WO2025139929A1 - Covered stent and stent delivery system - Google Patents

Abstract

Provided are a covered stent (100) and a stent delivery system (200). The covered stent (100) comprises a main stent (10) provided with a tubular body. Along an axial direction, the main stent (10) comprises a proximal support section (1) and a tumor cavity covered section (3). The tumor cavity covered section (3) is internally provided with a first embedded stent (4) and a second embedded stent (5) arranged radially. The distal end of the tumor cavity covered section (3) is provided with an opening (32) communicating with the exterior. Distal openings of the first embedded stent (4) and the second embedded stent (5) both communicate with the opening (32). The first embedded stent (4) has higher support strength than the second embedded stent (5). By configuring the first embedded stent (4) with relatively high support strength, patency of an external iliac artery corresponding to the first embedded stent (4) is ensured at least when the covered stent (100) is compressed. Further, extended covered configurations of the first embedded stent (4) and the second embedded stent (5) can ensure sealing integrity at an attachment gap (4021) after being sutured to the main stent (10), thereby preventing endoleaks at the embedded stents.

Description

Stent graft and stent delivery system Technical Field

The present invention relates to the technical field of medical devices, and in particular to a stent graft and a stent delivery system.

Background Art

The iliac artery, as one of the important vascular systems in the human body, originates from the terminal segment of the abdominal aorta. It is divided into two common iliac arteries, the left and right, which pass through the fourth segment of the lumbar vertebra, extend downward along the spine on the inner side of the psoas major muscle, and finally divide into the internal iliac artery and the external iliac artery. The internal iliac artery is responsible for supplying oxygen and nutrients to the pelvis and lower limbs, while the external iliac artery supplies blood to the ilium and surrounding tissues. However, the current iliac artery bifurcation stent has a series of problems, such as the opening of the internal iliac artery is easily closed by blood vessels, the internal iliac branch is prone to tortuosity and folding, leading to blockage, and the stent may cause blockage of the opening of the internal iliac branch when it moves or rotates slightly during operation.

To solve the above problems, an embedded branch stent is specifically designed in the prior art, in which the first branch is used to connect the external iliac artery and the second branch is used to connect the internal iliac artery. This innovative structural design has a wide range of patient applicability and can be extended to the proximal side of the iliac bifurcation without being limited by the length of the common iliac artery, and is suitable for treating internal and external iliac arteries of various diameters. This innovative structure makes it easier to align the stent during implantation, avoiding the trouble of the iliac bifurcation stent, thereby making it easier to access the internal and external iliac stents.

However, there are still some challenges in the design of the embedded branch stent, especially the possibility of internal leakage at the embedded stent.

Summary of the invention

Based on this, it is necessary to provide a new coated stent and stent delivery system to at least solve the problem of internal leakage of the embedded stent within the main stent.

A coated stent comprises a main body stent with a tubular body, the main body stent comprising a proximal support segment and a tumor cavity coated segment, the distal end of the proximal support segment is connected to the proximal end of the tumor cavity coated segment; the proximal segment comprises a support wave ring, the tumor cavity coated segment is provided with a first embedded stent and a second embedded stent arranged radially, the distal end of the tumor cavity coated segment is provided with an opening connected to the outside, the distal ends of the first embedded stent and the second embedded stent are both connected to the opening; the support strength of the first embedded stent is greater than the support strength of the second embedded stent.

In one embodiment, the first embedded stent and the second embedded stent comprise a mesh body, on which a wire diameter of the first embedded stent is greater than a wire diameter of the second embedded stent, and/or a mesh density of the first embedded stent is greater than a mesh density of the second embedded stent.

In one embodiment, the distal ends of the first embedded bracket and the second embedded bracket are respectively provided with a first distal oblique opening and a second distal oblique opening, and the first distal oblique opening and the second distal oblique opening are arranged to be opposite to each other.

In one embodiment, the proximal ends of the first embedded bracket and the second embedded bracket are respectively provided with a first proximal flat opening and a second proximal flat opening; or the proximal ends of the first embedded bracket and the second embedded bracket are respectively provided with a first proximal oblique opening and a second proximal oblique opening, and the first proximal oblique opening and the second proximal oblique opening are arranged opposite to each other.

In one embodiment, the coated stent further includes a transition section connected between the proximal support section and the tumor cavity coated section, and the transition section is provided with a transition stent.

In one embodiment, a first coating is provided on the surface of the first embedded stent, and a second coating is provided on the surface of the second embedded stent. The first coating and the second coating at least partially extend outward from the proximal ports of the first embedded stent and the second embedded stent, respectively, to form a connecting portion, and the connecting portion is connected to the tumor cavity coating segment.

In one embodiment, the connecting portion of the first covering film is connected to the connecting portion of the second covering film.

In one embodiment, the first covering film and the second covering film are integrally formed.

In one embodiment, the first distal bevel and the second distal bevel both include a major axis side wall and a minor axis side wall in the circumferential direction, the axial extension length of the major axis side wall is greater than the axial extension length of the minor axis side wall, the major axis side walls of the first embedded bracket and the second embedded bracket are arranged closely to each other, and a hooking portion for hooking is provided at the distal end of at least one of the major axis side walls.

In one embodiment, the supporting corrugation includes at least one anchoring corrugation, and a plurality of anchoring barbs are circumferentially arranged on the outer side of the anchoring corrugation.

A stent delivery system comprises the stent graft described above.

The benefit of the present invention lies in that the present invention provides a coated stent and a stent delivery system, the coated stent includes a main stent with a tubular body, the main stent includes a proximal support section and a tumor cavity coated section along the axial direction, a first embedded stent and a second embedded stent arranged radially are provided in the tumor cavity coated section, the distal end of the tumor cavity coated section is provided with an opening connected to the outside, and the distal ports of the first embedded stent and the second embedded stent are both connected to the opening; the support strength of the first embedded stent is greater than the support strength of the second embedded stent; by providing a first embedded stent with greater support strength, at least the passability of the external iliac channel opposite to the first embedded stent is ensured when the coated stent is under pressure; further, the extended coating of the first embedded stent and the second embedded stent can ensure the sealing of the fitting gap position after suturing with the main stent, thereby avoiding internal leakage at the embedded stent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a stent graft in Example 1 of the present invention;

FIG2 is a schematic diagram of the internal structure of the stent graft in Example 1 of the present invention;

FIG3 is a schematic diagram of the wire diameter distribution of the first embedded stent and the second embedded stent in Example 1 of the present invention;

FIG4 is a schematic diagram of the grid density distribution of the first embedded bracket and the second embedded bracket in Example 1 and Example 2 of the present invention;

FIG5 is a schematic diagram of the proximal flat ends of the first embedded stent and the second embedded stent in Example 2 of the present invention;

FIG6 is a schematic diagram of the development structure of the first embedded bracket and the second embedded bracket in Example 2 of the present invention;

FIG7 is a schematic diagram of the structure of the hook portion in the stent graft in Example 2 of the present invention;

FIG8 is a schematic diagram of a hook portion provided with a blocking member in Embodiment 2 of the present invention;

9 is a schematic diagram of a developing structure of a hooking portion blocking member in Embodiment 2 of the present invention;

FIG10 is a schematic diagram of a transition bracket as a special-shaped corrugated ring in Example 2 of the present invention;

FIG11 is a schematic diagram of the high wave at the far end of the special-shaped wave coil in Example 2 of the present invention;

FIG12 is a schematic diagram of the tapered high wave at the far end of the special-shaped wave coil in Example 2 of the present invention;

FIG13 is a schematic diagram of a transition bracket including a corrugated bracket in Embodiment 2 of the present invention;

FIG14 is a schematic diagram of a transition bracket including a mesh bracket in Example 2 of the present invention;

FIG15 is a schematic diagram of the first coating and the second coating structure in Example 3 of the present invention;

FIG16 is a schematic diagram of the structure of the connection portion between the first coating and the second coating in Example 3 of the present invention;

17 is a top view of the stent graft when the connecting portion of the first coating and the second coating is connected to the tumor cavity coating section in Example 3 of the present invention;

FIG18 is a schematic diagram of a structure in which a first coating and a second coating are connected via a connecting portion in Example 3 of the present invention;

19 is a top view of the stent graft when the first coating and the second coating are connected to the tumor cavity coating section through the connecting portion in Example 3 of the present invention;

FIG20 is a schematic diagram of the integrated molding structure of the first coating and the second coating in Example 3 of the present invention;

FIG21 is a top view of the stent graft when the first and second integrally formed coverings are connected to the tumor cavity covering segment in Example 3 of the present invention;

FIG22 is a schematic diagram of the structure of the middle anchoring wave ring in Example 4 of the present invention;

FIG. 23 is a schematic diagram of the hooking structure of the coated stent in the conveyor in Example 5 of the present invention.

DETAILED DESCRIPTION

In order to better understand the concept of the present application, the implementation methods of the present application are specifically described below in conjunction with the accompanying drawings. The following specific embodiments are only partial embodiments of the present application and are not limitations of the present application.

For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

In order to more clearly describe the structure of this application, the terms "proximal end" and "distal end" are defined here as commonly used terms in the field of interventional medicine. Specifically, "distal end" refers to the end of the blood vessel away from the heart, and "proximal end" refers to the end of the blood vessel close to the heart; "axial" refers to its length direction, and "radial" refers to the direction perpendicular to the "axial"; "upper end" and "lower end" are two ends that are relatively far away. When one end is defined as the "upper end", the other end that is far away is the "lower end".

Example 1

Please refer to Figure 1 and Figure 2. The present invention provides a coated stent 100. The coated stent 100 is generally composed of a metal skeleton and a coating material. As shown in Figure 3, the metal skeleton can adopt a Z-shaped wave or a woven mesh design. The coating material has a certain blood flow isolation ability and is combined with the metal skeleton by pressurization, heating, suturing, etc. to form a complete coated stent 100; the proximal end of the coated stent 100 is generally placed in the common iliac artery or connected to the abdominal aorta stent, and the lumen diameter generally matches the diameter of the common iliac artery. In this embodiment, the coated stent 100 includes a main stent 10 with a tubular body, and the surface of the main stent 10 is provided with a surface coating 31. The main stent 10 includes a proximal support segment 1 and a tumor cavity coating segment 3 along the axial direction. The distal end of the proximal support segment 1 is connected to the proximal end of the tumor cavity coating segment 3. The surface coating 31 of the proximal support segment 1 and the surface coating 31 of the tumor cavity coating segment 3 can be integrally formed by a single coating, or can be formed by splicing multiple coatings by suturing or bonding; the proximal segment includes a support wave ring 11, and the tumor cavity coating segment 3 is only provided with a surface coating 31, and the tumor cavity coating segment 3 is provided with There are a first embedded stent 4 and a second embedded stent 5 arranged radially, so that the main stent 10 reduces the support wave ring 11 at the position of the tumor cavity coating section 3 to improve the flexibility of the coated stent 100 at the tumor cavity section; the tumor cavity coating section 3 provides support performance through the first embedded stent 4 and the second embedded stent 5, and at the same time, when the blood flows through the tumor cavity coating section 3, the blood is diverted into the external iliac channel and the internal iliac channel. The first embedded stent 4 and the second embedded stent 5 are used to intervene in the external iliac stent and the internal iliac stent respectively, drain the blood to the external iliac artery and the internal iliac artery, isolate the blood, and prevent the blood from continuing to flow to the aneurysm.

In some embodiments, please continue to refer to Figure 2. The first embedded stent 4 and the second embedded stent 5 both adopt a mesh main body structure, the purpose of which is to emphasize better morphological support; the mesh main body structure can have better coating tension, so that even when a smaller braiding wire diameter is provided, it can also provide better coating tension to maintain the shape of the blood pathway; and the mesh main body can make the external iliac stent and the internal iliac stent respectively intervene in the first embedded stent 4 and the second embedded stent 5. There are more contact positions between the embedded stent and the intervened stent to provide greater friction, which can effectively enhance the anchoring force and adhesion force between the stents and provide the stent anti-slip performance.

Among them, the distal end of the tumor cavity coating section 3 is provided with an opening 32 connected to the outside world, and the distal ports of the first embedded stent 4 and the second embedded stent 5 are both connected to the opening 32; in order to make the coated stent 100 provided by the present application more preferentially emphasize the morphology of the passage leading to the external iliac blood vessels when under pressure, in this embodiment, the support strength of the first embedded stent 4 is greater than the support strength of the second embedded stent 5. Here, the support strength is manifested as the overall deformation of the first embedded stent 4 is less than the overall deformation of the second embedded stent 5 when the first embedded stent 4 and the second embedded stent 5 are subjected to equal pressure, so as to maintain a better passage morphology;

In this embodiment, referring to Figures 3 and 4, in order to make the external iliac channel and the internal iliac channel separated by the first embedded stent 4 and the second embedded stent 5 have the support strength distribution effect as described above, the wire diameter of the mesh body of the first embedded stent 4 can be larger than the wire diameter of the mesh body of the second embedded stent 5, and/or the mesh density of the first embedded stent 4 can be larger than the mesh density of the second embedded stent 5.

In one embodiment, please refer to Figure 3, so that the grid density of the first embedded stent 4 and the second embedded stent 5 is uniform, and the wire diameter of the mesh body of the first embedded stent 4 is larger than the wire diameter of the mesh body of the second embedded stent 5 so that the support strength of the first embedded stent 4 is greater than the support strength of the second embedded stent 5; here, the larger stent wire diameter has a smaller deformation ability and can provide a higher support force when under pressure, so by making the wire diameter of the first embedded stent 4 larger than the wire diameter of the second embedded stent 5, when the first embedded stent 4 and the second embedded stent 5 are under pressure at the same time, due to the large wire diameter of the first embedded stent 4, its ability to resist deformation is stronger, and the deformation amount generated is small, while the second embedded stent 5 has a relatively small wire diameter, and its ability to resist deformation is smaller than the first embedded stent 4, and the deformation amount generated is large, then the shape of the first embedded stent 4 can be better maintained to ensure that the coated stent 100 better maintains the shape of the external iliac channel, thereby ensuring the blood flow to the external iliac artery after the blood flows through the coated stent 100.

In another embodiment, please refer to FIG. 4 , the wire diameters of the first embedded bracket 4 and the second embedded bracket 5 are made uniform, and the grid density of the mesh body of the first embedded bracket 4 is greater than the mesh density of the mesh body of the second embedded bracket 5 so that the support strength of the first embedded bracket 4 is greater than the support strength of the second embedded bracket 5; here, the first embedded bracket 4 and the second embedded bracket 5 include a mesh body, and the mesh body has a plurality of mesh structures; wherein, a higher mesh density means an increase in the number of supporting wires required, and a smaller area of a single mesh means a greater pressure that can be withstood, and a larger mesh density can provide a greater support strength. In this embodiment, the first embedded bracket 4 and the second embedded bracket 5 have a diamond mesh structure, and the first embedded bracket 4 has a first diamond grid, and the second embedded bracket 5 has a second diamond grid. The first diamond grid and the second diamond grid both have an upper vertex and a lower vertex in the axial direction, and a left vertex and a right vertex in the radial direction. The spacing between the upper vertex and the lower vertex of the first diamond grid is D1, and the spacing between the left vertex and the right vertex is L1; the spacing between the upper vertex and the lower vertex of the second diamond grid is D2, and the spacing between the left vertex and the right vertex is L2; preferably, D1 and L1 can be made smaller than D2 and L2, so that the area occupied by a single first diamond grid is smaller than the area occupied by a single second diamond grid, so that, under the same bracket deployment area, the first embedded bracket 4 has a higher grid density, providing a stronger support strength than the second embedded bracket 5.

In some embodiments, please further refer to Figure 4, at least L1 of the first diamond grid is made smaller than L2 of the second diamond grid, so that the density of the first diamond grid is changed only in the circumferential direction of the first embedded bracket 4. In this way, the density of the first diamond grid can be increased at least in the radial direction, thereby achieving the effect of enhancing the support strength in the radial direction.

In one of the embodiments, the wire diameter of the first embedded stent 4 can be greater than the wire diameter of the second embedded stent 5 and the mesh density of the first embedded stent 4 can be greater than the mesh density of the second embedded stent 5. In this way, by setting the wire diameter and mesh density of the first embedded stent 4 and the second embedded stent 5 at the same time, the first embedded stent 4 and the second embedded stent 5 can form a difference in support strength while forming a more reasonable wire diameter size and mesh density distribution, thereby avoiding excessively large or small wire diameter settings and mesh density settings that result in the first embedded stent 4 and the second embedded stent 5 having too small or too large flexibility, affecting the folding and unfolding performance of the coated stent 100, and causing difficulty in assembling and releasing the coated stent 100 in the sheath.

In the present embodiment, the support strength is specifically manifested as the deformation of the overall tubular inner cavity after the first embedded bracket 4 and the second embedded bracket 5 are compressed, that is, under the same force conditions, the radial force tester is used to apply the same force (the force needs to make the first embedded bracket 4 and the second embedded bracket 5 both produce a certain amount of deformation) to the outer walls of the first embedded bracket 4 and the second embedded bracket 5, and the radial cross-sectional areas of the first embedded bracket 4 and the second embedded bracket 5 after the compression are measured and calculated. Here, the bracket with a larger total cross-sectional area measured after the compression has a greater support strength, and the bracket with a smaller total cross-sectional area has a smaller support strength. In some embodiments, the first embedded bracket 4 and the second embedded bracket 5 can be compressed respectively by a flat-plate dynamometer, and the required force is measured when the compression is compressed to the same deformation amount. The larger the measured force, the greater the support strength, and the smaller the measured force, the smaller the support strength. In the present embodiment, the force measured by the first embedded bracket 4 is always greater than the force measured by the second embedded bracket 5.

Example 2

In this embodiment, please continue to refer to Figure 4. The structures of the main support 10 and the first embedded support 4 and the second embedded support 5 of the coated support 100 are substantially the same as those in Example 1, except that the opening 32 at the distal end of the coated support 100 is set as an oblique opening. Specifically, the distal ends of the first embedded support 4 and the second embedded support 5 are respectively provided with a first distal oblique opening 41 and a second distal oblique opening 51, and the first distal oblique opening 41 and the second distal oblique opening 51 are arranged away from each other; here, the distal ports of the first embedded support 4 and the second embedded support 5 are the access ports for the intervention of the external iliac support and the internal iliac support, and the two The distal ends of the embedded stents are all configured as oblique openings, firstly to increase the size of the opening 32 for the insertion of the external iliac stent and the internal iliac stent, thereby reducing the difficulty of inserting the stents; secondly, since in the present application, the connection with the external iliac artery and the internal iliac artery is achieved by additionally intervening the external iliac stent and the internal iliac stent, the first distal oblique opening 41 and the second distal oblique opening 51 are arranged to be opposite to each other so that the two stents can be less constrained by the coated stent 100 in opposite directions after the intervention, thereby making it easier to separate the external iliac stent and the internal iliac stent after connection, thereby avoiding mutual influence between the two stents.

Among them, please refer to Figures 4 and 5. The proximal port positions of the first embedded stent 4 and the second embedded stent 5 can be set to a flat port or an oblique port. Specifically, the proximal ends of the first embedded stent 4 and the second embedded stent 5 can be respectively provided with a first proximal flat port 43 and a second proximal flat port 53. Here, in order to form a double-layer stent when setting the first embedded stent 4 and the second embedded stent 5 while reducing the overall volume of the stent after compression and sheathing, the first proximal flat port 43 and the second proximal flat port 53 can be staggered in the axial direction so as to be in different axial positions after compression, so as to avoid accumulation at one axial position resulting in excessive volume and difficulty in sheathing.

In another embodiment, please further refer to Figure 4. The proximal ends of the first embedded stent 4 and the second embedded stent 5 can be respectively provided with a first proximal oblique opening 42 and a second proximal oblique opening 52, and the first proximal oblique opening 42 and the second proximal oblique opening 52 are arranged opposite to each other; here, the two oblique openings form a V-shaped cross-section on the axial section, and the first proximal oblique opening 42 and the second proximal oblique opening 52 are blood flow entrances in the tumor cavity coating segment 3. The inclined oblique opening structure can increase the area of the entrance receiving blood, thereby ensuring the patency of the blood flow; further, the first proximal oblique opening 42 and the second proximal oblique opening 52 are arranged opposite to each other, so that a side wall with a higher oblique opening is in close contact with the side wall of the tumor cavity coating segment 3, thereby avoiding vibration or or swing, thereby reducing the patency of blood flow; in some embodiments, the first proximal bevel 42 and the first distal bevel 41, the second proximal bevel 52 and the second distal bevel 51 can have the same inclination angle, thereby forming a parallel opening structure to increase the versatility of the first embedded stent 4 and the second embedded stent 5; in other embodiments, the setting of the first proximal bevel 42 and the second proximal bevel 52 can cause the long-axis side wall and the short-axis side wall of the first embedded stent 4 and the second embedded stent 5 to be misaligned, so that when the coated stent 100 of the present application is compressed and placed into the delivery sheath, the long-axis side wall and the short-axis side wall of the misaligned structure can make the first embedded stent 4 and the second embedded stent 5 smaller in size after folding, and easier to deliver into the delivery sheath.

Here, the provision of the first proximal oblique opening 42 and the second proximal oblique opening 52 can also allow other stents to have a larger selection entrance when implanted, thereby reducing the difficulty of implantation and improving surgical efficiency.

Wherein, please refer to Figure 6, in order to facilitate identification of the positions of the first embedded stent 4 and the second embedded stent 5 in the blood vessel after the coated stent 100 is inserted into the human body, the proximal port and the distal port of the first embedded stent 4 and the second embedded stent 5 are respectively provided with a developing structure 6, wherein the developing structure 6 can be a single developing ring adapted to the shape of the proximal port and the distal port of the first embedded stent 4 and the second embedded stent 5, and connected to the edges of the proximal port and the distal port by weaving or winding; wherein the developing ring can be made of platinum wire or tantalum metal.

In some other embodiments, please refer to Figure 7, the inclination angle of the first distal bevel 41 and the second distal bevel 51 may be greater than the first proximal bevel 42 and the second proximal bevel 52. Here, since the first distal bevel 41 and the second distal bevel 51 are arranged to be away from each other, the two stents form a V-shaped tip protruding toward the distal direction when they are in a mutually fitted position. The V-shaped tip can be used for the coated stent 100 of the present application to be hooked and connected with the conveyor when it is transported in the conveyor for easy pushing and control; specifically, the first distal bevel 41 and the second distal bevel 51 both include a major axis side wall 501 and a minor axis side wall 502 in the circumferential direction to form an oblique structure, and the axial length of the major axis side wall 501 is greater than the axial length of the minor axis side wall 502. The major axis side walls 501 of the first embedded stent 4 and the second embedded stent 5 are arranged in close contact with each other to form a V-shaped tip at the distal end. The axial length of the V-shaped tip is longer than any other position at the distal end of the coated stent 100, so at The distal end of the long axis side wall 501 is provided with a hooking portion 503 for hooking, and the hooking portion 503 can be better hooked by the hooking member 2001, while avoiding the hooking member 2001 from affecting or contacting other positions of the coated stent 100 after hooking; wherein, the inclination angle of the first distal bevel 41 and the second distal bevel 51 can be set to 30°~60°. Considering the matching requirements of the distal clamping and release structure of the conveyor, an angle less than 30° may cause the conveyor to be unable to effectively clamp the coated stent 100, thereby affecting the progress of the operation; on the contrary, if it is greater than 60°, the angle will be too large, which may cause unnecessary extension of the stent to the position of the external iliac artery. Considering that the vascular diameter of the external iliac artery is small, this may be hindered when implanting the external iliac stent, which has a negative impact on the long-term patency rate of the stent; in addition, unnecessary extension of the stent length will increase the difficulty of the operation, which may cause difficulty in releasing the coated stent 100, thereby affecting the smooth progress of the operation.

Please refer to Figures 8 and 9. Here, the hooking portion 503 can be only arranged on the long-axis side wall 501 of the first distal oblique opening 41 of the mesh body of the first embedded stent 4; or only arranged on the long-axis side wall 501 of the second distal oblique opening 51 of the mesh body of the second embedded stent 5; the distal oblique opening of at least one embedded stent is provided with a hooking portion 503 to form a hooking position for a hooking member; wherein, in some embodiments, the hooking portion 503 can also be formed by the farthest end grid structure of the long-axis side wall 501 of the first distal oblique opening 41 and the second distal oblique opening 51 of the mesh body of the first embedded stent 4 and the second embedded stent 5, and the distal side of the hooking portion 503 includes at least one blocking member 5031 for hooking, The blocking member 5031 may be a wire of a mesh structure or a developing ring at the first distal bevel 41 and the second distal bevel 51. The blocking effect provided by the developing ring alone can reduce the number of brackets at this position, thereby making it easier to release the bracket at this position. Furthermore, in order to make the hooking effect of the hooking portion 503 and the hooking member 2001 better and not easy to fall off, the mesh structure at the farthest end of the long axis side wall 501 of the first distal bevel 41 and the second distal bevel 51 is set to a hollow structure, that is, the first coating 401 and the second coating 504 are not provided, so that the hooking member 2001 can completely pass through the mesh structure of the hooking portion 503 to form a hook, so as to avoid accidental detachment after the hooking connection.

In this embodiment, please further refer to Figures 1 and 10. Since the proximal support segment 1 and the first embedded stent 4 and the second embedded stent 5 in the tumor cavity coating segment 3 adopt different stent structures, structural mutations and faults will appear at the connection positions of different segments, which is not conducive to the long-term use of the stent. In order to make the connection transition between the proximal support segment 1 and the tumor cavity coating segment 3 of the coated stent 100 smoother, a transition segment 2 is provided between the proximal support segment 1 of the main stent 100 and the tumor cavity coating segment 3. The transition segment 2 is provided with a transition bracket 21. The transition segment 2 and the transition bracket 21 are arranged between the proximal support segment 1 and the tumor cavity coating segment 3 to transition between the two parts of the main stent 10; wherein, when the proximal ports of the first embedded stent 4 and the second embedded stent 5 are the first proximal flat port 43 and the second proximal flat port 53 respectively. When, the transition bracket 21 can be one of the supporting wave rings 11 of the proximal supporting segment 1, the proximal end of the transition bracket 21 is flush with the distal flat end of the proximal segment, and the distal end of the transition bracket 21 is flush with the proximal flat end of the first embedded bracket 4 and the second embedded bracket 5; here, since the surface coating 31 of the tumor cavity coating segment 3 is sutured with the first embedded bracket 4 and the second embedded bracket 5, it is close to the outer surface of the first embedded bracket 4 and the second embedded bracket 5, then after the first embedded bracket 4 and the second embedded bracket 5 are arranged side by side, they have a longer length direction and a shorter width direction. In the width direction, the width of the tumor cavity coating segment 3 is smaller than the diameter of the proximal supporting segment 1, so the transition bracket 21 has a circular cross-section at the proximal end, and a flat strip cross-section with a reduced width on at least one side at the distal end, and the transition bracket 21 has a tapered structure from the proximal end to the distal end.

In another embodiment, please continue to refer to Figures 10 and 11. When the proximal ports of the first embedded stent 4 and the second embedded stent 5 are respectively the first proximal oblique opening 42 and the second proximal oblique opening 52, the two oblique openings form a V-shaped cross-section on the axial section, and the tumor cavity coating segment 3 forms an unsupported area at this position, wherein the proximal end of the transition stent 21 is flush with the distal flat opening of the proximal segment, and the distal end of the transition stent 21 is flush with the proximal V-shaped double oblique openings formed by the first embedded stent 4 and the second embedded stent 5; here, the transition stent 21 can support the surface coating 31 of the unsupported area formed between the double oblique openings, thereby avoiding collapse or poor release caused by the lack of support structure at this position of the tumor cavity coating segment 3. The transition bracket 21 can be a special-shaped wave ring 211, and the distal part of the special-shaped wave ring 211 extends to the unsupported area of the tumor cavity coating section 3; specifically, the proximal end of the special-shaped wave ring 211 has a uniform proximal wave 2111 of equal height, and the distal end includes a plurality of distal high waves 2112 with unequal heights, and the distal high waves 2112 protrude toward the distal end, and the apex is aligned with the first proximal bevel 42 and the second proximal bevel 52 of the first embedded bracket 4 and the second embedded bracket 5 to support the unsupported area; wherein, the special-shaped wave ring 211 has at least two distal high waves 2112, and the two distal high waves 2112 are symmetrically arranged on both sides of the distal end along the diameter of the special-shaped wave ring 211, and the apex of the two distal high waves 2112 is close to the bottom of the V-shaped double bevel.

Further, please refer to Figure 12. The distal high wave 2112 of the special-shaped wave ring 211 can be set in multiple numbers, and a peak-like structure with the highest wave height in the middle and gradually decreasing wave height on both sides is formed on the opposite sides of the distal end of the special-shaped wave ring 211 to adapt to the shape of the unsupported area; the special-shaped wave ring 211 can avoid the lack of supporting structure in the unsupported area, resulting in local collapse or poor release that affects blood circulation. At the same time, the structure of the special-shaped wave ring 211 extending between the proximal support distal segment and the tumor cavity coating segment 3 can make the connection force of the coated stent 100 between the proximal support segment 1 and the tumor cavity coating segment 3 stronger, and the stent integrity is higher, thereby avoiding bending at the transition position between the tumor cavity segment and the proximal segment.

In some embodiments, please refer to Figures 13-14, the transition bracket 21 includes a wave ring bracket 212 and/or a mesh bracket 213; wherein, when the proximal ports of the first embedded bracket 4 and the second embedded bracket 5 are respectively the first proximal flat port 43 and the second proximal flat port 53, the transition bracket 21 can be an annular wave ring bracket 212; and when the proximal ports of the first embedded bracket 4 and the second embedded bracket 5 are respectively the first proximal oblique port 42 and the second proximal oblique port 52, the transition bracket 21 can include a wave ring bracket 212, such as the aforementioned special-shaped wave ring, which will not be repeated here; it can also include both the wave ring bracket 212 and The mesh stent 213 adopts the form of a wave coil stent 212, which is similar to the structure of the support wave coil 11 of the proximal support segment 1, so that it has a better connection with the proximal support segment 1 at this position, thereby improving the overall flexibility of the coated stent 100; the mesh stent 213 adopts a mesh stent 213 with a mesh woven structure or a mesh cut structure, and the structure of the mesh stent 213 is similar to the structure of the first embedded stent 4 and the second embedded stent 5, so that the integrity of the tumor cavity segment is higher, and the supporting tension of the mesh woven stent is stronger, making the inner wall smoother, which can further ensure the patency of blood flow at this position.

Example 3

In the present embodiment, please refer to Figures 15 to 17. The structures of the main support 10 and the first embedded support 4 and the second embedded support 5 of the coated support 100 are substantially the same as those in Example 1, except that the surfaces of the first embedded support 4 and the second embedded support 5 are respectively provided with a first coating 401 and a second coating 504. In order to further enable the first embedded support 4 and the second embedded support 5 to be tightly connected to the inner cavity surface of the tumor cavity coated segment 3 at the proximal port position after being connected to the tumor cavity coated segment 3, so as to avoid internal leakage between the first embedded support 4 and the second embedded support 5 and the tumor cavity coated segment 3, the first coating 401 at least partially extends outward from the proximal port of the first embedded support 4 to form a connecting portion 402, and the second coating 504 at least partially extends outward from the proximal port of the second embedded support 5 to form a connecting portion 402. The connecting portion 402 forms an unsupported coating that exceeds the proximal ports of the first embedded support 4 and the second embedded support 5, so that the proximal ports of the first embedded support 4 and the second embedded support 5 are closely connected to the inner cavity surface of the tumor cavity coated segment 3 along the port position. After the cavity wall is connected for the first time by suturing or gluing, the connecting portion 402 of the first embedded stent 4 and the connecting portion 402 of the second embedded stent 5 are connected to the tumor cavity covering segment 3 for the second time, thereby ensuring that the proximal ends of the connected first embedded stent 4 and the second embedded stent 5 completely cover the internal cavity of the tumor cavity covering segment 3 without any gap; wherein, the first embedded stent 4 and the second embedded stent 5 are arranged side by side in close contact in the tumor cavity covering segment 3, and two fitting gaps 40 are formed at the close tangent positions of the two embedded stents. 21. At the gap, it is often difficult to achieve a tight fit by suturing the gap position formed by the tumor cavity coating segment 3 and the first embedded stent 4 and the second embedded stent 5. Therefore, the outwardly extending connecting portion 402 is at least arranged on one side of the mutually fitting position of the proximal ends of the first embedded stent 4 and the second embedded stent 5, so as to at least cover the closely tangent positions of the two stents to form two fitting gaps 4021, and achieve a better gap sealing effect by using the coating covering sealing method instead of the direct connection and sealing method with the tumor cavity coating segment 3.

In some embodiments, please continue to refer to Figure 17, the outwardly extending connection part 402 is respectively arranged along the circumference of the proximal port of the first embedded bracket 4 and the second embedded bracket 5. In this way, in addition to the two fitting gaps 4021 formed by the first embedded bracket 4 and the second embedded bracket 5 at the tightly tangent position to be sealed, any position where the first embedded bracket 4 and the second embedded bracket 5 are connected to the tumor cavity covering segment 3 can be further closed through the secondary connection of the connection part 402 to avoid internal leakage.

In this embodiment, the first coating 401 and the second coating 504 are made of different materials from the surface coating 31 of the main stent 10. The surface coating 31 is made of PET in this embodiment. The first coating 401 and the second coating 504 are both ePTFE membranes. Here, the PET membrane has the characteristics of high strength, while the ePTFE membrane has weak strength, smooth surface, and is not easy to form thrombus. It has good long-term patency for small-sized blood vessels and small pores. Combining the PET membrane and the ePTFE membrane not only ensures the overall strength of the stent coating in the main stent 10, but also enables the first embedded stent 4 and the second embedded stent 5 to have a better effect of isolating blood flow in the tumor cavity coating section 3, ensuring the long-term patency of the branch, that is, the blocking effect is good.

In this embodiment, the provision of the second coating 504 effectively isolates the first embedded stent 4 and the second embedded stent 5 so that the guide wire will not pass through the first embedded stent 4 or the second embedded stent 5 when passing into the first embedded stent 4 or the second embedded stent 5, thereby ensuring that the guide wire is accurately passed into the corresponding inner cavity stent, avoiding the problem that the implanted branch stent cannot reach the designated embedded stent.

In another embodiment, please refer to Figures 18 and 19. In order to ensure the overall sealing after the connection part 402 is connected to the tumor cavity covering segment 3, the connection part 402 of the first covering 401 can be connected to the connection part 402 of the second covering 504, and then the two connection parts 402 are respectively connected to the tumor cavity covering segment 3 after the connection; in this way, the proximal ports of the first embedded stent 4 and the second embedded stent 5 are first connected through the connection part 402 to become one, so that before the first embedded stent 4 and the second embedded stent 5 enter the tumor cavity covering segment 3 and connect with the tumor cavity covering segment 3, the outer contours of the proximal ports of the two embedded stents are first enclosed and closed in the circumferential direction of the proximal ports, so that after the first embedded stent 4 and the second embedded stent 5 are embedded in the tumor cavity covering segment 3, the first connection of the proximal ports and the second connection of the connection part 402 are performed, a better edge sealing and anti-internal leakage effect is achieved.

In some other embodiments, please refer to Figures 20 and 21. In order to further ensure the sealing of the first embedded stent 4 and the second embedded stent 5 after being connected to the tumor cavity coating segment 3 at the proximal port position, so that the fitting gap 4021 between the first embedded stent 4 and the second embedded stent 5 does not produce internal leakage, the first coating 401 and the second coating 504 of the first embedded stent 4 and the second embedded stent 5 are integrally molded. Here, the integral molding refers to the first coating 401 and the second coating 504 being continuously molded by a single coating without bonding or suturing the splicing structure; the first embedded stent 4 and the second embedded stent 5 having the first coating 401 and the second coating 504 after molding The stent 5 is arranged as an integrated body and is connected together by a coating at least on the side where the proximal ports thereof are bonded to each other. Here, since the first coating 401 and the second coating 504 are continuously formed by a single coating and are connected together by a coating on the side where the proximal ports thereof are bonded to each other, the bonding gap 4021 after the first embedded stent 4 and the second embedded stent 5 are bonded side by side is covered and blocked by the coating. Therefore, after being connected to the coating of the tumor cavity segment, no internal leakage will occur at this position, and the blood is blocked by the coating at this position. Since the first coating 401 and the second coating 504 adopt ePTFE membrane, the good blood isolation ability of the ePTFE membrane enhances the blood isolation ability to avoid internal leakage at this position.

Example 4

In the present embodiment, referring to FIG. 1 and FIG. 22 , the structures of the tumor cavity coated segment 3, the first embedded stent 4 and the second embedded stent 5 of the coated stent 100 are substantially the same as those in Examples 1 to 3, except that, in order to enhance the anchoring force of the proximal support segment 1 in the lumen of a blood vessel or other stent, the support wave ring includes at least one anchoring wave ring. Here, the support wave ring 11 of the proximal support segment 1 may include only one anchoring wave ring 12, and a plurality of anchoring barbs 121 are circumferentially provided on the outer side of the anchoring wave ring 12 for enhancing the anchoring of the proximal support segment to the blood vessel wall or the inner wall of the stent.

In some embodiments, a plurality of support wave circles 11 are axially arranged on the surface coating 31 of the proximal support segment 1, and the plurality of support wave circles 11 include at least one anchoring wave circle 12; the anchoring wave circle 12 is used to provide a better anchoring force between the proximal support segment 1 and the blood vessel, wherein the anchoring wave circle 12 is arranged between the support wave circle 11 at the proximal end of the proximal support segment 1 and the support wave circle 11 at the distal end, and a plurality of anchoring barbs 121 are circumferentially arranged on the outside, wherein the anchoring barbs 121 protrude from the outer wall of the proximal support segment 1, and are inclined and extended toward the distal direction, so that when the proximal support segment 1 is released in the blood vessel, the support wave circle 11 provides support expansion and anchoring force while the anchor of the middle support wave circle 11 The fixed barbs 121 penetrate into the blood vessel wall to provide a more stable anchoring effect; further, the anchoring wave ring 12 is arranged between the support wave ring 11 at the proximal end of the proximal support segment 1 and the support wave ring 11 at the distal end, which can enhance the anchoring force near the middle of the proximal segment. In this way, whether from the middle to the proximal end or from the middle to the distal end, the anchoring wave ring 12 as a connecting point can ensure that both ends of the proximal support segment 1 can ensure that the stent has sufficient connection force when connected to the blood vessel; in some other embodiments, multiple anchoring wave rings 12 can also be provided, and the support wave ring 11 at the proximal end and the support wave ring 11 at the distal end can be located near the middle of the proximal segment to further enhance the anchoring force of the proximal support segment 1.

Among them, the design of the anchoring barbs 121 of the anchoring wave ring 12 ensures that after the proximal supporting segment 1 of the coated stent 100 is implanted in a blood vessel or other stent, when an external iliac stent or an internal iliac stent is implanted in the coated stent 100 of the present application, the anchoring barbs 121 enhance the anchoring force and the connecting force, so that the coated stent 100 itself will not shift or shake.

Example 5

In this embodiment, please refer to FIG. 23 , the structures of the main stent 10 and the first embedded stent 4 and the second embedded stent 5 of the coated stent 100 are substantially the same as those in Embodiments 1 to 4, and a stent delivery system 200 is also provided in this embodiment, wherein the stent delivery system 200 comprises the coated stent 100 and a conveyor as described in the aforementioned embodiment, the conveyor being used to deliver the coated stent 100 of the present application to a designated blood vessel position and release it, wherein the conveyor generally comprises a delivery sheath and a delivery handle, the delivery handle being used to control the advance and retreat of the delivery sheath to release the stent from the delivery sheath, and the conveyor is also provided with a push rod 2002, a hook 2001 is connected to the proximal end of the push rod 2002, and the hook portion 503 of the coated stent 100 is used to establish a connection with the hook 2001 and then control the relative position of the coated stent 100 in the delivery sheath of the conveyor through the push rod 2002; the hook 2001 can be controlled by external force to switch between an unlocked state and a locked state, wherein, when the hook 2001 is in a locked state, the hook portion 503 is connected to the hook 2001 and cannot be disengaged; when the hook 2001 is in an unlocked state, the hook portion 503 can be separated from the hook 2001 to perform a subsequent release step of the coated stent 100.

The above-mentioned specific embodiments are only some embodiments of the present invention and are not limitations of the present invention. This specification cannot be an exhaustive list of all embodiments of the present invention. Some features of the above-mentioned different embodiments may be replaced or combined with each other. Those skilled in the art may also make simple replacements according to actual needs. The concept of the present invention shall be subject to the required protection scope.

Claims (11)

A coated stent, characterized in that it includes a main stent with a tubular body, the main stent includes a proximal support segment and a tumor cavity coated segment, the distal end of the proximal support segment is connected to the proximal end of the tumor cavity coated segment; the proximal segment includes a supporting wave ring, the tumor cavity coated segment is provided with a first embedded stent and a second embedded stent arranged radially, the distal end of the tumor cavity coated segment is provided with an opening connected to the outside, the distal ends of the first embedded stent and the second embedded stent are both connected to the opening; the support strength of the first embedded stent is greater than the support strength of the second embedded stent. The coated stent according to claim 1 is characterized in that the first embedded stent and the second embedded stent comprise a mesh body, on which the wire diameter of the first embedded stent is greater than the wire diameter of the second embedded stent, and/or the mesh density of the first embedded stent is greater than the mesh density of the second embedded stent. The coated stent according to claim 1 is characterized in that the distal ends of the first embedded stent and the second embedded stent are respectively provided with a first distal bevel and a second distal bevel, and the first distal bevel and the second distal bevel are arranged away from each other. The coated stent according to claim 3 is characterized in that the proximal ends of the first embedded stent and the second embedded stent are respectively provided with a first proximal flat opening and a second proximal flat opening; or the proximal ends of the first embedded stent and the second embedded stent are respectively provided with a first proximal oblique opening and a second proximal oblique opening, and the first proximal oblique opening and the second proximal oblique opening are arranged opposite to each other. The coated stent according to claim 1 is characterized in that the coated stent also includes a transition section connected between the proximal support section and the tumor cavity coated section, and the transition section is provided with a transition stent. The coated stent according to claim 1 is characterized in that a first coating is provided on the surface of the first embedded stent, and a second coating is provided on the surface of the second embedded stent, and the first coating and the second coating at least partially extend outward from the proximal ports of the first embedded stent and the second embedded stent, respectively, to form a connecting portion, and the connecting portion is connected to the tumor cavity coating segment. The coated stent according to claim 6 is characterized in that the connecting portion of the first coating is connected to the connecting portion of the second coating. The coated stent according to claim 7 is characterized in that the first coating and the second coating are formed in one piece. The coated stent according to claim 3 is characterized in that the first distal bevel and the second distal bevel both include a long-axis side wall and a short-axis side wall in the circumferential direction, the axial extension length of the long-axis side wall is greater than the axial extension length of the short-axis side wall, the long-axis side walls of the first embedded stent and the second embedded stent are arranged closely to each other, and the distal end of at least one of the long-axis side walls is provided with a hooking portion for hooking. The coated stent according to claim 1 is characterized in that the supporting wave ring includes at least one anchoring wave ring, and a plurality of anchoring barbs are provided on the outer side of the anchoring wave ring along the circumferential direction. A stent delivery system, characterized by comprising the coated stent according to any one of claims 1-10.