CN114432000A - Covered stent - Google Patents

Abstract

The present invention relates to a covered stent, comprising a stent and a covered film covered on the stent, the covered film has an axially opposite first end and a second end, the first end of the covered film is on the A channel is formed having an open state and a closed state, the channel being open when impinged by the fluid and closed when there is no fluid impingement. The covered stent can avoid affecting the blood supply of branch blood vessels.

Description

stent graft

technical field

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

Background technique

This section provides merely background information related to the present disclosure and is not necessarily prior art.

Aneurysm is a common clinical vascular disease, which mostly occurs in the elderly. This disease easily leads to rupture of the aneurysm, which poses a great threat to the life of the patient.

With the continuous development of medical technology, the use of minimally invasive surgery to implant stent-grafts into the body, and the treatment of aortic aneurysms and dissecting aneurysms, has been widely used because of its small trauma and rapid recovery. This treatment method is to compress the stent-graft into the delivery device, guide it into the human body along the pre-implanted guide wire track, and after reaching the lesion location, release the stent-graft to isolate the lesion, reconstruct the blood flow channel, aneurysm and dissection After the blood supply is lost, the residual blood in the tumor cavity is gradually thrombosed and muscled into vascular tissue. The expanded aneurysm wall shrinks due to compression and gradually returns to its original state, so as to achieve the purpose of treating aortic aneurysms and dissecting aneurysms.

If the stent-graft is implanted close to the branch, the proximal covering may block the opening of the branch vessel, affect the blood supply of the branch vessel, and cause harm to the patient.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a stent-graft that can avoid affecting the blood supply of branch vessels.

A covered stent, comprising a stent and a covering covering the stent, the covering having an axially opposite first end and a second end, the first end of the covering is formed with A channel in an open state and a closed state, the channel being open when impacted by fluid and closed when not impacted by fluid.

In one of the embodiments, there are a plurality of the channels, and the plurality of channels are arranged at intervals along the circumferential direction of the coating film.

In one embodiment, the channel is an opening formed at the first end, the opening extending axially from the end of the first end toward the second end.

In one of the embodiments, the channel includes a first edge line and a second edge line, and in a closed state, the first edge line and the second edge line are coincident or aligned; between the first edge line and the second edge line one is overwritten.

In one embodiment, the channel includes a first edge line, a second edge line, a third edge line and a fourth edge line, and in a natural state, the first edge line and the third edge line coincide Or aligned, the second edge line and the fourth edge line are coincident or aligned; or, the third edge line and the fourth edge line are in a covered state.

In one of the embodiments, in a natural state, the first edge line and the third edge line are overlapped or aligned, the second edge line and the second fourth edge line are overlapped or aligned, and the The first edge line extends from the middle of the second edge line in a direction perpendicular to the second edge line.

In one embodiment, the stent-graft further includes a sealing member, and a window is opened on the first end of the covering film, the sealing member is disposed on the covering film, and can be opened to cover the covering window to form the channel.

In one of the embodiments, the window has an edge line which, in a closed state, is covered by the seal; in an open state, at least part of the edge line is not covered by the seal.

In one embodiment, the sealing member covers the window, and the opposite ends of the sealing member are respectively connected with the covering film, and the parts between the opposite ends of the sealing member overlap with each other. The channel is formed by being attached to the cover so that the seal can openably cover the window.

In one embodiment, the sealing member covers the window, and one end of the sealing member is connected with the film, so that the sealing member can openably cover the window to form the channel.

In one embodiment, the stent-graft further includes a marker structure, the marker structure is located at the first end of the cover, and the marker structure and the channel are staggered from each other.

A channel is formed on the first end of the membrane of the above-mentioned stent-graft. When the stent-graft is implanted into a blood vessel, since the channel is in an open state when it is impacted by blood flow, even if the first end of the membrane is located at the branch site , and will not affect the blood supply of the branch blood vessels because of the blockage of the blood flow of the branch blood vessels.

Description of drawings

1 is a schematic structural diagram of a stent graft according to an embodiment;

FIG. 2 is a schematic view of the channel of the stent-graft shown in FIG. 1 in an open state;

Fig. 3 is a partial enlarged view of Fig. 2;

FIG. 4 is a schematic diagram of the state of the stent-graft shown in FIG. 1 being implanted in a blood vessel;

5 is a schematic diagram of another state of the stent-graft shown in FIG. 1 being implanted in a blood vessel;

6 is a schematic structural diagram of a stent graft according to another embodiment;

FIG. 7 is a schematic view of the channel of the stent-graft shown in FIG. 6 in an open state;

Fig. 8 is a partial enlarged view of Fig. 7;

9 is a schematic diagram of a channel of the stent graft according to another embodiment in an open state;

Fig. 10 is a partial enlarged view of Fig. 9;

11 is a schematic structural diagram of a stent graft according to another embodiment;

Fig. 12 is a partial enlarged view of Fig. 11;

Fig. 13 is a schematic structural diagram of a channel of the stent-graft shown in Fig. 11;

14 is a schematic structural diagram of a stent graft according to another embodiment;

Fig. 15 is a partial enlarged view of Fig. 14;

16 is a schematic structural diagram of a stent graft according to another embodiment;

Fig. 17 is a partial enlarged view of Fig. 16;

18 is a schematic structural diagram of a channel of another embodiment;

19 is a schematic diagram of a partial structure of a stent graft according to an embodiment;

FIG. 20 is a schematic structural diagram of a stent graft according to another embodiment.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementation disclosed below.

Unless otherwise defined, 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 terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

As used herein, "proximal" is defined as the end close to the heart, and "distal" is defined as the end away from the heart. "Axial" 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, and "radial" refers to the direction perpendicular to the above-mentioned axial direction.

Referring to FIG. 1 , a stent graft 100 according to an embodiment includes a stent 10 and a graft 20 covering the stent 10 .

The stent 10 plays a supporting role for supporting the membrane 20 . The stent 10 is a hollow lumen structure with open ends. The stent 10 includes a plurality of wave rings 110 spaced apart in the axial direction. Each wave ring 110 is a closed structure with wave crests and wave troughs formed by a plurality of wave rods 112 connected end to end. The material of the corrugated ring 110 is a material with good biocompatibility and good elasticity. For example, Nitinol, stainless steel, etc.

In one embodiment, two adjacent wave rings 110 are connected by an axial connecting member (not shown). The shape of the axial connector is not limited, and can be a straight rod, a special-shaped rod, or the like.

In another embodiment, no axial connecting member is provided between two adjacent corrugated rings 110, and a plurality of corrugated rings 110 are connected together by the covering film 20, so that the whole of the stent graft 100 is formed. Good flexibility.

The membrane 20 is used to isolate the lesion and blood flow. The covering film 20 covers the stent 10 to form a lumen structure with open ends. The material of the coating 20 is a material with good biocompatibility, for example, e-PTFE, PET, and the like.

The membrane 20 has a first end 210 and a second end 220 that are axially opposed. A channel 230 having an open state and a closed state is formed on the first end 210 . The channel 230 is open when impinged by fluid (eg, blood flow) and closed when there is no fluid impingement. In a natural state, the channel 230 is in a closed state.

For the convenience of description, among the plurality of corrugated rings 110, the corrugated ring closest to the end of the first end 210 of the coating 20 is denoted as corrugated ring 110A, and the rest of the corrugated rings are referred to as corrugated rings 110 to show the difference.

When the stent graft 100 is implanted into the blood vessel, since the channel 230 is in an open state when it is impacted by blood flow, even if the first end 210 of the graft film 20 is located at the branch site, the branch will not be affected by blocking the blood flow of the branch blood vessel. vascular blood supply.

In one embodiment, as shown in FIG. 1 , the channel 230 is an opening formed at the first end 210 (the channel 230 may be multiple). The opening extends axially (the extending direction of the longitudinal center axis I-I of the stent graft 100 ) from the end of the first end 210 toward the direction close to the second end 220 . It can be understood that the length of the channel 230 is approximately equal to the axial length of the covered area of the stent-graft 100 at the branch vessel site, or slightly larger than the axial length of the covered area of the stent-graft 100 at the branch vessel site, so as to ensure blood flow It is smooth and avoids being too long to affect the occlusion effect of the rest of the stent graft 100 .

In one embodiment, the opening is an elongated slit extending axially from the end of the first end 210 toward the direction close to the second end 220 . When the stent-graft 100 is in a natural state (a state in which the stent-graft is not compressed or subjected to fluid impact), the channel 230 includes a first edge line and a second edge line (not shown), the first edge line and the The second edge lines overlap (or one of the first edge line and the second edge line is blocked or covered), so that the opening appears as a line, and this state is also the state that the channel 230 appears when closed. Please refer to FIG. 2 and FIG. 3 together. When the first end 210 of the covering film 20 is impacted by the fluid, the covering films 20 on both sides of the channel 230 are swept away by the fluid and fold or have a tendency to fold, so that the channel 230 is open. The membranes 20 on both sides of the channel 230 are flushed by the fluid and folded or have a tendency to fold to form a folded portion 230A and a folded portion 230B, so that the channel 230 is opened to form a triangle so as to facilitate the passage of fluid. In a natural state, the edges of the folded portion 230A and the folded portion 230B are aligned or overlapped, so that the channel 230 is in a closed state.

In one embodiment, the channel 230 is formed by directly cutting a slit at the first end 210 of the cover film 20 . In another embodiment, a triangular notch is formed by cutting the first end 210 of the covering film 20 , and one side of the triangular notch is located on the plane where the end face of the first end 210 of the covering film 20 is located. A folded portion 230A and a folded portion 230B are provided at the triangle, and the two edges of the folded portion 230A and the folded portion 230B are respectively aligned with the other two sides of the triangle, and the two edges are aligned with the other two sides of the triangle. Edge connection. The folded portion 230A and the folded portion 230B can be provided on the first end 210 of the cover film 20 by using methods known to those skilled in the art, including but not limited to sewing, gluing, and the like. In an embodiment in which one of the first edge line and the second edge line is blocked, one of the fold-over portion 230A and the fold-over portion 230B is at least partially blocked or covered by the other.

As shown in FIG. 4 , when the stent-graft 100 is implanted into the branched blood vessel 10, the channel 230 and the branched blood vessel 101 are radially opposite or partially opposite in the radial direction, that is, the part with the channel 230 is in a suspended state, It is not blocked or resisted by the blood vessel wall, so that under the impact of blood flow, the channel 230 is in an open state, and the blood flow flows from the opened channel 230 to the branch blood vessel 101 . The channel 230 extends axially from the end of the first end 210 to the direction close to the second end 220 , that is, the end of the channel 230 away from the second end 220 is an open end, so that the channel 230 is easily flushed by the blood flow, so as to protect the blood flow. Flow is smooth.

The channel 230 is formed by directly cutting a slit at the first end 210 of the cover film 20 . This method ensures that the channel 230 can be opened under the impact of blood flow, and the preparation is simple. The channel 230 is formed by cutting the first end 210 of the covering film 20 to form a triangular notch and then disposing the folded portion 230A and the folded portion 230B, so that the channel 230 can be easily opened to ensure smooth blood flow.

As shown in FIG. 5 , after the stent graft 100 is implanted into the branched blood vessel 10 , the first end 210 of the stent graft 20 does not extend to the branch blood vessel 101 , so that the channel 230 (not shown in FIG. 5 ) is connected to the branch blood vessel. 101 are not opposite to each other in the radial direction, but the portion of the membrane 20 of the channel 230 opened there is close to the blood vessel wall. Moreover, when the stent-graft 100 is in the implanted state, it is in a radially compressed state to a certain extent (the diameter of the stent-graft 100 in the implanted state is generally 90-95% of the diameter of the stent-graft 100 in the natural state) , so that the part of the film 20 with the channel 230 is radially compressed to a certain extent, and the area of the film 20 of the formed folded part 230A and the folded part 230B is partially overlapped, that is, the first edge line and the edge The lines no longer overlap, but rather one of the first edge line and the second edge line is covered so that the channel 230 is in a closed state. Therefore, the first end 210 of the covering film 20 can also be placed at a site without branch blood vessels.

Referring to FIG. 1 again, the corrugated ring 110A forms an area A on the coating 20, and the channel 230 is located in the area A1. For example, the channel 230 is an opening formed at the first end 210 . The opening is axially from the end of the first end 210 toward the direction close to the second end 220 , and the end of the opening away from the first end 210 does not exceed the wave-shaped ring 110A.

Referring to FIG. 6 , in one embodiment, the channel 230 is an opening formed at the first end 210 . The opening is an elongated slit extending axially from the end of the first end 210 to the direction close to the second end 220 (the extending direction of the longitudinal center axis I-I of the stent graft 100). In addition, the end of the opening close to the first end 210 of the covering film 20 is not flush with the end of the first end 210 (or the proximal edge of the covering film 20 ), but is kept constant with the end of the first end 210 distance. The opening is an elongated slit, including a first edge line and a second edge line (not shown), and in a natural state, the first edge line and the second edge line coincide. Alternatively, one of the first edge line and the second edge line is covered. Alternatively, the first edge line and the second edge line maintain a certain distance, that is, a gap is formed between the first edge line and the second edge line. This distance (width of the gap) does not exceed 2 mm. In one embodiment, the distance is not more than 1 mm, so as to ensure that the gap is closed when the stent graft 100 is compressed when implanted in a site without branch blood vessels. In one embodiment, the diameter of the stent-graft 100 in a natural state is 20-46 mm, and the compression rate is 5% (the difference between the diameter in the natural state and the diameter in the implanted state accounts for the percentage of the diameter in the natural state) , the distance is 1-2.3mm. Although the opening is an elongated slit, when the stent graft 100 is in the implanted state, the portion of the membrane 20 where the channel 230 is provided is radially compressed to a certain extent. Under the impact of blood flow, the channel 230 is flushed open, as shown in FIG. 7 and FIG. 8 . The end of the opening close to the first end 210 of the membrane 20 is not flush with the end of the first end 210 (or the proximal edge of the membrane 20 ), that is, both ends of the opening are closed ends. While being washed away by the blood flow, the strength of the first end 210 of the covering film 20 is not affected.

Referring to FIGS. 9 and 10, in one embodiment, the channel 230 includes a first edge line 230a, a second edge line 230b, a third edge line 230a' and a fourth edge line 230b'. The first edge line 230a and the second edge line 230b form an acute angle (or an obtuse angle). In a natural state, the first edge line 230a and the third edge line 230a' are coincident or aligned. The second edge line 230b and the fourth edge line 230b' are coincident or aligned. Alternatively, the third edge line 230a' and the fourth edge line 230b' are in a covered state. In the implanted state, the membrane 20 provided with the channel 230 is radially compressed to a certain extent, so that the membrane 20 is partially staggered, and the first edge line 230a and the third edge line 230a' no longer maintain the overlapping or aligned state , the second edge line 230b and the fourth edge line 230b' no longer keep the state of coincidence or alignment. Under the impact of blood flow, the distance between the first edge line 230a and the third edge line 230a' increases, the distance between the second edge line 230b and the fourth edge line 230b' increases, and a gap is formed between the four edge lines, so that blood flow through. Alternatively, under the impact of blood flow, the partial area of the covering film 20 is propped up by the blood flow to expose the third edge line 230a ′, the fourth edge line 230b ′, and the space between the first edge line 230a and the third edge line 230a ′ A gap is formed, and a gap is formed between the second edge line 230b and the fourth edge line 230b', thereby forming a blood flow channel.

It should be noted that in the natural state, when the first edge line 230a and the third edge line 230a' are overlapped or aligned, and the second edge line 230b and the fourth edge line 230b' are overlapped or aligned, the coating film 20 The channel 230 is formed in an up-cut manner. In the natural state, when the third edge line 230a' and the fourth edge line 230b' are in the covered state, the film 20 can be formed by splicing two pieces of film, and the channel 230 can be formed during splicing, so that the third edge line 230a' and the fourth edge line 230b' is in a covered state. Alternatively, the covering film 20 is a one-piece film, an opening is formed at the first end 210 of the covering film 20, and another covering film with a smaller area is pasted or sewed at the opening to form a channel 230, so that the third edge line 230a' and the The fourth edge line 230b' is in a covered state. It should be noted that when the channel 230 is formed by splicing, the covering film in the covering position (the covering film can cover the third edge line 230a' and the fourth edge line 230b') is located on the outer surface of the stent graft 100 to ensure When blood flows from the inside of the stent graft 100 to the outside, the channel 230 can be opened.

It can be understood that the above-mentioned method for forming the channel 230 is only an example, and any method mastered by those skilled in the art can be adopted.

Referring to FIGS. 11 and 12, in one embodiment, the channel 230 includes a first edge line 230c, a second edge line 230d, a third edge line 230c' (not shown) and a fourth edge line 230d' (not shown in the figure) Show). In a natural state, the first edge line 230c and the third edge line 230c' overlap, and the second edge line 230d and the fourth edge line 230d' overlap. Moreover, the first edge line 230c and the second edge line 230d are perpendicular, and the first edge 230c extends from the middle of the second edge line 230d in a direction perpendicular to the second edge line 230d. Under the impact of blood flow, the first edge line 230c and the third edge line 230c' are separated to form a gap, and the second edge line 230d and the fourth edge line 230d' are separated to form a gap, so that the channel 230 is in an open state. And, in the open state, the fourth edge line 230d' consists of two parts. The channel 230 in this embodiment is easier to open to keep blood flow unobstructed.

In one embodiment, the covering film 20 is 1 mm near the first edge line 230c, the second edge line 230d (not shown), the third edge line 230c' and the fourth edge line 230d' (not shown). is thicker than other regions of the film 20 . As shown in FIG. 13 , the cover film 20 is 1 mm from the attachments of the first edge line 230c, the second edge line 230d, the third edge line 230c' (not shown) and the fourth edge line 230d' (not shown). It refers to the area A2 enclosed by the dotted line in the figure, wherein D1=D2=D3=D4=1 mm. In another embodiment, the thickness of the region A2 is twice that of other regions of the cover film 20 . When the application site of the stent-graft 100 does not need to open the channel 230, the thickness of the membrane 20 at 1 mm near each edge line of the channel 230 is relatively large, so that during the assembly and release process, when the stent-graft 100 is in the sheath During the middle movement, the film 20 in the area around each edge line (ie, the area A2) can form a support to prevent the channel 230 from being opened.

Referring to FIGS. 14 and 15 , in one embodiment, the stent-graft 100 further includes a sealing member 30 . A window 240 is provided on the first end 210 of the covering film 20 . The sealing member 30 is disposed on the outer surface of the membrane 20 (the surface away from the lumen of the stent graft 100 ) and can openly cover the window 240 to form the channel 230 having an open state and a closed state. In the natural state, the sealing member 30 covers the window 240 so that the channel 230 is in a closed state. When impacted by the fluid, the seal 30 forms a gap with the membrane 20 to open the channel 230 .

In one embodiment, the window 240 has edge lines. In the closed state, the seal 30 covers the edge line and closes the window 240, thereby leaving the channel 230 in a closed state. The channel 230 is in an open state when at least part of the edge line is not covered by the seal 30 .

In one embodiment, the window 240 has four edge lines, which are connected edge lines 240A, edge lines 240B, edge lines 240C, and edge lines 240D, respectively. The edge line 240A is opposite to the edge line 240B, and the edge line 240C is opposite to the edge line 240D. The sealing member 30 is a sheet-like structure and has four edge lines, which are respectively connected edge line 30A, edge line 30B, edge line 30C and edge line 30D, wherein edge line 30A and edge line 30B are opposite, edge line 30C and edge line 30D relative. The sealing member 30 covers the window 240 , and both ends of the sealing member 30 are fixedly connected with the film 20 . For example, in position, edge line 30A of seal 30 corresponds to edge line 240A of window 240, edge line 30B corresponds to edge line 240B, edge line 30C and edge line 30D correspond to edge line 240C and edge line 240D, respectively correspond. The end where the edge line 30C of the sealing member 30 is located is fixedly connected with the coating film 20, the end where the edge line 30D is located is fixedly connected with the coating film 20, and the part between the end where the edge line 30C is located and the end where the edge line 30D is located overlaps. On the film 20, but not fixedly connected with the film 20, so that the sealing member 30 can openly cover the edge line 240A and the edge line 240B of the window 240. When the blood flow is impacted, the sealing member 30 is impacted and the edge line 240A and edge line 240B form a gap, thereby opening channel 230 . In this embodiment, the edge line 30C overlaps with the edge line 240C, and the edge line 30D overlaps with the edge line 240D. It can be understood that, in other embodiments, the edge line 30C and the edge line 240C may not overlap, and the edge line 30D and the edge line 240D may not overlap. In the natural state, the sealing member 30 completely shields the edge line 240A, edge line 240B, edge line 240C and edge line 240D, and when impacted by blood flow, edge line 240A, edge line B, edge line C and edge line D are exposed , thereby opening the channel 230 .

Please refer to FIG. 16 and FIG. 17 together. In another embodiment, the window 240 has four edge lines, which are connected edge lines 240A, edge lines 240B, edge lines 240C and edge lines 240D respectively. The edge line 240A is opposite to the edge line 240B, and the edge line 240C is opposite to the edge line 240D. The sealing member 30 is a sheet-like structure and has four edge lines, which are respectively connected edge line 30A, edge line 30B, edge line 30C and edge line 30D, wherein edge line 30A and edge line 30B are opposite, edge line 30C and edge line 30D relative. The edge line 30A coincides with the edge line 240A, and the sealing member 30 is located on the outer side (or outer surface) of the cover film 20 only by connecting one end of the edge line 30A with the cover film 20 , and other parts are not connected with the cover film 20 . When the stent graft 100 is implanted into the blood vessel, if the first end 210 of the graft film 20 is at the branch blood vessel, when the channel 230 is not resisted by the blood vessel wall, the sealing member 30 will be flushed under the impact of blood flow Open, the edge line 240B, edge line 240C, and edge line 240D of the window 240 are exposed, and the channel 230 is in an open state for blood flow to pass therethrough. If the first end 210 of the membrane 20 is not at the branch blood vessel, but the sealing member 30 is pressed against the vessel wall, the channel 230 is in a closed state, so that the membrane 20 plays an insulating role.

In one embodiment, the shape of the window 240 matches the shape of the seal 30, both being rectangular. It can be understood that in other embodiments, the shape of the window 240 and the shape of the sealing member 30 are not limited, and may be other shapes, such as oval, circular, square, and the like.

In one embodiment, the hardness of the sealing member 30 is greater than the hardness of the cover film 20, so that during the assembly and release process, the sealing member 30 can cover each edge line of the window 240, so that the channel 230 is in a closed state. Only when impacted by blood flow, the seal 30 is punched away to form a gap with the window 240, so that the channel 230 is opened.

In one embodiment, the material of the sealing member 30 is the same as that of the coating film 20 , but the thickness of the sealing member 30 is greater than that of the coating film 20 .

In one embodiment, the material of the sealing member 30 is different from the material of the film 20. For example, the material of the film 20 is e-PTFE or PET, and the material of the sealing member 30 is a metal material, such as stainless steel.

In one embodiment, referring to FIG. 18 , the window 240 is located between the two wave rods 112 , and the seal 30 extends from the edge line 30A to the outside of one wave rod 112 . When the stent-graft 100 is placed at the site where the channel 230 needs to be opened, because the blood flow has a certain pressure, even if the length of the sealing member 30 is slightly extended and extends beyond the corrugated rod 112, the blood flow can still remove the sealing member 30 Flush open to open channel 230 . When the use site of the stent-graft 100 does not need to open the channel 230, since the sealing member 30 extends beyond the corrugated rod 112, when the stent-graft 100 is fixed to the application site by the radial support force of the corrugated ring 110 One end of the sealing member 30 is connected with the stent-graft 20, and the other end is resisted by the wave rod 112, so that the sealing effect of this part is better, and the purpose of isolating aneurysm and arterial dissection rupture can be better achieved.

Referring to FIG. 19 , the corrugated ring 110A closest to the end of the first section 210 of the cover film 20 divides the first end 210 of the cover film 20 into two regions, namely the region A1 and the difference A3, wherein the region A1 Both the area A1 and the area A3 respectively include a plurality of triangular sub-areas, wherein the bases of the plurality of triangular sub-areas of the area A1 are coplanar with the end surface of the first end 210 . Regardless of the form of the channel 230, the channel 230 can be arranged in the triangular sub-region of the area A1, as shown in FIG. 19, or in the triangular sub-region of the area A3, as shown in FIG. 20.

No matter what form the channel 230 is, or whether the channel 230 is disposed in the area A1 or the area A3, in one embodiment, there are multiple channels 230, and the multiple channels 230 are distributed along the circumference of the coating 20 at intervals to ensure After implantation, the channel 230 can oppose the branch vessel.

Referring to FIG. 20 , in one embodiment, the wave number (or the number of peaks or troughs, the same below) of the wave ring 110A closest to the end of the first end 210 of the covering film 20 is greater than that of the other parts of the stent 10 The wave number of the corrugated ring 110, and the wave height of the corrugated ring 110A is smaller than that of the other corrugated rings 110, so that the sealing performance of the corrugated ring 110A is greater than that of the other corrugated rings 110, so that the film coating The end of the bracket 100 can achieve a good internal leakage prevention performance.

Please continue to refer to FIG. 20 , in one embodiment, the stent-graft 100 further includes anchoring bare stents 40 , and the number of anchoring bare stents 40 is two or one, and when the number of anchoring bare stents 40 is two, two anchoring bare stents 40 They are located at both ends of the stent-graft 100, respectively. When there is one, the anchored bare stent 40 is located at one end of the stent-graft 100 . The anchoring bare stent 40 is provided to further strengthen the anchoring performance of the end of the stent-graft 40 .

In the embodiment shown in FIG. 20 , there is one anchored bare stent 40 , and the anchored bare stent 40 is connected to the first end 210 of the covering film 20 or to the corrugated ring 110A. Referring back to FIG. 4 , when the stent-graft 100 is implanted into the branched blood vessel 10, the channel 230 is opposite to the branched blood vessel 101, and the anchored bare stent 40 extends to the area diametrically opposite to the branched blood vessel 102. The part with the channel 230 is located at the first end 210 of the membrane 20, and the part with the channel 230 is opposite to the branch blood vessel 101, without the support of the blood vessel wall, so that the anchoring performance of the first end 210 of the membrane 20 is poor, and an anchor is provided. The bare stent 40 is fixed to enhance the anchoring performance of the end of the stent-graft 100 without affecting the blood supply of the branch blood vessel 102 .

As shown in FIG. 20 , the anchored bare stent 40 includes a bare wave ring 410 , and the bare wave ring 410 is also a closed structure with wave crests and wave troughs formed by connecting a plurality of wave rods end to end. It can be understood that the bare wave ring 410 is not covered by the membrane 20, so that the anchored bare stent 40 is a hollow structure, so as to avoid the anchoring of the bare stent 40 from affecting the blood flow of the branch. The number of the bare wave coils 410 may be one or multiple, and when the number of the bare wave coils 410 is multiple, the plurality of bare wave coils 410 are arranged at intervals or non-spaced in the axial direction.

In one embodiment, the wave heights of the bare wave ring 410 are larger than the wave heights of the wave ring 110A and the wave ring 110 , and the wave numbers of the bare wave ring 410 are both smaller than those of the wave ring 110A and the wave ring 110 . The wave number, that is, the hollow rate of the bare wave ring 410 is relatively high, so even if the anchored bare stent 40 extends to the branch blood vessel, smooth blood flow can be ensured. At the same time, due to the high hollowing rate, it is also beneficial to avoid thrombosis. In addition, the wave height of the bare wave ring 410 is relatively large, so that the anchored bare stent 40 can cross the opening of the branch blood vessel and will not touch the inner wall of the branch blood vessel, thereby avoiding the risk of puncturing the blood vessel. The bare wave ring 410 has fewer wave numbers and fewer contact points with the blood vessel wall, which is beneficial to reduce damage to the blood vessel wall.

Referring back to FIG. 2 , in one embodiment, the stent graft 100 further includes a marker structure 50 , and the marker structure 50 is disposed on the first end 210 of the stent graft 20 for indicating the end position of the stent graft 100 . The marking structure 50 is not disposed at the position where the channel 230 is provided, that is, the marking structure 50 and the channel 230 are staggered to avoid blocking the channel 230 . The marking structure 50 is made of a material with strong developability under medical imaging equipment (the strength can satisfy the images collected by the medical imaging equipment visible to the human eye, such as DSA images), such as gold, platinum and the like. In one embodiment, the number of the marking structures 50 is three, and the three marking structures are disposed on the covering film 20 at intervals along the circumferential direction of the covering film 20 . The marking structure 50 may be provided on the inner surface of the coating film 20 or may be provided on the outer surface of the coating film 20 . Alternatively, when the cover film 20 is a two-layer or multi-layer structure, the marking structure 50 is located inside the cover film 20 . The marking structure 50 can be directly pasted on the surface of the covering film 20 with biological glue, or after the marking structure 50 is placed on the surface of the covering film 20 , the marking structure 50 can be fixed on the surface of the covering film 20 by sewing.

In one embodiment, one of the three marking structures 50 is in the shape of a number "8", one is in the shape of a letter "O" or a number "0", and the other is in the shape of a letter "e". Different shapes of marker structures 50 are used to facilitate differentiation of different sites. In addition, when the marking structure 50 of "8" shape, "O" shape or number "0" and "e" shape is used, when the marking structure 50 is fixed on the film 20 by sewing, because the marking structure 50 itself The structural feature enables the suture to hook the marking structure 50 reliably, so that the marking structure 50 can be reliably fixed on the surface of the film 20, and effectively avoid the risk of the marking structure 50 falling off.

In one embodiment, the overlay 20 is a two-layer or multi-layer structure, the marker structure 50 is located inside the overlay 20, and the marker structure 50, the overlay 20 and the wave ring 110A are secured together using sutures.

It can be seen that the covering film 20 not only serves to isolate the lesion and blood flow, but also functions to carry the marking structure 50 when the marking structure 50 needs to be provided at the first end 210 , which not only facilitates the operation of fixing the marking structure 50 It is more convenient, and more importantly, the marking structure 50 can be reliably fixed to prevent the marking structure 50 from falling off. When a plurality of marking structures 50 are provided on the first end 210, the bearing effect of the coating film 20 is more significant, which facilitates preparation and improves the reliability of fixing.

Therefore, when the stent graft 100 is implanted into a blood vessel with branches, and the first end 210 of the graft 20 is opposite to the branched blood vessel, the first end 210 of the graft 20 can carry the marker structure 50, so that the operator can The position of the end can be better determined, and at the same time, since the channel 230 at the first end 210 can be opened under the impact of blood flow, the membrane 20 will not block the opening of the branch blood vessel and block the blood flow.

In one embodiment, the number of marking structures 50 is three. The line connecting the two marking structures 50 passes through the geometric center of the end face of the stent-graft 100 . The connecting line between the other marking structure 50 and the geometric center of the end face of the stent graft 100 is perpendicular to the connecting line between the two marking structures 50 mentioned above. Alternatively, two marking structures 50 are located at 3 o'clock and 9 o'clock, respectively, and the other marking structure is located at 12 o'clock or 6 o'clock. For example, the "8" type marking structure 50 and the "O" type (digital "0" type) marking structure 50 are located at 3 o'clock and 9 o'clock, respectively, and the "e" type marking structure 50 is located at 12 o'clock or 6 o'clock. O'clock direction.

It can be understood that the shape of the marking structure 50 is not limited to the "8" shape, the "O" shape or the digital "0" shape and the "e" shape, any shape that can meet the visual requirements, has a distinction and can be reliably fixed on the film 20 on the shape can be. The setting positions of the marking structure 50 are also not limited to the directions of 3 o'clock, 9 o'clock, 12 o'clock and 6 o'clock, and any setting methods that can meet the visual requirements and have a degree of distinction can be used. For example, the plurality of marking structures 50 are uniformly distributed in the circumferential direction.

A channel 230 is formed on the first end 210 of the membrane 20 of the above-mentioned stent-graft 100. When the stent-graft 100 is implanted into a blood vessel, since the channel 230 is in an open state when it is impacted by blood flow, even if the membrane 20 is in an open state. The first end 210 of the blood vessel is located at the branch site, and the blood supply of the branch blood vessel will not be affected by blocking the blood flow of the branch blood vessel.

Moreover, since the channel 230 has an open state and a closed state, when the channel 230 is not resisted by the blood vessel wall, the channel 230 can be in an open state under the impact of blood flow. When the channel 230 is resisted by the blood vessel wall, the channel 230 can be in a closed state. The stent graft 100 can be applied to different application sites to suit different individuals.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims (11)

1. The covered stent is characterized by comprising a stent and a covering film covered on the stent, wherein the covering film is provided with a first end and a second end which are opposite in the axial direction, a channel with an open state and a closed state is formed at the first end of the covering film, the channel is in the open state when the channel is impacted by fluid, and the channel is in the closed state when the channel is not impacted by the fluid.

2. The stent graft as recited in claim 1, wherein the channel is a plurality of channels, and the plurality of channels are provided at intervals along a circumferential direction of the graft.

3. The stent graft as recited in claim 1, wherein the channel is an opening formed in the first end, the opening extending axially from an end of the first end in a direction proximal to the second end.

4. The stent graft as recited in claim 1, wherein the channel comprises a first edge line and a second edge line, the first edge line and the second edge line being coincident or aligned in the closed state; one of the first edge line and the second edge line is covered.

5. The stent-graft of claim 1, wherein the channel comprises a first edge line, a second edge line, a third edge line, and a fourth edge line, the first edge line and the third edge line being coincident or aligned in a natural state, the second edge line and the fourth edge line being coincident or aligned; alternatively, the third edge line and the fourth edge line are in a covered state.

6. The stent graft of claim 5, wherein in a natural state, the first edge line and the third edge line coincide or align, the second edge line and the second four edge line coincide or align, and the first edge line extends from a middle of the second edge line in a direction perpendicular to the second edge line.

7. The stent graft of claim 1, further comprising a sealing element, wherein the first end of the cover membrane defines a window, and wherein the sealing element is disposed on the cover membrane and openably covers the window to form the passageway.

8. The stent graft of claim 7, wherein the window has an edge line, the seal covering the edge line in the closed state; in the open state, at least part of the edge line is not covered by the seal.

9. The stent graft of claim 8, wherein the sealing element covers the window and opposite ends of the sealing element are respectively connected to the cover, and a portion of the sealing element between the opposite ends overlaps the cover such that the sealing element openably covers the window to form the channel.

10. The stent graft of claim 8, wherein the seal covers the window and an end of the seal is attached to the cover such that the seal openably covers the window to form the channel.

11. The stent graft of claim 1, further comprising a marker structure at the first end of the graft, the marker structure being offset from the channel.

Images