CN113662705A

CN113662705A - Modular branched stent for treating thoracoabdominal aortic aneurysm

Info

Publication number: CN113662705A
Application number: CN202111090383.2A
Authority: CN
Inventors: 王利新; 符伟国; 李哲昀
Original assignee: Zhongshan Hospital Fudan University
Current assignee: Zhongshan Hospital Fudan University
Priority date: 2021-09-17
Filing date: 2021-09-17
Publication date: 2021-11-19

Abstract

The invention relates to a modular branched stent for treating thoraco-abdominal aortic aneurysm, and belongs to the technical field of medical instruments. The stent is a covered stent and comprises a descending aorta region near-end anchoring module, a visceral artery region branch graft module and an abdominal aorta region far-end anchoring module which are sequentially communicated; the number of the proximal anchoring modules in the descending aorta section is at least one. The invention provides a modular branched endoluminal vascular graft for treating thoraco-abdominal aortic aneurysms in asian populations. The time required by customization can be effectively avoided by adapting to various anatomical structures of thoraco-abdominal aortic aneurysms in a modularized and different combination mode; visceral and renal arteries can be reconstructed by branching; sufficient friction is provided for graft anchoring and bridging through combined anchoring, and the branch is conveniently selected through a guide wire guiding area, so that the operation difficulty and time are reduced. Thereby effectively treating the thoraco-abdominal aortic aneurysm, and reducing the operation time and the occurrence of adverse reaction of contrast agent.

Description

Modular branched stent for treating thoracoabdominal aortic aneurysm

Technical Field

The invention relates to a modular branched stent for treating thoraco-abdominal aortic aneurysm, and belongs to the technical field of medical instruments. The present invention defines a direction with a blood flow direction flowing from a proximal end to a distal end.

Background

Thoracoabdominal aortic aneurysms (TAAAs) are localized dilatational diseases of the thoracic and abdominal aorta that are secondary to weakness of the aortic wall and consequent development. TAAA often affects a plurality of visceral arteries such as the celiac trunk artery, the superior mesenteric artery, and the bilateral renal arteries, and is a very dangerous aortic disease. The incidence of thoraco-abdominal aortic aneurysm is about 5.9 per 100000 human years. The natural course of the disease often develops dissection or rupture, and epidemiological studies have found that up to 80% of TAAA patients eventually develop rupture, resulting in an untreated patient 5-year survival rate of only 10% -20%. The main existing treatment modalities for thoraco-abdominal aortic aneurysms include traditional open surgery and intraluminal repair techniques. The open operation has high mortality and disability rate due to large operation wound, long operation time and many complications. Intraluminal repair techniques are a new therapeutic modality by implanting artificial endovascular stents within the lumen of a vessel. Compared with open surgery, intracavity treatment of TAAA can significantly reduce the physiological stress of patients, reduce the hospitalization time of patients, and reduce the hospitalization mortality. The current techniques for intraluminal treatment of thoraco-abdominal aortic aneurysms include the following: (1) the hybridization technique can be used for repairing tumor bodies by adopting thoracic aorta intracavity repair technique after the visceral artery is transplanted and reconstructed for patients without enough distal anchoring areas or patients with visceral artery affected by aneurysm. The hybridization technology has simple intracavity repair process, long-term anastomotic vessels are generally high, but still has the problems of huge surgical trauma, high requirements on renal artery anastomosis technology, high incidence rate of spinal cord ischemia and the like. (2) Surgeons modify vascular grafts by windowing and suturing finished stents to fit the TAAA anatomy of the patient without fitting vascular grafts, but this technique involves a certain risk of infection due to the need to manipulate the sterile graft externally, and such grafts are extremely demanding on the vascular surgeon's operating skills and are not as routine endoluminal treatment. (3) The sandwich technology adopts the existing intracavity equipment, and a plurality of small stents are sleeved and stacked in a large covered stent as branches, so that the operation is easy. The compression of multiple stents within the aortic lumen may result in obstructed blood flow and occlusion of branch arteries. And the method is easy to cause I-type internal leakage. (4) The octopus technique is similar to the sandwich technique, and the octopus technique also combines a plurality of existing branch stents to reconstruct the visceral artery and the renal artery, but the system structure is extremely complex, the digital subtraction angiography process is not easy to see, and the bridge joint between the stents is easy to leak. (5) Although the branched vascular graft is not approved by the FDA and is complex in operation and application, the branched vascular graft can better accord with the hemodynamics principle, and the patency rate of the branched artery is high, so that the branched vascular graft is a potential optimal scheme for the intracavitary repair of the thoraco-abdominal aortic aneurysm. Due to differences in aortic anatomy and range of affected branch vessels in TAAA patients, custom-made branched vessel grafts are a common option for intraluminal repair of thoraco-abdominal aortic aneurysms. Customized grafts will fit well with the patient's aortic aneurysm characteristics, but these grafts often take 10-12 weeks to prepare and finished stents will greatly reduce the waiting time for treatment. In addition, the existing thoraco-abdominal aorta branched vascular graft is mainly of an integral structure, cannot be well adapted to the complex anatomical structure of a patient, and can better give consideration to the individual requirements and finished product production of the patient by modularizing the integral branched vascular graft.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and obtain a technical problem of better adapting to the complex anatomical structure of a patient, and better considering the individual requirements of the patient and the finished product production by modularizing the whole branch vascular graft.

In order to solve the above problems, the technical solution of the present invention is to provide a modular branched stent for treating thoraco-abdominal aortic aneurysm, which is a covered stent and comprises a descending aorta region proximal anchoring module, a visceral artery region branched graft module and an abdominal aorta region distal anchoring module, which are sequentially connected; the descending aorta area near-end anchoring module is communicated with the abdominal aorta area far-end anchoring module through the visceral artery area branch graft module; the number of the proximal anchoring modules in the descending aorta section is at least one.

Preferably, the descending aorta section proximal anchoring module is a cone-shaped covered stent comprising a metal stent main body structure and a stent covered membrane arranged on the surface of the main body structure; the diameter of the proximal end of the covered stent is larger than that of the distal end; the outer peripheral wall of the near end is provided with a first barb extending outwards, and the inner side wall of the far end is provided with a second barb extending inwards.

Preferably, after a plurality of the descending aorta section proximal anchoring modules are connected in sequence, the distal end of the descending aorta section proximal anchoring module is connected with the proximal end of the visceral artery section branch graft module.

Preferably, the connection between the descending aorta section proximal anchoring modules is that the distal end of one descending aorta section proximal anchoring module is connected with the proximal end of another descending aorta section proximal anchoring module.

Preferably, the visceral artery area branch graft module comprises a proximal stent channel, an anterior-posterior guidewire guiding area, a dorsal short branch, a ventral short branch and a distal stent channel; a front guide wire guiding area and a rear guide wire guiding area are arranged between the near-end bracket channel and the far-end bracket channel; the near-end bracket channel is communicated with the far-end bracket channel through a bracket and is communicated with the ventral short branch and the dorsal short branch through front and back guide wire guide areas; the front and back guide wire guide areas are respectively provided with a dorsal side short branch and a ventral side short branch; the central axes of the dorsal side short branch and the ventral side short branch are parallel to the central axis of the far-end bracket channel; the diameter of the proximal stent passage is larger than that of the distal stent passage; the outer peripheral wall of the near-end support channel is provided with a first barb extending outwards, and the inner side wall of the far-end support channel is provided with a second barb extending inwards.

Preferably, the shape of the front and rear guide wire guiding areas is a cone, and the diameter of the proximal end of the front and rear guide wire guiding areas is larger than that of the distal end; the front and back guide wire guide areas are provided with a hollow ventral guide wire guide area and a hollow dorsal guide wire guide area; the ventral guide wire guiding area is provided with two hollow ventral short branches extending towards the far end; the dorsal guidewire guiding region is provided with two hollow dorsal short branches extending towards the distal end.

Preferably, the distal anchoring module of the abdominal aorta section comprises a proximal straight cylindrical stent and two distal branch stents; the near-end straight cylindrical bracket and the far-end two branch brackets are integrally formed; the two branch stents at the far end are set as iliac artery branch stents, and suture knots are arranged on the covered membranes of the iliac artery branch stents; the outer peripheral wall of the near-end straight cylindrical support is provided with a first barb extending outwards.

Compared with the prior art, the invention has the following beneficial effects:

1. the modular design is adopted: the existing finished vascular grafts at home and abroad are designed integrally, and the requirement that enough proximal end and distal end anchoring areas are provided when the positions of branches of the grafts correspond to the positions of branch vessels is met, so that the finished vascular grafts are not easy to realize in thoraco-abdominal aortic aneurysms with complicated and variable anatomical conditions, and the suitability rate of the grafts is influenced. The inventive endoluminal vascular graft is divided into three modules, namely a descending aorta region proximal anchoring module (hereinafter referred to as module one), a visceral artery region branch graft module (hereinafter referred to as module two) and an abdominal aorta region distal anchoring module (hereinafter referred to as module three). The first module is a tapered straight-tube type graft with various lengths and is used for anchoring at the near end and meeting the diameter change when the descending aorta moves to the abdominal aorta; the second module is a universal branched graft which is bridged with the first module and sends out four branches to rebuild the blood supply of the abdominal trunk, the superior mesenteric artery and the bilateral renal arteries; module three is a bifurcated graft, distal anchoring of the common iliac artery while bridging with module two, and bridging can also be done using a commercially available branch stent in abdominal aortic endoluminal repair.

The modular design can effectively solve the severe requirement of the existing finished graft on the aorta of a patient, divide the active lesion of the patient into 3 sections, select proper graft modules according to the lesion characteristics of different sections, and reconstruct the visceral artery and the renal artery by the visceral artery branch bridging stent, thereby greatly increasing the adaptability of the intracavity graft of the invention. Meanwhile, the modular graft can also avoid the problems of overlong waiting time of the customized vascular graft and the like. The different combinations of the three modules of the graft meet the anatomical requirements of the vascular graft on the visceral branches and the distal and proximal anchoring areas, and further realize the maximum matching of the anatomical structures of patients.

2. Graft combination anchoring: the degree of anchoring of the anchoring zone and the tightness of the bridge between the stents has a significant impact on the therapeutic outcome of the endoluminal vascular graft, and modular stents are more in need of strong inter-modular anchoring to prevent endoleaks and migration. The invention designs a combined anchoring system aiming at the modular branch vascular graft, and the combined anchoring system is combined by a plurality of anchoring and bridging means to improve the treatment effectiveness of the graft. A proximal metal barb of the module faces the outside of the stent to provide a more secure anchorage; the lower half part of the metal barb faces the inner side of the bracket so as to improve the friction force when the lower half part of the metal barb is bridged with the second module. The near end of the second module is connected with the first module in a bridging tight mode through the barb, and the lower half portion is also provided with the internal barb to enhance the connection strength with the third module. Module three also employs a barb structure at the proximal end, while the distal end uses a knot to increase the anchoring strength of the distal end. By the combined anchoring system among the multiple modules, firm vessel anchoring and module bridging are provided, and the application effectiveness of the vascular graft is increased.

3. Designing a guide wire guide area: branched endoluminal vascular grafts tend to have the graft and branch directly connected without any transition. In the process of the intracavity surgery, the surgeon needs to repeatedly perform radiography under the fluoroscopy condition, and the guide wire is operated to enter the corresponding branch, which has certain difficulty. This problem is more pronounced during endoluminal treatment of multi-branch stents. Therefore, a guide wire guide area is newly designed in the graft, the guide area is a large funnel-shaped branch, and 2 visceral artery branches or 2 renal artery branches are connected below the guide area. The front and the back of the second module main body are respectively provided with a guide wire guiding area, and the front guiding area comprises an abdominal trunk branch and an superior mesenteric artery branch; the posterior guide region includes the left and right renal artery branches. The operator only needs to put the guide wire into the guide area with larger area and then slightly adjust the guide wire to enter different branches, thus effectively shortening the operation time and reducing the use of contrast medium.

4. Fit asian patient anatomy: because of the small size of the asian population, the diameters of the aorta, renal artery and visceral artery are smaller than those of the western population. Foreign TAAA endograft may not be effectively applied to asian patients with thoraco-abdominal aortic aneurysm, and the diameter of the celiac trunk and superior mesenteric artery is still large although branch diameters are adjusted with the domestic G-branch stent. The invention reduces the diameter of the branch stent according to the anatomical characteristics of blood vessels of Asian people so as to better match the corresponding artery, and provides more flexible and free selection when the branch matches the artery through the parallel branch design. In addition, the prolonged branch part is designed to obtain a longer branch artery bridging area, so that the device can be better applied to the reconstruction of blood circulation of visceral branches and bilateral human renal arteries of Asian patients.

Drawings

FIG. 1 is a schematic view of the proximal anchoring module in the descending aorta section according to the present invention.

FIG. 2 is a schematic view of the visceral artery differentiating branch graft module according to the present invention.

Wherein, the A is the front view, the B is the back view, and the C is the top view.

FIG. 3 is a schematic view of the distal anchoring module structure in the abdominal aorta region of the present invention.

Fig. 4 is a rear view structural diagram of the descending aorta section proximal anchoring module, the visceral artery section branch graft module and the abdominal aorta section distal anchoring module connected in sequence according to the present invention.

Fig. 5 is a schematic front view showing the structure of the distal anchoring module of the abdominal aorta region, the visceral artery region branch graft module and the descending aorta region connected in sequence according to the present invention.

Reference numerals: 1. a first barb; 2. a metal bracket; 3. covering a membrane on the stent; 4. a second barb; 5. a ventral guidewire guidance zone; 6. a backside short branch; 7. ventral short branches; 8. a dorsal guidewire guidance region; 9. iliac artery branch stents; 10. a suture knot; 11. a descending aorta region proximal anchoring module; 12. a visceral arterial area branch graft module; 13. the distal anchoring module of the abdominal aorta region.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings:

as shown in fig. 1-5, the technical solution adopted by the present invention is to provide a modular branched stent for treating thoraco-abdominal aortic aneurysm, which is a covered stent, and comprises a descending aorta region proximal anchoring module 11, a visceral artery region branched graft module 12 and an abdominal aorta region distal anchoring module 13 connected in sequence; the descending aorta section proximal anchoring module 11 is communicated with the abdominal aorta section distal anchoring module 13 through the visceral artery section branch graft module 12; the number of the descending aorta section proximal anchoring modules 11 is at least one. The descending aorta region near-end anchoring module 11 is a cone-barrel-shaped covered stent and comprises a main body structure of a metal stent 2 and a stent covered membrane 3 arranged on the surface of the main body structure; the diameter of the proximal end of the covered stent is larger than that of the distal end; the outer peripheral wall of the near end is provided with a barb I1 which extends outwards, and the inner side wall of the far end is provided with a barb II 4 which extends inwards. After the plurality of descending aorta section proximal anchoring modules 11 are connected in sequence, the distal end of the descending aorta section proximal anchoring module 11 is connected with the proximal end of the visceral artery section branch graft module 12. The connection between the descending aorta section proximal anchoring modules 11 is that the distal end of one descending aorta section proximal anchoring module 11 is connected with the proximal end of another descending aorta section proximal anchoring module 11. The visceral artery region branch graft module 12 comprises a proximal stent channel, an anterior and posterior guide wire guiding region, a dorsal short branch 6, a ventral short branch 7 and a distal stent channel; the near-end stent channel stent is connected with the far-end stent channel and is communicated with the ventral short branch 7 and the dorsal short branch 6 through front and back guide wire guide areas; the central axes of the dorsal side short branch 6 and the ventral side short branch 7 are parallel to the central axis of the far-end stent passage; the diameter of the proximal stent passage is larger than that of the distal stent passage; the outer peripheral wall of the near-end support channel is provided with a barb I1 which extends outwards, and the inner side wall of the far-end support channel is provided with a barb II 4 which extends inwards. The shape of the front and rear guide wire guiding areas is a cone, and the diameter of the near end of the front and rear guide wire guiding areas is larger than that of the far end; the front and back guide wire guide areas are provided with a hollow ventral guide wire guide area 5 and a hollow dorsal guide wire guide area 8; the ventral guide wire guiding area 5 is provided with two hollow ventral short branches 7 extending towards the far end; the dorsal guidewire guidance zone 8 is distally extended with two hollow dorsal short branches 6. The distal anchoring module 13 of the abdominal aorta region comprises a proximal straight cylindrical bracket and two distal branch brackets; the near-end straight cylindrical bracket and the far-end two branch brackets are integrally formed; the two branches at the far end are set as iliac artery branch stents 9, and suture knots 10 are arranged on the covering films of the iliac artery branch stents 9; the peripheral wall of the near-end straight cylindrical support is provided with a barb I1 which extends outwards.

Examples

The inventive endoluminal vascular graft is divided into three modules, namely a descending aorta region proximal anchoring module (hereinafter referred to as module one), a visceral artery region branch graft module (hereinafter referred to as module two) and an abdominal aorta region distal anchoring module (hereinafter referred to as module three)

Wherein, the module i.e. the descending aorta region proximal anchoring module 11: the tapered straight tube type graft has the proximal end diameter of 28-46mm, the distal end diameter of 18-35mm, the tapered design with gradually reduced diameter from the proximal end to the distal end, and the length of the first module is 100 mm and 300mm so as to adapt to different anchoring positions of the proximal end of the aorta. While the proximal end is sufficiently anchored, the distal end subsequently bridges the visceral artery differentiating branch graft module. When the length of a single module is not enough, another module can be implanted in the first module to complete the connection so as to achieve the enough length.

As shown in fig. 1, a metal barb 1 which extends outwards is arranged at the proximal end of the stent, and a nickel-titanium alloy material can be adopted for anchoring the blood vessel at the proximal end so that the stent is firmly anchored on the blood vessel wall; the metal stent 2 is used as a main body structure and is a Z-shaped stent so as to enhance the strength of the stent, and a nickel-titanium alloy material can be adopted; the main structure is provided with a stent covering film 3 which can be made of nylon or polytetrafluoroethylene and can effectively isolate blood flow and prevent the occlusion of a lumen; the distal end is provided with a second metal barb 4 extending towards the inner side, which can be made of nickel-titanium alloy material and is used for firmly bridging the next module so as to prevent the vascular graft from shifting when being bridged.

The first module is a tapered straight-tube type graft, and the tapered design with gradually reduced diameter can meet the diameter change of the descending aorta of a patient when the descending aorta moves to the abdominal aorta. Since the descending aorta often requires sufficient anchoring area to secure the graft and adequately isolate the blood flow. Because the modularized stent is bridged by a plurality of stents to isolate tumor cavities, higher requirements are put forward on the anchoring and bridging stability of the stent, and the metal barb design with the proximal end extending outwards is used for anchoring a blood vessel at the proximal end so that the stent is firmly anchored on the blood vessel wall; a metallic barb extending distally and medially to securely bridge the next module and prevent migration of the vascular graft when bridged.

Module two, the visceral artery differentiating branch graft module 12; the module is a core component of the design, is a universal module suitable for most thoraco-abdominal aortic aneurysms, and has the function of carrying out blood transportation reconstruction on the celiac trunk artery, the superior mesenteric artery and the bilateral renal arteries while isolating a tumor cavity. The diameter of the proximal end of the second module is 20-38mm, and the length of the second module is 20-30 mm. The branch part is provided with a front wide-mouth branch opening and a rear wide-mouth branch opening which are used as guide wire guide areas, namely a ventral guide wire guide area 5 and a dorsal guide wire guide area 8, the length of the branch part is 5-8mm, the width of the front guide area (ventral guide wire guide area 5) is narrower, the branch part internally comprises two branches, and the two branches are symmetrical in position, namely ventral short branches 7; both arms may be used as branches of the celiac trunk or superior mesenteric artery to provide more freedom in branch vessel selection. The posterior guide area (dorsal guidewire guide area 8) is wider and also contains two branches inside, which are bilaterally symmetrical, i.e. the dorsal short branch 6, is farther away. The four branches are all downward, the diameter is 6mm, and the length is 10 mm. The second module can be released slightly above the region of the internal artery and fixed in the first module. The branch vessels are used for reconstructing branch arterial blood supply by bridging a covered stent with the diameter of 6-8 mm. For 6mm branch blood vessels, a novel ball-expanded type covered stent can be selected to ensure the firm anchoring of the near end. The anchoring area at the far end of the second module is 25mm in length and 12-20mm in diameter.

As shown in fig. 2, a first metal barb 1 is extended outwards from the proximal end of the stent, and a nickel-titanium alloy material can be adopted for anchoring the blood vessel at the proximal end so that the stent is firmly anchored on the blood vessel wall; the main structure is a metal bracket 2 which is a Z-shaped bracket, the covering part comprises a module II, a near-end bracket main body, a front guide wire guiding area, a rear guide wire guiding area and a far-end bracket main body so as to enhance the strength of the bracket and prevent the bracket main body and the guide wire guiding area from being deformed under pressure, and the bracket main body can be made of nickel-titanium alloy materials; the stent is provided with a stent covering film 3 which can be made of nylon material or polytetrafluoroethylene and can effectively isolate blood flow and prevent the occlusion of a lumen; a ventral guide wire guiding area 5, the opening of the proximal end is larger and is about 60 degrees, the distal end is gradually reduced, and two short branches (ventral short branch 7) are extended to rebuild the visceral artery; two short branches (dorsal side short branch 6) extending from the dorsal side guide wire guiding area 8 are used for reconstructing bilateral renal arteries, an annular stent is adopted on the branches to improve the flexibility and the bendable angle of the branches, and polyester fibers are coated outside the stent to prevent the occlusion of a lumen while reconstructing blood flow; two short branches (ventral short branch 7) extending from the ventral guide wire guiding area are used for reconstructing the abdominal trunk and superior mesenteric artery, the branches adopt annular stents to improve the flexibility and the bendable angle of the branches, and the stents are coated with polyester fibers to prevent the occlusion of the lumen while reconstructing blood flow; the distal end is provided with a metal barb II 4 extending towards the inner side, which can be made of nickel-titanium alloy material and is used for firmly bridging the next module so as to prevent the vascular graft from shifting when being bridged; the dorsal guidewire guidance region 8 has a larger proximal opening of about 150 degrees and a tapered distal end with two short branches (dorsal short branches 6) extending therefrom for reconstruction of the visceral artery.

The second module is designed into a universal module suitable for most thoraco-abdominal aortic aneurysms, and has the function of carrying out blood transportation reconstruction on the abdominal trunk artery, the superior mesenteric artery and the bilateral renal arteries while isolating a tumor cavity. The proximal diameter, length and branch opening diameter of the second module are all designed according to the Asian aorta standard. Because the opening of the branch artery is smaller in the process of releasing the stent and carrying out radiography, the branch artery is difficult to control and pass through under radiography, and the guide wire guide area structure is designed, so that the operation difficulty and the operation time are effectively reduced, and the use of a contrast agent is reduced. The anterior and posterior guide regions each comprise two branches, symmetrically positioned, both of which may serve as branches of the celiac trunk or superior mesenteric artery, to provide more freedom in branch vessel selection. Because the structure of the guide wire guide area is flat and long and is easy to deform, the Z-shaped bracket is adopted to prevent the guide wire guide area from deforming under pressure. The four branches all adopt an annular bracket to improve the flexibility and the bendable angle of the branches, and the bracket is externally coated with polyester fiber to prevent the occlusion of a lumen while reconstructing blood flow. The metal barb structure at the near end of the second module is also designed for firm bridging, so that the support is prevented from being displaced.

Module three, distal anchoring module 13 in the abdominal aorta region;

module three is a commercial bifurcated graft, similar to an abdominal aortic branch stent. The near end is a straight cylinder type bracket with the diameter of 15-25mm and the length of 15-30 mm. The far end is connected with two iliac artery branches with the length of 20-40mm and the diameter of 10 mm. The near-end anchoring area also adopts a barb structure, so that the friction force between the near-end anchoring area and the second module bridge is increased; the distal anchoring area is covered with a suture knot 10 designed to increase the friction of the graft with the iliac artery and prevent endoleaks and migration. And a suitable commercialized abdominal aorta branch graft can be selected according to the TAAA anatomical structure of a patient, and the combination is more abundant and convenient.

As shown in fig. 3, the proximal end of the stent is provided with a first metal barb 1 which extends outwards and can be made of nickel-titanium alloy material for anchoring the blood vessel at the proximal end so that the stent is firmly anchored on the blood vessel wall; the stent is provided with a stent covering film 3 which can be made of nylon material or polytetrafluoroethylene and can effectively isolate blood flow and prevent the occlusion of a lumen; the main structure is a metal stent 2 which is a Z-shaped stent, the covering part comprises three module near-end stent main bodies and a far-end iliac artery branch stent 9 so as to enhance the strength of the stent and prevent the stent main bodies from deforming under pressure, and the stent can be made of nickel-titanium alloy materials; two iliac artery branch stents 9 extending from the main body of the near-end stent are used for reconstructing bilateral iliac arteries and anchoring the far section; the iliac artery branch stent 9 is provided with a suture knot 10 which is positioned outside the iliac artery branch tectorial membrane and used for increasing the friction force between the iliac artery branch and the iliac artery and preventing the stent from displacement and internal leakage.

The near-end anchoring area of the module III also adopts a barb structure, so that the friction force between the near-end anchoring area of the module III and the near-end anchoring area of the module II is increased; the covering film of the far-end anchoring area is designed with a suture knot to increase the friction force of the graft and the iliac artery and prevent internal leakage and displacement.

As shown in fig. 4 and 5, in thoraco-abdominal aortic aneurysms, the module-one, which is adapted to the diameter of the patient's aorta, is released at a suitable location proximal to the tumor lumen to firmly anchor the vessel wall, leaving the proximal barb anchored to the artery; releasing the second module at the far end of the first module to ensure that the near end of the second module and the far end of the second module have a certain superposition part so as to enhance the friction force, and ensuring that the inward barb second at the far end of the first module is hooked into the film covering at the near end of the second module, and simultaneously the barb first at the near end of the second module is hooked into the far end of the first module so as to ensure firm bridging, and ensuring that the second module is positioned above the abdominal trunk, the superior mesenteric artery and the bilateral renal arteries so as to ensure that the visceral arterial blood flow is subsequently reconstructed through branches. Releasing the third module at the far end of the second module, simultaneously enabling the second module and the third module to have a certain overlapping part to enhance friction force, and enabling the barb I at the near end of the third module to hook into the far end of the second module outwards to ensure firm bridging. The three distal iliac artery branches of the module are anchored with the left and right iliac arteries, so that the three distal iliac artery branches of the module have a certain length in the iliac arteries, the distal anchoring is ensured to be firm, and the formation of internal leakage is avoided.

And the blood supply of the branch artery is reconstructed by bridging a 6-8mm diameter covered stent or a spherical expansion covered stent through two branches of the ventral guide wire guide area. The bridging stent needs to be overlapped with the two branches of the module to ensure that the proximal bridging is firm, and the distal end can be freely anchored by selecting the abdominal trunk or the superior mesenteric artery so as to reconstruct the visceral blood flow. And the branch arterial blood supply is reconstructed by bridging the covered stent or the spherical expansion covered stent with the same diameter through two branches of the dorsal guide wire guiding area. The bridging stent needs to be overlapped with the two module branches to a certain extent so as to ensure that the bridging at the near end is firm, and the far end can freely select the left and right renal arteries to anchor so as to reconstruct the blood flow of the bilateral renal arteries.

The present invention provides a novel modular branched endoluminal vascular graft for the treatment of thoraco-abdominal aortic aneurysms in asian populations. The finished graft is designed for Asian population, adapts to the anatomical structures of various thoraco-abdominal aortic aneurysms in a modularization and different combination modes, can effectively avoid the time required for customization, and reconstructs visceral arteries and renal arteries affected by the aneurysms through branches. In addition, sufficient friction is provided for graft anchoring and bridging through a combined anchoring design, and a guide wire guide area is innovatively designed so as to ensure the convenience of selecting branches in the contrast process and reduce the operation difficulty and time. Thereby effectively treating the thoraco-abdominal aortic aneurysm, and reducing the operation time and the adverse reaction of the contrast agent.

While the invention has been described with respect to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Those skilled in the art can make various changes, modifications and equivalent arrangements, which are equivalent to the embodiments of the present invention, without departing from the spirit and scope of the present invention, and which may be made by utilizing the techniques disclosed above; meanwhile, any changes, modifications and variations of the above-described embodiments, which are equivalent to those of the technical spirit of the present invention, are within the scope of the technical solution of the present invention.

Claims

1. A modular branched stent for treating thoraco-abdominal aortic aneurysm is a covered stent, and is characterized in that: comprises a descending aorta region near-end anchoring module, a visceral artery region branch graft module and an abdominal aorta region far-end anchoring module which are connected in sequence; the descending aorta area near-end anchoring module is communicated with the abdominal aorta area far-end anchoring module through the visceral artery area branch graft module; the number of the proximal anchoring modules in the descending aorta section is at least one.

2. The modular branched stent for treating thoraco-abdominal aortic aneurysms of claim 1, wherein: the descending aorta region near-end anchoring module is a cone-barrel-shaped covered stent and comprises a metal stent main body structure and a stent covered membrane arranged on the surface of the main body structure; the diameter of the proximal end of the covered stent is larger than that of the distal end; the outer peripheral wall of the near end is provided with a first barb extending outwards, and the inner side wall of the far end is provided with a second barb extending inwards.

3. The modular branched stent for treating thoraco-abdominal aortic aneurysms of claim 2, wherein: after the descending aorta area proximal anchoring modules are connected in sequence, the distal ends of the descending aorta area proximal anchoring modules are connected with the proximal ends of the visceral artery area branch graft modules.

4. The modular branched stent for treating thoraco-abdominal aortic aneurysms of claim 3, wherein: the descending aorta section proximal anchoring modules are connected with each other in such a way that the distal end of one descending aorta section proximal anchoring module is connected with the proximal end of another descending aorta section proximal anchoring module.

5. The modular branched stent for treating thoraco-abdominal aortic aneurysms of claim 1, wherein: the visceral artery area branch graft module comprises a proximal stent channel, an anterior and posterior guide wire guiding area, a dorsal side short branch, a ventral side short branch and a distal stent channel; a front guide wire guiding area and a rear guide wire guiding area are arranged between the near-end bracket channel and the far-end bracket channel; the near-end bracket channel is communicated with the far-end bracket channel through a bracket and is communicated with the ventral short branch and the dorsal short branch through front and back guide wire guide areas; the front and back guide wire guide areas are respectively provided with a dorsal side short branch and a ventral side short branch; the central axes of the dorsal side short branch and the ventral side short branch are parallel to the central axis of the far-end bracket channel; the diameter of the proximal stent passage is larger than that of the distal stent passage; the outer peripheral wall of the near-end support channel is provided with a first barb extending outwards, and the inner side wall of the far-end support channel is provided with a second barb extending inwards.

6. The modular branched stent for treating thoraco-abdominal aortic aneurysms of claim 5, wherein: the shape of the front and rear guide wire guiding areas is a cone, and the diameter of the near end of the front and rear guide wire guiding areas is larger than that of the far end; the front and back guide wire guide areas are provided with a hollow ventral guide wire guide area and a hollow dorsal guide wire guide area; the ventral guide wire guiding area is provided with two hollow ventral short branches extending towards the far end; the dorsal guidewire guiding region is provided with two hollow dorsal short branches extending towards the distal end.

7. The modular branched stent for treating thoraco-abdominal aortic aneurysms of claim 1, wherein: the distal anchoring module of the abdominal aorta area comprises a proximal straight cylindrical bracket and two distal branch brackets; the near-end straight cylindrical bracket and the far-end two branch brackets are integrally formed; the two branch stents at the far end are set as iliac artery branch stents, and suture knots are arranged on the covered membranes of the iliac artery branch stents; the outer peripheral wall of the near-end straight cylindrical support is provided with a first barb extending outwards.