Covered stent and stent conveying system

Abstract

The invention provides a covered stent and a stent delivery system.The covered stent comprises a main body stent with a tubular main body, the main body stent comprises a near-end supporting section and a tumor cavity covered section in the axial direction, and a first embedded stent and a second embedded stent which are arranged in the radial direction are arranged in the tumor cavity covered section; an opening communicated with the outside is formed in the far end of the tumor cavity film covering section, and far end openings of the first embedded stent and the second embedded stent are both communicated with the opening; the supporting strength of the first embedded support is larger than that of the second embedded support. The first embedded stent with high supporting strength is arranged to at least ensure the passing ability of the covered stent in the external iliac channel corresponding to the first embedded stent when the covered stent is pressed; furthermore, the first embedded stent and the second embedded stent are provided with extended covering films, so that the sealing performance at the attaching gap position after the first embedded stent and the second embedded stent are sewn with the main stent can be ensured, and the inner leakage at the embedded stent is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a covered stent and a stent delivery system. Background Art

[0002] 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 the right, which pass through the fourth lumbar vertebra, extend downward along the medial 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 its surrounding tissues. However, the current iliac artery bifurcation stents have a series of problems, such as the opening of the internal iliac artery is easily compressed by blood vessels, the internal iliac branch is prone to tortuosity and kinking, resulting in blockage, and the stent may cause blockage of the opening of the internal iliac branch when it moves or rotates slightly during the operation process.

[0003] To solve the above problems, in the prior art, an inlaid branch stent has been designed specifically, 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 wide patient applicability, can be extended to the proximal side of the iliac bifurcation without being limited by the length of the common iliac artery, and is applicable to treating the internal iliac artery and the external iliac artery of various diameters. This innovative structure makes the stent easier to align during implantation, avoiding the troubles of the iliac bifurcation stent, and thus more conveniently accessing the internal iliac and external iliac stents.

[0004] However, there are still some challenges in the design of this inlaid branch stent, especially the occurrence of endoleakage may occur at the inlaid stent. Summary of the Invention

[0005] Based on this, it is necessary to provide a new covered stent and a stent delivery system to at least solve the problem of endoleakage of the inlaid stent within the main stent.

[0006] A covered stent includes a main stent having a tubular body, the main stent includes a proximal support section and a lumen covered section, the distal end of the proximal support section is connected to the proximal end of the lumen covered section; the proximal section includes support wave rings, the lumen covered section is provided with a first inlaid stent and a second inlaid stent arranged radially, the distal end of the lumen covered section is provided with an opening communicating with the outside, and the distal ports of the first inlaid stent and the second inlaid stent are both communicated with the opening; the support strength of the first inlaid stent is greater than that of the second inlaid stent.

[0007] In one embodiment, the first inlaid stent and the second inlaid stent include a mesh body, on the mesh body, the wire diameter of the first inlaid stent is greater than that of the second inlaid stent, and / or the mesh density of the first inlaid stent is greater than that of the second inlaid stent.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] In one embodiment, the connecting portion of the first covering film is connected to the connecting portion of the second covering film.

[0013] In one embodiment, the first covering film and the second covering film are integrally formed.

[0014] 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.

[0015] 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.

[0016] A stent delivery system comprises the stent graft described above.

[0017] The advantages of the present invention are as follows. The present invention provides a covered stent and a stent delivery system. The covered stent includes a main stent with a tubular body. The main stent axially includes a proximal support section and a lumen-covered section. The lumen-covered section is provided with a first embedded stent and a second embedded stent arranged radially. The distal end of the lumen-covered section is provided with an opening communicating with the outside. The distal ports of the first embedded stent and the second embedded stent are both communicated with the opening. The support strength of the first embedded stent is greater than that of the second embedded stent. By providing the first embedded stent with a greater support strength, at least the passability of the external iliac channel opposite to the first embedded stent when the covered stent is compressed can be ensured. Further, the extended covered setting of the first embedded stent and the second embedded stent can ensure the sealing performance at the fitting gap position after being sutured to the main stent, avoiding internal leakage at the embedded stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic structural diagram of the covered stent in Embodiment 1 of the present invention;

[0019] Figure 2 Schematic internal structure diagram of the covered stent in Embodiment 1 of the present invention;

[0020] Figure 3 Schematic diagram of the wire diameter distribution of the first embedded stent and the second embedded stent in Embodiment 1 of the present invention;

[0021] Figure 4 Schematic diagram of the mesh density distribution of the first embedded stent and the second embedded stent in Embodiment 1 and Embodiment 2 of the present invention;

[0022] Figure 5 Schematic diagram of the proximal flat mouth of the first embedded stent and the second embedded stent in Embodiment 2 of the present invention;

[0023] Figure 6 Schematic diagram of the imaging structure of the first embedded stent and the second embedded stent in Embodiment 2 of the present invention;

[0024] Figure 7 Schematic diagram of the structure of the hooking part in the covered stent in Embodiment 2 of the present invention;

[0025] Figure 8 Schematic diagram of the hooking part provided with a blocking member in Embodiment 2 of the present invention;

[0026] Figure 9 Schematic diagram of the blocking member of the hooking part being an imaging structure in Embodiment 2 of the present invention;

[0027] Figure 10 Schematic diagram of the transition stent being a special-shaped wave ring in Embodiment 2 of the present invention;

[0028] Figure 11 Schematic diagram of the high wave at the distal end of the special-shaped wave ring in Embodiment 2 of the present invention;

[0029] Figure 12 Schematic diagram of the gradual reduction of the high wave at the distal end of the special-shaped wave ring in Embodiment 2 of the present invention;

[0030] Figure 13 Schematic diagram of the wave ring support included in the transition support in Embodiment 2 of the present invention;

[0031] Figure 14 Schematic diagram of the mesh support included in the transition support in Embodiment 2 of the present invention;

[0032] Figure 15 Schematic diagram of the structures of the first film and the second film in Embodiment 3 of the present invention;

[0033] Figure 16 Schematic diagram of the connection part structure of the first film and the second film in Embodiment 3 of the present invention;

[0034] Figure 17 Top view of the film-covered stent when the connection part of the first film and the second film is connected to the film-covered section of the tumor cavity in Embodiment 3 of the present invention;

[0035] Figure 18 Schematic diagram of the connection structure of the first film and the second film through the connection part in Embodiment 3 of the present invention;

[0036] Figure 19 Top view of the film-covered stent when the first film and the second film are connected through the connection part and then connected to the film-covered section of the tumor cavity in Embodiment 3 of the present invention;

[0037] Figure 20 Schematic diagram of the integrally formed structure of the first film and the second film in Embodiment 3 of the present invention;

[0038] Figure 21 Top view of the film-covered stent when the integrally formed first film and second film are connected to the film-covered section of the tumor cavity in Embodiment 3 of the present invention;

[0039] Figure 22 Schematic diagram of the intermediate anchoring wave ring structure in Embodiment 4 of the present invention;

[0040] Figure 23 Schematic diagram of the hooking structure of the film-covered stent in the delivery device in Embodiment 5 of the present invention. Detailed implementation manners

[0041] In order to better understand the concept of the present application, the following specifically describes the implementation manners of the present application with reference to the accompanying drawings. The following specific embodiments are only partial embodiments of the present application and do not limit the present application.

[0042] For ease of description, spatial relative relationship terms may be used in the text to describe the relationship of one element or feature shown in the figure with respect to another element or feature. These relative relationship terms such as "inner", "outer", "inner side", "outer side", "below", "beneath", "above", "over" etc. This spatial relative relationship term is intended to include different orientations of the device during use or operation other than the orientations depicted in the figure. For example, if the device in the figure is flipped, then the element described as "below" or "beneath" other elements or features will subsequently be oriented as "above" or "over" other elements or features. Thus, the exemplary term "below" can include both the upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used in the text are interpreted accordingly.

[0043] Although terms such as first, second, third, etc. may 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 may be used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Unless the context clearly indicates otherwise, terms such as "first", "second", etc. and other numerical terms do not imply an order or sequence when used in the text. Thus, the first element, component, region, layer, or section discussed below may be referred to as the second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0044] To more clearly describe the structure of the present application, the terms "proximal end" and "distal end" are defined herein as common terms in the field of interventional medicine. Specifically, the "distal end" refers to the end of the blood vessel away from the heart, and the "proximal end" refers to the end of the blood vessel close to the heart; the "axial direction" refers to its length direction, and the "radial direction" refers to the direction perpendicular to the "axial direction"; the "upper end" and the "lower end" are relatively distant ends. When one end is defined as the "upper end", the relatively distant other end is the "lower end".

[0045] Embodiment 1

[0046] Please refer to FIGS. 1 and Figure 2 , the present invention provides a covered stent 100. The covered stent 100 is generally composed of a metal skeleton and a covering material, such as Figure 3As shown, the metal skeleton can adopt a Z-shaped wave or a braided mesh design. The film material has a certain blood flow isolation ability and is combined with the metal skeleton by means of pressurization, heating, suturing, etc. to form a complete covered stent 100. The proximal end of the covered stent 100 is generally placed in the common iliac artery or connected to the abdominal aortic stent, and the lumen diameter generally matches the diameter of the common iliac artery. In this embodiment, the covered stent 100 includes a main stent 10 with a tubular body. A surface film 31 is provided on the surface of the main stent 10. The main stent 10 includes a proximal support section 1 and a lumen film section 3 along the axis. The distal end of the proximal support section 1 is connected to the proximal end of the lumen film section 3. The surface film 31 of the proximal support section 1 and the surface film 31 of the lumen film section 3 can be integrally formed by a single film, or can be spliced and formed by multiple films in a suturing or bonding manner. The proximal section includes a support wave ring 11, while the lumen film section 3 is only provided with a surface film 31, and a first embedded stent 4 and a second embedded stent 5 are arranged radially in the lumen film section 3. In this way, the main stent 10 reduces the support wave ring 11 at the position of the lumen film section 3 to improve the flexibility of the covered stent 100 at the lumen section position. The lumen film section 3 provides support performance through the first embedded stent 4 and the second embedded stent 5. At the same time, when blood flows through the lumen film section 3, the blood is shunted into an external iliac channel and an 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.

[0047] In some embodiments, please continue to refer to Figure 2 , both the first embedded stent 4 and the second embedded stent 5 adopt a mesh main structure, aiming to emphasize better morphological support. The mesh main structure can have better film tension, so that even when providing a smaller braided wire diameter, it can still provide better film tension to maintain the shape of the blood passage. And the mesh main body can enable more contact positions between the embedded stent and the intervened stent when the external iliac stent and the internal iliac stent intervene in the first embedded stent 4 and the second embedded stent 5 respectively, thereby providing greater friction force, effectively enhancing the anchoring force and adhesion force between the stents, and providing the performance of preventing the stent from slipping off.

[0048] Wherein, a distal end of the covered section 3 of the tumor cavity is provided with an opening 32 communicating with the outside, and distal ends of the first embedded stent 4 and the second embedded stent 5 are both communicated with the opening 32; in order to make the covered stent 100 provided in the present application, when under pressure, more preferably emphasize maintaining the shape of the passage leading to the external iliac blood vessel, in this embodiment, the support strength of the first embedded stent 4 is greater than that of the second embedded stent 5. Here, the support strength is manifested as that when the first embedded stent 4 and the second embedded stent 5 are under the same pressure, the overall deformation amount of the first embedded stent 4 is less than that of the second embedded stent 5, so as to maintain a better passage shape;

[0049] In this embodiment, please refer to Figure 3 and Figure 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 above-mentioned support strength distribution effect, the wire diameter of the mesh body of the first embedded stent 4 can be made larger than that of the mesh body of the second embedded stent 5, and / or the mesh density of the first embedded stent 4 is greater than that of the second embedded stent 5.

[0050] In one embodiment, please refer to Figure 3 , so that the mesh densities of the first embedded stent 4 and the second embedded stent 5 are uniform, and the wire diameter of the mesh body of the first embedded stent 4 is made larger than that of the mesh body of the second embedded stent 5 to make the support strength of the first embedded stent 4 greater than that of the second embedded stent 5; here, the larger wire diameter of the stent has a smaller deformation ability and can provide a higher support force when under pressure. Therefore, by making the wire diameter of the first embedded stent 4 larger than that of the second embedded stent 5, when the first embedded stent 4 and the second embedded stent 5 are simultaneously under pressure, due to the larger wire diameter of the first embedded stent 4, its ability to resist deformation is stronger, and the generated deformation amount is small, while the second embedded stent 5 has a relatively smaller wire diameter, and its ability to resist deformation is less than that of the first embedded stent 4, and the generated deformation amount is large. Then, the shape of the first embedded stent 4 can be maintained better to ensure that the covered stent 100 better maintains the shape of the external iliac channel, and further ensure the blood flow rate of the blood flowing through the covered stent 100 and then flowing to the external iliac artery.

[0051] In another embodiment, please refer to Figure 4, so that the wire diameters of the first inner stent 4 and the second inner stent 5 are uniform, and the grid density of the mesh body of the first inner stent 4 is greater than that of the mesh body of the second inner stent 5, so that the support strength of the first inner stent 4 is greater than that of the second inner stent 5; here, the first inner stent 4 and the second inner stent 5 include a mesh body, and the mesh body has a plurality of grid structures; among them, the higher the grid density, it means that the number of support wires required increases, and the area of a single grid is smaller, and the pressure that can be borne is greater, and the greater the support strength that a larger grid density can provide. In this embodiment, the first inner stent 4 and the second inner stent 5 have a diamond grid structure. The first inner stent 4 has a first diamond grid, and the second inner stent 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 distance between the upper vertex and the lower vertex of the first diamond grid is D1, and the distance between the left vertex and the right vertex is L1; the distance between the upper vertex and the lower vertex of the second diamond grid is D2, and the distance 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. Thus, under the same stent deployment area, the first inner stent 4 has a higher grid density and provides a support strength stronger than that of the second inner stent 5.

[0052] In some embodiments, please further refer to Figure 4 , at least make L1 of the first diamond grid smaller than L2 of the second diamond grid, so that only the density of the first diamond grid is changed in the circumferential direction of the first inner stent 4. In this way, the density of the first diamond grid can be increased at least in the radial direction, so as to achieve the effect of enhancing the support strength in the radial direction.

[0053] In one embodiment, the wire diameter of the first inner stent 4 can be made larger than that of the second inner stent 5 and the grid density of the first inner stent 4 can be made greater than that of the second inner stent 5 at the same time. In this way, by setting the wire diameters and grid densities of the first inner stent 4 and the second inner stent 5 at the same time, while the difference in the support strength that the first inner stent 4 and the second inner stent 5 can form can be formed, a more reasonable wire diameter size and grid density distribution can be formed, avoiding too large or too small wire diameter settings and grid density settings that result in too small or too large flexibility of the first inner stent 4 and the second inner stent 5, affecting the folding and deployment performance of the covered stent 100, and causing difficulties in assembling and releasing the covered stent 100 in the sheath tube.

[0054] In this embodiment, the support strength is specifically manifested as the deformation amount of the overall tubular inner cavity after the first embedded stent 4 and the second embedded stent 5 are compressed. That is, under the same force condition, the outer side walls of the first embedded stent 4 and the second embedded stent 5 are pressed by a radial force tester with the same force (this force needs to cause a certain amount of deformation in both the first embedded stent 4 and the second embedded stent 5), and then the radial cross-sectional areas of the first embedded stent 4 and the second embedded stent 5 after pressing are measured and calculated. Here, the stent with a larger total cross-sectional area measured after pressing has a greater support strength, and the stent with a smaller total cross-sectional area has a smaller support strength. In some embodiments, the first embedded stent 4 and the second embedded stent 5 can be compressed separately by a flat plate dynamometer. When they are compressed by the same amount of deformation, the force required is measured. The stent with a larger measured force has a greater support strength, and the stent with a smaller measured force has a smaller support strength. In this embodiment, the force measured for the first embedded stent 4 is always greater than the force measured for the second embedded stent 5.

[0055] Embodiment 2

[0056] In this embodiment, please continue to refer to Figure 4 ., the structures of the main stent 10, the first embedded stent 4, and the second embedded stent 5 of the covered stent 100 are substantially the same as those in Embodiment 1. The difference is that the opening 32 at the distal end of the covered stent 100 is set as an inclined opening. Specifically, the distal ends of the first embedded stent 4 and the second embedded stent 5 are respectively provided with a first distal inclined opening 41 and a second distal inclined opening 51, and the first distal inclined opening 41 and the second distal inclined opening 51 are arranged away from each other. Here, the distal ports of the first embedded stent 4 and the second embedded stent 5 are the access ports for the external iliac stent and the internal iliac stent to intervene. Setting the distal ports of the two embedded stents as inclined openings is first to increase the size of the opening 32 when the external iliac stent and the internal iliac stent are inserted, thereby reducing the difficulty of inserting the stent. Secondly, since in this application, the connection with the external iliac artery and the internal iliac artery is achieved by additionally inserting the external iliac stent and the internal iliac stent, arranging the first distal inclined opening 41 and the second distal inclined opening 51 away from each other can make the two stents less restricted by the covered stent 100 in the direction away from each other after intervention, so that it is easier for the external iliac stent and the internal iliac stent to separate from each other after connection, and avoid mutual influence between the two stents.

[0057] Among them, please refer to Figure 4 and Figure 5, at the proximal port positions of the first inner stent 4 and the second inner stent 5, it can be set as a flat port or an inclined port. Specifically, the proximal ends of the first inner stent 4 and the second inner 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 while setting the first inner stent 4 and the second inner stent 5, and reduce the overall volume after the stent is compressed and sheathed, the first proximal flat port 43 and the second proximal flat port 53 can be arranged with an axial offset so as to be at different axial positions after compression, avoiding excessive volume caused by stacking at one axial position and difficulty in sheathing.

[0058] In another embodiment, please further refer to Figure 4 , the proximal ends of the first inner stent 4 and the second inner stent 5 can be respectively provided with a first proximal inclined port 42 and a second proximal inclined port 52, and the first proximal inclined port 42 and the second proximal inclined port 52 are arranged oppositely; here, the two inclined ports form a V-shaped cross-section on the axial section. The first proximal inclined port 42 and the second proximal inclined port 52 are the blood flow inlets in the aneurysmal cavity covered membrane segment 3. The inclined inclined port structure can increase the area for receiving blood at the inlet, thereby ensuring the patency of blood flow; further, the first proximal inclined port 42 and the second proximal inclined port 52 are arranged oppositely, so that the higher side wall of the inclined port is closely attached to the side wall of the aneurysmal cavity covered membrane segment 3, avoiding vibration or swinging during blood flushing and reducing the blood flow patency; in some embodiments, the first proximal inclined port 42 and the first distal inclined port 41, the second proximal inclined port 52 and the second distal inclined port 51 can have the same inclination angle, so as to form a parallel opening structure to increase the versatility of the first inner stent 4 and the second inner stent 5; in other embodiments, the arrangement of the first proximal inclined port 42 and the second proximal inclined port 52 can cause the long-axis side walls and short-axis side walls of the first inner stent 4 and the second inner stent 5 to be misaligned. Thus, when the covered stent 100 of the present application is compressed and placed into the delivery sheath, the long-axis side walls and short-axis side walls of the misaligned structure can make the volume of the first inner stent 4 and the second inner stent 5 smaller after folding, and it is easier to be sent into the delivery sheath.

[0059] Here, the arrangement of the first proximal inclined port 42 and the second proximal inclined port 52 can also provide a larger selection inlet for other stents during implantation, thereby reducing the implantation difficulty and improving the surgical efficiency.

[0060] Among them, please refer to Figure 6In 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. Here, the developing structure 6 can be a single developing ring that is 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 is 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.

[0061] In some other embodiments, see Figure 7 The inclination angle of the first distal bevel 41 and the second distal bevel 51 can 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. The end 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 blood vessel 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.

[0062] See also Figure 8 and Figure 9, here, the hooking part 503 can be disposed only on the long-axis sidewall 501 of the first distal inclined opening 41 of the mesh body of the first embedded bracket 4; or only on the long-axis sidewall 501 of the second distal inclined opening 51 of the mesh body of the second embedded bracket 5; the distal inclined opening of at least one embedded bracket is provided with the hooking part 503 to form a hooking position for the hooking member; wherein, in some embodiments, the hooking part 503 can also be formed by the grid structure at the outermost distal ends of the long-axis sidewall 501 of the first distal inclined opening 41 and the long-axis sidewall 501 of the second distal inclined opening 51 of the mesh bodies of the first embedded bracket 4 and the second embedded bracket 5. The distal side of the hooking part 503 includes at least one blocking member 5031 for hooking, and the blocking member 5031 can be a wire of the grid structure or a developing ring at the first distal inclined opening 41 and the second distal inclined opening 51. The blocking effect provided only by the developing ring can reduce the number of brackets at this position, so that the bracket is more easily released at this position; further, in order to make the hooking effect between the hooking part 503 and the hooking member 2001 better and not easily fall off, the grid structure at the outermost distal ends of the long-axis sidewall 501 of the first distal inclined opening 41 and the long-axis sidewall 501 of the second distal inclined opening 51 is set as a hollow structure, that is, the first coating film 401 and the second coating film 504 are not provided, so that the hooking member 2001 can completely pass through the grid structure of the hooking part 503 to form a hook, so as to avoid accidental detachment after the hook connection.

[0063] In this embodiment, please further refer to Figure 1 and Figure 10, since the proximal support section 1, the first embedded stent 4, and the second embedded stent 5 in the aneurysmal cavity covered section 3 adopt different stent structures, structural mutations and faults will occur at the connection positions of different sections, which is not conducive to the long-term use of the stent. In order to make the connection transition between the proximal support section 1 and the aneurysmal cavity covered section 3 of the covered stent 100 smoother, a transition section 2 is provided between the proximal support section 1 and the aneurysmal cavity covered section 3 of the main stent 100. The transition section 2 is provided with a transition stent 21. The transition section 2 and the transition stent 21 are arranged between the proximal support section 1 and the aneurysmal cavity covered section 3 for transitioning between the two parts of the main stent 10. Among them, when the proximal ports of the first embedded stent 4 and the second embedded stent 5 are the first proximal flat mouth 43 and the second proximal flat mouth 53 respectively, the transition stent 21 can be one of the support corrugated rings 11 of the proximal support section 1. The proximal end of the transition stent 21 is flush with the distal flat mouth of the proximal section, and the distal end of the transition stent 21 is flush with the proximal flat mouths of the first embedded stent 4 and the second embedded stent 5. Here, since the surface covering 31 of the aneurysmal cavity covered section 3 is sutured to the first embedded stent 4 and the second embedded stent 5 and closely adheres to the outer surfaces of the first embedded stent 4 and the second embedded stent 5, after the first embedded stent 4 and the second embedded stent 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 aneurysmal cavity covered section 3 is smaller than the diameter of the proximal support section 1. Therefore, the transition stent 21 has a circular cross-section at the proximal end and at least a flat strip cross-section with a reduced width on one side at the distal end, and the transition stent 21 has a tapered structure from the proximal end to the distal end.

[0064] In another embodiment, please continue to refer to Figure 10 and Figure 11, when the proximal ports of the first inner stent 4 and the second inner stent 5 are the first proximal bevel 42 and the second proximal bevel 52 respectively, the two bevels form a V-shaped cross-section on the axial section, and the aneurysm cavity membrane-covered section 3 forms an unsupported area at this position. Among them, the proximal end of the transition stent 21 is flush with the distal flat port of the proximal section, and the distal end of the transition stent 21 is flush with the proximal V-shaped double bevel formed by the first inner stent 4 and the second inner stent 5. Here, the transition stent 21 can support the surface membrane 31 of the unsupported area formed between the double bevels, so as to avoid the collapse or poor release caused by the lack of a support structure at this position of the aneurysm cavity membrane-covered section 3. The transition stent 21 can be a special-shaped wave ring 211, and the distal part of the special-shaped wave ring 211 extends into the unsupported area of the aneurysm cavity membrane-covered section 3. Specifically, the proximal end of the special-shaped wave ring 211 has uniformly equal-height proximal waves 2111, and the distal end includes a plurality of distal high waves 2112 with unequal heights. The distal high waves 2112 protrude towards the distal end, and the vertices are flush with the first proximal bevel 42 and the second proximal bevel 52 of the first inner stent 4 and the second inner stent 5 to support the unsupported area. Among them, at least two distal high waves 2112 of the special-shaped wave ring 211 are provided, 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 vertices of the two distal high waves 2112 are close to the bottom of the V-shaped double bevel.

[0065] Further, please refer to Figure 12 , a plurality of distal high waves 2112 of the special-shaped wave ring 211 can also be provided, forming a mountain-shaped structure with the highest middle wave height and gradually decreasing wave height towards both sides on the opposite sides of the distal end of the special-shaped wave ring 211 to adapt to the shape of the unsupported area. While the special-shaped wave ring 211 can avoid local collapse or poor release caused by the lack of a support structure in the unsupported area and affect blood patency, the structure of the special-shaped wave ring 211 extending between the proximal support section and the aneurysm cavity membrane-covered section 3 at the proximal end can make the connection force between the proximal support section 1 and the aneurysm cavity membrane-covered section 3 of the membrane-covered stent 100 stronger, and the integrity of the stent higher, thereby avoiding the situation of bending at the transition position between the aneurysm cavity section and the proximal section.

[0066] In some embodiments, please refer to Figures 13 - 14, the transition stent 21 includes a corrugated ring stent 212 and / or a mesh stent 213; wherein, when the proximal ports of the first inner stent 4 and the second inner stent 5 are respectively the first proximal flat port 43 and the second proximal flat port 53, the transition stent 21 can be an annular corrugated ring stent 212; and when the proximal ports of the first inner stent 4 and the second inner stent 5 are respectively the first proximal beveled port 42 and the second proximal beveled port 52, the transition stent 21 can include a corrugated ring stent 212, such as the special-shaped corrugated ring described above, which will not be elaborated here; it can also include both the corrugated ring stent 212 and the mesh stent 213 at the same time. The form of the corrugated ring stent 212 is similar to the support corrugations 11 of the proximal support section 1, so that there is a better connection with the proximal support section 1 at this position, thereby improving the overall flexibility of the covered stent 100; the mesh stent 213 is a mesh stent 213 with a mesh weaving structure or a mesh cutting structure. The structure of the mesh stent 213 is similar to that of the first inner stent 4 and the second inner stent 5, so that the integrity of the aneurysm section is higher, and the support tension of the mesh weaving stent is stronger, making the inner wall smoother, which can further ensure the patency of blood flow at this position.

[0067] Embodiment 3

[0068] In this embodiment, please refer to Figures 15 - 17, the structures of the main stent 10 of the covered stent 100, the first embedded stent 4 and the second embedded stent 5 are substantially the same as those in Embodiment 1. The difference is that the surfaces of the first embedded stent 4 and the second embedded stent 5 are respectively provided with a first film 401 and a second film 504. In order to further ensure that after the first embedded stent 4 and the second embedded stent 5 are connected to the aneurysmal cavity covered segment 3, they are closely connected to the inner cavity surface of the aneurysmal cavity covered segment 3 at the proximal port position, and to avoid internal leakage between the first embedded stent 4 and the second embedded stent 5 and the aneurysmal cavity covered segment 3, at least part of the first film 401 extends outward at the proximal port of the first embedded stent 4 to form a connecting portion 402, and at least part of the second film 504 extends outward at the proximal port of the second embedded stent 5 to form a connecting portion 402. The connecting portion 402 forms a unsupported film that extends beyond the proximal ports of the first embedded stent 4 and the second embedded stent 5. Thus, after the first connection is completed between the inner cavity wall of the aneurysmal cavity covered segment 3 and the connecting portions 402 of the first embedded stent 4 and the second embedded stent 5 at the proximal port position along the port position by suture or bonding, 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 aneurysmal cavity covered segment 3 again for a second connection, so as to ensure that the proximal ports of the first embedded stent 4 and the second embedded stent 5 after connection completely cover the internal cavity of the aneurysmal cavity covered segment 3 without gaps; wherein, the first embedded stent 4 and the second embedded stent 5 are arranged side by side closely in the aneurysmal cavity covered segment 3, and two fitting gaps 4021 are formed at the closely tangent position of the two embedded stents. At this gap, it is often difficult to achieve a tightly fitting effect when suturing the gap position formed by the aneurysmal cavity covered segment 3 and the first embedded stent 4 and the second embedded stent 5. Therefore, the outward-extending connecting portion 402 is at least arranged on one side of the mutually fitting position of the proximal ports of the first embedded stent 4 and the second embedded stent 5 to at least cover the two fitting gaps 4021 formed at the closely tangent position of the two stents, and a better gap blocking effect is achieved by the method of covering and blocking with the film instead of directly connecting and blocking with the aneurysmal cavity covered segment 3.

[0069] In some embodiments, please continue to refer to Figure 17 , the outward-extending connecting portions 402 are respectively arranged circumferentially along the proximal ports of the first embedded stent 4 and the second embedded stent 5. In this way, while sealing the two fitting gaps 4021 formed at the closely tangent position of the first embedded stent 4 and the second embedded stent 5, any position where the first embedded stent 4 and the second embedded stent 5 are connected to the aneurysmal cavity covered segment 3 can be further sealed through the secondary connection of the connecting portion 402, avoiding the generation of internal leakage.

[0070] In this embodiment, the first film covering 401 and the second film covering 504 are made of different materials from the surface film covering 31 of the main body stent 10. The surface film covering 31 uses a PET material film covering in this embodiment. Both the first film covering 401 and the second film covering 504 are ePTFE films. Here, the PET film has the characteristic of high strength, while the ePTFE film has weak strength, is smooth on the surface, is not easy to form thrombus, has good long-term patency for small-sized blood vessels, and has small pores. Combining the PET film and the ePTFE film can not only ensure the overall strength of the stent film covering of the main body stent 10, but also enable the first embedded stent 4 and the second embedded stent 5 to have a better effect of isolating blood flow in the aneurysm cavity film covering section 3, ensuring the long-term patency of the branches, that is, the occlusion effect is good.

[0071] In this embodiment, the setting of the second film covering 504 effectively isolates the first embedded stent 4 and the second embedded stent 5, so that when the guide wire is inserted into the first embedded stent 4 or the second embedded stent 5, it will not pass through the first embedded stent 4 or the second embedded stent 5, ensuring that the guide wire is accurately inserted into the corresponding inner cavity stent and avoiding the problem that the implanted branch stent cannot reach the designated embedded stent.

[0072] In another embodiment, please refer to Figure 18 and Figure 19 To ensure the overall sealing performance after the connection part 402 is connected to the aneurysm cavity film covering section 3, the connection part 402 of the first film covering 401 can be connected to the connection part 402 of the second film covering 504, and then the two connection parts 402 are respectively connected to the aneurysm cavity film covering section 3 after 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 an integral body, so that before the first embedded stent 4 and the second embedded stent 5 enter the aneurysm cavity film covering section 3 and are connected to the aneurysm cavity film covering section 3, the outer contours of the proximal ports of the two embedded stents are enclosed and sealed in the circumferential direction of the proximal port. Thus, after the first embedded stent 4 and the second embedded stent 5 are embedded in the aneurysm cavity film covering section 3 and the first connection of the proximal port and the second connection of the connection part 402 are carried out, a better edge sealing and anti-endoleakage effect is achieved.

[0073] In some other embodiments, please refer to Figure 20 and Figure 21, to further ensure the sealing performance after the first inner stent 4 and the second inner stent 5 are connected to the aneurysmal cavity covered segment 3 at the proximal port position, and to prevent internal leakage from occurring at the fitting gap 4021 between the first inner stent 4 and the second inner stent 5, the first covering film 401 of the first inner stent 4 and the second covering film 504 of the second inner stent 5 are integrally formed. Here, integral forming means that the first covering film 401 and the second covering film 504 are continuously formed from a single covering film without an adhesive or stitched splicing structure; after forming, the first inner stent 4 and the second inner stent 5 with the first covering film 401 and the second covering film 504 are integrally connected, and at least on the side where they are mutually fitted at their proximal ports, they are connected together by the covering film. Here, since the first covering film 401 and the second covering film 504 are continuously formed from a single covering film and are connected together by the covering film on the side where they are mutually fitted at their proximal ports, the fitting gap 4021 after the first inner stent 4 and the second inner stent 5 are arranged side by side and fitted is covered and blocked by the covering film, so no internal leakage will occur at this position after being connected to the aneurysmal cavity covered segment, and the blood is blocked by the covering film at this position; and since the first covering film 401 and the second covering film 504 are made of ePTFE film, the good blood isolation ability of the ePTFE film enhances the blood isolation ability to avoid internal leakage at this position.

[0074] Embodiment 4

[0075] In this embodiment, please refer to Figure 1 and Figure 22 , the structure of the aneurysmal cavity covered segment 3 of the covered stent 100, the first inner stent 4 and the second inner stent 5 is substantially the same as that in Embodiments 1 to 3. The difference is 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 rings include at least one anchoring wave ring. Here, the support wave rings 11 of the proximal support segment 1 may only include one anchoring wave ring 12, and a plurality of anchoring barbs 121 are circumferentially arranged on the outer side of the anchoring wave ring 12 for enhancing the anchoring property of the proximal support segment to the blood vessel wall or the inner wall of the stent.

[0076] In some embodiments, a plurality of support wave loops 11 are provided axially on the surface coating film 31 of the proximal support section 1, and at least one anchoring wave loop 12 is included in the plurality of support wave loops 11; the anchoring wave loop 12 is used to provide better anchoring force between the proximal support section 1 and the blood vessel. Among them, the anchoring wave loop 12 is provided between the support wave loop 11 at the proximal end and the support wave loop 11 at the distal end of the proximal support section 1, and a plurality of anchoring barbs 121 are provided on the outer side in the circumferential direction. Here, the anchoring barbs 121 protrude from the outer wall of the proximal support section 1 and incline and extend in the distal direction. In this way, when the proximal support section 1 is released in the blood vessel, while the support wave loop 11 provides support expansion and anchoring force, the anchoring barbs 121 of the middle support wave loop 11 are inserted into the blood vessel wall to provide a more stable anchoring effect; further, the anchoring wave loop 12 is provided between the support wave loop 11 at the proximal end and the support wave loop 11 at the distal end of the proximal support section 1, which can enhance the anchoring force near the middle position of the proximal section. In this way, whether it is from the middle to the proximal or from the middle to the distal, the anchoring wave loop 12 as a connection point can ensure that there is sufficient connection force when the stent is connected to the blood vessel at both ends of the proximal support section 1; in some other embodiments, a plurality of anchoring wave loops 12 can also be provided, and between the support wave loop 11 at the proximal end and the support wave loop 11 at the distal end, which can further enhance the anchoring force of the proximal support section 1 near the middle position of the proximal section.

[0077] Among them, the design of the anchoring barbs 121 of the anchoring wave loop 12 enables the proximal support section 1 of the covered stent 100 not to shift or shake itself when the covered stent 100 of the present application is implanted with an external iliac stent or an internal iliac stent after being implanted into a blood vessel or other stents, because the anchoring barbs 121 enhance the anchoring force and the connection force.

[0078] Embodiment 5

[0079] In this embodiment, please refer to Figure 23, the structures of the main stent 10, the first embedded stent 4, and the second embedded stent 5 of the covered stent 100 are substantially the same as those in Embodiments 1 to 4. Moreover, in this embodiment, a stent delivery system 200 is also provided. The stent delivery system 200 includes the covered stent 100 as described in the foregoing embodiments and a delivery device. The delivery device is used to deliver the covered stent 100 of the present application to a specified blood vessel position and release it. The delivery device generally includes a delivery sheath and a delivery handle. The delivery handle is used to control the advancement and retraction of the delivery sheath to release the stent from the delivery sheath. The delivery device is further provided with a push rod 2002. A hook member 2001 is connected to the proximal end of the push rod 2002. The hook portion 503 of the covered stent 100 is used to establish a connection with the hook member 2001 and then control the relative position of the covered stent 100 in the delivery sheath of the delivery device through the push rod 2002. The hook member 2001 can be controlled by an external force to switch between an unlocked state and a locked state. When the hook member 2001 is in the locked state, the hook portion 503 is connected to the hook member 2001 and cannot be disengaged. When the hook member 2001 is in the unlocked state, the hook portion 503 can be separated from the hook member 2001 to perform the subsequent release steps of the covered stent 100.

[0080] The above specific embodiments are only partial embodiments of the present invention and do not limit the present invention. This specification cannot enumerate all embodiments of the inventive concept of the present invention. Moreover, some features of the above different embodiments can be mutually replaced or combined, and those skilled in the art can also make simple replacements according to actual needs. The inventive concept of the present invention is subject to the claimed protection scope.

Claims

1. A covered stent, characterized in that, It comprises a main body support with a tubular body, the main body support comprises a proximal support section and a tumor cavity covering section, the distal end of the proximal support section is connected to the proximal end of the tumor cavity covering section; the proximal section comprises a support wave ring, the tumor cavity covering section is provided with a first embedded support and a second embedded support arranged radially, the distal end of the tumor cavity covering section is provided with an opening connected to the outside, the distal ends of the first embedded support and the second embedded support are both connected to the opening; the support strength of the first embedded support is greater than the support strength of the second embedded support.

2. The covered stent according to claim 1, wherein The first embedded bracket and the second embedded bracket include a mesh body, on which a wire diameter of the first embedded bracket is greater than a wire diameter of the second embedded bracket, and / or a mesh density of the first embedded bracket is greater than a mesh density of the second embedded bracket.

3. The covered stent according to claim 1, wherein 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.

4. The covered stent according to claim 3, wherein 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.

5. The covered stent according to claim 1, 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.

6. The covered stent according to claim 1, 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. 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 to form a connecting portion, and the connecting portion is connected to the tumor cavity coating segment.

7. The covered stent according to claim 6, characterized in that, The connection portion of the first coating is connected to the connection portion of the second coating.

8. The covered stent according to claim 7, wherein, The first coating and the second coating are integrally formed.

9. The covered stent according to claim 3, wherein 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 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 long-axis side walls.

10. The covered stent according to claim 1, characterized in that, The supporting wave ring includes at least one anchoring wave ring, and a plurality of anchoring barbs are arranged on the outer side of the anchoring wave ring along the circumferential direction.

11. A stent delivery system, characterized in that, Including the coated stent according to any one of claims 1-10.

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