A type of aortic endovascular stent

Abstract

This utility model discloses an aortic endovascular stent graft, comprising a skeleton and a graft covering the circumferential surface of the skeleton. The graft has a mesh area with a plurality of docking holes distributed in the mesh area. After the aortic endovascular stent graft is placed into the patient's aorta, the docking holes can automatically close. The beneficial effects of this utility model are: it eliminates the need for precise preoperative incision, simplifies intraoperative alignment, and allows treatment to be completed without relying on top-of-the-line equipment and a team of experienced experts. It effectively breaks through the limitations of technical conditions on treatment, enabling primary healthcare institutions to perform this type of interventional treatment for aortic diseases.

Description

Technical Field

[0001] This utility model relates to vascular stents, specifically to an aortic endovascular stent graft. Background Technology

[0002] In interventional treatment of aortic diseases (such as aortic aneurysm and aortic dissection), endovascular stent grafts are commonly used key devices. They support the diseased blood vessels with a metal skeleton and rely on the endovascular membrane on the surface to isolate the impact of blood flow on the diseased area, thereby preventing blood vessel rupture and maintaining smooth blood flow.

[0003] The human aorta has many important branches, such as the brachiocephalic artery, left common carotid artery, and left subclavian artery in the thoracic aorta, and the celiac trunk, superior mesenteric artery, right renal artery, and left renal artery in the abdominal aorta. These branches are the main blood supply channels to the head, neck, upper limbs, and internal organs, and must be kept patent during treatment. Therefore, when the lesion area involves the openings of these branches, side holes corresponding to the branches need to be pre-drilled on the covered stent beforehand. The covered stent is then placed into the aorta, and the pre-drilled side holes on the covered stent are aligned with the branch inlets. Finally, the branch stent is placed through the side holes to maintain blood flow to the branch.

[0004] However, in clinical practice, aligning the pre-drilled side holes with the branch vessel inlets during the placement of covered stents into the aorta is extremely difficult, requiring a high level of skill from the physician and precision from the equipment. This procedure can only be performed in a few large hospitals, and primary healthcare institutions often find it difficult to implement due to technical limitations, resulting in patients not receiving timely and effective treatment.

[0005] Therefore, there is an urgent need for a covered stent that can simplify the side hole alignment operation and improve the universality of surgery, so as to solve the core pain points of traditional covered stents in clinical application. Utility Model Content

[0006] In view of this, the present invention provides an aortic endovascular stent graft, which can simplify the operation and improve the applicability of the operation.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] An aortic endovascular stent graft includes a skeleton and a graft covering the circumferential surface of the skeleton. The key feature is that the graft has a mesh area with a plurality of docking holes distributed in the mesh area; after the aortic endovascular stent graft is placed into the patient's aorta, the docking holes can automatically close.

[0009] With the above structure, due to the numerous docking holes distributed in the mesh area, when the covered stent is placed into the patient's blood vessel, at least one docking hole corresponding to the branch vessel location will be directly aligned with the branch vessel inlet. Therefore, the physician can directly insert a guidewire through this docking hole to achieve the installation of the branch vessel stent. Simultaneously, after the aortic covered stent is placed, the other docking holes will slowly and automatically close. Once the docking holes close, blood leakage from the gap between the stent and the aortic wall is blocked, ensuring the integrity of the covered stent's outer wall and confirming that the method of rapid alignment through numerous small holes is effective and feasible.

[0010] Preferably, the edges of the docking holes are provided with a bio-responsive closure material, which is capable of absorbing liquid and fusing to close each docking hole. Using this structure, other docking holes can be slowly and automatically closed.

[0011] Preferably, the bioresponsive closure material is a hydrogel composited on the circumferential edge of the docking hole. With this structure, the hydrogel exhibits high water absorption and swelling capacity, as well as biocompatibility. After the stent is inserted into the aorta, the gel slowly absorbs water from the blood, gradually softens, and undergoes viscous fusion, achieving complete closure of the docking hole after several hours to a day.

[0012] Preferably, the hydrogel is a polyacrylamide-based hydrogel or a polyvinyl alcohol-based hydrogel.

[0013] Preferably, the skeleton is constructed as a radially expandable annular mesh structure. This structure ensures that the stent, after being inserted into the aorta, fits tightly against the vessel wall in the diseased area, providing stable support for the diseased vessel, avoiding the risk of rupture, and offering a stable foundation for subsequent fitting of the docking ports and branch vessels.

[0014] Preferably, the coating has a cylindrical structure, with each of the mating holes arranged in a row along the axial direction. Each row of mating holes is evenly distributed circumferentially along the coating, and the mating holes in adjacent rows are staggered. This structure ensures the density of the mating hole distribution and improves the alignment efficiency.

[0015] As a preferred option, the aortic endovascular stent graft is a thoracic aortic endovascular stent graft. Using the above structure, it can be applied in interventional treatment of thoracic aortic diseases.

[0016] Preferably, the aortic endovascular stent graft is an abdominal aortic endovascular stent graft. This structure allows for its application in interventional treatment of abdominal aortic diseases.

[0017] Preferably, the lower part of the abdominal aortic stent has two branch stents, which are respectively used for implantation into the left and right iliac arteries. With this structure, the complex procedures of individually aligning the iliac artery opening and placing stents in stages are eliminated, reliably ensuring blood supply to the lower limbs and pelvic organs, and avoiding the risk of endoleak at the junction.

[0018] Preferably, the membrane is made of polytetrafluoroethylene (PTFE) or polyethylene terephthalate (PET). With this structure, PTFE possesses excellent flexibility and wear resistance, allowing for synchronous deformation with the radial expansion of the scaffold. It conforms to the scaffold surface without wrinkling and can withstand long-term blood flow and friction from branch stent movement, avoiding the risk of endoleak due to membrane rupture. PET, on the other hand, has high strength and degradation resistance, making it less prone to aging and damage due to body fluid erosion during long-term implantation. It can stably maintain the membrane's insulating function, making it particularly suitable for treatments requiring long-term support for abdominal aortic lesions.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. The aortic endovascular stent graft provided by this invention features numerous docking holes distributed throughout its mesh area. After the stent graft is placed into the patient's blood vessel, at least one docking hole in the mesh area corresponding to the branch vessel location will align directly with the branch vessel inlet. Therefore, the surgeon can directly insert a guidewire through this docking hole to achieve stent placement in the branch vessel. This structure directly eliminates the need for pre-drilling and alignment steps required by traditional endovascular stent grafts, simplifying the procedure, increasing its versatility, and significantly reducing reliance on intraoperative equipment precision and surgeon experience. Furthermore, after the aortic endovascular stent graft is placed, the other docking holes will slowly and automatically close. This closure prevents blood leakage from the gap between the stent and the aortic wall, ensuring the integrity of the stent graft's outer wall and confirming the effectiveness and feasibility of the rapid alignment method achieved through numerous small holes.

[0021] 2. The aortic endovascular stent graft provided by this utility model eliminates the need for precise preoperative perforation and simplifies intraoperative alignment. Treatment can be completed without relying on top-of-the-line equipment and a team of experienced experts, effectively breaking the limitations of technical conditions on treatment and enabling primary healthcare institutions to carry out such interventional treatments for aortic diseases. Attached Figure Description

[0022] Figure 1 A schematic diagram of the aortic endovascular stent graft structure;

[0023] Figure 2 A schematic diagram of the aortic endovascular stent graft;

[0024] Figure 3A schematic diagram of a thoracoagulant stent graft placed in the thoracoagulant aorta;

[0025] Figure 4 This is a schematic diagram of inserting guidewire 3 through the docking hole 2a into the corresponding branch blood vessel;

[0026] Figure 5 A schematic diagram showing the closure of the thoracic aortic docking port 2a after the thoracic aortic endovascular stent graft has been inserted.

[0027] Figure 6 This is a partial cross-sectional view of the membrane 2;

[0028] Figure 7 A schematic diagram of the thoracic aortic endovascular stent graft structure;

[0029] Figure 8 A schematic diagram of a thoracoagulant stent graft placed in the thoracoagulant aorta;

[0030] Figure 9 A schematic diagram of the thoracic aortic graft after the aortic docking port 2a has been closed. Detailed Implementation

[0031] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0032] like Figure 1 and 2 As shown, an aortic endovascular stent graft includes a skeleton 1 covered with a endovascular membrane 2 on its circumferential surface. In this embodiment, the skeleton 1 is a metal stent, and it is constructed as a radially expandable annular mesh structure. During manufacturing, the aortic endovascular stent graft can be constricted into a thin strip by constraint lines; therefore, the skeleton 1 and the endovascular membrane 2 are preferably made of elastic materials, such as a nickel-titanium alloy for the skeleton 1 and polytetrafluoroethylene or polyethylene terephthalate for the endovascular membrane 2. The endovascular membrane 2 has a mesh area with a number of docking holes 2a distributed within it. When the aortic endovascular stent graft is placed in the aorta, the docking holes 2a automatically close.

[0033] Based on the above structural design, this aortic endovascular stent graft can specifically address the clinical limitations of traditional endovascular stent grafts caused by difficulties in preoperative opening and intraoperative alignment of side holes in interventional treatment of diseases such as aortic aneurysms and aortic dissections. Specific technical effects are as follows: The radial expansion characteristics of the skeleton 1 ensure that the stent fits tightly against the vessel wall of the lesion area after placement in the aorta. This provides stable support for the diseased vessel, avoids the risk of rupture, and provides a stable foundation for the subsequent adaptation of the docking holes 2a to the branch vessels. Because the mesh area has a large number of docking holes 2a, after the endovascular stent graft is placed in the patient's vessel, at least one docking hole 2a will be directly aligned with the branch vessel inlet in the mesh area corresponding to the branch vessel location. Therefore, the surgeon can directly insert a guidewire through the docking hole 2a at that location, thereby achieving the installation of the branch vessel stent. This structure directly eliminates the steps of preoperative opening and alignment required by traditional endovascular stent grafts, simplifying the surgical procedure, increasing its versatility, and significantly reducing the reliance on intraoperative equipment precision and surgeon experience. Meanwhile, after the aortic stent graft is placed, the other docking holes 2a will also slowly and automatically close. After the docking holes 2a close, blood leakage from the gap between the stent and the aortic wall is blocked, ensuring the integrity of the outer wall of the stent graft and ensuring that the method of rapid alignment by opening a large number of small holes is effective and feasible.

[0034] To achieve automatic closure of the mating hole 2a, one or more of the following methods can be used in combination:

[0035] 1. The entire membrane 2 is supported by a bioresponsive closure material, or the bioresponsive closure material is provided at the edge of the docking holes 2a. In this embodiment, it is preferable to provide the bioresponsive closure material at the edge of the docking holes 2a. The bioresponsive closure material can absorb liquid and fuse to close each docking hole 2a. The bioresponsive closure material can be: hydrogel, superabsorbent polymer (SAPs), or inorganic material, wherein the inorganic material can be natural mineral bentonite or silicone composite material.

[0036] 2. A shape memory polymer is placed at the edge of the docking hole 2a. During the fabrication of docking hole 2a, it is initially processed into a closed state. Then, through low temperature or external force, it is temporarily shaped into an open state. After the stent is placed in the blood vessel, the body temperature of 37°C triggers the reconstruction of the material's molecular chains, causing docking hole 2a to slowly recover its original shape, thus gradually closing. Commonly used shape memory polymers include polycaprolactone (PCL), polyurethane (PU), and polylactic-co-glycolic acid copolymer (PLGA). Among them, PCL has good biocompatibility and biodegradability, and its glass transition temperature can be adjusted by its molecular weight. It slowly recovers its shape at body temperature, and the closing time of docking hole 2a can be controlled from several days to several months. PLGA combines support and biodegradability. By adjusting the ratio of lactic acid to glycolic acid, the shape recovery rate and degradation time can be controlled, typically from several months to two years. The closing process of docking hole 2a is synchronized with material degradation, making it suitable for scenarios requiring long-term support before closure. Polyurethane has strong support, stable shape memory effect, and good biocompatibility. The closing time of the 2a docking hole can be controlled by the degree of crosslinking, which is suitable for the need to complete the closure within a few weeks.

[0037] 3. A self-healing polymer is placed at the edge of the docking hole 2a. This self-healing polymer can repair damage through dynamic chemical bonds (such as hydrogen bonds and covalent bonds) within the material. After the stent is implanted into the arterial vessel, the pre-set dynamic cross-linked structure at the edge of the docking hole 2a is activated in the blood environment. The molecular chains slowly diffuse and recombine, causing the docking hole 2a to gradually shrink until it closes. The closure time can be controlled by the cross-linking density. Commonly used self-healing polymers include Schiff base-based polymers and dynamic polyurethanes. Schiff base-based polymers can slowly hydrolyze and re-bond at physiological pH, achieving self-healing. The closure process of the docking hole 2a is gentle and has high biocompatibility. Dynamic polyurethanes, on the other hand, achieve self-healing through reversible urea or ester bonds, combining elasticity and support, making them suitable for low-pressure vascular stents such as those used in veins.

[0038] In this embodiment, method 1 above is used to achieve pore healing. Specifically, the bioresponsive closure material set at the edge of the docking hole 2a is a hydrogel. The hydrogel has high water absorption and swelling properties and biocompatibility. After the stent is placed in the aorta, the gel can slowly absorb water from the blood, gradually soften, and undergo viscous fusion, achieving complete closure of the docking hole 2a after several hours to one day. Specifically, the hydrogel can be a polyacrylamide (PAAm)-based hydrogel, a polyvinyl alcohol (PVA)-based hydrogel, or a composite hydrogel of both.

[0039] Polyacrylamide (PAAm)-based hydrogels possess a typical three-dimensional framework structure and extremely high chemical stability. They can be prepared using methods such as redox initiation systems, for example, by grafting polyacrylamide segments onto polyvinyl alcohol-based foam materials, or by forming composite hydrogels with other polymers through crosslinking, copolymerization, and other reactions.

[0040] Polyvinyl alcohol (PVA)-based hydrogels can be prepared by repeatedly freezing and thawing PVA aqueous solutions to gel the gel. They have a crystallinity of 50%-60% and possess excellent lubrication properties, strong shock absorption, good biocompatibility, high elasticity, high strength, and the ability to firmly bond with host bone. In addition to the repeated freeze-thaw method, chemical cross-linking can also be used in production. This involves using a cross-linking agent to induce a cross-linking reaction between PVA molecular chains to form a hydrogel. Composite hydrogels can also be prepared by physical mixing or graft copolymerization with other substances.

[0041] The composite hydrogel, which combines PAAm and PVA, can be used to prepare an interpenetrating network hydrogel that combines the flexibility of PAAm and the toughness of PVA. The internal structure is dense and uniform, exhibiting high extensibility, high toughness and strong tear resistance, while maintaining good water absorption and biocompatibility.

[0042] refer to Figure 6 The hydrogel a is set at the edge of the docking hole 2a as shown in the figure. The initial volume of the hydrogel a is two-thirds of the volume inside the docking hole 2a. At this time, the water absorption and expansion rate of the hydrogel a can reach 50%, which means that the hydrogel a can fill the docking hole 2a within two days, ensuring the closing speed of the docking hole 2a.

[0043] like Figure 2 As shown, the coating 2 has a cylindrical structure, with each mating hole 2a arranged in a row along the axial direction. Each row of mating holes 2a is evenly distributed around the circumference of the coating 2, and the mating holes between adjacent rows are staggered. Each row here constitutes one ring. This design ensures the density of the mating holes 2a and improves the alignment efficiency.

[0044] The aortic endovascular stent graft provided in this embodiment can be a thoracic aortic endovascular stent graft or an abdominal aortic endovascular stent graft.

[0045] Depend on Figures 1 to 2 As shown, in the thoracic aortic endovascular stent graft, the framework 1 is the thoracic aortic stent, and the thoracic aortic stent and its circumferential endovascular ... Figure 3 A pleural stent graft is placed into the thoracic aorta. Based on the entry points of the three branches—the brachiocephalic artery A1, the left common carotid artery A2, and the left subclavian artery A3—a corresponding docking port 2a is selected as the blood flow channel. Then, a guidewire 3 is inserted through the docking port 2a into the corresponding branch vessel (see reference). Figure 4 Subsequently, a balloon is implanted at the docking port 2a using guidewire 3. The balloon is inflated to enlarge the docking port 2a to match the width of the corresponding branch vessel inlet. Then, a covered stent is placed into the branch vessel using guidewire 3. After the procedure, refer to... Figure 5 The remaining docking holes 2a that are not aligned with the branches of the thoracic aorta can be closed by the slow absorption and fusion of the bio-responsive closure material at the edge in vivo. This ensures smooth blood flow in the branches of the thoracic aorta and avoids blood leakage caused by unclosed holes.

[0046] like Figure 7 As shown, in the abdominal aortic endovascular stent graft, the framework 1 is the abdominal aortic stent, the upper part of the abdominal aortic stent and the endovascular graft 2 on its circumferential surface are constructed into a cylindrical structure, and the lower part of the abdominal aortic stent has two branch stents 11, combined with... Figure 8 As shown, the two branch stents 11 are used for implantation in the left iliac artery B5 and the right iliac artery B6, respectively.

[0047] Reference Figure 8 and Figure 9 The procedure for interventional treatment of abdominal aortic disease is as follows: A endovascular stent graft is placed into the abdominal aorta. Based on the entry locations of the four branches—cave trunk B1, superior mesenteric artery B2, left renal artery B3, and right renal artery B4—a corresponding access point 2a is flexibly selected as the blood flow channel. A guidewire 3 is then inserted through the access point 2a into the corresponding branch vessel. Subsequently, a balloon is implanted at the access point 2a using the guidewire 3. The balloon expands to enlarge the access point 2a to match the width of the corresponding branch vessel entry. Finally, a endovascular stent graft is placed into the branch vessel using the guidewire 3. After the procedure, any remaining access points 2a that are not aligned with the abdominal aortic branches can be closed by the slow absorption and fusion of a bio-responsive closure material at the edges within the body.

[0048] Finally, it should be noted that the above description is merely a preferred embodiment of the present utility model. Those skilled in the art, under the guidance of the present utility model, can make various similar representations without departing from the spirit and claims of the present utility model, and such modifications all fall within the protection scope of the present utility model.

Claims

1. An aortic endovascular stent graft, comprising a skeleton (1) and a graft (2) covering the circumferential surface of the skeleton (1), characterized in that: The membrane (2) has a mesh area with a number of docking holes (2a) distributed in the mesh area; after the aortic endovascular stent is placed into the patient's aorta, the docking holes (2a) can close automatically.

2. The aortic endovascular stent graft according to claim 1, characterized in that: The edges of the docking holes (2a) are provided with a bio-responsive closure material, which can absorb liquid and fuse to close each docking hole (2a).

3. The aortic endovascular stent graft according to claim 2, characterized in that: The bioresponsive closure material is a hydrogel composite on the circumferential edge of the docking hole (2a).

4. The aortic endovascular stent graft according to claim 3, characterized in that: The hydrogel is a polyacrylamide-based hydrogel or a polyvinyl alcohol-based hydrogel.

5. The aortic endovascular stent graft according to claim 1, characterized in that: The skeleton (1) is constructed as a ring-shaped mesh structure that can expand radially.

6. The aortic endovascular stent graft according to claim 1, characterized in that: The coating (2) has a cylindrical structure, and each of the docking holes (2a) is arranged in a row along the axial direction. Each row of docking holes (2a) is evenly distributed along the circumference of the coating (2), and the docking holes between adjacent rows are staggered.

7. The aortic endovascular stent graft according to claim 1, characterized in that: The aortic endovascular stent graft is a thoracic aortic endovascular stent graft.

8. The aortic endovascular stent graft according to claim 1, characterized in that: The aortic endovascular stent graft is an abdominal aortic endovascular stent graft.

9. The aortic endovascular stent graft according to claim 8, characterized in that: The lower part of the abdominal aortic stent has two branch stents (31), which are used for implantation into the left iliac artery and the right iliac artery, respectively.

10. The aortic endovascular stent graft according to claim 1, characterized in that: The coating (2) is made of polytetrafluoroethylene or polyethylene terephthalate.

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