of the preset guide wire 20, and facilitating the preset guide wire 20 to smoothly pass through the branch stent corresponding to the limiting member 112.

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

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. The utility model provides a covered stent, its characterized in that, includes main part support and branch support, branch support has relative near-end opening and distal end opening, near-end opening with one of them is located in the lateral wall of main part support, just the lumen of branch support with the lumen of main part support is linked together, covered stent is still including presetting the seal wire, it wears to locate to preset the seal wire in the lumen of branch support, covered stent still includes limit structure, limit structure can carry on spacingly to the preset seal wire that gets into branch support, limit structure is located on the outer wall or the inner wall of main part support, just limit structure is close to branch support's opening.

2. The stent graft as claimed in claim 1, wherein the limiting structure comprises at least one limiting member, and the limiting member and the surface of the main stent form a through hole, and the preset guide wire axially passes through the through hole.

3. The stent graft as recited in claim 2, wherein the limiting structure comprises 2 or more limiting members, and the 2 or more limiting members are arranged along the axis of the branch stent or arranged in a curve.

4. The stent graft of claim 3, wherein the retaining member comprises a wire, both ends of the wire are fixed to the outer wall of the main stent to form the through hole.

5. The stent graft as recited in claim 3, wherein the 2 or more than 2 position-limiting members are distributed in a staggered manner in the axial direction of the main stent, and the staggered portions of the 2 or more than 2 position-limiting members jointly enclose a channel for the preset guide wire to pass through.

6. The stent graft of claim 3, wherein the axial spacing between two adjacent limiting members is between 5mm and 20 mm.

7. The stent graft of claim 3, wherein the axial distance between the stop closest to the end opening of the branch stent and the end opening of the branch stent is between 5mm and 20 mm.

8. The stent graft as recited in claim 2, wherein the retaining member comprises a sheet material secured to the main body stent and forming a channel with a surface of the main body stent for the pre-guidewire to pass through.

9. The stent graft as recited in claim 8, wherein the retaining member has an axial length in the range of 10mm to 40mm, and the through-hole surrounded by the retaining member has an exit end opposite to the end opening of the branch stent.

10. The stent graft of claim 9, wherein the outlet end is axially spaced from the end openings of the branch stents by between 5mm and 25 mm.

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