Mounting and connecting structure for additional stent and aorta stent

Abstract

The utility model discloses a mounting and connecting structure for an additional stent and an aorta covered stent. The mounting and connecting structure comprises the aorta covered stent and a macromolecular polyester material additional stent which can be absorbed by a human body, the additional bracket is tubular and is provided with a grid filiform structure formed by laser engraving; the wire diameter of the grid is the same as the wall thickness; the aorta covered stent is also provided with covered latticed textures; the additional stent can be mounted at the end part of the aorta covered stent in a fastened butt-connection or cross-connection or stacked connection manner; the additional stent is additionally arranged at the end of the aorta covered stent, more stable supporting force is provided, expansion of a false cavity is helped to be reduced, and therefore the risk of Ia type and Ib type inner leakage is reduced; the positioning precision of the aorta covered stent can be improved, and postoperative complications can be reduced. The additional stent and aortic covered stent cross-connection installation connecting structure provides a solution for enhancing support and promoting vascular remodeling for a lesion area.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical equipment, and relates to an installation connection structure of an additional stent and an aortic stent; the utility model is suitable for thoracic aorta intracavitary isolation and abdominal aorta intracavitary isolation in cardiovascular surgery. Background Art

[0002] In the field of cardiovascular surgery, thoracic aortic endovascular exclusion has become one of the main methods for treating thoracic aortic diseases such as thoracic aortic dissection, thoracic aortic aneurysm, and thoracic aortic penetrating ulcer. Abdominal aortic endovascular exclusion has become one of the main methods for treating abdominal aortic diseases such as abdominal aortic aneurysm and abdominal aortic dissection.

[0003] Endovascular exclusion of the thoracic and abdominal aorta often requires the placement of an artificial vascular stent in the aortic diseased area; type Ia endoleak in the proximal artery or type Ib endoleak in the distal artery after aortic surgery is an important complication of endovascular exclusion of the thoracic and abdominal aorta, with an incidence rate as high as 3.6% to 13.1%.

[0004] Type Ia endoleak and type Ib endoleak refer to blood flowing into the false lumen through the gap between the stent end and the aortic wall, which can cause the dissection false lumen to continue to expand, reducing the therapeutic effect of the operation; in severe cases, it can lead to tearing of the inner wall of the blood vessel, reverse aortic dissection and distal aneurysm formation, thereby increasing the risk of aortic rupture. The root cause of type Ia endoleak and type Ib endoleak is usually poor fit between the artificial vascular stent and the proximal or distal end of the aorta, the artificial vascular stent is not firmly clamped, or improper placement technology during surgery.

[0005] The artificial vascular stent and the proximal or distal end of the aorta require a suitable clamping structure; if the clamping structure between the artificial vascular stent and the proximal or distal end of the aorta is improper, it is insufficient to provide sufficient mechanical support, and the clamping is not firm. Under the impact of aortic blood pulsation, migration, slippage, and internal leakage may occur, endangering the patient's life safety; if the clamping structure between the artificial vascular stent and the proximal or distal end of the aorta is improper, the mechanical support is too great, which increases the patient's pain. What is more serious is that the patient's arterial blood vessels are aged and lack elasticity, or blood vessels are torn, which can severely cause retrograde aortic dissection.

[0006] Existing technology mostly uses metal stents in aortic surgery. Metal is non-degradable. Under intense aortic movement and high-speed blood flow impact, the stent may migrate or leak again in the aortic cavity for a long time, increasing the risk of injury. Metal can cause excessive burden on blood vessels and increase the risk of long-term aortic true lumen thrombosis. The released metal ions can easily cause local inflammatory reactions.

[0007] Up to now, there is no ideal and suitable artificial vascular stent and aortic proximal or distal clamping structure; a few patents provide solutions, but they all have certain limitations.

[0008] Patent CN110721007A: Barbs are set on the outer wall of the stent: the blood vessel wall is easily damaged when the stent moves; the interaction between the barbs and the blood vessel wall leads to chronic inflammation and increases the risk of vascular complications.

[0009] Patent CN218391850U balloon dilatation method: adjust the position and shape of the stent through balloon dilatation technology to reduce or eliminate endoleak. However, since the edge of the stent is very fragile, excessive dilatation can easily cause additional damage to the blood vessel wall; the dilatation process may cause new intimal tears, which may seriously cause reverse aortic dissection.

[0010] Patent CN101675904A: Provides an additional device, which installs a membrane-like braid on the existing aortic endograft to ensure blood supply to the branch vessels and strengthen the stent. However, this device itself does not play a supporting role on the aortic endograft and is not suitable for aortic dissection areas with fewer branch vessels.

[0011] Patent CN204306860U Spring sheath occlusion: The spring sheath is placed at the end of the stent graft to seal any potential leakage points. However, in a high-pressure blood flow environment, the spring sheath is prone to migrate to non-target areas, causing new blood vessel blockage or organ ischemia; and its precise positioning is difficult.

[0012] Absorbable biomedical materials have been used as surgical sutures for surgical incision suturing. However, due to the complexity of the cardiovascular aortic anatomical structure and the fatal risk of improper proximal or distal aortic structure of artificial vascular stents; although absorbable biomedical materials can completely or partially replace metal stents and eliminate or reduce the damage of metal to the human body, there is no shaping solution for absorbable biomedical materials in the aorta.

[0013] Due to the complexity of the cardiovascular aorta's anatomical structure, different artificial vascular stents and proximal or distal aortic clamping structures are required for different vascular imaging conditions. In the treatment of aortic dissection (aortic aneurysm), especially when vascular imaging technology reveals that the proximal or distal lesion area of ​​the aorta shows irregular vascular morphology, there is a large false lumen or the risk of continuous expansion of the false lumen, the limitations of traditional treatment options become particularly obvious. What kind of structure can relieve the patient's pain, be effective, have a firm support, biodegradable and suitable human absorption time, eliminate the existence of internal leakage in the aortic blood vessels, and have no risk of reverse aortic dissection has become a difficult problem for scientific and technological personnel in this field. Summary of the invention

[0014] The utility model discloses an installation connection structure of an additional stent and an aortic stent to solve the problems in the prior art that the metal stent is non-degradable, the stent may migrate or leak again in the aortic cavity for a long time, and the risk of injury is increased; the metal increases the risk of long-term aortic true lumen thrombosis; the metal ions cause physical harm; the need for biomedical materials to completely or partially replace the metal stent; the urgent need for a structure that can both reduce the patient's pain and be effective in function, eliminate the risk of aortic vascular leakage and reverse aortic dissection, and for different vascular imaging conditions, a new structure suitable for the artificial vascular stent and the proximal or distal clamping of the aorta.

[0015] The utility model discloses an installation connection structure of an additional stent and an aortic stent graft, and the technical solution is as follows:

[0016] It includes an aortic stent graft and an additional stent made of a high-molecular polyester material that can be absorbed by the human body; the additional stent is tubular and has a grid-like structure formed by laser engraving; the grid wire diameter is the same as the wall thickness; the aortic stent graft also has a coated grid-like texture; the additional stent is firmly installed at the end of the aortic stent graft; the end of the aortic stent graft can be the front end of the aortic stent graft or the rear end of the aortic stent graft; the additional stent installed and connected to the front end of the aortic stent graft is correspondingly installed at the proximal end of the aorta; the additional stent installed and connected to the rear end of the aortic stent graft is correspondingly installed at the distal end of the aorta.

[0017] An optimization scheme of the utility model is that the outer diameter of the additional stent is the same as the outer diameter of the end of the aortic covered stent; the additional stent is firmly installed on the end of the aortic covered stent; the additional stent is in close contact with the end of the aortic covered stent and is connected without overlapping to form a connecting structure connection.

[0018] The connecting structure is mainly used for the proximal aorta, especially for the scenario where the proximal end of the aortic stent graft needs to be accurately positioned at the beginning of the lesion area, especially for the case where the blood vessel diameter is consistent and the shape is regular; it can also be used for the distal aorta under certain circumstances; especially when the local lesions of the aortic dissection or aneurysm are relatively concentrated, and the diameter of the distal blood vessel does not change much. The connecting structure helps to simplify the stent placement process, ensuring that the stent can be stably fixed in the target position without overlap; accurately positioning and firmly fixing without increasing the inner cavity diameter; avoiding excessive material overlap, and the degradation time is short, reducing the foreign body sensation inside the blood vessel, helping to reduce hemodynamic interference, and reducing the risk of vascular damage or blood flow obstruction. It improves the radial support force of the proximal end of the aortic stent graft, improves its fit with the aortic vessel wall, and prevents the occurrence of type Ⅰa endoleak; it also prevents the type Ⅰb endoleak and continuous expansion of the false lumen in the distal aorta after thoracic aortic endovascular isolation.

[0019] Another optimization scheme of the utility model is that the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic covered stent; the additional stent is fastened to the end of the aortic covered stent; the additional stent and the aortic covered stent are axially one grid wide, called a grid ring; the grid ring widths of the additional stent and the aortic covered stent are equal; the additional stent overlaps and is joined to an axial grid ring of the end of the aortic covered stent; forming a cross-connected structure.

[0020] The optimized cross-linking structure of the utility model is as follows: the wall thickness of the additional stent is 0.4-1.5 mm, the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic stent graft, and the difference in outer diameter does not exceed 2 mm.

[0021] The cross-connected structure of the additional stent and the aortic covered stent of the utility model is particularly applicable to patients whose vascular images show that the vascular morphology of the proximal and distal lesions of the aorta is irregular, the false lumen is large, or there is a risk of continuous expansion of the false lumen, and the aorta needs additional support to promote vascular remodeling and false lumen closure. The additional stent is cross-connected with the aortic covered stent axially through a grid ring, and the additional stent provides additional support force at the end of the covered stent, provides more stable support, and promotes the adhesion of the distal vascular wall and the closure of the false lumen.

[0022] Another optimization scheme of the utility model is that the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic covered stent; the additional stent is fastened to the end of the aortic covered stent; the additional stent and the aortic covered stent are axially one grid wide, called a grid ring; the grid ring widths of the additional stent and the aortic covered stent are equal; the additional stent and the two axial grid rings of the end of the aortic covered stent overlap and are joined to form a stacked connection structure.

[0023] The optimized overlapping structure scheme of the utility model is: the wall thickness of the additional stent is 0.4-1.5 mm, the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic stent graft, and the outer diameter difference is 1-4 mm.

[0024] The stacked installation connection structure greatly improves the support force and stability, and is particularly suitable for lesions with small blood vessel inner diameter or complex morphology; it helps to ensure close fit of the stent, improve stability, and reduce the risk of type Ia and type Ib endoleaks.

[0025] There are anatomical differences between the proximal and distal ends of the aorta. The diameter of the aorta in Western populations varies less, and the aorta may be closer to a straight cylinder to a certain extent, while the diameter of the aorta in Asian populations gradually decreases from the proximal to the distal end, and tends to be more tapered. There are also differences in hemodynamics between the proximal and distal ends of the aorta. The proximal part is closer to the heart and bears greater blood impact force. When treating aortic diseases, the proximal stent often needs a larger diameter to adapt to the width of the aortic root or ascending aorta, and requires stronger support to prevent the formation of endoleaks. Therefore, in order to provide sufficient Sufficient support area to meet these challenges, while the distal stent is aimed at the relatively narrow lower aorta or abdominal aorta. The additional stent at the front end of the aortic covered stent is often selected with a larger diameter; when the outer diameter of the additional stent tube of the utility model is selected, it is evaluated by angiography that the outer diameter of the additional stent tube at the front end of the aortic covered stent is greater than or equal to the outer diameter of the additional stent tube at the rear end of the aortic covered stent; the outer diameter of the additional stent tube installed and connected to the front end of the aortic covered stent is 26~46 mm; the outer diameter of the additional stent tube installed and connected to the rear end of the aortic covered stent is 22~42 mm.

[0026] The additional bracket of the utility model is a mesh wire structure formed by laser engraving, and the mesh wire shape may include: diamond, honeycomb, ellipse, wave, spiral sine curve, reverse Z-shaped and bridge-shaped or parallel Z-shaped and bridge-shaped structures.

[0027] The additional stent of the utility model can absorb the polymer polyester material, including polylactic acid, polyglycolide, polydioxanone and poly-ε-caprolactone one or more, or selected from polylactic acid, polyglycolide and poly-ε-caprolactone in two or three substances of the copolymer; the absorbable polyester material number average molecular weight range is 3 to 600,000 Daltons, the molecular weight distribution index of the absorbable polyester material is 1.01 to 3;

[0028] An optimization scheme of the utility model is that before the operation, the additional stent and the aortic covered stent are separate structures outside the human body; during the operation, a catheter is used to transmit the additional stent to the end of the aortic covered stent under the guidance of X-ray or other image-assisted equipment, and the additional stent is fastened to the end of the aortic covered stent to form an integrated connection structure.

[0029] Another optimization scheme of the utility model is that before the operation, the additional stent and the aortic covered stent are fastened to the end of the external axis of the human body to form an integrated connection structure; according to the outer diameter of the additional stent tube, the wall thickness, the difference between the outer diameter of the additional stent and the outer diameter of the end of the aortic covered stent and the multi-type grouping of the grid filamentous structure, the selection can be quickly carried out according to the evaluation of vascular imaging conditions.

[0030] The positive effects of the utility model are:

[0031] It provides a flexible adaptation strategy for different vascular lesions and surgical needs, which helps to improve the success rate and safety of aortic stent graft implantation. Adding an additional stent at the end of the aortic stent graft provides more stable support and helps reduce the expansion of the false lumen, thereby reducing the risk of type Ia and type Ib endoleak; it helps to improve the positioning accuracy of the aortic stent graft and reduce postoperative complications. The additional stent and the cross-connected installation connection structure of the aortic stent graft provide solutions for enhanced support and vascular remodeling for the lesion area. The degradation time of the cross-connected installation connection structure is short, the degradation time of the cross-connected installation connection structure is moderate; the degradation time of the overlapped installation connection structure is long; in the preoperative planning and intraoperative execution process, the most suitable connection method is selected according to the patient's specific lesion conditions and vascular anatomical characteristics to cope with the different vascular conditions and surgical needs that may be encountered in the aortic stent graft implantation surgery. Doctors can formulate the most appropriate treatment plan based on the results of CT or MRI or angiography imaging examinations, combined with clinical experience and the physical properties of the stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of the additional stent and the front end of the aortic stent graft of the utility model being connected;

[0033] Figure 2 This is a schematic diagram of the cross-connection structure between the additional stent and the rear end of the aortic stent graft of the utility model;

[0034] Figure 3 This is a schematic diagram of the stacked structure of the additional stent and the front end of the aortic stent graft of the utility model;

[0035] In the figure: 1 additional stent, 2 aortic stent graft, A cross-connection area. DETAILED DESCRIPTION

[0036] Several embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0037] In the first and second embodiments of the utility model, according to the evaluation of vascular imaging conditions, the vascular imaging shows that the aortic stent graft needs to be accurately located at the front end or rear end of the lesion area, and the inner diameter of the blood vessel is relatively consistent and the shape is relatively regular, and the local lesion area of ​​the aortic dissection or aneurysm is relatively concentrated. The mounting connection structure of the additional stent of the utility model and the aortic stent graft is implemented at the proximal and distal ends of the aorta.

[0038] The first embodiment Figure 1As shown, an aortic covered stent 2 and an additional stent 1 made of a polymer polyester material that can be absorbed by the human body; the additional stent 1 is an absorbable polymer polyester material that is a copolymer of polylactic acid and poly-ε-caprolactone and is tubular; the wall thickness of the additional stent is 0.75 mm, and it has a diamond mesh filament structure formed by laser engraving, and the mesh wire diameter is the same as the wall thickness; before the operation, the additional stent 1 and the aortic covered stent 2 are separate structures outside the human body; during the operation, a catheter is used to deliver the additional stent 1 to the front end of the aortic covered stent 2 under X-ray guidance, and the outer diameter of the additional stent is the same as that of the end of the aortic covered stent, which is 46 mm and the wall thickness is 1.5 mm; the axial ends of the two are in close contact and non-overlapping connection to form a connected structure; excessive material overlap is avoided, the foreign body sensation inside the blood vessel is reduced, which helps to reduce the interference of hemodynamics and reduces the risk of vascular damage or blood flow obstruction. It improves the radial support force of the proximal end of the aortic covered stent, improves its fit with the aortic vessel wall, and prevents type Ia endoleak; it also prevents type Ib endoleak and continuous expansion of the false lumen in the distal aorta after thoracic aortic endovascular isolation.

[0039] The second embodiment of the utility model, as Figure 1 As shown, it includes an additional stent 1 and an aortic covered stent 2; the additional stent 1 is an absorbable high molecular polyester material, which is a copolymer of polylactic acid and poly-ε-caprolactone and is tubular; it has a diamond grid filament structure formed by laser engraving, and the grid wire diameter is the same as the wall thickness; before the operation, the additional stent 1 and the rear end of the aortic covered stent 2 are in close axial contact and non-overlapping connection outside the human body to form a connected structure; the additional stent tube at the front end of the aortic covered stent has an outer diameter of 26~46 mm and a wall thickness of 0.4~1.5 mm. The outer diameter, wall thickness and grid filament structure of the additional stent 1 are multi-type groupings. According to the evaluation of vascular imaging conditions, the additional stent 1 with an outer diameter of 45 mm and a wall thickness of 0.45 mm is quickly selected. The utility model has an integrated connection structure.

[0040] In the third and fourth embodiments of the present invention, according to the evaluation of vascular imaging conditions, the vascular imaging shows that the vascular morphology of the proximal and distal lesions of the aorta is irregular, or the false lumen is large, or there is a risk of continuous expansion of the false lumen.

[0041] like Figure 2As shown, the first embodiment includes an additional stent 1 and an aortic stent graft 2; the additional stent 1 is an absorbable high molecular polyester material, which is a copolymer of polylactic acid and poly-ε-caprolactone and is tubular; the wall thickness of the additional stent tube is 0.75 mm, and it has a diamond mesh filament structure formed by laser engraving, and the mesh wire diameter is the same as the wall thickness; the aortic stent graft 2 also has a coated mesh texture; the additional stent 1 and the aortic stent graft 2 are axially one mesh wide, called a mesh ring; the mesh ring widths of the additional stent 1 and the aortic stent graft 2 are equal; the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic stent graft, and the outer diameter difference is 1 mm; before the operation, the additional stent 1 and the aortic stent graft 2 are separate structures outside the human body; during the operation, a catheter is used to transmit the additional stent 1 to the rear end of the aortic stent graft 2 under X-ray guidance, so that the two are axially cross-connected with a mesh ring, and the front ends of the additional stent 1 and the aortic stent graft 2 have a cross-connection area A in the axial direction to form a cross-connection structure; it is applied and installed at the proximal end of the aorta. The additional stent provides additional support at the end of the stent graft, providing more stable support and promoting the adhesion of the distal vessel wall and the closure of the false lumen.

[0042] The fourth embodiment of the utility model, as Figure 2 As shown, it includes an additional stent 1 and an aortic covered stent 2; the additional stent 1 is an absorbable high molecular polyester material, which is a copolymer of polylactic acid and poly-ε-caprolactone and is tubular; it has a parallel Z-shaped and bridged mesh filament structure formed by laser engraving, and the mesh wire diameter is the same as the wall thickness; the aortic covered stent 2 also has a covered mesh texture; the mesh ring widths of the additional stent 1 and the aortic covered stent 2 are equal; the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic covered stent, and the outer diameter difference is 2 mm; before the operation, the additional stent 1 and the rear end of the aortic covered stent 2 are cross-connected with a mesh ring axially outside the human body to form a cross-connected integrated connection structure; the outer diameter of the additional stent tube at the front end of the aortic covered stent is 26~46 mm, and the wall thickness is 0.4~1.5 mm. The outer diameter, wall thickness and mesh filament structure of the additional stent 1 are multi-type grouping. According to the evaluation of vascular imaging conditions, the utility model cross-connected integrated connection structure with an outer diameter of 40 mm and a wall thickness of 0.75 mm of the additional stent 1 is quickly selected.

[0043] In the fifth embodiment of the present invention, based on the evaluation of vascular imaging conditions, the aortic stent graft is poorly fitted at the proximal end of the aorta, requiring a more stable support force to resist blood flow pressure and reduce the expansion of the distal false lumen; the utility model is implemented in the proximal end of the aorta with an additional stent and an aortic stent graft stacked and installed connecting structure.

[0044] The fifth embodiment of the utility model, as Figure 3As shown, it includes an additional stent 1 and an aortic covered stent 2; the additional stent 1 is an absorbable high molecular polyester material, which is a copolymer of polylactic acid and poly-ε-caprolactone and is tubular; the wall thickness of the additional stent is 0.75 mm, and it has a diamond mesh filament structure formed by laser engraving, and the mesh filament diameter is the same as the wall thickness; the aortic covered stent 2 also has a covered mesh texture; the additional stent 1 and the aortic covered stent 2 are one mesh wide in the axial direction, which is called a mesh ring; the mesh ring widths of the additional stent 1 and the aortic covered stent 2 are equal; the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic covered stent, and the outer diameter size difference is 1 mm; before the operation, the additional stent 1 and the aortic covered stent 2 are separate structures outside the human body; during the operation, a catheter is used to transmit the additional stent 1 to the front end of the aortic covered stent 2 under the guidance of X-rays, so that the two mesh rings of the two axial directions overlap and join, and the front ends of the additional stent 1 and the aortic covered stent 2 have an overlapping joining area A in the axial direction to form a stacked structure; it is applied and installed at the proximal end of the aorta. Ensure close cooperation between the additional stent 1 and the aortic covered stent 2, improve the stability of the joint site, and reduce the risk of postoperative complications such as type Ia endoleak.

[0045] In the sixth embodiment of the present invention, based on the evaluation of vascular imaging conditions, the complexity of the anatomical structure of the proximal aorta leads to increased difficulty in stent placement technology, and the stacked installation connection structure of the additional stent of the present invention and the aortic covered stent is applied in the proximal aorta.

[0046] The sixth embodiment Figure 3 As shown, it includes an additional stent 1 and an aortic covered stent 2; the additional stent 1 is an absorbable high molecular polyester material, which is a copolymer of polylactic acid and poly-ε-caprolactone and is tubular; it has an elliptical mesh filament structure formed by laser engraving, and the mesh wire diameter is the same as the wall thickness; the aortic covered stent 2 also has a covered mesh texture; the mesh ring widths of the additional stent 1 and the aortic covered stent 2 are equal; the outer diameter of the additional stent is larger than the outer diameter of the end of the aortic covered stent, and the outer diameter size difference is 2 mm; before the operation, the additional stent 1 and the front end of the aortic covered stent 2 overlap and join two mesh rings axially outside the human body to form a stacked integrated connection structure; the outer diameter of the additional stent tube at the front end of the aortic covered stent is 26~46 mm, and the wall thickness is 0.4~1.5 mm. The outer diameter, wall thickness and mesh filament structure of the additional stent 1 are multi-type groupings. According to the evaluation of vascular imaging conditions, the stacked integrated connection structure of the utility model with an outer diameter of 40 mm and a wall thickness of 0.75 mm of the additional stent 1 is quickly selected.

[0047] In the first, second, third, fourth, fifth and sixth embodiments, the additional stent 1 is a mesh filament structure formed by laser engraving, and the mesh filament shape also implements a honeycomb shape, a wave shape, an ellipse, a spiral sine curve, a reverse Z-shaped parallel bridge, a parallel Z-shaped parallel bridge and other structures. The additional stent can absorb high molecular polyester materials, and also applies and implements one or more of polylactic acid, polyglycolide, polydioxanone and poly-ε-caprolactone, or a copolymer of two or three substances selected from polylactic acid, polyglycolide and poly-ε-caprolactone; the number average molecular weight range of the absorbable polyester material is 300,000 to 600,000 Daltons, and the molecular weight distribution index of the absorbable polyester material is 1.01 to 3;

[0048] The listed structures are only part of the support structures of the utility model, not all of them. Based on these basic structures, all other support structures obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

Claims

1. A mounting connection structure of an additional stent and an aortic stent, characterized in that: It includes an aortic stent graft and an additional stent made of a high-molecular polyester material that can be absorbed by the human body; the additional stent is tubular and has a grid-like structure formed by laser engraving; the grid wire diameter is the same as the wall thickness; the aortic stent graft also has a coated grid-like texture; the additional stent is firmly installed at the end of the aortic stent graft; the end of the aortic stent graft can be the front end of the aortic stent graft or the rear end of the aortic stent graft; the additional stent installed and connected to the front end of the aortic stent graft is correspondingly installed at the proximal end of the aorta; the additional stent installed and connected to the rear end of the aortic stent graft is correspondingly installed at the distal end of the aorta.

2. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: The outer diameter of the additional stent is the same as that of the end of the aortic covered stent; the additional stent is firmly installed on the end of the aortic covered stent; the additional stent is in close contact with the end of the aortic covered stent and is connected without overlapping to form a butt connection structure.

3. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: The outer diameter of the additional stent is larger than the outer diameter of the end of the aortic covered stent; the additional stent is fixedly installed on the end of the aortic covered stent; the additional stent and the aortic covered stent are one grid wide axially, called a grid ring; the grid ring widths of the additional stent and the aortic covered stent are equal; the additional stent overlaps and is joined with an axial grid ring at the end of the aortic covered stent to form a cross-connected structure.

4. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: The outer diameter of the additional stent is larger than the outer diameter of the end of the aortic stent graft; the additional stent is fixedly installed on the end of the aortic stent graft; the axial width of the additional stent and the aortic stent graft is one grid, which is called a grid ring; the grid ring widths of the additional stent and the aortic stent graft are equal; the two axial grid rings of the additional stent and the end of the aortic stent graft overlap and connect to form a stacked connection structure.

5. The mounting connection structure of an additional stent and an aortic stent according to claim 2, 3 or 4, characterized in that: The wall thickness of the additional stent is 0.4 to 1.5 mm. The outer diameter of the additional stent in the cross-connected and overlapping installation connection structure is larger than the outer diameter of the end of the aortic covered stent; for the cross-connected installation connection structure, the difference between the outer diameter of the additional stent and the outer diameter of the end of the aortic covered stent does not exceed 2 mm; for the overlapping installation connection structure, the difference between the outer diameter of the additional stent and the outer diameter of the end of the aortic covered stent is 1-4 mm.

6. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: The outer diameter of the additional stent tube at the front end of the aortic covered stent is greater than or equal to the outer diameter of the additional stent tube at the rear end of the aortic covered stent; the outer diameter of the additional stent tube installed and connected to the front end of the aortic covered stent is 26~46 mm; the outer diameter of the additional stent tube installed and connected to the rear end of the aortic covered stent is 22~42 mm.

7. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: The mesh filament structure of the additional stent formed by laser engraving may have shapes including: diamond, honeycomb, ellipse, wave, spiral sinusoidal curve, reverse Z-shaped and bridged, or parallel Z-shaped and bridged.

8. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: Before the operation, the additional stent and the aortic covered stent are separate structures outside the human body; during the operation, the additional stent is fastened to the end of the aortic covered stent in the body to form an integrated connection structure.

9. The mounting and connecting structure of the additional stent and the aortic stent according to claim 1, characterized in that: The additional stent and the aortic covered stent before surgery are an integrated connection structure that overlaps and connects a mesh ring on the outer axis of the human body. They are divided into multiple types according to the outer diameter of the additional stent tube, the wall thickness and the mesh filament structure.

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