Covered stent and covered stent system for implantation in blood vessel branches

Abstract

The present application relates to a coated stent for implantation at a blood vessel branch, the coated stent comprising a stent body and a coating fixedly connected to the stent body, characterized in that a microporous area is provided on the coating, the microporous area has a plurality of micropores, the plurality of micropores are arranged in an array with a pore spacing in the range of 0.2 mm to 2.0 mm, the micropores can allow blood to flow through, and during the implantation of the coated stent, the microporous area is used to identify the blood vessel branch area and provide an access route for the implantation of the branch stent, so that the blood flow of the nearby branch vessels will not be blocked while treating vascular lesions.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a stent graft and a stent graft system for implantation in a blood vessel branch. Background Art

[0002] Hypertension, connective tissue diseases, and chest trauma may all lead to aortic disease. Endovascular repair has become a reliable option for treating various aortic diseases. As aortic diseases involving branch vessels (such as aneurysms, arterial dissections, and arterial penetrating ulcers) become increasingly serious, and the importance of branch vessel blood supply reconstruction has gradually been discovered, how to effectively treat aortic disease without affecting the blood supply of branch vessels near the lesion has become the focus of interventional treatment of aortic disease.

[0003] At present, the main interventional technologies for treating lesions at the aortic branches in clinical practice include "chimney" technology, branch stent technology, in situ fenestration technology, etc. The main defects of the above three treatment technologies are: 1. The chimney stent will affect the adhesion of the stent graft to the aorta, which is easy to cause internal leakage. In addition, the aortic stent graft will compress the chimney stent, which is easy to cause the cross-section of the chimney stent channel to become smaller or occluded, and the long-term patency rate is low. 2. The branch stent is difficult to position, and the operator is difficult and time-consuming; the branch stent is not correctly positioned, and the long-term patency rate of the branch blood vessels is low. 3. The main defect of the in situ fenestration technology is that before the membrane is broken and the window is opened, the membrane will completely block the blood supply of the branch blood vessels, which may cause serious intraoperative complications and even lead to the death of the patient. In this case, extracorporeal circulation needs to be established in advance before the operation can be performed, which increases the complexity and operation time of the operation. In addition, when using a balloon to expand the window, it is easy to cause the membrane to tear in the direction of the weaving pattern and cause internal leakage.

[0004] Therefore, in view of the deficiencies of existing treatment technologies, it is of great significance to design a covered stent that can preserve the blood flow of its branch vessels while treating aortic lesions. Summary of the invention

[0005] The object of the present invention is to provide a covered stent and a covered stent system for blood vessel branches, which can treat aortic lesions without blocking blood flow in nearby branch vessels.

[0006] One object of the present invention is achieved through the following technical solutions:

[0007] A coated stent for implantation at a blood vessel branch, the coated stent comprising a stent body and a coating fixedly connected to the stent body, a microporous area being provided on the coating, the microporous area having a plurality of micropores, the plurality of micropores being arranged in an array with a pore spacing ranging from 0.2 mm to 2.0 mm, the micropores being capable of allowing blood to flow through, and during the implantation of the coated stent, the microporous area being used to identify a blood vessel branch area and provide an access route for implantation of a branch stent.

[0008] In one embodiment, the diameter of the micropores is in the range of 0.1 mm to 0.6 mm.

[0009] In one embodiment, one or more microporous regions are provided on the stent graft, and the microporous regions are provided within a region ranging from 15 degrees to 360 degrees along the circumferential direction of the stent graft.

[0010] In one embodiment, the length of the microporous region is in the range of 3 mm to 100 mm.

[0011] In one embodiment, the stent body is formed by weaving or by laser cutting.

[0012] In a preferred embodiment, the support body has sufficient supporting force, and the shape of the support body is straight cylinder or cone.

[0013] In a preferred embodiment, the stent body is partially covered with a membrane, and the stent located at the proximal end portion of the stent body is not covered with a membrane.

[0014] In a preferred embodiment, the stent body is completely covered.

[0015] In a preferred embodiment, the material of the stent body includes but is not limited to nickel-titanium alloy, cobalt-chromium alloy, magnesium alloy, 316L stainless steel, tantalum metal, polymer material, etc.

[0016] In one embodiment, a plurality of development marks are provided at the edge of the microporous area to mark the position of the microporous area.

[0017] In a preferred embodiment, the developing mark is connected to the edge of the microporous area by precision sewing or riveting.

[0018] In a preferred embodiment, the shape of the development mark includes but is not limited to a circle, an ellipse, an "8" shape, etc.

[0019] In a preferred embodiment, the number of the development marks is 2-10.

[0020] In a preferred embodiment, the material of the development mark includes but is not limited to platinum, gold, tantalum metal, medical stainless steel, etc.

[0021] In one embodiment, the coating is biocompatible, and the material of the coating includes but is not limited to polytetrafluoroethylene, dacron, polyester, polyurethane, etc.

[0022] Another object of the present invention is achieved through the following technical solutions:

[0023] A coated stent system for implantation at a blood vessel branch, the coated stent system comprising a conveying system and a coated stent, a membrane breaker, an expansion balloon and a branch stent arranged in the conveying system, the coated stent comprising a stent body and a coating fixedly connected to the stent body, a microporous area being arranged on the coating, the microporous area having a plurality of micropores, the plurality of micropores being arranged in an array with a hole spacing ranging from 0.2 mm to 2.0 mm, the micropores being capable of supplying blood flow, when the coated stent is delivered to a target area by the conveying system and released, the blood flow flowing through the micropores guides the microporous area to be placed at an opening of a blood vessel branch, the microporous area being capable of temporarily supplying blood to the blood vessel branch, the membrane breaker being used to penetrate the microporous area to provide an expansion opening for facilitating the passage of the expansion balloon, the expansion balloon being used to further increase the size of the expansion opening so that the branch stent can pass through the microporous area and be supported at the blood vessel branch to establish a blood supply channel for the blood vessel branch.

[0024] In one embodiment, the diameter of the micropores is in the range of 0.1 mm to 0.6 mm.

[0025] In a preferred embodiment, one or more microporous regions are provided on the membrane, and the microporous regions are arranged within a region ranging from 15 degrees to 360 degrees along the circumferential direction of the stent graft.

[0026] In a preferred embodiment, the length of the microporous region is in the range of 3 mm to 100 mm.

[0027] In one embodiment, a plurality of development marks are provided at the edge of the microporous area to mark the position of the microporous area.

[0028] In a preferred embodiment, the developing mark is connected to the edge of the microporous area by precision sewing or riveting.

[0029] In a preferred embodiment, the shape of the development mark includes but is not limited to a circle, an ellipse, an "8" shape, etc.

[0030] In a preferred embodiment, the number of the development marks is 2-10.

[0031] In a preferred embodiment, the material of the development mark includes but is not limited to platinum, gold, tantalum metal, medical stainless steel, etc.

[0032] In one embodiment, the main body support is formed by weaving or by laser cutting.

[0033] In a preferred embodiment, the support body has sufficient supporting force, and the shape of the support body is straight cylinder or cone.

[0034] In a preferred embodiment, the material of the stent body includes but is not limited to nickel-titanium alloy, cobalt-chromium alloy, magnesium alloy, 316L stainless steel, tantalum metal, polymer material, etc.

[0035] In one embodiment, the coating is biocompatible, and the material of the coating includes but is not limited to polytetrafluoroethylene, dacron, polyester, polyurethane, etc.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. The coated stent and coated stent system provided by the present invention are provided with a microporous area on the coating thereof, wherein the microporous area has a plurality of micropores, and the micropores can supply blood flow. During the implantation of the coated stent, the microporous area can identify the branch area of ​​the blood vessel and temporarily supply blood to the branch blood vessel; and the plurality of micropores provided in the microporous area are arranged into an array with a hole spacing in the range of 0.2 mm to 2.0 mm, and the diameter of the micropores is in the range of 0.1 mm to 0.6 mm. Such a setting of the micropore diameter and the hole spacing can not only ensure the blood supply to the branch blood vessel, but also prevent the tearing of the coating during the puncture of the membrane breaker. Even if the expansion balloon is further expanded, it only changes the size of the micropores adjacent to it in the microporous area without tearing the coating. Therefore, the microporous area can provide a good access indication and access window for the implantation of the branch stent.

[0038] 2. The present invention provides a plurality of developing marks at the edge of the microporous area to indicate the position of the microporous area. Under the monitoring of digital subtraction angiography (DSA), the microporous area of ​​the stent graft can be placed at the opening of the branch vessel through the developing marks. The stent graft will not block the blood flow of the branch vessel while treating aortic lesions. Moreover, the developing marks are also conducive to the positioning of the branch stent. The branch stent can be released at the target position after passing through the microporous area to establish a blood supply channel for the branch vessel.

[0039] 3. The diameter of the micropores of the present invention is in the range of 0.1 mm to 0.6 mm. There are no micropores located at the openings of blood vessel branches that are close to the blood vessel wall. Due to the limitation of the micropore diameter and the characteristics of fast blood flow velocity and high pressure in the aorta, blood will accumulate in the micropores after a period of time, causing the micropores to be permanently closed. Therefore, there is no need to worry about internal leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of an implementation method of using the "chimney" technology in the prior art to treat aortic disease.

[0041] Figure 2 It is a schematic diagram of the structure of a covered stent for treating aortic lesions using branch stent technology in the prior art.

[0042] Figure 3 It is a schematic diagram of the structure of a covered stent for treating aortic lesions using the in situ fenestration technology in the prior art.

[0043] Figure 4a It is a structural schematic diagram of the membrane breaker of the present invention.

[0044] Figure 4b It is a schematic structural diagram of the expansion balloon of the present invention.

[0045] Figure 4c It is a schematic structural diagram of the branch support of the present invention.

[0046] Figure 4d It is a schematic structural diagram of the guide wire of the present invention.

[0047] Figure 4e It is a structural schematic diagram of a conveying system in the prior art.

[0048] Figure 5a-5d It is a structural schematic diagram of an implementation manner of Example 1 of the covered stent applicable to a blood vessel branch of the present invention.

[0049] Figure 6a-6c It is a structural schematic diagram of another implementation manner of Example 1 of the covered stent suitable for blood vessel branches of the present invention.

[0050] Figure 7a-7d It is a schematic diagram of the operation process of the first embodiment of the covered stent system applicable to the blood vessel branch of the present invention.

[0051] Figure 8a-8d It is a structural schematic diagram of an implementation manner of Example 2 of the covered stent applicable to a blood vessel branch of the present invention.

[0052] Figure 9a-9d It is a schematic diagram of the operation process of the second embodiment of the covered stent system applicable to the blood vessel branch of the present invention.

[0053] Figure 10a-Figure 10d It is a structural schematic diagram of an implementation manner of Example 3 of the covered stent suitable for blood vessel branches of the present invention.

[0054] Figure 11a-Figure 11d It is a schematic diagram of the operation process of Example 3 of the covered stent system suitable for blood vessel branches of the present invention.

[0055] Fig.12a and Figure 12b It is a schematic structural diagram of another embodiment of the third embodiment of the covered stent applicable to a blood vessel branch of the present invention. DETAILED DESCRIPTION

[0056] The technical solution of the present invention and the advantages brought by it are further described in detail below in conjunction with the accompanying drawings and specific embodiments. Among them, the components in the accompanying drawings are not necessarily drawn to scale, and the focus is on illustrating the concept of the present invention.

[0057] In various specific embodiments of the present invention, the well-known structures or materials involved therein are not described in detail. In addition, those skilled in the art should understand that the various embodiments described below are only used for illustration and are not used to limit the scope of protection of the present invention.

[0058] Before describing the specific embodiments of the present invention in detail, the terms involved in the present invention are explained as follows:

[0059] "Micropore area" refers to an area defined by a plurality of micropores arranged on the covering film. The plurality of micropores are arranged in arrays according to different rules, and one array is a micropore area. The arrangement rules of each array can be the same or different. The pore size and / or pore spacing of the micropores in each array can be the same or different.

[0060] The "chimney" technique is a commonly used procedure for treating aortic lesions in the existing technology. Figure 1 As shown, the specific operation process is as follows: first, under the monitoring of digital subtraction angiography (DSA), the main stent 10 and the chimney stent 11 are respectively delivered to the aorta 9 and the corresponding vascular branch 91, and are not released temporarily; then, after the positioning of each stent is clarified by digital subtraction angiography, the main stent 10 in the aortic cavity is released first, and then the chimney stent 11 is released between the main stent 10 and the aortic wall, and a blood supply channel to the branch is squeezed out by the supporting force of the chimney stent 11. In order to facilitate the blood to flow into the chimney stent 11, when released, the chimney stent 11 needs to exceed the front edge of the main stent 10 by at least 5 mm.

[0061] The "branch stent" technique is a common procedure for treating aortic disease in the prior art. The structure of the branch stent graft is as follows: Figure 2 As shown. The main stent 20 and the branch stent 21 in the branch coated stent are usually an integrated structure. The specific operating steps of the "branch stent" technology are as follows: First, under the monitoring of digital subtraction angiography (DSA), the guide wire passing through the branch stent 21 is pushed into the corresponding branch blood vessel, and the guide wire passing through the main stent 20 is pushed to the aortic lesion. Then, the main stent 20 is transported to the aortic lesion along its internal guide wire and ensures that the branch stent is pre-placed at the opening of the branch blood vessel along its internal guide wire. After adjusting the stent position and confirming it by angiography, the main stent 20 and the branch stent 21 are released to isolate the aortic lesion and maintain blood flow in the branch blood vessel.

[0062] "Windowing" technology is a commonly used procedure for treating aortic diseases in existing technologies. Figure 3 The structure of the coated stent for in situ window opening technology is shown. In this structure, the main stent 30 and the branch stent 31 of the coated stent are separate structures. The specific operation steps of the coated stent are as follows: First, under the monitoring of digital subtraction angiography (DSA), the main stent 30 of the coated stent is placed in the aortic cavity of the diseased aorta. At this time, the coating at the opening of the branch blood vessel will completely block the blood flow of the branch blood vessel; secondly, acupuncture (or laser, or radiofrequency) is used to break the membrane and open a window on the coating at the opening of the branch blood vessel; then, a balloon is used to expand the original window; finally, after the window expansion is completed, the branch stent 31 is implanted to support the window and keep the branch blood flow unobstructed.

[0063] Embodiment 1

[0064] like Figure 5a-5d As shown, the present application provides a coated stent 100 for implantation at a blood vessel branch, the coated stent comprising a stent body 101 and a coating fixedly connected to the stent body 101, the stent body 101 being a straight cylindrical structure woven from nickel-titanium alloy wires, having sufficient supporting force, a microporous area 102 being arranged on the coating, the microporous area 102 having a plurality of micropores, the plurality of micropores being arranged in an array with a pore spacing in the range of 0.2 mm to 2.0 mm, the micropores being capable of allowing blood to flow through, and during the implantation of the coated stent 100, the microporous area 102 is used to identify the blood vessel branch area and provide an access route for the implantation of the branch stent.

[0065] In one embodiment, the diameters of the plurality of micropores disposed in the micropore region 102 are equal, or the diameter of the micropores disposed in the middle portion of the micropore region 102 is greater than the diameter of the micropores disposed in the edge portion of the micropore region, and the diameter of the micropores is in the range of 0.1 mm to 0.6 mm. The micropore region 102 is disposed in the region of 15 degrees to 360 degrees along the circumferential direction of the stent graft 100. The length b of the micropore region 102 is in the range of 3 mm to 100 mm.

[0066] In one embodiment, the intervals between the micropores arranged in the middle part of the micropore area 102 are smaller than the intervals between the micropores arranged in the edge part of the micropore area 102. The shape of the micropore area 102 includes but is not limited to circular, elliptical, square, ribbon-shaped, etc. The length of the micropore area 102, as well as the diameter of the micropores and the arrangement of the micropores can be adjusted accordingly according to the diameter and position of the branch blood vessels at the lesion. Due to the restrictions on the aperture and arrangement of the micropores of the present invention and the characteristics of the fast flow rate and high pressure of the aorta blood flow, for the micropores that are not located at the opening of the blood vessel branch and are attached to the blood vessel wall, after a period of time, blood will accumulate in the micropores, causing the micropores to be permanently closed, so there is no need to worry about internal leakage.

[0067] In one embodiment, a plurality of developing marks 103 are provided at the edge of the microporous region 102 to indicate the position of the microporous region 102. The developing marks 103 are connected to the edge of the microporous region 102 by precision suturing or riveting. The shape of the developing marks includes but is not limited to circular, oval, "8" shape, etc. The number of the developing marks 103 is 2-10. The material of the developing marks 103 includes but is not limited to platinum, gold, tantalum metal, medical stainless steel, etc. In the present invention, a plurality of developing marks 103 are provided at the edge of the microporous region 102 to indicate the position of the microporous region 102. Under the monitoring of digital subtraction angiography (DSA), the microporous region section of the coated stent can be placed at the opening of the branch vessel through the developing marks 103. The coated stent will not block the blood flow of the branch vessel while treating aortic lesions. Moreover, the developing marks 103 are also conducive to the positioning of the branch stent. The branch stent can be released at the target position after passing through the microporous region 102 to establish a blood vessel branch blood supply channel.

[0068] In a preferred embodiment, the main stent is partially coated, and the stent located at the proximal end of the stent body is not coated. In a preferred embodiment, the main stent is fully coated.

[0069] like Figure 6a-6cAs shown, in another embodiment, the stent body 101 is a conical structure formed by laser cutting, and the structure can adapt to the shape characteristics of the human blood vessels (such as the carotid artery) at the implantation site.

[0070] like Figure 4a-4e As shown, the present invention also provides a stent graft system for implantation in a blood vessel branch, the system comprising a delivery system 108, a guide wire 107, a stent graft, a membrane breaker 105, an expansion balloon 106 and a branch stent 104 arranged in the delivery system, as shown in FIG. Figure 5a-5d As shown, the coated stent 100 includes a stent body 101 and a coating fixedly connected to the stent body 101, a microporous area 102 is arranged on the coating, the microporous area 102 has a plurality of micropores, and the plurality of micropores are arranged in an array with a hole spacing in the range of 0.2 mm to 2.0 mm, the micropores can supply blood flow, when the coated stent 100 is delivered to the target area by the conveying system and released, the blood flow flowing through the micropores guides the microporous area 102 to be placed at the opening of the blood vessel branch, the microporous area 102 can temporarily supply blood to the blood vessel branch, the membrane breaker 105 is conveyed to the microporous area 102 by the conveying system, the membrane breaker 105 is used to penetrate the microporous area 102 to provide an expansion opening for facilitating the passage of the expansion balloon 106, the expansion balloon 106 is used to further increase the size of the expansion opening so that the branch stent 104 can pass through the microporous area 102 and support at the blood vessel branch to establish a blood supply channel for the blood vessel branch.

[0071] In this embodiment, the delivery system 108, membrane breaker 105, expansion balloon 106 and branch stent 104 can all use structures commonly used in the prior art, and their specific structures will not be described in detail here.

[0072] In this embodiment, the material of the stent body 101 includes but is not limited to nickel-titanium alloy, cobalt-chromium alloy, magnesium alloy, 316L stainless steel, metal tantalum, polymer material, etc. The coating is biocompatible and is fixed to the stent body 101 by precision suturing or hot pressing. The material of the coating includes but is not limited to polytetrafluoroethylene, dacron, polyester, polyurethane, etc.

[0073] like Figure 7a-7d As shown, the operating steps of the stent graft system of the present invention are as follows:

[0074] In the first step, as shown in 7a, under the monitoring of digital subtraction angiography (DSA), the delivery system loaded with the coated stent 100 is delivered to the diseased blood vessel along the guide wire 107, and the microporous area 102 is placed at the opening of the branch vessel under the condition of blood flow passing through the visible microporous area 102 and / or under the indication of the development mark 103. After accurate positioning, the coated stent is released. At this time, the coated stent not only covers the lesion position of the aorta, but also ensures the blood supply of the branch vessel due to the permeability of the microporous area 102 to blood flow.

[0075] The second step is, Figure 7b As shown, the membrane breaker 105 is transported along the guide wire 107 to the branch blood vessel opening where the microporous area 102 is located, and the membrane is punctured to form an opening, and then the membrane breaker 105 is withdrawn. Since the presence of the microporous area 102 reduces the membrane puncture force, the membrane puncture becomes easier.

[0076] The third step is Figure 7c As shown, the expansion balloon is delivered to the flared portion along the guide wire 107 to further increase the size of the flared portion. Since the window expansion is performed in the microporous area 102, the risk of tearing of the window membrane caused by balloon expansion is reduced to a certain extent.

[0077] The fourth step is Figure 7d As shown, the branch stent 104 is implanted into the opening of the branch blood vessel along the guide wire 107 to support and stabilize the window, thereby maintaining smooth blood flow in the branch.

[0078] From the above description, it can be seen that the present invention does not adopt the "chimney" technology that is prone to internal leakage. The coated stent and coated stent system provided by the present invention are provided with a microporous area on the coating, and the microporous area has a plurality of micropores, and the micropores can supply blood flow. During the implantation of the coated stent, the microporous area can identify the blood vessel branch area and temporarily supply blood to the blood vessel branch. Therefore, the operation is simple, there is no need to establish extracorporeal circulation, the operation time is short, the difficulty is low, and the plurality of micropores provided in the microporous area are arranged in an array with a hole spacing in the range of 0.2 mm to 2.0 mm. The diameter of the micropores is in the range of 0.1mm to 0.6mm. The setting of the micropore diameter and the hole spacing can not only ensure the blood supply to the branch blood vessels, but also prevent the tearing of the membrane during the puncture of the membrane breaker. Even if the expansion balloon further expands, it only changes the size of the micropores adjacent to it in the micropore area without tearing the membrane. Therefore, the micropore area can provide a good access indication and access window for the implantation of the branch stent, which not only solves the problems of difficult positioning and difficult operation of the existing "branch stent" technology, but also solves the problems of serious surgical complications and complex surgery of the "window opening" technology.

[0079] Embodiment 2

[0080] like Figure 8a-8d As shown, a coated stent 200 for implantation at a branch of a blood vessel, the coated stent 200 includes a stent body 201 and a coating fixedly connected to the stent body 201, the stent body 201 is a straight cylindrical structure woven from nickel-titanium alloy wire, and has sufficient supporting force. The difference between this embodiment and the first embodiment is that: a plurality of microporous areas 202 are provided on the coating, and the plurality of microporous areas 202 can be respectively placed at different branch blood vessel openings, and this structure is suitable for the situation where there are multiple branch blood vessels at the lesion location. The aperture and pore spacing of the plurality of micropores in the microporous area 202 can be adjusted accordingly according to the diameter and position of the branch blood vessel at the lesion location. In one embodiment, a plurality of developing marks 203 are provided at the edges of the plurality of microporous areas 202 to indicate the position of the microporous area 102.

[0081] Figure 9a-9d The operating steps of the coated stent system of this embodiment are shown. The difference between the operating steps of this embodiment and those of implementation one is that multiple microporous areas 202 need to be placed at different branch blood vessel openings to ensure the accuracy of positioning so that blood flow in each branch blood vessel is unobstructed, and then the second to fourth steps are repeated multiple times.

[0082] Embodiment 3

[0083] like Figures 10a-10d As shown, a covered stent 300 for implantation at a branch of a blood vessel comprises a stent body 301 and a covering film fixedly connected to the stent body 301. The stent body 301 is a straight cylindrical structure woven from nickel-titanium alloy wires and has sufficient supporting force. The difference between this embodiment and the first embodiment is that micropores are arranged at a certain area of ​​the covering film along the circumferential direction of the stent body 301 for 360 degrees, that is, the micropore area 302 is arranged along the circumferential direction of the covered stent for 360 degrees. The structure of the covered stent 300 is suitable for the situation where there are multiple branch vessels in the same radial direction at the lesion position, such as renal artery vascular lesions.

[0084] Figure 11a-Figure 11dThe operation steps of the coated stent system of this embodiment are shown. The difference between the operation steps of the embodiment 1 is that a developing mark 303 is provided at the edge of the microporous area 302. Under the indication of the developing mark 303, the microporous area 302 is placed at the opening of the branch blood vessel. At this time, there is no need to consider the radial position of the microporous area 302. The coating is provided with micropores at 360 degrees in a certain area segment, which can not only adapt to the situation where there are multiple branch blood vessels in the same radial direction at the lesion position, but also reduce the difficulty for the operator to align the microporous area 302 with the opening of the branch blood vessel. In addition, due to the limitation of the micropore aperture and the characteristics of fast blood flow velocity and high pressure in the arterial blood flow, after a period of time, blood will accumulate in the micropores that are not located at the opening of the blood vessel branch in the same radial direction, causing the micropores to be permanently closed, and there is no need to worry about internal leakage.

[0085] Embodiment 4

[0086] like Fig.12a and Figure 12b As shown, a covered stent 400 for implantation in a blood vessel branch comprises a stent body 401 and a covering fixedly connected to the stent body 401. The stent body 401 is a straight cylindrical structure woven from nickel-titanium alloy wires and has sufficient supporting force. The difference from the first embodiment is that the covered stent in this embodiment is provided with microporous areas 402 on the entire covering. The covered stent involved in this embodiment is suitable for cases where the aortic lesions have complex branches and many branches, and the structure will not block the blood supply of the branch vessels.

[0087] In this embodiment, the operation steps are different from those of the first embodiment in that development marks 403 are provided at both ends of the coated stent. After the coated stent 400 is placed at the aortic lesion site through the delivery system under the indication of the development marks 403, subsequent operations such as puncturing, expanding, and implanting branch stents can be performed. Since there are micropores on the entire coating, there is no problem of aligning the micropore area 403 with the opening of the branch blood vessel, and there is no need to worry about the coating blocking the branch blood vessel. In addition, due to the limitation of the micropore aperture and the characteristics of fast blood flow velocity and high pressure in the aorta, for micropores that are not located at the opening of the blood vessel branch, blood will accumulate in the micropores after a period of time, causing the micropores to be permanently closed, and there is no need to worry about internal leakage.

[0088] In a specific application process, the number and range of appropriate microporous regions can be set according to the anatomical structure of the lesion area, and the microporous regions can be set in an area ranging from 15 degrees to 360 degrees along the circumferential direction of the coated stent.

[0089] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A covered stent for implantation in a blood vessel branch, the covered stent comprising a stent body and a covering fixedly connected to the stent body, characterized in that: A microporous area is provided on the coating, and the microporous area has a plurality of micropores, and the plurality of micropores are arranged in an array with a hole spacing ranging from 0.2mm to 2.0mm. The micropores can allow blood to flow through, and during the implantation of the coated stent, the blood flow flowing through the micropores guides the microporous area to be placed at the opening of the blood vessel branch. The microporous area is used to identify the blood vessel branch area and provide an access for the implantation of the branch stent. The diameter of the micropore is in the range of 0.1mm to 0.6mm, and the length of the micropore area is in the range of 3mm to 100mm. For the micropores that are not located at the opening of the blood vessel branch and are attached to the blood vessel wall, blood will accumulate in the micropores, causing the micropores to be permanently closed, and a plurality of developing marks are provided at the edge of the micropore area to indicate the position of the micropore area.

2. The covered stent for implantation in a blood vessel branch according to claim 1, characterized in that: One or more microporous regions are arranged on the membrane, and the microporous regions are arranged within a region ranging from 15 degrees to 360 degrees along the circumferential direction of the membrane stent.

3. The covered stent for implantation in a blood vessel branch according to claim 1, characterized in that: The developing mark is connected to the edge of the microporous area by precision sewing or riveting.

4. A covered stent system for implantation in a blood vessel branch, characterized in that: The invention comprises a conveying system and a coated stent, a membrane breaker, an expansion balloon and a branch stent arranged in the conveying system, wherein the coated stent comprises a stent body and a membrane fixedly connected to the stent body, a microporous area is arranged on the membrane, the microporous area has a plurality of micropores, and the plurality of micropores are arranged in an array with a hole spacing in the range of 0.2 mm to 2.0 mm, the micropores can supply blood flow through, when the coated stent is delivered to the target area by the conveying system and released, the blood flow flowing through the micropores guides the microporous area to be placed at the opening of the blood vessel branch, the microporous area can temporarily supply blood to the blood vessel branch, and the membrane breaker is used to penetrate the microporous area to provide The expansion opening is provided to facilitate the passage of the expansion balloon, and the expansion balloon is used to further increase the size of the expansion opening so that the branch stent can pass through the microporous area and support the blood vessel branch to establish a blood supply channel for the blood vessel branch. The diameter of the micropore is in the range of 0.1mm to 0.6mm, and the length of the microporous area is in the range of 3mm to 100mm. For micropores that are not located at the opening of the blood vessel branch and are attached to the blood vessel wall, blood will accumulate in the micropores, causing the micropores to be permanently closed. The diameters of the multiple micropores arranged in the microporous area are equal, or the diameter of the micropores arranged in the middle part of the microporous area is larger than the diameter of the micropores arranged at the edge part of the microporous area.

5. The stent graft system for implantation in a blood vessel branch according to claim 4, characterized in that: One or more microporous regions are arranged on the membrane, and the microporous regions are arranged within a region ranging from 15 degrees to 360 degrees along the circumferential direction of the membrane stent.

6. The stent graft system for implantation in a blood vessel branch according to claim 4, characterized in that: A plurality of developing marks are arranged at the edge of the microporous area to mark the position of the microporous area.

7. The stent graft system for implantation in a blood vessel branch according to claim 6, characterized in that: The developing mark is connected to the edge of the microporous area by precision sewing or riveting.

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