Vascular sheath structure with variable diameter

Abstract

The invention relates to a diameter-variable blood vessel sheath structure, which solves a series of problems of large operative wound, incapability of intraoperative radiography and the like in the process of treating arterial embolism of lower limbs through open thrombus extraction of a traditional Fogarty catheter. The device comprises an outer sheath, an inner sheath and a sheath core which are sequentially nested from outside to inside, the outer sheath comprises an outer sheath main body and an outer sheath base arranged at the near end of the outer sheath main body; the inner sheath comprises an inner sheath body, an inner sheath base is arranged at the near end of the inner sheath body and connected with a hemostasis valve, the far end of the inner sheath body is connected with a self-expansion covered stent sample structure with two open ends, and the length of the inner sheath is larger than that of the outer sheath. The sheath core comprises a sheath core body, a sheath core base is arranged at the near end of the sheath core body, a conical end with the outer diameter gradually reduced is arranged at the far end of the sheath core body, a middle hole for a guide wire to penetrate through is formed in the sheath core body, and the length of the sheath core is larger than that of the inner sheath. The device has the advantages of high effectiveness, high safety, strong adaptability, good adaptability, simple structure and convenience in operation.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a device for treating vascular embolism, and in particular to a vascular sheath structure with a variable diameter. Background Art

[0002] Acute lower limb arterial embolism is a serious lower limb arterial ischemic disease in clinical practice, with an annual incidence of about 1.5 cases / 10,000 people. Middle-aged and elderly patients are the main affected population of this disease. The cause of acute lower limb arterial embolism is mostly due to blood clots that fall off from the inner wall of the heart or aorta and block the distal lower limb artery with blood flow, resulting in interruption of blood flow in the lower limb artery. In a short period of time, it can lead to lower limb ischemic necrosis. In severe cases, it can cause systemic infection, sepsis, amputation and even death. The disease develops rapidly, and timely, complete and thorough removal of the embolus and restoration of forward blood flow are the key to saving ischemic tissue.

[0003] At present, the treatment of acute lower extremity arterial embolism is still a difficult problem in vascular surgery. The main existing treatment measures include: Solution 1: 1) Technical solution: Open thrombectomy with Fogarty catheter: After anesthesia, a 10 cm skin incision is made in the groin to expose the femoral artery, block the blood flow in the femoral artery under direct vision, and insert a Fogarty catheter with an inflatable balloon to reach the thrombus after the femoral artery is cut open. After inflation, the thrombus is removed to restore vascular patency. This technology is suitable for the treatment of acute lower limb arterial embolism, especially those caused by cardiogenic emboli. The operation must be performed under general anesthesia.

[0004] 2) Disadvantages: ① Patients need general anesthesia, which carries anesthesia risks, especially for elderly patients; ② A 10-cm incision is required in the groin, which is quite traumatic and carries the risk of surgical infection, poor wound healing, fat liquefaction, and lymphatic leakage; ③ During the operation, the femoral artery blood flow is blocked, which leads to a. easy induction of new thrombus; b. simultaneous angiography cannot be performed to assess whether the thrombus has been completely removed; ④ It is impossible to continue interventional procedures such as balloon dilatation and stent implantation at the same time. If further intervention is required to treat the diseased blood vessels, the femoral artery incision needs to be sutured first, the vascular sheath needs to be reinserted, and then the interventional procedure can be continued through the vascular sheath.

[0005] ⑤ Once residual thrombus is found during angiography after vascular suture, further treatment is required. The femoral artery needs to be blocked again and opened, and a thrombectomy catheter needs to be inserted. The operation must be repeated, and the process is cumbersome and complicated.

[0006] ⑥ New stenosis may occur after the incised blood vessel is sutured.

[0007] Option 2: 1) Technical solution: Catheter thrombolysis: Catheter thrombolysis refers to the percutaneous puncture of a thrombolytic catheter into the target blood vessel under the guidance of DSA or ultrasound, and the thrombolytic drug is directly infused into the thrombus site through the thrombolytic catheter to dissolve the formed thrombus and restore the patency of the blood vessel. The infusion time of thrombolytic drugs is usually more than 12 hours.

[0008] 2) Disadvantages: ① Catheter-directed thrombolysis can only dissolve fresh thrombi that arise on the basis of old thrombi, while thrombi that detach from the heart are often old thrombi that are difficult to dissolve.

[0009] ② Catheter-directed thrombolysis takes time to dissolve the thrombus and is slow to take effect. However, patients with acute arterial embolism are at risk of limb necrosis due to prolonged ischemia.

[0010] ③Catheter thrombolysis will take a long time to restore arterial blood flow (low-pressure perfusion), causing perfusion injury.

[0011] ④ Bleeding is the most common complication of catheter-directed thrombolysis, among which the most serious complication is intracranial hemorrhage.

[0012] ⑤Risk of infection and catheter displacement due to long-term catheterization.

[0013] Option 3: 1) Technical solution: Mechanical embolic aspiration catheter aspirates the blood clot, commonly used ones include AngioJet, Rotarex (Straub) embolic aspiration catheter. The surgical procedure is to implant the embolic aspiration catheter into the artery through percutaneous puncture, and then place the embolic aspiration catheter into the thrombus to aspirate the blood clot.

[0014] 2) Disadvantages: ① It is difficult to completely remove the thrombus by catheter aspiration. Regardless of the type of thrombus aspiration catheter, there is a certain thrombus removal rate, and it is difficult to completely remove the thrombus, especially for old thrombi of cardiac origin, the removal efficiency is lower.

[0015] ② During the process of clearing thrombus, small emboli may appear and block distal arterioles along the direction of blood flow.

[0016] ③ Because the diameter of the calf artery below the knee is small, the above-mentioned mechanical embolic aspiration catheter device is difficult to use in embolism involving the calf artery below the knee.

[0017] ④ Mechanical embolus removal catheter equipment is expensive.

[0018] Since middle-aged and elderly patients are the main affected population of this disease, they often have multiple underlying diseases. At the same time, due to age-related vascular degeneration, atherosclerosis, etc., vascular fragility increases, and different treatment methods may have differences in effectiveness and safety. Among them, dissecting and exposing the patient's femoral artery under general anesthesia, and then using Fogarty catheter thrombectomy is the mainstream classic procedure for the treatment of acute lower extremity arterial embolism. At the beginning of the operation, locate the bifurcation of the patient's femoral artery, make an incision of about 10cm on the surface of the skin, separate and expose the femoral artery layer by layer, then block the blood flow of the femoral artery, and insert the Fogarty thrombectomy catheter after cutting the femoral artery, and deliver it to the distal end of the embolized artery under fluoroscopy. At this time, inflate the distal balloon of the Fogarty thrombectomy catheter, pull back the balloon in the inflated state, and the balloon can remove the thrombus from the cut femoral artery. The incision and thrombectomy with Fogarty thrombectomy catheter is the main treatment for lower extremity arterial embolism today, but there are still many disadvantages. 1) The incision and thrombectomy with Fogarty thrombectomy catheter requires a long time to completely block the blood flow of the proximal lower extremity artery, and there is a possibility of inducing new fresh thrombus during the incision and thrombectomy; 2) The incision and thrombectomy with Fogarty thrombectomy catheter requires a complete blockage of the blood flow of the proximal lower extremity artery during the operation, so it is impossible to use angiography at the same time to check whether the thrombus has been removed, and if vascular damage occurs during the thrombectomy, it is impossible to use balloon dilatation, stent implantation and other interventional surgery methods for further treatment at the same time. 3) When angiography is required, the Fogarty thrombectomy catheter needs to be completely withdrawn, the femoral artery incision is sutured, and the vascular sheath is inserted before angiography. If the angiography is not satisfactory and the thrombus needs to be removed again, the sutured femoral artery incision needs to be opened again and the Fogarty thrombectomy catheter needs to be reinserted. The process is cumbersome, the operation is complicated, and it may induce new blood clots, resulting in more and more blood clots. 4) Open thrombectomy requires general anesthesia. The operation is traumatic, and the anesthesia and surgical risks are very high for patients with atrial fibrillation and the elderly. Summary of the invention

[0019] The purpose of the present invention is to solve a series of problems in the traditional Fogarty catheter open thrombectomy for the treatment of lower limb arterial embolism, such as large surgical trauma, high risk, and inability to perform intraoperative angiography. The present invention provides a vascular sheath structure with a variable diameter, which can be implanted into an artery through percutaneous puncture under local anesthesia to reduce surgical trauma, and can be used in conjunction with the Fogarty catheter to perform thrombectomy through the restraint and release of the inner sheath by the outer sheath during the expansion and contraction of the inner sheath, and can be directly angiographically and subsequently intervened after thrombectomy, without the need to suture the blood vessels or replace the access equipment.

[0020] The technical solution adopted by the present invention to solve its technical problems is: a variable diameter vascular sheath structure, characterized in that: an outer sheath, an inner sheath, and a sheath core are nested in sequence from the outside to the inside; the outer sheath is a hollow hose with openings at both ends, the outer sheath includes an outer sheath body and an outer sheath base arranged at the proximal end of the outer sheath body; the inner sheath is a hollow hose with openings at both ends, the inner sheath includes an inner sheath body, an inner sheath base is arranged at the proximal end of the inner sheath body, a self-expanding stent with openings at both ends is connected to the distal end of the inner sheath body, and the length of the inner sheath is greater than that of the outer sheath; the sheath core is a flexible hose, the sheath core includes a sheath core body, a sheath core base is arranged at the proximal end of the sheath core body, the distal end of the sheath core body has a tapered end with a gradually decreasing outer diameter, a middle hole for passing a guide wire is arranged inside the sheath core body, and the length of the sheath core is greater than the length of the inner sheath.

[0021] In the original structure of the Fogarty catheter thrombectomy, after the guidewire passes through the thrombus position, the Fogarty catheter is inserted along the guidewire. The Fogarty catheter is equipped with an inflatable balloon at the distal end of the thrombus position, and the thrombus is removed by the balloon. In the original Fogarty catheter thrombectomy, an open surgery was used, so the patient needed to undergo surgery under general anesthesia. For elderly patients with poor general conditions, anesthesia cannot be tolerated, and the risk of anesthesia itself is very high. Angiography is required to verify the effect of open thrombectomy. The Fogarty thrombectomy catheter needs to be completely withdrawn, and the femoral artery incision is sutured and the vascular sheath is inserted before angiography. If the angiography is not satisfactory and the thrombus needs to be removed again, the sutured femoral artery incision needs to be opened again and the Fogarty thrombectomy catheter needs to be reinserted. The process is cumbersome, the operation is complicated, the operation time is prolonged, and repeated operations may be required, which is a great test for both patients and doctors. This device can be used in conjunction with the existing Fogarty guidewire balloon to perform minimally invasive thrombectomy. Compared with traditional open surgery, it does not require general anesthesia, is safer, and can perform real-time angiography during the operation. There is no need for repeated suturing and incision, which greatly simplifies the surgical process and effectively shortens the operation time.

[0022] Preferably, the self-expanding stent is a mesh structure.

[0023] Preferably, the self-expanding stent is a self-expanding coated stent, and both inner and outer walls of the self-expanding stent are provided with an elastic coating layer to prevent scratching of the blood vessel wall.

[0024] Preferably, the connection position between the self-expanding stent and the inner sheath body is tapered.

[0025] Preferably, when the inner sheath base abuts against the end surface of the outer sheath base, the self-expanding stent completely extends out of the end of the outer sheath body.

[0026] Preferably, the proximal end of the inner sheath base is detachably connected to a hemostatic valve, and the hemostatic valve is connected to a three-way valve via an extension tube.

[0027] Preferably, the three-way valve has three openings, and except for the opening connected to the extension tube, the other two openings are provided with protective caps.

[0028] Preferably, the outer diameter of the outer sheath body is 5F-18F, and the length is 20-110cm; the outer diameter of the inner sheath body is 4F-16F (F is Fr, French is the unit of sheath size, 1F is approximately equal to 1 / 3mm), and the length is 30-120cm; the length of the sheath core body is 40-140cm.

[0029] Preferably, the self-expanding stent is firmly connected to the distal end of the inner sheath body, and the diameter of the self-expanding stent after expansion is 3mm-12mm and the length is 4mm-20mm.

[0030] The present invention has the following beneficial effects: (1) High effectiveness. The front end of the self-expanding stent adheres well to the blood vessel wall when expanded. When used in conjunction with the Fogarty thrombectomy catheter, it can completely collect the captured thrombus, effectively avoiding the possibility of thrombus or plaque falling off when the thrombectomy balloon is withdrawn, thereby improving the efficiency of thrombus capture.

[0031] (2) High safety. The percutaneous implantation of the vascular sheath can be performed under local anesthesia. It is less traumatic, has a quick recovery, and has fewer postoperative complications. After the thrombectomy balloon removes the thrombus, it is withdrawn from the blood vessel through the channel formed by the self-expanding stent and the inner sheath, reducing the damage to the vascular endothelium caused by withdrawal. When there are vascular lesions that require simultaneous balloon dilatation or stent implantation, the operation can continue through the vascular sheath, reducing the number of operation steps.

[0032] (3) Strong adaptability and good adaptability. By adjusting the expansion degree of the self-expanding stent, it can adapt to blood vessels of various sizes, and the narrowed section of the blood vessel can be guaranteed to pass smoothly, ensuring the smooth progress of the thrombectomy operation.

[0033] (4) Simple structure and easy operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below in conjunction with the accompanying drawings.

[0035] Figure 1 It is a schematic diagram of the structure of the present invention in a non-working state.

[0036] Figure 2 It is a schematic diagram of the working state structure of the present invention.

[0037] Figure 3 This is a schematic diagram of a split structure of the present invention. Figure 4 It is a schematic diagram of the vascular sheath placement process of the present invention.

[0038] Figure 5It is a schematic diagram of the vascular sheath thrombectomy process of the present invention.

[0039] In the figure: 1: outer sheath body; 2: inner sheath body; 3: sheath core body; 4: hemostatic valve; 5: extension tube; 6: three-way connecting valve; 7: protective cap; 8: outer sheath base; 9: inner sheath base; 10: sheath core base; 11: self-expanding stent, 12: outer sheath; 13: hemostatic device; 14: inner sheath; 15: sheath core. DETAILED DESCRIPTION

[0040] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0041] Embodiment: A vascular sheath structure with a variable diameter, such as Figure 1 , 2 , 3. The device is nested with an outer sheath 12, an inner sheath 14, and a sheath core 15 from the outside to the inside in sequence; the outer sheath 12 is a hollow hose with openings at both ends, and the outer sheath includes an outer sheath body and an outer sheath base 8 arranged at the proximal end of the outer sheath body 1. The inner sheath 14 is a hollow hose with openings at both ends, and the inner sheath 14 includes an inner sheath body 2, and an inner sheath base 9 is arranged at the proximal end of the inner sheath body. The distal end of the inner sheath body is connected to a self-expanding stent 11 with openings at both ends, and the length of the inner sheath body 2 is greater than that of the outer sheath body 1. When the inner sheath base 9 abuts against the end face of the outer sheath base 8, the self-expanding stent 11 completely extends out of the end of the outer sheath body. The sheath core 15 is a flexible hose, and the sheath core 15 includes a sheath core body 3, and a sheath core base 10 is arranged at the proximal end of the sheath core body 3. The distal end of the sheath core body has a tapered end with a gradually reduced outer diameter. The sheath core body is provided with a middle hole for passing a guide wire, and the length of the sheath core is greater than that of the inner sheath, and an inflatable balloon is arranged at the front end of the guide wire. The proximal end of the inner sheath base 9 is detachably connected with a hemostatic device 13. Figure 3 As shown, the hemostatic device 13 includes a hemostatic valve 4, which is connected to a three-way valve 6 via an extension tube 5. The three-way valve 6 has three openings, and except for the opening connected to the extension tube, the other two openings are provided with protective caps 7.

[0042] The self-expanding stent 11 is a mesh structure, and the self-expanding stent 11 is a self-expanding coated stent, and the inner and outer walls of the self-expanding stent 11 are provided with an elastic coating layer to prevent scratching of the blood vessel wall. The self-expanding stent 11 is firmly connected to the distal end of the inner sheath body 2, and the connection position between the self-expanding stent 11 and the inner sheath body 2 is tapered.

[0043] The outer diameter of the outer sheath body is 5F-18F, and the length is 20-110cm; the outer diameter of the inner sheath body is 4F-16F, and the length is 30-120cm; the length of the sheath core body is 40-140cm. After the self-expanding stent is expanded, the diameter is 3mm-12mm, and the length is 4mm-20mm.

[0044] The variable diameter vascular sheath of this device combined with Fogarty balloon minimally invasive thrombectomy is placed in the blood vessel. Figure 4 As shown: S11: First, insert the guide wire to the distal end of the thrombus through the vascular puncture point along the direction of the blood vessel; S12: The outer sheath, inner sheath, and sheath core are pushed to the proximal end of the thrombus along the guide wire; S13: The sheath core is withdrawn, and the outer sheath and inner sheath are placed in appropriate positions along the guide wire; S14: Keep the position of the inner sheath fixed, withdraw the outer sheath, so that the inner sheath self-expanding stent is partially or completely not covered by the outer sheath, and self-expand and fit the blood vessel wall. In this process, if it is judged that the position of the inner sheath is incorrect, the outer sheath can be pushed forward to cover the inner sheath self-expanding stent, and the inner sheath self-expanding stent is compressed into the outer sheath, and then the position of the inner sheath and the outer sheath is adjusted; S15: The Fogarty thrombectomy balloon is pushed to the distal end of the thrombus along the guide wire through the hollow channel inside the inner sheath; S16: The Fogarty thrombectomy balloon is expanded to fit the blood vessel wall. At this time, the thrombus is located in the middle of the inner sheath self-expanding stent and the Fogarty thrombectomy balloon.

[0045] This device uses the variable diameter vascular sheath of the Fogarty balloon to remove the thrombus. Figure 5 As shown: S21: The thrombus is located in the middle of the inner sheath self-expanding stent and the Fogarty thrombectomy balloon; S22: withdraw the Fogarty thrombectomy balloon and pull the thrombus into the inner sheath self-expanding stent; S23: continue to withdraw and adjust the size of the Fogarty thrombectomy balloon to withdraw the Fogarty thrombectomy balloon and the thrombus into the inner sheath body; S24: continue to withdraw the Fogarty thrombectomy balloon; S25: separate the connection between the inner sheath base and the hemostatic valve, and remove the thrombus and the Fogarty thrombectomy balloon through the proximal end of the inner sheath body; S26: push the outer sheath forward to partially cover the inner sheath self-expanding stent, restore forward blood flow, and inject contrast agent for angiography to observe whether there is residual thrombus and other vascular lesions (dissection, stenosis, etc.). The thrombectomy process can be repeated to ensure that all thrombi are removed. When subsequent interventional operations such as stent implantation are required, the vascular sheath can continue to be used for subsequent interventional operations.

Claims

1. A vascular sheath structure with a variable diameter, characterized in that: The outer sheath, inner sheath and sheath core are nested in sequence from the outside to the inside; the outer sheath is a hollow hose with openings at both ends, the outer sheath includes an outer sheath body and an outer sheath base arranged at the proximal end of the outer sheath body; the inner sheath is a hollow hose with openings at both ends, the inner sheath includes an inner sheath body, the proximal end of the inner sheath body is provided with an inner sheath base, the distal end of the inner sheath body is connected with a self-expanding stent with openings at both ends, and the length of the inner sheath is greater than that of the outer sheath; the sheath core is a flexible hose, the sheath core includes a sheath core body, the proximal end of the sheath core body is provided with a sheath core base, the distal end of the sheath core body has a tapered end with a gradually decreasing outer diameter, a middle hole for passing a guide wire is arranged inside the sheath core body, the length of the sheath core is greater than the length of the inner sheath, and an inflatable balloon is arranged at the front end of the guide wire.

2. A variable diameter vascular sheath structure according to claim 1, characterized in that: The self-expanding stent is a mesh structure.

3. The variable diameter vascular sheath structure according to claim 1, characterized in that: The self-expanding stent is a self-expanding coated stent, and both the inner and outer walls of the self-expanding stent are provided with an elastic coating layer to prevent the blood vessel wall from being scratched.

4. The variable diameter vascular sheath structure according to claim 1, characterized in that: The connection position between the self-expanding stent and the inner sheath body is tapered.

5. The variable diameter vascular sheath structure according to claim 1, characterized in that: When the inner sheath base abuts against the end surface of the outer sheath base, the self-expanding stent completely extends out of the end of the outer sheath body.

6. The variable diameter vascular sheath structure according to claim 1, characterized in that: The proximal end of the inner sheath base is detachably connected with a hemostatic valve, and the hemostatic valve is connected with a three-way valve through an extension tube.

7. The variable diameter vascular sheath structure according to claim 1, characterized in that: The three-way valve has three openings. Except for the opening connected to the extension tube, the other two openings are provided with protective caps.

8. The variable diameter vascular sheath structure according to claim 1, characterized in that: The outer diameter of the outer sheath body is 5F-18F, and the length is 20-110cm; the outer diameter of the inner sheath body is 4F-16F, and the length is 30-120cm; the length of the sheath core body is 40-140cm.

9. The variable diameter vascular sheath structure according to claim 8, characterized in that: The self-expanding stent is firmly connected to the distal end of the inner sheath body. After the self-expanding stent is expanded, the diameter is 3mm-12mm and the length is 4mm-20mm.

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