Recoverable stent for guiding branch artery reconstruction

Abstract

The utility model relates to a recoverable stent for guiding branch artery reconstruction. The recoverable stent comprises a navigation tube and a guide sheath of a recoverable simple stent, the navigation pipe comprises a guide catheter, and the head of the guide catheter is connected and communicated with one end of the recycling barrel; an indicating ring of which the outer diameter is larger than that of the recycling barrel body is fixedly arranged at the other end of the recycling barrel body; the indicating ring is made of a radiopaque material or is provided with a radiopaque coating material; a memory metal support which is in a spiral shape after being expanded and reset is arranged in the recycling barrel, a guide wire is arranged in an inner hole of the guide catheter, and the guide wire is connected with the memory metal support and can push the memory metal support out of the recycling barrel and pull the memory metal support back to the recycling barrel. The guiding sheath is of a double-layer rod-shaped structure with a cavity, a sheath head at the head of the guiding sheath is provided with a radiopaque guiding coating, and the annular range is matched with the size of the indicating ring.

Description

Technical Field

[0001] The utility model relates to a recyclable stent for guiding branch artery reconstruction, belonging to the technical field of medical equipment. Background Art

[0002] Aortic aneurysm and aortic dissection are common diseases in vascular surgery, with high mortality and disability rates. Aortic branches include the bilateral renal arteries and the celiac trunk. Endovascular repair is difficult to treat aortic aneurysms and aortic dissections involving branch arteries, with a low technical success rate. The relative position of visceral branch arteries and abdominal aorta is not fixed. The variation and distortion of visceral artery lesions increase the difficulty and technical requirements of surgery. Complications such as endoleak and distal ischemia are prone to occur after surgery.

[0003] At present, in situ fenestration technology has become an important surgical method for arterial branch reconstruction during endovascular aortic repair. The anatomical relationship between the aorta and the branch arteries is clarified through intraoperative angiography. After the main stent is released, the opening is made through the fenestration device (puncture catheter, radiofrequency catheter or laser catheter), and then a suitable branch covered stent is placed to ensure blood perfusion of the aorta and visceral vessels. However, in vitro fenestration is prone to difficulties in positioning the window and the arterial branch opening during surgery. The process of forming the window will damage the normal structure of the stent, making it difficult to ensure the long-term stability of the stent. The existing stents used for in situ fenestration often cannot control the position of the metal skeleton relative to the branch opening, resulting in difficulty in fenestration or local stenosis of the branch stent due to angle compression. In the case of inaccurate positioning, the fenestration device often causes damage to the wall of the branch artery. For example, when aortic lesions involve the area around the opening of the branch arteries, if the branch arteries are twisted and deformed, it is difficult to position the in situ window and there is a risk of damaging the blood vessel wall. The current technology is to pre-insert a stent in the branch artery, and then insert the branch stent again in the previous stent after the in situ window. However, the diameter of branch arteries such as the renal artery is less than 5 cm, and the double-layer stent increases the risk of postoperative restenosis and stent breakage, resulting in an increased risk of long-term distal arterial ischemia. Based on this, the utility model designs a recyclable stent to solve this problem. Utility Model Content

[0004] The purpose of the utility model is to provide a recyclable stent and method for guiding branch artery reconstruction, so as to solve the above technical problems.

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

[0006] A retrievable stent for guiding branch artery reconstruction, comprising a navigation tube and a guide sheath of a retrievable simple stent; the navigation tube comprises a guide catheter 6, the head of which is connected and communicated with one end of a recovery cylinder 1; the other end of the recovery cylinder 1 is fixedly provided with an indicator ring 2 with an outer diameter larger than that of the recovery cylinder 1 itself, the indicator ring 2 is made of a radiopaque material or has a radiopaque coating material thereon; the recovery cylinder 1 is provided with a memory metal stent 3 which is spiral after being expanded and relocated, the inner hole of the guide catheter 6 is provided with a guide wire 5, the guide wire 5 is connected to the memory metal stent 3, and the memory metal stent 3 can be pushed out and pulled back into the recovery cylinder 1; the guide sheath 15 is a double-layer rod-shaped structure with a cavity 10, the sheath head 7 at its head has a radiopaque guidance coating 13, and the annular range is adapted to the size of the indicator ring 2.

[0007] Preferably, the head of the guide sheath 15 has a curved portion 8, and the head of the navigation tube also has a curved portion.

[0008] Preferably, the memory metal stent 3 has a weak supporting force, can change its shape under external force or thermal conditions, and can be released and recovered through the recovery cylinder 1. The surface can be coated with anti-proliferative drugs and / or anticoagulant drugs to make withdrawal easier and avoid damaging the blood vessel wall. During the operation, it is tightly attached to the coated stent 16 to form a circular notch on the latter.

[0009] Preferably, an arc-shaped support frame 4 is provided at the end of the memory metal stent 3. The arc-shaped support frame 4 is made of a harder metal material and is coated with a radiopaque coating material on the surface. When the memory metal stent 3 is fully released to the branch artery, the support frame 4 and the first circle of the memory metal stent 3 form a circle, so that the opening of the branch artery in the X-ray is indicated as a circle.

[0010] Preferably, a laser catheter 12 containing a laser optical fiber runs in the cavity 10 of the guide sheath. After the sheath head 7 successfully locates the opening of the branch artery, the laser catheter 12 can run through the guide wire delivery system and emit a laser at the tip of the sheath head toward the branch artery to burn the coated stent wall, thereby forming a branch stent window.

[0011] A branch stent navigation method for visceral artery reconstruction during arterial stent surgery, using the branch stent navigation device, comprises the following steps:

[0012] S1, DSA angiography reconstructs the anatomical structure of the branch artery and the aorta, and inserts the guide catheter 6 through the radial artery puncture point, and according to the reconstructed image, it is sent along the aorta to the approximate position of the branch artery opening, and angiography is performed again to indicate the branch opening, and the memory metal stent 3 is sent into the recovery cylinder 1 by using the guide wire 5, and the outer wall of the recovery cylinder 1 changes the shape of the stent 3, so that the diameter of the memory metal stent 3 is increased and released to the branch artery, wherein the indicator ring 2 is tangent to the branch artery opening and faces the abdominal aorta;

[0013] S2, release the stent graft 16 in the abdominal aorta, the stent graft 16 and the guide catheter 6 are parallel to the abdominal aorta, and the guide catheter 6 runs outside the stent graft 16. At this time, the ring formed by the indicator ring 2 forms a notch on the stent graft 16. During the operation, an X-ray examination is performed. The indicator ring 2 is opaque and appears as a high-signal circle on the X-ray.

[0014] S3, insert the guide sheath 15 through the femoral artery puncture point, ascend to the abdominal aorta, and the guide sheath 15 runs in the stent graft 16. The curved sheath 8 is adjusted by the extracorporeal guide wire delivery system, and the direction of the sheath head 7 is rotated to change to face the branch artery in the stent graft 16;

[0015] S4. Intraoperative X-ray examination: the indicator circle 2 and the sheath head 7 are opaque high signal shadows, and the indicator sheath head 7 is aligned with the center of the indicator circle 2, indicating successful positioning;

[0016] S5. According to the circular notch of the recovery circle, it can be indicated whether the Z-shaped metal frame of the stent graft is in the opening position. The balloon expansion Z-shaped metal frame is run through the cavity 10, so that the angle of the Z-shaped metal frame avoids the branch artery opening, which is convenient for the subsequent branch artery stent placement. The laser catheter 12 is run in the cavity 10, and the laser optical fiber can reach the branch artery opening in the stent graft along the cavity 10. The extracorporeal laser therapy device connected to the tail of the laser optical fiber is started to accurately burn the opening of the branch artery on the coating of the stent graft 16;

[0017] S6. The guide wire 5 is retracted, the memory metal stent 3 is recovered through the recovery cylinder 1, and the guide catheter 6 is withdrawn from the abdominal aorta.

[0018] The utility model aims to improve the positioning difficulty of branch artery reconstruction technology in percutaneous aortic endovascular stent implantation. The existing technology lacks clear imaging marks to determine the fenestration position, and most branch stents are faced with insufficient anchoring area. The beneficial effects are:

[0019] 1) Improve the accuracy of branch artery positioning in situ fenestration technology to improve the success rate of branch stent implantation and reduce serious complications such as mismatch between branch stent and main stent and endoleak caused by deviation of branch artery opening position after surgery;

[0020] 2) Shorten the operation time, reduce repeated attempts and DSA angiography during branch vessel positioning, reduce the amount of radiation exposure to patients and operators, and reduce the possibility of iatrogenic dissection caused by endothelial damage in patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the navigation tube of the retrievable simple bracket.

[0022] Figure 2 yes Figure 1A partial enlarged view of the recovery cylinder, memory metal bracket, etc.

[0023] Figure 3 is a schematic diagram of the introducer sheath structure.

[0024] Figure 4 yes Figure 1 Schematic diagram of the cross-section of the introducer sheath head.

[0025] Figure 5 This is a schematic diagram of the positions of the guide sheath and the memory metal stent.

[0026] Figure 6 It is a schematic diagram of the recyclable stent for guiding branch artery reconstruction of the utility model when it is working.

[0027] In the figure, 1. recovery cylinder, 2. indicator ring, 3. memory metal stent, 4. support frame, 5. guide wire, 6. guide catheter, 7. sheath head, 8. bending part, 9. extension part, 10. cavity, 11. sheath protective layer, 12. laser catheter, 13. guide coating, 15. guide sheath, 16. coated stent. DETAILED DESCRIPTION

[0028] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] Aiming at the difficult positioning of branch artery reconstruction technology during percutaneous aortic endovascular stent implantation and the long-term isolation of branch artery ischemia during the operation, the utility model designs a recyclable stent and method for guiding branch artery reconstruction.

[0030] Application scenario: During aortic stent graft implantation, it is necessary to locate the opening of the aortic branch arteries and perform in situ fenestration and branch artery reconstruction.

[0031] The retrievable stents for branch artery reconstruction are divided into two main parts: retrievable simple stents ( Figure 1 )'s navigation tube( Figure 3 ), introducer sheath, see Figure 1-6 , the following is an introduction to the structure and function of each component distributed in these two main components:

[0032] Recovery cylinder 1: The guide wire 5 passes through the middle. When the guide wire 5 is withdrawn, the shape of the memory metal 3 can be changed through the special external force or thermal system of the recovery barrel wall, so that the diameter of the memory metal becomes smaller and is recovered into the guide catheter 6 ( Figure 2 from the left side of the recovery cylinder 1 to the right side).

[0033] Indicator ring 2: Contains opaque coating materials, such as platinum, gold, palladium and other metals, which show high signals in intraoperative X-rays, indicating the location of branch arteries and providing weak support to branch arteries, and showing the branch opening as a circle in X-rays. Since opaque materials are soft and not suitable as the main body of the memory stent, the coating material is applied to the surface of the first ring of the memory stent 3.

[0034] Memory metal stent 3: It is a stent made of medical memory metal with weak supporting force. The head end is connected to the guide wire 5 and enters the recovery cylinder 1 under the guidance of the guide wire. According to the characteristics of memory metal, it can be designed to change its shape under external force or thermal conditions, and released and recovered through the recovery cylinder 1. The surface can be coated with anti-proliferative drugs and / or anticoagulant drugs to make withdrawal easier and avoid damaging the blood vessel wall. During the operation, it is tightly attached to the coated stent 16 to form a circular notch on the latter.

[0035] Arc-shaped support frame 4: It is made of harder metal material, such as common support materials such as stainless steel, nickel-titanium alloy, etc., with an opaque coating material coated on the surface. The two ends are two circles with a diameter slightly larger than the metal support frame 3. It can slide on the indicator circle 2 with appropriate resistance. When the support frame 3 is fully released to the branch artery, the support frame 4 and the first circle of the support frame 3 form a circle, so that the opening of the branch artery in the X-ray is indicated as a circle.

[0036] Guide wire 5: runs in the guide catheter cavity 6. When the guide catheter runs, the head end is connected to the memory metal stent 3, which can assist the stent 3 to enter the recovery cylinder 1. After recovery, it is withdrawn through the guide catheter 6, and the tail end is connected to the extracorporeal guide wire delivery system, which can be delivered into the cavity by the guide wire delivery system. In specific applications, according to each person's different vascular distribution and treatment needs, any catheter structure such as single bend tube, double hook, hunter head, special-shaped tube, Simon wire series, pigtail tube, cobra tube, etc. can be selected to meet the needs of different occasions.

[0037] Guide catheter 6: assists in guiding the guide wire 5, retrieves the memory metal stent 3 into the abdominal aorta and positions it at the opening of the branch artery.

[0038] Sheath head 7: The sheath head 7 is a guide sheath 15 with a guiding coating 13 at its tip end, which can be rotated to change direction through the bending portion 8. The sheath head 7 positions the opening of the branch artery through the circular notch formed by the simple stent 3 on the coated stent 16.

[0039] Curved portion 8: This structure is a curved structure with adjustable direction, and the direction can be controlled by the catheter delivery system. Different guide sheaths have different curvature radii to suit the reconstruction of arterial branches in different anatomical conditions of different people.

[0040] Extension part 9: the extension part of the main catheter, the tail end of which is connected to the extracorporeal catheter operation device.

[0041] Cavity 10: The cavity structure in the center of the sheath head can pass any device used for intravascular treatment, such as laser optical fiber, guide wire, branch vessel stent, balloon catheter, thrombus aspiration catheter, drug delivery catheter, etc., so as to perform various operations at the location of the branch vessel according to the operator's needs.

[0042] Sheath protective layer 11 : a protective layer on the inner side of the guiding coating 13 , which reduces the wear of the instrument running in the cavity 11 and the guiding coating 13 .

[0043] Laser catheter 12: contains laser optical fiber. After the sheath head 7 locates the branch artery opening successfully, it can be routed through the guidewire delivery system. The laser is emitted from the sheath head toward the branch artery to burn the coated stent wall, forming a branch stent window.

[0044] The guide coating 13 contains an opaque coating material, which shows a low signal in X-ray and DSA angiography to indicate the shape and position. After the guide sheath is inserted, DSA angiography can be performed again to confirm that the indicator ring 2 and the sheath head 7 are positioned successfully.

[0045] Guide sheath 15: The sheath head 7, the curved portion 8 and the extending portion 9 together constitute the guide sheath 15. There is a cavity 10 inside the guide sheath for guiding guide wires, laser optical fibers and other tools. The tail of the main magnetic catheter is connected to the extracorporeal catheter operating device. In specific applications, according to each person's different blood vessel distribution and treatment needs, any catheter structure such as single curved tube, double hook, hunter head, special-shaped tube, Simon wire series, pigtail tube, cobra tube, etc. can be selected to meet the needs of different occasions.

[0046] The following is combined with Figure 6 , the specific implementation steps are explained in detail with examples:

[0047] S1. DSA angiography is used to reconstruct the anatomical structure of the renal artery and abdominal aorta. The guide catheter 6 is inserted through the radial artery puncture point and sent along the aorta to the approximate position of the renal artery opening according to the reconstructed image. Angiography is performed again to indicate the branch opening. The memory metal stent 3 is sent into the recovery cylinder 1 using the guide wire 5. The special external force / thermal system on the outer wall of the recovery cylinder 1 changes the shape of the stent 3, increases the diameter of the stent 3 and releases it to the branch artery, where the indicator circle 2 is tangent to the renal artery opening and faces the abdominal aorta.

[0048] S2. Release the main covered stent 16 into the abdominal aorta. The covered stent 16 and the guiding catheter 6 are parallel to the abdominal aorta, and 6 runs outside 9. At this time, the ring formed by the indicator ring 2 forms a notch on the covered stent 16. During the operation, an X-ray examination is performed. The indicator ring 2 is opaque and appears as a high-signal circle on the X-ray.

[0049] S3. The guide sheath 15 is inserted through the femoral artery puncture point and ascends to the abdominal aorta. The guide sheath 15 runs in the stent graft 16. The curved sheath 8 is adjusted by the extracorporeal guidewire delivery system, and the direction of the sheath head 7 is rotated to change toward the renal artery in the stent graft 16.

[0050] S4. Intraoperative X-ray examination showed that the indicator circle 2 and the sheath head 7 were opaque high-signal shadows, and the indicator sheath head 7 was aligned with the center of the indicator circle 2, indicating successful positioning.

[0051] S5. According to the circular notch of the recovery circle, it can be indicated whether the Z-shaped metal frame of the stent graft is in the opening position. The balloon expansion Z-shaped metal frame can be run through the cavity 10 to make the angle of the metal frame avoid the branch artery opening, which is convenient for the subsequent branch artery stent placement. The laser catheter 13 is run in the cavity 10, and the laser optical fiber can reach the renal artery opening (inside the stent graft) along the cavity 10. Start the extracorporeal laser therapy device connected to the tail of the laser optical fiber to accurately burn the opening of the renal artery on the stent graft.

[0052] S6, the guide wire 5 is withdrawn, the memory metal stent 3 is recovered through the outer wall system of the recovery cylinder 1, and the guide catheter 6 is withdrawn from the abdominal aorta, and this operation process is completed.

[0053] The utility model improves the accuracy of branch artery positioning in the in situ fenestration technology, so as to improve the success rate of branch stent implantation and reduce serious complications such as mismatch between the branch stent and the main stent and internal leakage caused by the deviation of the branch artery opening position after surgery; shortens the operation time, reduces repeated attempts and DSA angiography in the process of branch blood vessel positioning, reduces the amount of radiation received by the patient and the operator, and reduces the possibility of iatrogenic dissection caused by endothelial damage to the patient's blood vessels.

[0054] The above are preferred embodiments of the present invention. Ordinary technicians in this field can also make their own changes or improvements on this basis. Without departing from the overall concept of the present invention, these changes or improvements should fall within the scope of protection required by the present invention.

Claims

1. A retrievable stent for guiding branch artery reconstruction, characterized in that: Including a navigation tube and guide sheath for retrieving a simple stent; The navigation tube comprises a guide catheter (6), the head of which is connected to and communicated with one end of a recovery cylinder (1); an indicator ring (2) having an outer diameter larger than that of the recovery cylinder (1) is fixedly provided at the other end of the recovery cylinder (1), the indicator ring (2) being made of a radiopaque material or having a radiopaque coating material thereon; a memory metal stent (3) which is in a spiral shape after being expanded and relocated is installed in the recovery cylinder (1), a guide wire (5) is provided in the inner hole of the guide catheter (6), the guide wire (5) being connected to the memory metal stent (3), and the memory metal stent (3) can be pushed out of and pulled back into the recovery cylinder (1); The guide sheath (15) is a double-layer rod-shaped structure with a cavity (10), and the sheath head (7) at the head thereof has a radiopaque annular guiding coating (13), and the annular range is adapted to the size of the indicator ring (2).

2. The retrievable stent for guiding branch artery reconstruction according to claim 1, characterized in that: The head of the guide sheath (15) has a curved portion (8), and the head of the navigation tube also has a curved portion.

3. The retrievable stent for guiding branch artery reconstruction according to claim 1, characterized in that: The end of the memory metal stent (3) is provided with an arc-shaped support frame (4), which is made of a relatively hard metal material and coated with a radiopaque coating material on its surface. When the memory metal stent (3) is completely released to the branch artery, the support frame (4) and the first circle of the memory metal stent (3) form a circle, so that the opening of the branch artery in the X-ray is indicated as a circle.

4. The retrievable stent for guiding branch artery reconstruction according to claim 1, characterized in that: A laser catheter (12) is run in the cavity (10) of the guide sheath. The laser catheter (12) contains a laser optical fiber. After the sheath head (7) successfully locates the opening of the branch artery, the laser catheter (12) can be run through the guide wire delivery system. A laser is emitted from the sheath head end toward the branch artery to burn the coated stent wall, thereby forming a branch stent window.

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