Bracket for reconstructing abdominal aortic bifurcation

Abstract

The utility model relates to a stent for reconstructing abdominal aortic bifurcation, which is characterized in that a stent body is of a metal net-shaped structure and is woven with a film covering material, and the proximal end of the stent is of a cylindrical shape with a cavity; the telecentric end of the stent is in a shorts shape and is provided with two openings, namely an opening I and an opening II, which are communicated with the stent for placing the common iliac arteries on the two sides. According to the covered stent, the distal end is in a shorts shape, the covered stent is used for reconstructing abdominal aorta bifurcation, and the problem that the probability of inner leakage is increased due to the fact that a gap exists between a traditional main body stent and a branch stent is solved.

Description

Technical Field

[0001] The utility model relates to a medical supply, in particular to a stent for reconstructing the abdominal aortic bifurcation. Background Art

[0002] Compared with traditional open surgery, endovascular repair and reconstruction of the abdominal aortic bifurcation has less invasiveness and lower perioperative mortality, providing a treatment opportunity for patients who cannot tolerate open surgery. However, the disadvantage of endovascular treatment is that it has a higher reintervention rate after surgery, mainly due to the formation of endoleak. Once endoleak occurs, continuous blood flow enters the space between the graft and the vessel wall. Coupled with the compression of the graft on the vessel wall, local inflammatory changes occur, increasing the brittleness of the vessel wall, which may lead to the risk of aneurysm or dissection.

[0003] Aortoiliac arteriosclerosis obliterans involves both common iliac arteries. Therefore, endovascular repair for vascular reconstruction involves bilateral common iliac artery reconstruction. It not only requires implanting a covered stent in the infrarenal abdominal aorta, but also requires implanting two branch stents to connect the reconstructed abdominal aorta and the bilateral iliac arteries. Currently, the main stents implanted in the abdominal aorta clinically are mostly straight tube-shaped covered stents, and kiss technique and CERAB technique are used to implant branch stents in the bilateral common iliac arteries. However, the disadvantage of the currently commonly used straight tube-shaped stent is that after two branch stents of the common iliac arteries are implanted into the main abdominal aortic stent, there will inevitably be unfilled gaps, resulting in some blood flow flowing out from the distal end of the main abdominal aortic stent and entering the space between the distal end of the stent and the abdominal aortic bifurcation, thus causing endoleak. And because there is an average angle of about 62 degrees (22 degrees - 90 degrees) between the left and right common iliac artery bifurcations, it is difficult to achieve close fitting between module components when the branch module implanted in the common iliac artery is connected to the straight tube-shaped stent implanted in the abdominal aorta, increasing the probability of endoleak occurring at the position close to the abdominal aortic wall, resulting in a higher reintervention rate after surgery. Summary of the Invention

[0004] The utility model aims to provide a covered stent for reconstructing the abdominal aortic bifurcation. The distal end of the stent is in the shape of "shorts", which solves the problem of gaps between the traditional main stent and branch stents, increasing the probability of endoleak. At the same time, according to the anatomical relationship between the abdominal aorta and the common iliac arteries, a suitable angle for implanting the branch stent is set, improving the tightness of the fit between the branch stent of the common iliac artery and the main abdominal aortic stent during reconstruction of the infrarenal abdominal aorta, reducing the risk of endoleak and the reintervention rate after surgery.

[0005] The utility model adopts the following technical solutions:

[0006] A stent for reconstructing the abdominal aortic bifurcation, the stent body is a metal mesh structure and is woven with a membrane material. The proximal end 202 of the stent 2 is a cylindrical shape with a cavity; the distal end of the stent is "shorts-shaped" and is provided with two openings for communicating with the stents that can be inserted into the bilateral common iliac arteries: opening one 3 and opening two 4.

[0007] Preferably, the area 5 between the opening one 3 and the opening two 4 is the area where the distal end of the stent is closed by the metal mesh structure and the membrane material.

[0008] Further, the two ends of the area 5 are wider and the middle part is narrower.

[0009] Preferably, the angle formed by the axial direction of the opening one 203 and the opening two 204 and the axial direction of the stent body is 30-45 degrees.

[0010] Preferably, the length of the stent 2 is 80-110 mm, and the inner diameters of the opening one 3 and the opening two 4 are 7-11 mm.

[0011] Further, the length of the stent 2 is 90 mm.

[0012] Preferably, the metal mesh structure is formed by cross-weaving metal wires or by laser engraving.

[0013] Further, the metal wire is nitinol alloy.

[0014] Preferably, the membrane material is made of one of polytetrafluoroethylene, polyurethane, and polyester.

[0015] Preferably, the distal end of the stent is provided with radiopaque marker points for positioning during the delivery of the stents for the bilateral common iliac arteries; the radiopaque marker points are platinum marker points.

[0016] The beneficial effects of the present utility model are as follows: The stent of the present utility model is designed with a distal end in the shape of "shorts", which is a covered stent for reconstructing the abdominal aortic bifurcation. It not only solves the problem of the gap between the traditional main stent and the branch stent, increasing the probability of endoleak, but also sets an appropriate angle (30-45 degrees with the axial direction of the stent body) for the placement of the branch stent according to the anatomical relationship between the abdominal aorta and the common iliac arteries, improving the tightness of the fit between the branch stent of the common iliac artery and the main stent of the abdominal aorta during the reconstruction of the infrarenal abdominal aortic bifurcation, reducing the risk of endoleak and the rate of postoperative reintervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of the stent for reconstructing the abdominal aortic bifurcation of the present utility model.

[0018] Figure 2It is a view from the proximal end perspective of the stent for reconstructing the abdominal aortic bifurcation of the present utility model.

[0019] Figure 3 It is a surgical schematic diagram.

[0020] In the figure, 1. abdominal aorta, 2. stent, 3. left common iliac artery, 4. right common iliac artery, 5. left branch stent, 6. right branch stent; 202. proximal end, 203. opening one, 204. opening two, 205. region. Detailed implementation manners

[0021] The present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0022] Refer to Figure 1 , the stent for reconstructing the abdominal aortic bifurcation adopts an integrated design and is a stent made of a metal mesh and woven with a film material.

[0023] As Figure 1 shown, the proximal end 202 of the stent is a cylindrical shape with an internal cavity, and the distal end of the stent is designed as a "shorts shape" and is provided with 2 openings: opening one 203 and opening two 204, which can be connected to the stents placed in the two common iliac arteries. Figure 1 The 205 shown is the region closed by the metal mesh structure and the film material at the distal end of the stent, which can prevent part of the blood flow that cannot pass through the common iliac artery stents placed through opening one 203 and opening two 204 from flowing out of the stent after the reconstruction of the abdominal aorta.

[0024] Figure 2 is the perspective of observing the stent from the proximal end to the distal end inside the stent. Opening one 203 and opening two 204 can be respectively connected to the two common iliac artery branch stents for reconstructing the main-iliac artery lesions, guiding most of the blood flow into the branch stents. The region 5 closed by the metal mesh structure and the film material at the distal end of the stent ensures that opening one 203 and opening two 204 are the only blood outflow channels at the distal end of the stent for reconstructing the abdominal aortic bifurcation, and can prevent part of the blood flow that does not enter the common iliac artery through opening one 203 or opening two 204 from entering between the stent and the abdominal aorta, reducing the risk of endoleak. It effectively guarantees the blood flow supply of the two common iliac arteries after reconstructing the abdominal aortic bifurcation and solves the problem of easy occurrence of endoleak in traditional straight tube type covered stents.

[0025] Continue to refer to Figure 2 , the region 5 between opening one 3 and opening two 4 is the region closed by the metal mesh structure and the film material at the distal end of the stent. The two ends of the region 5 are wider and the middle part is narrower.

[0026] In this embodiment, to match the angle of bifurcation of the common iliac artery (average 62 degrees), the angle formed by the axial directions of the first opening 203 and the second opening 204 and the axial direction of the stent body is preferably 30 - 45 degrees, conforming to the anatomical relationship and reducing unnecessary stent bending during intraoperative placement of the branched stent.

[0027] Specifically, referring to Figure 1 , the length of the stent is preferably 80 - 110 mm, such as 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, etc., more preferably 90 mm; the inner diameter of the stent is preferably 13 - 18 mm, such as 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, etc.; the inner diameters of the first opening 203 and the second opening 204 of the stent are preferably 7 - 11 mm, such as 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, etc.

[0028] Selection of braided materials and techniques: In this embodiment, the covered stent has a metal mesh structure as the framework, with a covering material braided on the surface.

[0029] The metal mesh structure can be processed in different ways. The metal mesh structure can be formed by cross - braiding metal wires or by laser engraving. The metal wire is preferably nitinol alloy, which has good strength and toughness. The covering material can be processed from various common materials, and PTFE (polytetrafluoroethylene), PTU (polyurethane), PET (polyester) and other common covering materials can be selected.

[0030] In this embodiment, radiopaque marker points are provided at the distal end of the stent to assist in positioning during stent delivery. In some specific embodiments, radiopaque marker points are provided at the distal end of the stent. Preferably, a radiopaque marker point is provided at the center of the distal end of the stent, and a radiopaque marker point is provided at the center of the proximal end of the stent. The radiopaque marker points are preferably platinum marker points. The drawings do not clearly identify this.

[0031] During the specific operation, such as Figure 3As shown in the figure, before the operation, the distance between the renal artery level and the bifurcation level of the abdominal aorta of the patient is analyzed based on the patient's CTA, and a stent described in this patent with an appropriate length is selected. The length of the stent should be slightly shorter than the distance analyzed by the above CTA. During the operation, according to the clinical endovascular interventional treatment operation specifications, using a guide wire and X-ray imaging technology, the stent 2 described in this patent is sent into the abdominal aorta 1 of the patient through the femoral artery approach. The proximal end of the stent is positioned below the renal artery level by tracking the proximal end imaging marker of the stent through X-ray; the distal end imaging marker of the stent is tracked, and the distal end of the stent is positioned above the bifurcation of the abdominal aorta, so that the distal end opening of the stent is aligned with the common iliac arteries on both sides, and then the main body stent is released so that the main body stent can cover the stenotic segment of the abdominal aorta. Through the approach of the left common iliac artery 3, it is confirmed by X-ray that the proximal end of the left branch stent 5 enters the stent 2 through the opening, and the distal end of the left branch stent 5 is located in the left common iliac artery 3, and the left branch stent 5 is released; through the approach of the right common iliac artery 4, it is confirmed by X-ray that the proximal end of the right branch stent 6 enters the stent 2 through the opening, and the distal end of the right branch stent 6 is located in the right common iliac artery, and the right branch stent 6 is released. The branch stent 5 and the branch stent 6 have a partial length overlap with the main body stent to make the branch stent firmly fixed. If necessary, a balloon can be used to expand at the overlapping part of the branch stent and the main body stent to ensure the fixing degree of the stent. The branch stent should be completely fitted with the openings on both sides of the main body stent to ensure that after the reconstruction of the abdominal aortic bifurcation, the lumen formed by the stent 2, the left branch stent 5, and the right branch stent 6 is the only flow path for the blood flow in the abdominal aorta, reducing the risk of endoleak. Since the distal end of the main body stent adopts a "shorts-like" design that conforms to the anatomical relationship, the angle between the openings to the common iliac arteries on both sides and the axis of the main body stent can be selected between 30-45 degrees, so that the branch stent has good conformity with the main body stent and the common iliac arteries after being implanted into the patient's body, and can further reduce the risk of endoleak in the long term; in addition, since the common iliac arteries on both sides cover the stenotic segment of the blood vessel, the successful reconstruction of the stenosis of the main iliac artery blood vessel is ensured, and the ischemia problem of the pelvis and lower limbs is solved.

[0032] The above is the preferred embodiment of the present invention. Those of ordinary skill in the art can also make various transformations or improvements on this basis. Without departing from the general concept of the present invention, these transformations or improvements should all fall within the scope of protection required by the present invention.

Claims

1. A stent for reconstructing the abdominal aortic bifurcation, the stent body is a metal mesh structure and is woven with a membrane material, and is characterized in that: The proximal end (202) of the stent (2) of the stent is a cylindrical shape with a cavity; the distal end of the stent is "shorts-shaped", and is provided with two openings for communicating with the stents that can be inserted into the bilateral common iliac arteries: opening one (203) and opening two (204).

2. The stent for reconstructing the abdominal aortic bifurcation according to claim 1, wherein: The area (205) between the opening one (203) and the opening two (204) is the area where the distal end of the stent is closed by the metal mesh structure and the membrane material.

3. The stent for reconstructing the abdominal aortic bifurcation according to claim 2, wherein: Both ends of the area (205) are wider, and the middle part is narrower.

4. The stent for reconstructing the abdominal aortic bifurcation according to claim 1, wherein: The angle formed by the axial direction of the opening one (203) and the opening two (204) and the axial direction of the stent body is 30-45 degrees.

5. The stent for reconstructing the abdominal aortic bifurcation according to claim 1, wherein: The length of the stent (2) is 80-110 mm, and the inner diameters of the opening one (203) and the opening two (204) are 7-11 mm.

6. The stent for reconstructing the abdominal aortic bifurcation according to claim 5, characterized in that: The length of the stent (2) is 90 mm.

7. The stent for reconstructing the abdominal aortic bifurcation according to claim 1, wherein: The metal mesh structure is formed by cross-weaving metal wires or by laser engraving.

8. The stent for reconstructing the abdominal aortic bifurcation according to claim 7, wherein: The metal wire is nitinol alloy.

9. The stent for reconstructing the abdominal aortic bifurcation according to claim 1, characterized in that: The membrane material is made of one of polytetrafluoroethylene, polyurethane, and polyester.

10. The stent for reconstructing the abdominal aortic bifurcation according to claim 1, wherein: The distal end of the stent is provided with a radiopaque marker point for positioning during the delivery of the stents for the bilateral common iliac arteries; the radiopaque marker point is a platinum marker point.

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