A coronary artery unloaded stent retrieval catheter

Abstract

A coronary stent recovery catheter belongs to the field of medical devices, and discloses a catheter for recovering a coronary stent after it is unloaded, including a recovery tube and a connecting tube, one end of the recovery tube and the connecting tube are fixedly connected, and the other end of the recovery tube is a head end, which is arranged as a bell mouth, and the small end of the bell mouth is integrally connected with the recovery tube, and a fold from the edge to the center is arranged on the bell mouth, so that the bell mouth can be folded and contracted along the fold; the other end of the connecting tube is connected to a handle. The present invention has a simple structure and a novel concept, and can effectively wrap the unloaded stent to pull it back into the guiding catheter, has a high success rate, has low requirements on the operator, and can prevent the stent steel beam from scratching and damaging the inner wall of the head end of the guiding catheter.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a catheter for recovering a coronary stent after it has been unloaded. Background Art

[0002] Percutaneous coronary intervention (PCI) is a treatment method that uses cardiac catheterization technology to clear the narrowed or even blocked coronary artery lumen, thereby improving myocardial blood perfusion. In order to prevent the coronary artery lumen from narrowing again, a stent is placed in the coronary artery lumen. Therefore, the interventional treatment for coronary heart disease is intracoronary stent implantation, which is currently an important means of treating coronary heart disease.

[0003] However, stents implanted in coronary arteries sometimes shift, i.e., stent unloading. The internationally reported stent unloading rate is 0.5%. The reasons for unloading are: ① When passing through tortuous and severely calcified lesions, the stent is pushed too hard, and the stent gets stuck in the lesion and falls off the balloon; ② The coaxiality between the guiding catheter and the coronary artery ostium is not good, and the proximal edge of the stent scrapes the tip of the guiding tube and partially or completely falls off the balloon; ③ The balloon and the stent are not tightly bonded, and the resistance encountered during the pushing process is slightly greater, and the stent is unloaded from the balloon. Once it happens, it often leads to difficulties in recovery, and even requires surgical removal. In severe cases, it causes complications such as damage to the vascular wall, intravascular thrombosis, and even death of the patient.

[0004] There are two types of stent unloading, partial unloading and complete unloading. Partial unloading means that when the stent is retracted into the guiding catheter, the tail end of the stent is deformed and the steel beam of the stent is wrinkled, making it impossible to retract it into the guiding catheter, but most of the stent is not separated from the balloon; complete unloading is usually caused by partial unloading of the stent, which is caused by the operator forcibly withdrawing the stent. There are many ways to deal with stent unloading: ① Balloon retraction method, a small balloon is sent along the original guide wire, and the balloon is pulled back after the distal end of the stent is expanded. This is theoretically feasible, but the success rate is low, and sometimes it will cause more serious deformation of the stent; ② Double guide wire winding method, a guide wire is sent outside the stent wall, and two guide wires are rotated outside the body to entangle them, which is usually unsuccessful; ③ Balloon release method, an appropriate balloon is sent along the original guide wire to release the stent in situ, and then expand it when necessary. Although this method is convenient, it actually releases the stent in a position where the stent was not originally needed, which increases the number of stent implants in the patient, and a new stent needs to be inserted into the distal target position through this stent. The stent is When passing through the stent, new problems may arise, such as scratches on the stent and difficulty in passing; ④ Balloon extrusion method, a guide wire and balloon are inserted outside the stent wall to squeeze the original unloaded stent on the blood vessel wall, increasing the number of stents to be implanted, and there are three layers of stent steel beams on the blood vessel wall; ⑤ Snare fishing method, a snare is inserted along the original guide wire, the unloaded stent is pulled back into the guide catheter, and the success rate is not high; ⑥ Guiding catheter aspiration method, the guiding catheter is deeply inserted to aspirate the unloaded stent, and the guiding catheter is deeply inserted into the coronary artery, which may damage the blood vessel wall; ⑦ Bidirectional catheter connection method, a new puncture site is added, and another guiding catheter is inserted into the blood vessel. The steps are cumbersome and require high requirements for the operator. For completely unloaded stents, the above methods either increase unnecessary stent implantation or use a snare to remove them. The operation time is long and the requirements for the operator are relatively high. For partially unloaded stents, the current method commonly used is to pull them back to the brachial artery or radial artery, and then surgically cut the blood vessel, remove the stent and suture the blood vessel, which brings additional pain and burden to patients. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a coronary stent retrieval catheter.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0007] A coronary unloaded stent recovery catheter comprises a recovery tube and a connecting tube, wherein one end of the recovery tube and the connecting tube are fixedly connected, and the other end of the recovery tube is a head end, which is arranged as a bell mouth, and the small mouth end of the bell mouth is integrally connected to the recovery tube, and a fold from the edge to the center is arranged on the bell mouth, so that the bell mouth can be folded and contracted along the fold; the other end of the connecting tube is connected to a handle.

[0008] In the present invention, the bell mouth at the head end has three or four symmetrical folds.

[0009] In the present invention, the length of the recovery tube is 24 cm, the length of the head end is 1 cm, the outer diameter of the recovery tube is 1.68 mm, the inner diameter is 1.45 mm, the wall thickness is 115 μm, and the length of the connecting tube is 120 cm.

[0010] Furthermore, the edge of the bell mouth at the head end is soft, and its wall thickness is smaller than that of the recovery pipe, which is 50-100 μm. The outer diameter of the bell mouth after opening is 3 mm.

[0011] In the present invention, the recovery pipe adopts a three-layer composite pipe body structure of a polyethylene plastic outer layer, a steel wire braided middle layer, and a polytetrafluoroethylene (PTFE) inner coating.

[0012] In the present invention, the coronary unloaded stent recovery catheter is used in PCI surgery and passes through the guiding catheter. The inner diameter of the existing 6F guiding catheter is 1.78mm, and the gap between the recovery tube and the guiding catheter is 50μm, so that the recovery tube can move forward and backward or rotate in the guiding catheter under the push of the connecting tube. The head end is a foldable trumpet, which is naturally opened before being sent into the guiding catheter. After being sent into the guiding catheter, it is constrained by the guiding catheter and is in a contracted state. After the head end extends out of the guiding catheter, it is naturally opened again. Since there is a larger lumen space in the open state, the unloaded stent can be wrapped when the recovery catheter is sent forward. The recovery catheter and the stent rod are pulled back, and the unloaded stent will be pulled back together synchronously. Since the deformed stent steel beam is wrapped with a catheter outside, the friction between it and the guiding catheter can be reduced, and it is convenient to recover it into the guiding catheter. After being recovered into the guiding catheter, the head end of the recovery catheter is located between the stent and the guiding catheter, flattening the deformed stent steel beam, and avoiding the deformation of the stent steel beam and the guide catheter. Scratching.

[0013] In the present invention, the unique capture structure of the coronary unloaded stent retrieval catheter makes it widely used in the capture and cleaning of foreign bodies in blood vessels, such as thrombus, which can be captured through the trumpet mouth at the head end and then drawn out through the recovery tube to achieve the therapeutic purpose of extracting thrombus, and sometimes it can also facilitate the next step of stent implantation surgery.

[0014] Compared with the prior art, the present invention has a simple structure and a novel concept. It can effectively wrap the unloaded stent to pull it back into the guiding catheter, with a high success rate. It can wrap around the outside of the stent to separate the stent from the guiding catheter, preventing the stent steel beam from scratching and damaging the head end and inner wall of the guiding catheter. The surgical procedure is simple, with low difficulty and low requirements for the operator. The operation can be repeated if a single failure occurs, and repeated operations have no effect on the patient, effectively improving the success rate of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention;

[0016] Figure 2 is a side view of the head end of the present invention;

[0017] Figure 3 A side view of the head end of another embodiment of the present invention;

[0018] Figure 4 A side view of the head end of a third embodiment of the present invention;

[0019] Figure 5 It is a side view of the head end of the fourth embodiment of the present invention.

[0020] In the figure: recovery tube 1, connecting tube 2, head end 3, handle 4, fold 5. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0022] Embodiment 1:

[0023] See also Figure 1 and 2 The coronary unloaded stent retrieval catheter shown includes a retrieval tube 1 and a connecting tube 2. One end of the retrieval tube 1 and the connecting tube 2 are fixedly connected. The other end of the retrieval tube 1 is a head end 3. The head end is arranged as a bell mouth. The small mouth end of the bell mouth is integrally connected to the retrieval tube 1. Two folds 5 are arranged on the bell mouth from the edge to the center, so that the bell mouth can be folded and contracted along the folds 5. The other end of the connecting tube 2 is connected to a handle 4.

[0024] Embodiment 2:

[0025] See also Figure 1 and 3 The coronary unloaded stent retrieval catheter shown includes a retrieval tube 1 and a connecting tube 2. One end of the retrieval tube 1 and the connecting tube 2 are fixedly connected. The other end of the retrieval tube 1 is a head end 3. The head end is arranged as a bell mouth. The small mouth end of the bell mouth is integrally connected to the retrieval tube 1. Three folds 5 are arranged on the bell mouth from the edge to the center, so that the bell mouth can be folded and contracted along the folds 5. The other end of the connecting tube 2 is connected to a handle 4.

[0026] Embodiment three:

[0027] See also Figure 1 and 4 The coronary unloaded stent retrieval catheter shown includes a retrieval tube 1 and a connecting tube 2. One end of the retrieval tube 1 and the connecting tube 2 are fixedly connected, and the other end of the retrieval tube 1 is a head end 3. The head end is arranged as a bell mouth, and the small mouth end of the bell mouth is integrally connected to the retrieval tube 1. Four folds 5 from the edge to the center are arranged on the bell mouth, so that the bell mouth can be folded and contracted along the folds 5; the other end of the connecting tube 2 is connected to a handle 4.

[0028] Embodiment 4:

[0029] See also Figure 1 and 5 The coronary unloaded stent retrieval catheter shown includes a retrieval tube 1 and a connecting tube 2. One end of the retrieval tube 1 and the connecting tube 2 are fixedly connected, and the other end of the retrieval tube 1 is a head end 3. The head end is arranged as a bell mouth, and the small mouth end of the bell mouth is integrally connected to the retrieval tube 1. Five folds 5 are arranged on the bell mouth from the edge to the center, so that the bell mouth can be folded and contracted along the folds 5; the other end of the connecting tube 2 is connected to a handle 4.

[0030] By comprehensively comparing the above embodiments, it is appropriate to have three or four folds on the bell-mouth at the head end. When the folds are less than three, the opened bell-mouth is difficult to maintain a larger lumen, making it difficult to capture and wrap the unloaded stent. When the folds are more than four, the opened bell-mouth can maintain a larger lumen, but the contraction effect is not good when folded, and the processing cost is higher.

[0031] In the present invention, the length of the recovery tube 1 is 24 cm, the length of the head end 3 is 1 cm, the outer diameter of the recovery tube 1 is 1.68 mm, the inner diameter is 1.45 mm, the wall thickness is 115 μm, the edge of the bell mouth at the head end is soft, and its wall thickness is smaller than that of the recovery tube, which is 50-100 μm. The outer diameter after opening is 3 mm, and the connecting tube is 120 cm long.

[0032] In the present invention, the recovery pipe adopts a three-layer composite pipe body structure of a polyethylene plastic outer layer, a steel wire braided middle layer, and a polytetrafluoroethylene inner coating layer.

[0033] When the present invention is applied to recover the unloaded coronary stent during PCI surgery, the head end 3 is first folded and contracted along the crease 5, the recovery tube 1 is sent into the guiding catheter and pushed forward so that the head end 3 extends from the front end of the guiding catheter. After the head end 3 is naturally opened, it is continuously pushed so that the head end 3 is wrapped around the unloaded stent, and then the recovery tube 1 is pulled back, and the head end 3 is naturally contracted. At this time, the head end 3 interacts with the stent steel beam, and the head end 3 carries the stent back into the recovery tube 1. At this time, the head end 3 is located between the stent and the guiding catheter, flattening the deformed stent steel beam, thereby avoiding the deformation of the stent steel beam and the guiding catheter. Then the recovery tube 1 is pulled back to pull the stent out of the guiding catheter, thereby completing the recovery of the unloaded stent.

[0034] The present invention was applied in clinical trials. For example, a certain hospital performed a total of 2,470 PCI coronary stent implantation operations within two years. During the operations, the stent was dislocated 11 times. The coronary stent retrieval catheter of the present invention was used to capture and retrieve the stent successfully 10 times. One failure was successfully removed by cutting the blood vessel, and the success rate reached 90.9%.

[0035] In summary, combined with the above-mentioned structure of the coronary unloaded stent retrieval catheter and its working process, it can be found that the present invention has a simple structure, novel concept, can effectively wrap the unloaded stent to pull it back into the guide catheter, and has a high success rate; it can wrap around the outside of the stent to separate the stent and the guide catheter to prevent the stent steel beam from scratching and damaging the inner wall of the guide catheter; the surgical procedure is simple, low in difficulty, and does not require high standards from the operator. The operation can be repeated if a single failure occurs, and repeated operations have no effect on the patient, effectively improving the success rate of the operation.

Claims

1. A coronary stent retrieval catheter, characterized in that: It comprises a recovery pipe and a connecting pipe, one end of the recovery pipe and the connecting pipe are fixedly connected, the other end of the recovery pipe is a head end, the head end is arranged as a bell mouth, the small mouth end of the bell mouth is connected with the recovery pipe in an integral manner, and a fold from the edge to the center is arranged on the bell mouth, so that the bell mouth can be folded and contracted along the fold; the other end of the connecting pipe is connected to a handle; the folds of the bell mouth at the head end are symmetrically three or four; the edge of the bell mouth at the head end is soft, and its wall thickness is smaller than that of the recovery pipe; the recovery pipe adopts a three-layer composite pipe body structure of a polyethylene plastic outer layer, a steel wire braided middle layer, and a polytetrafluoroethylene inner coating; the head end adopts a three-layer composite pipe body structure of a polyethylene plastic outer layer, a steel wire braided middle layer, and a polytetrafluoroethylene inner coating; the head end is wrapped on a deloaded bracket; the head end interacts with the bracket steel beam; the head end is located between the bracket and the guiding catheter, and the head end flattens the deformed bracket steel beam.

2. The coronary stent retrieval catheter according to claim 1, characterized in that: The length of the recovery tube is 24 cm, the length of the head end is 1 cm, the outer diameter of the recovery tube is 1.68 mm, the inner diameter is 1.45 mm, the wall thickness is 115 μm, and the length of the connecting tube is 120 cm.

3. The coronary stent retrieval catheter according to claim 2, characterized in that: The edge of the bell mouth at the head end is soft, the wall thickness is 50-100 μm, and the outer diameter of the bell mouth after opening is 3 mm.

Images