Thrombus aspiration catheter

Abstract

The present invention relates to a thrombus aspiration catheter, comprising: an aspiration tube extending along an axis and having an aspiration port at a distal end; the guide wire tube is connected to the far-end side of the suction tube, the near-end side of the guide wire tube is fixed to the periphery of the suction tube, the part, overlapped with the suction tube, of the guide wire tube forms a connecting section, and the part, extending towards the far end, of the guide wire tube forms a suspended section; the flexural rigidity of the suction section and the flexural rigidity of the guide wire tube are both smaller than the flexural rigidity of the main body section; or the inner wall of the suction tube is provided with a sliding groove extending to the far end along the axis, the far end of the sliding groove is provided with a containing section, and the far end of the connecting rod is fixed to the near end of the guide wire tube. Through deformation of the guide wire tube or embedding of the guide wire tube into the tube wall of the suction tube, the guide wire can be used for guiding to quickly reach the preset position, the sectional area of the suction cavity of the suction tube is not damaged, and the suction efficiency and the pushing performance of the suction tube can be improved at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a thrombus aspiration catheter. BACKGROUND

[0002] Thrombus is an abnormal blood clot formed at the site of injury or repair of the inner wall of the blood vessels in the cardiovascular system, which is composed of insoluble fibrin, deposited platelets, accumulated white blood cells and trapped red blood cells. When thrombus forms an obstruction in the blood vessels, it can interrupt blood flow and cause serious clinical consequences. For example, coronary artery obstruction leads to myocardial infarction, cerebral artery obstruction causes cerebral infarction, pulmonary artery obstruction causes pulmonary embolism, and arterial obstruction of the limbs causes limb infarction, all of which can be life-threatening and require timely intervention.

[0003] For the treatment of thrombus, thrombus aspiration is widely used in clinical practice due to its advantages of simple operation, rapid removal and low cost. Existing aspiration catheters generally include single-lumen tube structure and double-lumen tube structure. The single-lumen tube structure has only an aspiration lumen without a guide wire lumen, which leads to poor push performance without guide wire guidance during the push process. The double-lumen tube structure includes an aspiration lumen and a guide wire lumen arranged in parallel, which occupies the volume of the aspiration lumen under the premise of a certain inner diameter of the catheter, resulting in a smaller cross-sectional area of the aspiration lumen, which causes low aspiration efficiency and easy blockage. SUMMARY

[0004] Therefore, the present application provides a thrombus aspiration catheter, which includes an aspiration tube extending along an axis and having an aspiration port at a distal end; a guide wire tube for a guide wire to pass through and connected to the distal end of the aspiration tube; the proximal end of the guide wire tube is fixed to the outer periphery of the aspiration tube, the part of the aspiration tube overlapping with the guide wire tube forms a connecting section and the part extending distally forms a hanging section, the length of the hanging section is 1-3 times the length of the connecting section, the aspiration tube includes an aspiration section and a main section, the bending stiffness of the aspiration section and the guide wire tube is less than the bending stiffness of the main section; or the inner wall of the aspiration tube has a sliding groove extending along the axis to the distal end, the outer periphery of the aspiration tube is provided with a guide hole in communication with the sliding groove, the guide wire can enter from the distal end of the aspiration tube and pass out from the guide hole, the distal end of the sliding groove has an accommodation section, the side wall stiffness of the side wall close to the axis is 0.1-0.7 times the side wall stiffness of the side wall away from the axis, and a connecting rod slidingly arranged in the sliding groove is further included, the distal end of the connecting rod is fixed to the proximal end of the guide wire tube, and under the driving of the connecting rod, the guide wire tube can be completely retracted into the accommodation section or slide out of the accommodation section.

[0005] Further, the guide wire tube is fixedly connected to the aspiration tube, and the outer layer of the guide wire tube is composed of a high molecular material, and the hardness is 25D-35D.

[0006] Further, the outer layer of the suction pipe is composed of a high polymer material, the hardness of the outer layer of the suction section is 35D-45D, and the hardness of the outer layer of the main body section is 45D-72D.

[0007] Further, the hardness of the outer layer of the main body section decreases stepwise or gradually from the proximal end to the distal end.

[0008] Further, the main body section further has an intermediate reinforcing layer between the outer layer and the inner layer of the suction pipe.

[0009] Further, the guide wire pipe is in sliding connection with the suction pipe, and at least one reinforcing member is arranged on the outer periphery of the distal end side of the suction pipe.

[0010] Further, the proximal end of the guide wire pipe has a necked portion, and the connecting rod is fixedly connected with the necked portion.

[0011] Further, the proximal end side of the sliding groove comprises a sliding section, the cross-sectional area of the accommodating section is greater than that of the sliding section, and a step is formed at the connection between the two.

[0012] Further, an elastic member is further arranged in the accommodating section, the distal end of the necked portion has an enlarged portion, the connecting rod is connected with the enlarged portion, one end of the elastic member abuts against the step, and the other end abuts against the enlarged portion.

[0013] Further, the suction port is a bevelled cut, and one side or both sides of the distal end of the suction port further has a pointed portion, and / or one side or both sides of the suction port further has a cutting portion.

[0014] Further, the outlet end of the guide wire pipe is arranged as a bevelled cut. The technical scheme of the present application has the following beneficial effects: The guide wire pipe is attached to the suction pipe, and the guide wire pipe is deformed or embedded in the wall of the suction pipe. The presence of the guide wire pipe realizes the guidance of the suction pipe without affecting the suction cross-sectional area of the suction pipe, and without the need to increase the size of the sheath pipe, and can improve the suction efficiency and pushing performance of the suction pipe. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a whole structure diagram of the thrombus suction catheter in the first embodiment; Figure 2 It is a first three-dimensional structure diagram of the thrombus suction catheter in the first embodiment; Figure 3 It is a second three-dimensional structure diagram of the thrombus suction catheter in the first embodiment; Figure 4 It is a sectional view of the thrombus suction catheter in the first embodiment; Figure 5 Cross-sectional view of the thrombus aspiration catheter of the first embodiment with annotations Figure 6 Schematic view of the thrombus aspiration catheter of the first embodiment entering the sheath tube Figure 7 Perspective view of the thrombus aspiration catheter of the second embodiment Figure 8 Exploded view of the thrombus aspiration catheter of the second embodiment Figure 9 Cross-sectional view of the thrombus aspiration catheter of the second embodiment Figure 10a Detail view of the connection between the guide wire tube and the connecting rod of the second embodiment Figure 10b Detail view of the connection between the guide wire tube and the connecting rod of another embodiment Figure 11 Cross-sectional view of the aspiration tube of the second embodiment Figure 12 Perspective view of the guide wire tube entering the aspiration tube of the second embodiment Figure 13 Cross-sectional view of the Figure 12 Cross-sectional view of the Figure 14 Cross-sectional view of the guide wire tube entering the aspiration tube of another embodiment Figure 15 Detail view of A in the Figure 14 Detail view of A in the Detail view of B in the Figure 16 Detail view of B in the Detail view of B in the Figure 17 Detail view of B in the Detail view of B in the Figure 18 Detail view of B in the Figure 17 Detail view of B in the DETAILED DESCRIPTION

[0016] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order not to unnecessarily obscure the present application.

[0017] It is to be understood that where an element such as a layer, region or substrate is described as being "on" or "connected, attached or coupled to" another element, it can be directly on or connected, attached or coupled to the other element, or intervening elements can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0019] It is to be understood that for medical devices, the end of the medical device closer to the operator is referred to as the "proximal end", and the end of the medical device farther from the operator is referred to as the "distal end", and the "proximal end" and "distal end" of any component of the delivery system are defined according to this principle; the "axial direction" or "longitudinal axis" refers to the direction parallel to the line connecting the center of the distal end and the center of the proximal end of the medical device; the "radial direction" or "transverse direction" refers to the direction perpendicular to the axial direction.

[0020] First embodiment Referring to Figure 1 As shown, the embodiment provides a thrombus aspiration catheter 100, which includes an aspiration tube 20 extending in the axial direction, and a distal end of the aspiration tube 20 is provided with an aspiration port 21. The aspiration tube 20 sequentially includes an aspiration section 20a and a main body section 20b from the distal end to the proximal end. The aspiration section 20a is a partial section located at the distal end of the aspiration tube 20 (the side where the aspiration port 21 is located), and the length of the aspiration section 20a is 5-30 mm. When the aspiration port 21 is provided in the form of a bevel, the aspiration section 20a is the section where the aspiration port 21 is located, and the length of the aspiration section 20a is substantially the projection length of the aspiration port 21 in the axial direction. In this application, substantially means that the deviation is within ±10%. The main body section 20b is the remaining part of the aspiration tube 20 after removing the aspiration section 20a, and the main body section 20b is integrally provided or fixedly provided with the aspiration section 20a. A guide wire tube 10 is provided on the opposite side of the aspiration port 21. The proximal end of the aspiration tube 20 is connected with a catheter seat 30, and the catheter seat 30 can be connected with a negative pressure source to realize negative pressure aspiration of the aspiration tube 20. The bending stiffness of the aspiration section 20b and the guide wire tube 10 is less than the bending stiffness of the main body section 20b.

[0021] Referring to Figures 2-4As shown, the thrombus aspiration catheter 100 is continued to be described. For the aspiration tube 20, it extends in the axial direction, and the distal end is provided with an aspiration port 21 in the form of a beveled port, and the bevel angle of the bevel surface where the aspiration port 21 is located is 15-75°. Compared with the end face circular aspiration port, the beveled port can increase the aspiration area by 15%-50%, improve the aspiration flow, increase the aspiration probability of the adherent thrombus, and improve the aspiration efficiency. In other embodiments, the aspiration port can also be the distal end opening of the aspiration tube, i.e. not provided in the form of a beveled port.

[0022] The outer layer of the aspiration tube 20 is a continuous whole, which can be generated by extrusion. The extruded material can be one or more than two kinds of thermoplastic polymer materials with different hardness mixed in different proportions. The thermoplastic material includes one or more of polyether block amide, polyamide, polyurethane, or block polyether amide resin PEBAX. Considering that for the above thermoplastic polymer material or its mixture, when it constitutes the outer layer of the aspiration tube 20, in the case of the same size, the higher the hardness, the greater the bending stiffness. Therefore, the hardness of the outer layer of the aspiration section 20a is set to 36D-45D, and the hardness of the outer layer of the main body section 20b is set to 46D-72D. For the outer layer of the main body section 20b, the hardness thereof can gradually increase from 46D to 72D from the distal end to the proximal end, or it can be increased from 46D to 72D in steps, so that the stiffness of the main body section 20b increases from the distal end to the proximal end. For example, the second outer layer can include four regions in sequence along the length direction, and the hardness of the four regions can be set to 46D, 55D, 60D, and 72D from the distal end to the proximal end. With the above hardness setting, the bending stiffness of the aspiration section is smaller than that of the main body section, so that the aspiration section is more easily bent relative to the main body section; in addition, since the main body section adopts the variable hardness setting, the stiffness thereof increases in sequence from the distal end to the proximal end, so that the main body section 20b has good flexibility and pushing performance. For the entire aspiration tube 20, the hardness of the outer layer increases in sequence from the distal end to the proximal end, so that the closer to the distal end of the aspiration tube 20, the easier to bend.

[0023] In the embodiment, the intermediate reinforcing layer is arranged in the main body section 20b but not arranged in the suction section 20a. The intermediate reinforcing layer can be a single layer, which can be a braided layer or a spiral spring layer. Alternatively, the intermediate reinforcing layer can be a double layer, which includes both the braided layer and the spiral spring layer. In the embodiment, the intermediate reinforcing layer is arranged in the main body section 20b but not arranged in the suction section 20a, which can further improve the bending stiffness of the main body section 20b and increase the difference in stiffness between the main body section 20b and the suction section 20a, so that the suction section 20a is more easily bent relative to the main body section 20b. Referring to Figure 2 As shown in the drawings, two tip portions 22 are arranged at the distal end side of the suction port 21, i.e. at the connection between the suction port 21 and the guide wire tube 10. The two tip portions 22 are arranged at two sides of the suction port 21, i.e. at different positions in the circumferential direction of the guide wire tube 10. In the embodiment, the tip portions 22 are arranged to loosen the thrombus during the advancing or thrombus suction process, so that the thrombus is broken or detached from the vessel wall, which facilitates the subsequent suction operation. In other embodiments, only one tip portion 22 can be arranged.

[0024] The guide wire tube 10 has a two-layer structure, including a guide wire tube inner layer and a guide wire tube outer layer. The material of the guide wire tube outer layer includes one or more of block polyether amide resin, thermoplastic polyurethane elastomer, and polyamide, and the outer layer has a hardness of 25D-35D. The guide wire tube inner layer is made of PTFE. The above-mentioned hardness setting makes the bending stiffness of the guide wire tube 10 smaller than the bending stiffness of the suction section, so that the guide wire tube 10 is more flexible and easier to bend relative to the suction section 20a.

[0025] Referring to Figure 1 As shown in the drawings, the guide wire tube 10 has an inlet end 11 at the distal end side and an outlet end 12 at the proximal end side, and includes a connection section 10a and a suspended section 10b. The guide wire tube 10 is arranged axially parallel to the suction tube 20, and the portion of the guide wire tube 10 axially overlapping the suction tube 20 constitutes the connection section 10a, and the portion extending distally constitutes the suspended section 10b. At least part or all of the connection section 10a of the guide wire tube 10 is fixedly connected to the opposite side of the suction port 21, and the suspended section 10b extends from the distal end of the connection section 10a to a suspended state. In actual use, the guide wire 40 can enter the guide wire tube 10 from the inlet end 11 and exit from the outlet end 12. In the embodiment, the outlet end 12 is arranged in the form of a beveled cut, and the beveled cut outlet end 12 can achieve smooth connection of the distal end of the guide wire tube 10 and the suction tube 20, so that the distal end face of the guide wire tube 10 smoothly transitions to the outer periphery of the suction tube 20, preventing the distal end face of the guide wire tube 10 from protruding outward from the outer periphery of the guide wire tube 10 and causing damage to the blood vessel. In the embodiment, the difference in bending stiffness is achieved by controlling the hardness distribution of the outer layer of the suction tube and the outer layer of the guide wire tube and whether or not an intermediate reinforcing layer is arranged between the two layers. For example, the guide wire tube 10 in the embodiment is provided with only two layers and the outer layer has a hardness of 25D-35D, while the suction segment 10a of the suction tube 20 has a hardness of 36D-45D, the main body segment 10b has a hardness of 46D-72D, and the suction segment 10a is not provided with an intermediate reinforcing layer while the main body segment 10b is provided with an intermediate reinforcing layer. Through the above arrangement, the guide wire tube 10 itself and the suction segment 20a are prone to bending deformation when subjected to the extrusion force, and the stiffness of the suction tube 20 increases from the distal end to the proximal end and is the lowest at the suction segment 20a, so that the distal end of the overall suction tube 20, especially the suction segment 20a, is prone to bending deformation.

[0026] Referring to Figure 5 As shown, the length L1 of the overhanging segment 10b is at least 1-3 times the length L2 of the connecting segment 10a. Under the premise that the total length of the guide wire tube 10 is constant, the longer the length L1 of the overhanging segment 10b, the easier the overhanging segment 10b bends. Through the above arrangement, the suction tube 20 can enter a sheath tube 200 of the same type (i.e., the inner diameter of the sheath tube is equal to the outer diameter of the suction tube). Referring to Figure 6 As shown, when the suction tube 20 is inserted into the sheath tube 200 of the same type, the suction tube 20 and the guide wire tube 10 will be subjected to the extrusion force from the inside of the sheath tube 200 because the inner diameter of the sheath tube 200 is smaller than the sum of the outer diameters of the guide wire tube 10 and the suction tube 20. Since the guide wire tube 10 is arranged in a cantilevered manner and the bending stiffness of the suction segment 20a and the guide wire tube 10 is smaller than the bending stiffness of the main body segment 20a, under the action of the extrusion force, the suction tube 20 will bend in the counterclockwise direction and the suction segment 20a connected thereto will also bend, so that the suction tube 20 can enter the sheath tube 200 of the same type. When reaching the predetermined position, the suction tube 20 is stretched out of the sheath tube 200 to restore the deformation.

[0027] In summary, on one hand, the entire lumen of the suction tube 20 can be used as a suction chamber under the premise that the outer diameter of the suction tube 20 is constant, the arrangement of the guide wire tube 10 does not occupy the volume of the suction chamber and does not cause the reduction of the cross-sectional area of the suction chamber; in addition, since the suction tube can be delivered by the same model of the sheath tube 200, the model of the sheath tube 200 does not need to be increased, and the arrangement of the guide wire tube 10 does not affect the delivery performance of the suction tube; finally, the guide wire tube 10 can be used to guide the suction tube 20 by the guide wire 40, so that the suction tube 20 can reach the target position under the guidance of the guide wire 40, thereby improving the efficiency of the operation. Therefore, for the thrombus aspiration catheter 100 of the embodiment, the arrangement of the guide wire tube 10 can guide the suction tube 20 while avoiding the influence of the arrangement of the guide wire tube 10 on the suction cross-sectional area of the suction tube 20 to the greatest extent, and the size of the sheath tube 200 does not need to be increased, the push performance and the suction efficiency can be considered, the thrombus blockage is prevented, and the small-sized blood vessel is adapted.

[0028] Second embodiment The thrombus aspiration catheter in the embodiment is basically the same as the scheme in the first embodiment, except that the guide wire tube in the embodiment is in sliding connection with the suction tube.

[0029] Referring to Figures 7-9 As shown in the figure, the aspiration catheter 100a in the embodiment includes a suction tube 20 and a guide wire tube 10, and the guide wire tube 10 is in sliding connection with the suction tube 20. The distal end of the suction tube 20 has a suction port 21, which is a bevel. The inner wall of the suction tube 20 has a sliding groove 23 extending to the distal end along the axis, and the outer periphery of the suction tube 20 is provided with a guide hole 24 in communication with the sliding groove 23, and the guide wire 40 can be inserted into the sliding groove 23 from the distal end of the suction tube 20 and pass out of the guide hole 24. In order to facilitate the opening of the sliding groove 23 at the distal end of the suction tube 20, a plane perpendicular to the axis of the suction tube 20 is cut out at the distal end of the suction tube 20, and the sliding groove 23 is opened starting from the plane, and the two sides of the plane form a sharp end 22. The end of the connecting rod 50 is connected with the guide wire tube 10, for driving the guide wire tube 10 to slide along the axis, and the connecting rod 50 can drive the guide wire tube 10 to contract into the accommodating section 23b or slide out of the accommodating section 23b.

[0030] Referring to Figure 10aAs shown, the distal end of the connecting rod 50 is fixedly connected with the proximal end of the guide wire tube 10. The connecting rod 50 can be made of metal material, for example, nickel-titanium alloy with compliance, which has good elasticity and pushing performance. The proximal end side of the guide wire tube 10 has a necked portion 13, which is tapered and gradually decreases in cross section from the proximal end to the distal end along the axial direction to be close to the cross-sectional area of the connecting rod 50. The connecting rod 50 is connected with the proximal end of the necked portion 13, and the outlet end 12 provided with an inclined cut is arranged on the necked portion 13. Considering that the size of the guide wire tube 10 is larger than that of the connecting rod 50, the necked portion 13 is arranged to realize the stable connection of the connecting rod 50 and the guide wire tube 10, and the pulling force or pushing force applied by the connecting rod 50 can be uniformly transmitted to the guide wire tube 10 in the circumferential direction through the necked portion 13, so as to ensure that the guide wire tube 10 moves along the axial line under the action of the connecting rod 50.

[0031] Referring to Figure 10b As shown, in other embodiments, a disc-shaped enlarged portion 14 can also be arranged at the distal end of the necked portion 13. The cross-sectional area of the enlarged portion 14 is larger than that of the distal end of the necked portion 13, and the connecting rod 50 is connected with the enlarged portion 14, that is, the enlarged portion 14 is located between the connecting rod 50 and the necked portion 13.

[0032] Referring to Figure 11 As shown, the structure of the suction tube 20 is further described. The sliding groove 23 includes a sliding section 23a and a containing section 23b which are sequentially communicated from the proximal end to the distal end, and a step 26 is formed at the connection position of the two sections. The containing section 23b is an inflatable hole, which is located at the proximal end side of the suction tube 20, and has a cross-sectional area larger than that of the sliding section 23a and a length larger than that of the guide wire tube 10, so as to realize the complete containing of the suction tube 20. In the embodiment, the sliding section 23a is mainly used for the sliding of the connecting rod 50, and the containing section 23b is mainly used for containing the contracted guide wire tube 10. In other embodiments, the sliding groove can also be a through hole structure with a constant cross-sectional area, that is, the step 26 is not provided at this time. The accommodation section 23b is anisotropic in the circumferential direction, and has different mechanical properties in different directions of the circumference. The suction tube 20 is in the section of the accommodation section, and the rigidity of the outer layer is greater than that of the outer layer. In particular, the rigidity of the side wall of the accommodation section close to the side of the suction tube center (i.e. the side wall inside the suction tube) is 0.1-0.7 times the rigidity of the side wall far from the center of the suction tube (i.e. the side wall outside the suction tube). In this embodiment, different materials can be used to achieve this, such as setting the outer layer material to PEBAX and the inner layer to a well elastic TPU material, or both using PEBAX material to make the outer layer material harder than the inner layer. Through the above setting, in order to make most of the deformation occur in the inner layer of the suction tube when the guide wire tube enters the accommodation section, the accommodation section expands inwardly and the outer diameter of the suction tube 20 is basically unchanged. In addition, at least one reinforcing member 25 is arranged on the outer circumference of the accommodation section of the suction tube 20. The reinforcing member 25 is used to enhance the rigidity of the accommodation section, further enhance the structural rigidity, and reduce the expansion amount of the outer layer when the guide wire tube enters the accommodation section. The reinforcing member 25 can be directly embedded into the inner wall of the suction tube 20, and a groove can be provided on the outer circumference of the suction tube 20, and the reinforcing member is embedded in the groove. Exemplarily, the reinforcing member 25 includes two first reinforcing members 25a and a second reinforcing member 25b. The second reinforcing member 25b is annular, and the first reinforcing member 25a is arranged on the opposite side of the suction port 21 in the form of a bevel. In order to prevent the suction port 21 from being blocked, the first reinforcing member 25a is arranged in a fan-shaped strip structure.

[0033] Referring to Figures 12-13 When it is necessary to accommodate the guide wire tube 10 in the accommodation section 23b, the connecting rod 50 can be pulled proximally to drive the guide wire tube 10 to slide proximally along the chute 23 and gradually enter the accommodation section 23b until it is all accommodated in the accommodation section 23b. When the suction tube 20 enters the accommodation section 23b, it will be extruded with the inner wall of the accommodation section 23b. The extrusion force will make the suction tube 20 shrink and the accommodation section 23b expand. At this time, the inner layer 26 of the suction tube 20 located in the accommodation section will expand inwardly, and the outer diameter contour will basically remain unchanged, so that the suction tube 20 can still pass through the same type of sheath after the guide wire tube 10 is accommodated in the accommodation hole 23b, and will not be affected by the retraction of the guide wire tube 10.

[0034] In use, when the guide wire 40 is not needed, the connecting rod 50 can be pulled to retract the guide wire tube 10 into the storage hole 23b. Since the increase of the outer profile of the suction tube 20 is very small or negligible, the suction tube 20 can be delivered through a same type of sheath tube. When the suction tube 20 reaches the lesion site in the body, the connecting rod 50 is pushed forward to extend the guide wire tube 10 out of the storage hole 23b. At this time, since the guide wire tube 10 has been located outside the storage hole 20b, the inner layer 26 of the guide wire tube 10 at the storage hole will restore the deformation, and will no longer expand to the side of the lumen due to the extrusion, so as to restore the cross-sectional area of the suction cavity of the suction section of the suction tube 20 to the area of the lumen of the suction tube, improving the suction efficiency.

[0035] When it is needed to send the suction tube 20 along the guide wire 40, the connecting rod 50 can be pushed forward to extend the guide wire tube 10 out of the storage hole 23b. The guide wire 40 is inserted into the guide wire tube 10, the sliding groove 23 and then out of the guide hole 24 outside the body, and then the connecting rod 50 is pulled back to retract the guide wire tube 10 containing the guide wire 40 into the storage hole 23b and delivered into the human body through the sheath tube. When the suction tube 20 reaches the lesion site under the guidance of the guide wire 40, the connecting rod 50 is pushed forward again to extend the guide wire tube 10 out of the storage hole 23b to increase the suction area. 0When it is needed to send the suction tube 20 along the guide wire 40, the connecting rod 50 can be pushed forward to extend the guide wire tube 10 out of the storage hole 23b. The guide wire 40 is inserted into the guide wire tube 10, the sliding groove 23 and then out of the guide hole 24 outside the body, and then the connecting rod 50 is pulled back to retract the guide wire tube 10 containing the guide wire 40 into the storage hole 23b and delivered into the human body through the sheath tube. When the suction tube 20 reaches the lesion site under the guidance of the guide wire 40, the connecting rod 50 is pushed forward again to extend the guide wire tube 10 out of the storage hole 23b to increase the suction area.

[0036] When the thrombus suction is completed and it is needed to withdraw the suction tube 20 from the human body, the connecting rod 50 can be pulled back to retract the guide wire tube 10 into the suction tube 20 so as to be delivered through the same type of sheath tube. Through the above arrangement, the presence of the guide wire tube 10 will not increase the size of the sheath tube, facilitating the entry into the blood vessels with smaller size. Therefore, in the embodiment, the guide wire tube 10 is slidably connected with the suction tube 20, so as to reduce the profile size for delivery through the sheath tube 200 when needed, and to restore the suction cross-sectional area for improving the suction efficiency when suctioning.

[0037] Referring to Figures 14-15 In other embodiments, in order to facilitate the extension of the guide wire tube 10 out of the storage hole 23b, an elastic member 60 is further arranged in the storage hole 23b. The elastic member 60 can be a helical spring or an elastic rod, etc. One end of the elastic member 60 can abut against the step 26, and the other end can abut against the enlarged portion 14. When the guide wire tube 10 enters the storage hole 23b, the elastic member 60 is compressed. At this time, the guide wire tube 10 can be kept in the storage hole 23b by keeping the connecting rod 50 stationary relative to the suction tube 20 through the handle. When it is needed to withdraw the guide wire tube 10 from the storage hole 23b, the handle is released, and the guide wire tube 10 will automatically pop out of the storage hole 23b under the elastic restoring force of the elastic member 60, thereby omitting the subsequent pushing action.

[0038] Referring to Figure 16As shown, in other embodiments, a cutting portion 28 for cutting the thrombus can also be provided on one side or both sides of the suction port 21. The cutting portion 28 is serrated or wavy, for cutting or loosening the thrombus, facilitating the suction of the thrombus which is long in time and tough in texture. When the thrombus is being suctioned, the suction tube 20 can be moved back and forth along the guide wire, and the cutting portion 28 is used to contact and loosen the mural thrombus, and the thrombus is suctioned from the suction cavity by the negative pressure device. This design greatly improves the removal rate and in-place degree of the thrombus, improves the thrombus suction efficiency, and shortens the operation time.

[0039] Referring to Figures 17-18 As shown, in other embodiments, in order to facilitate the entry of the guide wire 40 into the chute 23 and the exit of the guide wire 40 from the guide-out hole 24, a connecting piece 70 is also provided. The connecting piece 70 is a block structure as a whole, and at least two connecting legs 71 are provided on one end face of the connecting piece 70 in an up-down arrangement. Corresponding connecting holes (not shown in the figure) are provided on the guide wire 40 and the connecting rod 50. A mark point 51 is provided on the connecting rod 50, and the distance between the connecting holes and the mark point 51 is less than the radius of the guide-out hole 24. When the end face of the guide wire 40 is aligned with the mark point 51, the connecting holes on the guide wire 40 and the connecting rod 50 are also aligned up and down, and at this time the connecting legs 71 on the connecting piece 70 are inserted into the corresponding connecting holes, thereby realizing the connection of the guide wire 40 and the connecting rod 50. When the connection of the guide wire 40 and the connecting rod 50 is realized by the connecting piece 70, in the process of pulling the connecting rod 50 into the chute 23, the connecting rod 50 will drive the guide wire 40 to move together to the guide-out hole 24. When the connecting piece 70 reaches the position of the guide-out hole 24, the connecting piece 70 is separated from the connecting rod 50 and the guide wire 40, and the connection between them is released, and then the end of the guide wire 40 can be pulled out to make the guide wire 40 extend out of the guide-out hole 24. In order to ensure that the connecting piece 70 has reached the position of the guide-out hole 24 before the guide wire tube 10 is completely inserted into the chute 23 to facilitate the removal of the connecting piece 70, in this embodiment, assuming that the distance between the center of the guide-out hole 24 and the distal end of the suction tube 20 is L4, the distance between the mark point 51 and the distal end of the connecting rod 50 is L3, and the length of the guide wire tube 10 is L5, it is required that L3+L5>L4.

[0040] For the connecting piece 70, in other embodiments, a binding rope or a binding belt can also be used. When the end face of the guide wire 40 is aligned with the mark point 51, the guide wire 40 and the connecting rod 50 are tied and fixed by the binding rope or the binding belt in a slipknot manner near the mark point 51, and then when the connecting piece 70 reaches the position of the guide-out hole 24, the slipknot is untied to release the connection between the guide wire 40 and the connecting rod 50.

[0041] The above-described embodiments only express several implementation ways of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation to the patent scope of the application. It should be noted that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. The patent protection scope of the present application should be subject to the appended claims.

Claims

1. A thrombus aspiration catheter, characterized in that, include: A suction tube extends along the axis and has a suction port at the distal end; A guidewire tube, through which the guidewire passes, is connected to the distal end of the suction tube; The proximal end of the guidewire is fixed to the outer periphery of the suction tube. The part of the guidewire that overlaps with the suction tube forms a connecting section, while the part that extends to the distal end forms a suspended section. The length of the suspended section is 1-3 times the length of the connecting section. The suction tube includes a suction section and a main body section. The bending stiffness of both the suction section and the guidewire is less than that of the main body section. Alternatively, the inner wall of the suction tube has a groove extending along the axis to the distal end, and the outer periphery of the suction tube has an outlet hole communicating with the groove. The guide wire can enter from the distal end of the suction tube and exit through the outlet hole. The distal end of the groove has a receiving section. The side wall stiffness of the receiving section near the center of the suction tube is 0.1-0.7 times that of the other side. It also includes a connecting rod that slides through the groove, the distal end of which is fixed to the proximal end of the guide wire tube. Under the action of the connecting rod, the guide wire tube can be completely retracted into the receiving section or slide out from the receiving section.

2. The thrombus aspiration catheter according to claim 1, characterized in that, The guide wire is fixedly connected to the suction tube, and the outer layer of the guide wire is made of a polymer composite material with a hardness of 25D-35D.

3. The thrombus aspiration catheter according to claim 2, characterized in that, The outer layer of the suction tube is made of a polymer composite material, the hardness of the outer layer of the suction section is 36D-45D, and the hardness of the outer layer of the main body section is 46D-72D.

4. The thrombus aspiration catheter according to claim 3, characterized in that, The hardness of the outer layer of the main body section decreases in a step-like or gradual manner from the proximal end to the distal end.

5. The thrombus aspiration catheter according to claim 3, characterized in that, The main body section also has an intermediate reinforcing layer, which is located between the outer and inner layers of the suction tube.

6. The thrombus aspiration catheter according to claim 1, characterized in that, The guide wire tube is slidably connected to the suction tube, and at least one reinforcing member is provided at the receiving section.

7. The thrombus aspiration catheter according to claim 6, characterized in that, The guide wire has a constricted end at its proximal end, and the connecting rod is fixedly connected to the constricted end.

8. The thrombus aspiration catheter according to claim 7, characterized in that, The proximal side of the chute includes a sliding section, the cross-sectional area of ​​the receiving section is larger than that of the sliding section, and a step is formed at the connection between the two.

9. The thrombus aspiration catheter according to claim 8, characterized in that, It also includes an elastic member disposed in the receiving section, the distal end of the constricted portion having an enlarged portion, the connecting rod being connected to the enlarged portion, one end of the elastic member abutting against the step, and the other end abutting against the enlarged portion.

10. The thrombus aspiration catheter according to any one of claims 1-9, characterized in that, The suction port is a slanted cut, and one or both sides of its distal end have a pointed tip, and / or, one or both sides of the suction port are provided with a cutting part.

11. The thrombus aspiration catheter according to any one of claims 1-9, characterized in that, The outlet end of the guide wire tube is set with a bevel.

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