Variable Aperture Stent Graft

Abstract

The present invention belongs to the technical field of medical devices, and specifically relates to a variable aperture coated stent. The variable aperture coated stent comprises a stent body and a filter membrane. The stent body comprises a proximal portion, a distal portion and a middle portion between the proximal portion and the distal portion according to the direction of blood flow. The proximal portion is used to be installed on the common carotid artery, the middle portion is used to be opposite to the entrance of the external carotid artery, and the distal portion is used to be installed on the internal carotid artery. The filter membrane is connected to the stent body, and the filter membrane comprises a proximal aperture section, a distal aperture section and an intermediate aperture section between the proximal aperture section and the distal aperture section. The proximal aperture section covers the proximal portion, the distal aperture section covers the distal portion, the intermediate aperture section covers the middle portion, and the pore area of ​​the intermediate aperture section is larger than the pore area of ​​the proximal aperture section and the distal aperture section, so as to prevent the plaques on the common carotid artery and the internal carotid artery from falling off and flowing to the downstream of the blood vessels, and enable blood to enter the external carotid artery normally. The variable aperture coated stent of the present invention is safer.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a variable-aperture coated stent. 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 variable-aperture 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 variable pore size covered stent, comprising:

[0012] A stent body, wherein the stent body includes a proximal portion, a distal portion, and a middle portion located between the proximal portion and the distal portion according to the direction of blood flow, wherein the proximal portion is used to be installed on the common carotid artery, the middle portion is used to be opposite to the entrance of the external carotid artery, and the distal portion is used to be installed on the internal carotid artery;

[0013] A filter membrane connected to the support body, the filter membrane comprising a near pore segment, a far pore segment and an intermediate pore segment located between the near pore segment and the far pore segment; the near pore segment covers the near end portion, the far pore segment covers the far end portion, the intermediate pore segment covers the middle portion, and the pore area of ​​the intermediate pore segment is greater than the pore areas of the near pore segment and the far pore segment.

[0014] Preferably, in the above-mentioned variable-aperture stent graft, the pore diameters of the near pore diameter section and the far pore diameter section are 10 μm-200 μm, and the pore diameter of the middle pore diameter section is 50 μm-1000 μm.

[0015] Preferably, in the above-mentioned variable-aperture stent graft, the pore diameters of the near pore diameter section and the far pore diameter section are 50 μm-200 μm, and the pore diameter of the middle pore diameter section is 100 μm-800 μm.

[0016] Preferably, in the above-mentioned variable aperture coated stent, a developing component is installed on the stent body.

[0017] Preferably, in the above-mentioned variable aperture coated stent, the number of the developing parts is at least two, at least two of the developing parts are installed at the junction of the middle part and the proximal part and / or at least two of the developing parts are installed at the junction of the middle part and the distal part.

[0018] Preferably, in the above-mentioned variable aperture coated stent, the number of the developing members is at least two, and at least two of the developing members are distributed along the circumference of the stent body.

[0019] Preferably, in the above-mentioned variable aperture coated stent, the developing member is a developing wire or a developing ring.

[0020] Preferably, in the above-mentioned variable-aperture stent graft, the filter membrane is connected to the inner surface or outer surface of the stent body by heat pressing, laser welding, glue bonding, ultrasonic welding or needle and thread suturing.

[0021] Preferably, in the above-mentioned variable-aperture coated stent, the stent body is formed by laser cutting of medical metal pipes or braiding of medical metal wires.

[0022] Preferably, in the above-mentioned variable-aperture coated stent, the stent body is a cylindrical or conical cylindrical structure.

[0023] The beneficial effect of the variable aperture covered stent of the present invention is that the pore area of ​​the near aperture section covering the proximal end and the far aperture section covering the distal end is small, thereby preventing the plaque on the common carotid artery and the internal carotid artery from falling off and flowing to the downstream of the blood vessels. In addition, since the pore area of ​​the intermediate aperture section covering the middle part is large, blood can enter the external carotid artery normally. Compared with the existing filter membranes with the same pore area at each location, the variable aperture covered stent of the present invention is safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a carotid artery according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of a variable-aperture covered stent being released into a carotid artery according to an embodiment of the present invention;

[0026] Figure 3 This is an expanded view of the first filter membrane of the variable-aperture stent graft according to an embodiment of the present invention;

[0027] Figure 4 is an expanded view of the second filter membrane of the variable-aperture stent graft according to an embodiment of the present invention;

[0028] Figure 5 is an expanded view of the third filter membrane of the variable-aperture stent graft according to an embodiment of the present invention;

[0029] Figure 6 is an expanded view of the fourth filter membrane of the variable-aperture stent graft according to an embodiment of the present invention;

[0030] Figure 7 It is a partial structural diagram of the stent body of the variable aperture coated stent according to an embodiment of the present invention.

[0031] The names and numbers of the components in the figure are as follows:

[0032] Carotid artery 10 , common carotid artery 11 , internal carotid artery 12 , external carotid artery 13 , plaque 14 , variable aperture coated stent 20 , stent body 21 , proximal portion 211 , distal portion 212 , middle portion 213 , developing element 214 , filter membrane 22 , proximal aperture segment 221 , distal aperture segment 222 , and intermediate aperture segment 223 . DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Figure 1 Schematic diagram of the structure 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 stent at the lesion to expand the blood vessels and ensure the normal passage of blood. However, after the existing stent is placed in the carotid artery 10, the plaque 14 is easily squeezed and broken by the stent rod, and the fragments form a thrombus, which enters the brain with the blood flow, blocks the cerebral blood vessels, causes stroke, and even death.

[0038] The pore size of the filter membrane of the existing stent graft is consistent everywhere. If the pore size is set larger, blood can enter the external carotid artery 13 normally. However, the larger pore size will reduce the ability of the filter membrane to block the plaque 14, making it easy for fragments of the plaque 14 to fall off and enter the downstream of the blood vessel. If the pore size is set smaller, the plaque 14 can be effectively blocked to prevent the fragments of the plaque 14 from falling off and entering the downstream of the blood vessel. However, it is easy to block blood from entering the external carotid artery 13 from the bifurcation of the common carotid artery 11.

[0039] Figure 2 It is a schematic diagram of the variable aperture covered stent according to an embodiment of the present invention being released into the carotid artery. Figure 3 FIG. 2 is an expanded view of the first filter membrane 22 of the variable aperture stent graft 20 according to an embodiment of the present invention. Figure 2 and Figure 3 As shown, in order to solve the above technical problems, the present embodiment discloses a variable aperture coated stent 20, which comprises a stent body 21 and a filter membrane 22. The stent body 21 comprises a proximal portion 211 and a distal portion 212 according to the direction of blood flow, and a middle portion 213 located between the proximal portion 211 and the distal portion 212. The proximal portion 211 is used to be installed on the common carotid artery 11, the middle portion 213 is used to be opposite to the entrance of the external carotid artery 13, and the distal portion 212 is used to be installed on the internal carotid artery 12. The filter membrane 22 is connected to the stent body 21, and the filter membrane 22 comprises a proximal aperture section 221, a distal aperture section 222, and a middle aperture section 223 located between the proximal aperture section 221 and the distal aperture section 222. The near aperture section 221 covers the near end 211 , the far aperture section 222 covers the far end 212 , the middle aperture section 223 covers the middle portion 213 , and the hole area of ​​the middle aperture section 223 is larger than the hole areas of the near aperture section 221 and the far aperture section 222 .

[0040] The beneficial effect of the variable aperture coated stent 20 of the present invention is that the pore area of ​​the near aperture section 221 covering the proximal portion 211 and the far aperture section 222 covering the far portion 212 is small, thereby preventing the plaque 14 on the common carotid artery 11 and the internal carotid artery 12 from falling off and flowing to the downstream of the blood vessels. In addition, since the pore area of ​​the intermediate aperture section 223 covering the middle portion 213 is large, blood can enter the external carotid artery 13 normally. Compared with the existing filter membranes with the same pore area at each location, the variable aperture coated stent 20 of the present invention is safer.

[0041] Specifically, the near aperture section 221 and the far aperture section 222 account for one sixth to one half, preferably one fifth to one third, of the total length of the filter membrane 22. The rest is the length of the middle aperture section 223. For example, the near aperture section 221 and the far aperture section 222 account for one sixth, one half, or one third of the total length of the filter membrane 22. The variable aperture filter membrane 22 of this embodiment can be obtained by weaving or heat treatment.

[0042] The mesh shapes of the filter membrane 22 of this embodiment can be various. Specifically, Figure 3 As shown, the mesh shape of the filter membrane 22 of this embodiment is a structure in which diamond holes and square holes are superimposed. Figure 4 FIG. 2 is an expanded view of the second filter membrane 22 of the variable aperture stent graft 20 according to an embodiment of the present invention. Figure 4 As shown, the mesh of the filter membrane 22 of this embodiment can also be a rectangular structure, for example, the mesh of the filter membrane 22 is a square structure. Figure 5 FIG. 2 is an expanded view of the third filter membrane 22 of the variable aperture stent graft 20 according to an embodiment of the present invention. Figure 5 As shown, the mesh of the filter membrane 22 of this embodiment can also be circular. Figure 6 FIG. 2 is an expanded view of the fourth filter membrane 22 of the variable aperture stent graft 20 according to an embodiment of the present invention. Figure 6 As shown, the mesh of the filter membrane 22 of this embodiment is also circular, but the distribution of the mesh is different from Figure 5 The distribution of the meshes shown in is different.

[0043] like Figure 4 and Figure 6 As shown, in the present application, the aperture of the non-circular mesh is calculated according to the diameter of the inscribed circle of the mesh.

[0044] Preferably, the apertures of the near aperture section 221 and the far aperture section 222 are 10 μm-200 μm, and the aperture of the middle aperture section 223 is 50 μm-1000 μm. Under this aperture, the filter membrane 22 of this embodiment can well prevent the plaque 14 from falling off and flowing to the downstream of the blood vessel, and can allow blood to smoothly enter the external carotid artery 13.

[0045] Preferably, the apertures of the near aperture section 221 and the far aperture section 222 are 50 μm-200 μm, and the aperture of the middle aperture section 223 is 100 μm-800 μm. Under this aperture, the present embodiment can further improve the effect of preventing the plaque 14 from falling off and flowing to the downstream of the blood vessel and allowing blood to smoothly enter the external carotid artery 13.

[0046] Figure 7 FIG. 2 is a partial structural diagram of a stent body 21 of a variable aperture stent graft 20 according to an embodiment of the present invention. Figure 7As shown, preferably, a developing member 214 is installed on the stent body 21. The developing member 214 is used to assist in positioning the variable aperture coated stent 20 when the variable aperture coated stent 20 is installed to the blood vessel, so that the middle aperture section 223 covering the middle portion 213 of the stent body 21 is opposite to the entrance of the external carotid artery 13, thereby further ensuring that blood can enter the external carotid artery 13 normally.

[0047] Preferably, the number of the developing members 214 is at least two, at least two developing members 214 are installed at the junction of the middle portion 213 and the proximal portion 211, or at least two developing members 214 are installed at the junction of the middle portion 213 and the distal portion 212, or at least two developing members 214 are distributed at the junction of the middle portion 213 and the distal portion 212 and at the junction of the middle portion 213 and the distal portion 212. Such a distribution method can improve the positioning accuracy of the variable aperture stent graft 20, thereby further ensuring that blood can enter the external carotid artery 13 normally.

[0048] Preferably, at least two developing members 214 are distributed along the circumference of the stent body 21. Such a distribution can also improve the positioning accuracy of the variable aperture stent graft 20, thereby further ensuring that blood can enter the external carotid artery 13 normally.

[0049] Preferably, the developing member 214 is a developing wire or a developing ring, and it is convenient to install the developing wire or the developing ring to the bracket body 21 .

[0050] Preferably, the filter membrane 22 is connected to the inner surface or outer surface of the support body 21 by heat pressing, laser welding, glue bonding, ultrasonic welding or needle and thread sewing.

[0051] Preferably, the stent body 21 is laser cut from a medical metal tube or woven from a medical metal wire. 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 into the blood vessel, it can be opened and drive the filter membrane 22 to open to closely adhere to the inner wall of the blood vessel. The opened stent body 21 can increase the diameter of the vascular lesion to ensure normal blood circulation.

[0052] Preferably, the stent body 21 is a cylindrical or conical cylindrical structure to adapt to the size of the blood vessel.

[0053] The filter membrane 22 of this embodiment is woven from medical metal or polymer filaments, or is formed by laser punching of polymer membranes. Polymer materials include medical chitin, medical fibrin, medical polyglycolic acid, medical polylactic acid, ePTFE, PET, PU, ​​PEEK, PE, etc. The opened filter membrane 22 covers the plaque 14, reducing the pressure of the stent body 21 on the plaque 14 and preventing the plaque 14 from breaking. Even if the plaque 14 breaks, the filter membrane 22 can prevent the fragments of the plaque 14 from entering the downstream of the blood vessel.

[0054] In this embodiment, the thickness of the filter membrane 22 is 10 μm-200 μm, preferably 10 μm-50 μm. For example, the thickness of the filter membrane 22 is 10 μm, 100 μm or 200 μm.

[0055] 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 variable-aperture stent graft, characterized in that: include: A stent body (21), wherein the stent body (21) comprises a proximal portion (211) and a distal portion (212) according to the direction of blood flow, and a middle portion (213) located between the proximal portion (211) and the distal portion (212), wherein the proximal portion (211) is used to be installed on the common carotid artery (11), the middle portion (213) is used to be opposite to the entrance of the external carotid artery (13), and the distal portion (212) is used to be installed on the internal carotid artery (12); a filter membrane (22), the filter membrane (22) being connected to the support body (21), the filter membrane (22) comprising a near aperture section (221), a far aperture section (222), and an intermediate aperture section (223) located between the near aperture section (221) and the far aperture section (222); the near aperture section (221) covers the near end portion (211), the far aperture section (222) covers the far end portion (212), the intermediate aperture section (223) covers the middle portion (213), and the pore area of ​​the intermediate aperture section (223) is greater than the pore areas of the near aperture section (221) and the far aperture section (222); The apertures of the near aperture section (221) and the far aperture section (222) are 10 μm-200 μm, and the aperture of the middle aperture section (223) is 50 μm-1000 μm.

2. The variable aperture stent graft according to claim 1, characterized in that: The apertures of the near aperture section (221) and the far aperture section (222) are 50 μm-200 μm, and the aperture of the middle aperture section (223) is 100 μm-800 μm.

3. The variable aperture stent graft according to claim 1, characterized in that: A developing component (214) is installed on the support body (21).

4. The variable aperture stent graft according to claim 3, characterized in that: The number of the developing components (214) is at least two, and at least two of the developing components (214) are installed at the junction of the middle portion (213) and the proximal portion (211) and / or at least two of the developing components (214) are installed at the junction of the middle portion (213) and the distal portion (212).

5. The variable aperture stent graft according to claim 3, characterized in that: The number of the developing parts (214) is at least two, and the at least two developing parts (214) are distributed along the circumference of the support body (21).

6. The variable pore size stent graft according to claim 3, characterized in that: The developing member (214) is a developing wire or a developing ring.

7. The variable-aperture stent graft according to claim 1, characterized in that: The filter membrane (22) is connected to the inner surface or outer surface of the support body (21) by means of heat pressing, laser welding, glue bonding, ultrasonic welding or needle and thread sewing.

8. The variable-aperture stent graft according to claim 1, characterized in that: The stent body (21) is formed by laser cutting of medical metal pipes or braiding of medical metal wires.

9. The variable-aperture stent graft according to claim 1, characterized in that: The support body (21) is a cylindrical or conical cylindrical structure.

Images