Stent Graft

Abstract

The present invention belongs to the technical field of medical devices, and specifically relates to a coated stent. The coated stent includes a stent body and a film, and the stent body has a proximal end and a distal end, and the proximal end is used to be arranged upstream of the blood vessel relative to the distal end. The film is installed and covered on the stent body, and a plurality of openings are opened on the surface of the film, and the openings face the proximal end or the distal end of the stent body. After the stent body of the present invention is installed at the Y-shaped bifurcation of the carotid artery, the stent body opens, and the film opens with the stent body, and the film covers the plaque in the blood vessel, thereby preventing the plaque from breaking and falling off due to the squeezing of the stent body. In addition, after the stent body is installed to the common carotid artery and the internal carotid artery, the blood flow entering the external carotid artery from the common carotid artery can easily break the film located at the entrance of the external carotid artery, thereby ensuring that the blood enters the external carotid artery normally. In summary, the coated stent of the present invention has better safety in use.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a stent graft. Background Art

[0002] Cerebrovascular disease is a major disease threatening human health today and is the third leading cause of death after cardiovascular disease and tumors. Among them, 25% of ischemic strokes are related to carotid artery stenosis or occlusion.

[0003] The treatment of carotid artery stenosis is mainly divided into drug therapy, carotid endarterectomy, and carotid artery stenting. Among them, carotid artery stenting has the advantages of simple surgery, less trauma, and fewer complications, and is currently one of the effective methods for treating carotid artery stenosis.

[0004] The carotid artery is divided into the common carotid artery, external carotid artery and internal carotid artery. The common carotid artery, external carotid artery and internal carotid artery present a Y-shaped bifurcation structure. The blood of the common carotid artery flows into the internal carotid artery and the external carotid artery respectively at the bifurcation. Among them, the blood of the internal carotid artery mainly flows to the brain, and the blood of the external carotid artery mainly supplies the facial organs.

[0005] Currently, the common carotid artery stents include bare stents and covered stents. After the carotid artery stent is placed in the common carotid artery and internal carotid artery, the carotid artery stent expands to open the narrowed blood vessels and restore normal blood supply to the carotid artery.

[0006] Existing bare stents are usually tubular structures made by laser cutting or metal wire weaving. The mesh of the bare stent is relatively large. When the bare stent is released at the stenotic site of the carotid artery, the stent rods can easily cut the plaque, causing the plaque to break and fall off. The broken plaques will enter the brain with the blood flow, and then block the cerebral blood vessels, causing stroke or even death.

[0007] The existing covered stent is installed at the Y-shaped bifurcation structure of the carotid artery. The film of the covered stent easily covers the entrance of the external carotid artery, causing ischemia of the external carotid artery and affecting the blood supply to the facial organs.

[0008] In summary, existing carotid artery stents have low safety. Summary of the invention

[0009] The purpose of the present invention is to provide a covered stent to solve the problem of low safety of existing carotid artery stents.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] A stent graft, comprising:

[0012] A stent body, the stent body having a proximal end and a distal end, the proximal end being arranged upstream of the blood vessel relative to the distal end;

[0013] A film is installed and covered on the support body, and a plurality of openings are formed on the surface of the film, and the openings face the proximal end or the distal end of the support body.

[0014] Preferably, in the above-mentioned stent graft, the opening is formed in the film by laser cutting.

[0015] Preferably, in the above-mentioned stent graft, a plurality of groups of openings are sequentially arranged in the length direction of the film, each group of openings has a plurality of openings, and the plurality of openings in each group of openings are continuously distributed along the circumference of the film.

[0016] Preferably, in the above-mentioned stent graft, the opening is a semicircular structure.

[0017] Preferably, in the above-mentioned stent graft, the opening is a rectangular structure.

[0018] Preferably, in the above-mentioned stent graft, the opening is a triangular structure.

[0019] Preferably, in the above-mentioned stent graft, the film is a single-layer structure.

[0020] Preferably, in the above-mentioned stent graft, the film is a two-layer structure, and there is an overlapping area between the openings of the two layers of the film.

[0021] Preferably, in the above-mentioned stent graft, the film is a two-layer structure, and the closed end of the opening of the film of the outer layer is overlapped to the open end of the opening of the film of the inner layer.

[0022] Preferably, in the above-mentioned stent graft, the stent body is a cylindrical or conical structure formed by laser cutting of medical metal pipes or braiding of medical metal wires.

[0023] The beneficial effects of the stent graft of the present invention are:

[0024] After the stent body is installed at the Y-shaped bifurcation of the carotid artery, the stent body is expanded, and the film is expanded along with the stent body, and the film covers the plaque in the blood vessel, thereby preventing the plaque from breaking and falling off due to the squeezing of the stent body.

[0025] In addition, after the stent body is installed in the common carotid artery and the internal carotid artery, the blood flow from the common carotid artery into the external carotid artery can easily break open the membrane at the entrance of the external carotid artery, thereby ensuring that the blood enters the external carotid artery normally.

[0026] In summary, the coated stent of the present invention is safer to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a structural diagram of the carotid artery in Examples 1 and 2 of the present invention;

[0028] Figure 2 is a structural diagram of a stent graft according to embodiment 1 of the present invention;

[0029] Figure 3 This is a structural diagram of the first single-layer film of the stent graft in Example 1 of the present invention;

[0030] Figure 4 This is a structural diagram of the second single-layer film of the stent graft in Example 1 of the present invention;

[0031] Figure 5 This is a structural diagram of the third single-layer film of the stent graft in Example 1 of the present invention;

[0032] Figure 6 is a structural diagram of two layers of thin films of a stent graft according to Example 2 of the present invention;

[0033] Figure 7 is a diagram of the initial state of the stent grafts of Examples 1 and 2 of the present invention after being installed in the carotid artery;

[0034] Figure 8 It is a state diagram of the coated stents of Examples 1 and 2 of the present invention when they are impacted by blood flow at the external carotid artery.

[0035] The names and numbers of the components in the figure are as follows:

[0036] Carotid artery 10 , common carotid artery 11 , internal carotid artery 12 , external carotid artery 13 , plaque 14 , covered stent 20 , stent body 21 , film 22 , opening 221 , overlapping area 222 , through port 223 , proximal end 23 , middle part 24 , and distal end 25 . DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0041] Example 1

[0042] Figure 1 1 is a structural diagram of the carotid artery 10 according to an embodiment of the present invention. Figure 1 As shown, the carotid artery 10 is divided into the common carotid artery 11, the internal carotid artery 12 and the external carotid artery 13, and the common carotid artery 11, the internal carotid artery 12 and the external carotid artery 13 form a Y-shaped bifurcation structure. The blood of the common carotid artery 11 flows into the internal carotid artery 12 and the external carotid artery 13 at the Y-shaped bifurcation structure. Among them, the blood of the internal carotid artery 12 mainly flows to the brain, and the blood of the external carotid artery 13 mainly supplies the facial organs. There are plaques 14 on the common carotid artery 11 and the internal carotid artery 12, and the plaques 14 cause the blood vessels to narrow and affect the blood circulation. Therefore, it is necessary to install a covered stent at the lesion to expand the blood vessels and ensure the normal passage of blood. However, after the existing covered stent is installed in the carotid artery 10, the plaque 14 is easily broken, and the fragments form a thrombus, which flows to the downstream of the blood vessel, causing a stroke or even death.

[0043] The covered stent 20 of the present invention is installed in the common carotid artery 11 and the internal carotid artery 12 at the Y-shaped bifurcation structure to ensure the normal circulation of blood and prevent thrombus from flowing to the downstream of the blood vessel.

[0044] Figure 2 2 is a structural diagram of a stent graft 20 according to an embodiment of the present invention. Figure 2As shown, this embodiment discloses a coated stent 20, which includes a stent body 21 and a film 22. The stent body 21 has a proximal end 23, a middle part 24 and a distal end 25, and the proximal end 23 is used to be arranged upstream of the blood vessel relative to the distal end 25. The film 22 is installed and covered on the stent body 21, and a plurality of openings 221 are provided on the surface of the film 22, and the openings 221 are facing the proximal end 23 or the distal end 25 of the stent body 21. The film 22 itself has mesh holes, and the openings 221 are additionally processed on the film 22. The function of the mesh holes is to allow blood to pass through and block blood clots. The openings 221 are to allow blood to enter the external carotid artery 13 normally after passing through the film 22.

[0045] After the stent body 21 of the stent graft 20 of this embodiment is installed at the Y-shaped bifurcation of the carotid artery 10, the stent body 21 is opened, and the film 22 is opened along with the stent body 21, and the film 22 covers the plaque 14 in the blood vessel, thereby preventing the plaque 14 from being crushed and falling off due to the squeezing of the stent body 21. Specifically, the film 22 presses the plaque 14 against the inner wall of the blood vessel, and even if the plaque 14 detaches from the inner wall of the blood vessel, it will not fall off due to the presence of the film 22, and will not flow to the downstream of the blood vessel.

[0046] also, Figure 7 This is a diagram of the initial state of the coated stent 20 according to an embodiment of the present invention after being installed in the carotid artery 10. Figure 8 1 is a state diagram of the stent graft 20 of the embodiment of the present invention when it is impacted by blood flow at the external carotid artery 13. Figure 7 and Figure 8 As shown, after the stent body 21 is installed on the common carotid artery 11 and the internal carotid artery 12, the blood flow entering the external carotid artery 13 from the common carotid artery 11 easily breaks open the film 22 at the entrance of the external carotid artery 13, thereby ensuring that the blood normally enters the external carotid artery 13. Breaking open here means that under the impact of the blood flow entering the external carotid artery 13, a plurality of openings 221 on the film 22 at the impacted position are opened.

[0047] In summary, compared with the prior art, the coated stent 20 of this embodiment is safer to use.

[0048] The stent graft 20 of this embodiment is convenient to install on the carotid artery 10, and there is no need to find the entrance of the external carotid artery 13. The stent body 21 of this embodiment can be entirely covered with the film 22, and there is no need to avoid the entrance of the external carotid artery 13.

[0049] The film 22 of this embodiment can be woven from polymer filaments, or can be made of polymer film material punched by laser, and the mesh holes can be circular, square, diamond, elliptical, etc.

[0050] Preferably, the film 22 is formed with the opening 221 by laser cutting, and the forming method is simple.

[0051] Preferably, a plurality of groups of openings 221 are sequentially arranged in the length direction of the film 22, each group of openings 221 has a plurality of openings 221, and the plurality of openings 221 in each group of openings 221 are continuously distributed along the circumference of the film 22. The openings 221 of this embodiment may cover the entire surface of the stent body 21, or may cover a portion of the surface of the stent body 21. When the stent body 21 is fully opened, the film 22 is also fully opened, and no two adjacent openings 221 overlap.

[0052] The shape, size, and position distribution of the opening 221 can be designed according to the diameters of the blood vessels at the Y-shaped bifurcation to better adapt to different blood vessels.

[0053] This embodiment preferably uses three shapes of openings 221 .

[0054] Figure 3 2 is a structural diagram of a first type of single-layer film 22 of a stent graft 20 according to an embodiment of the present invention. The opening 221 is a semicircular structure. Multiple groups of openings 221 form a fish-scale distribution structure.

[0055] Figure 4 2 is a structural diagram of the second type of single-layer film 22 of the stent graft 20 according to an embodiment of the present invention. The opening 221 is a rectangular structure.

[0056] Figure 5 2 is a structural diagram of a third single-layer film 22 of a stent graft 20 according to an embodiment of the present invention. The opening 221 is a triangular structure.

[0057] Preferably, the stent body 21 is a cylindrical or conical structure made by laser cutting of medical metal pipes or weaving of medical metal wires. The medical metal materials include medical stainless steel, nickel-titanium alloy, cobalt-based alloy, titanium alloy, magnesium alloy, etc., preferably nickel-titanium alloy. After the stent body 21 is released in the human body's blood vessels, the stent body 21 will open, and as the temperature rises, the tension of the stent body 21 gradually increases until it is fully opened. After the stent body 21 is fully opened, the blood vessels that are narrowed due to lesions will be opened by the stent body 21, so that blood can pass normally.

[0058] The film 22 is fully opened as the stent body 21 is fully opened, and the film 22 can allow blood to pass normally. The film 22 can be woven from medical polymer filaments or laser cut from medical polymer membrane materials, and the medical polymer materials include medical chitin, medical fibrin, medical polyglycolic acid, medical polylactic acid, ePTFE, PET, PU, ​​PEEK, PE, etc.

[0059] The film 22 can be connected to the surface of the bracket body 21 by glue bonding, ultrasonic welding, laser welding, needle and thread sewing, hot pressing, etc.

[0060] like Figure 7 and Figure 8 As shown, after the stent body 21 is installed to the common carotid artery 11 and the internal carotid artery 12 , the opening 221 will form a passage 223 under the impact of blood entering the external carotid artery 13 , thereby ensuring that blood enters the external carotid artery 13 normally.

[0061] Example 2

[0062] This embodiment is basically the same as the embodiment 1, except that the film 22 of the embodiment 1 is a single-layer structure, while the film 22 of this embodiment is a double-layer structure.

[0063] Figure 6 2 is a structural diagram of two layers of film 22 of a stent graft 20 according to an embodiment of the present invention. Figure 6 As shown, preferably, there is an overlapping area 222 between the openings 221 of the two layers of film 22. Specifically, each opening 221 of each layer of film 22 is a semicircular structure, and the multiple groups of openings 221 form a fish scale structure as a whole.

[0064] Preferably, the closed end of the opening 221 of the outer film 22 is overlapped to the open end of the opening 221 of the inner film 22. The open end of the opening 221 refers to the open end of the figure surrounded by the outline of the opening 221, and the closed end of the opening 221 refers to the closed end of the figure surrounded by the outline of the opening 221.

[0065] Compared with Example 1, the film 22 of this embodiment can further prevent the plaque 14 from falling off and flowing to the downstream blood vessels. In addition, the film 22 of this embodiment can still form a passage 223 under the impact of the blood flow entering the external carotid artery 13, so that blood can normally enter the external carotid artery 13 and then supply blood to the facial organs. Compared with the prior art, the stent graft 20 of this embodiment is safer to use.

[0066] The stent graft 20 of this embodiment is convenient to install on the carotid artery 10, and there is no need to find the entrance of the external carotid artery 13. The stent body 21 of this embodiment can be entirely covered with the film 22, and there is no need to avoid the entrance of the external carotid artery 13.

[0067] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A stent graft, characterized in that: include: A stent body (21), the stent body (21) having a proximal end (23) and a distal end (25), the proximal end (23) being used to be arranged upstream of a blood vessel relative to the distal end (25); A film (22), the film (22) being mounted on and covering the stent body (21), a surface of the film (22) being provided with a plurality of openings (221), the openings (221) facing the proximal end (23) or the distal end (25) of the stent body (21); the openings (221) covering the entire surface of the stent body (21); A plurality of groups of openings (221) are sequentially arranged in the length direction of the film (22), each group of openings (221) comprises a plurality of openings (221), and the plurality of openings (221) in each group of openings (221) are continuously distributed along the circumference of the film (22); The covered stent is installed in the common carotid artery (11) and the internal carotid artery (12) at the Y-shaped bifurcation structure. The opening (221) forms a passage (223) under the impact of blood entering the external carotid artery (13), thereby ensuring that blood enters the external carotid artery (13) normally.

2. The stent graft according to claim 1, characterized in that: The thin film (22) forms the opening (221) by laser cutting.

3. The stent graft according to claim 1, characterized in that: The opening (221) is a semicircular structure.

4. The stent graft according to claim 1, characterized in that: The opening (221) is a rectangular structure.

5. The stent graft according to claim 1, characterized in that: The opening (221) is a triangular structure.

6. The stent graft according to claim 1, characterized in that: The film (22) is a single-layer structure.

7. The stent graft according to claim 1, characterized in that: The film (22) has a two-layer structure, and there is an overlapping area (222) between the openings (221) of the two layers of the film (22).

8. The stent graft according to claim 1, characterized in that: The film (22) is a two-layer structure, and the closed end of the opening (221) of the outer film (22) is overlapped with the open end of the opening (221) of the inner film (22).

9. The stent graft according to claim 1, characterized in that: The stent body (21) is a cylindrical or conical structure formed by laser cutting of medical metal pipes or braiding of medical metal wires.

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