Thrombus breaking suction catheter

Abstract

The invention provides a broken thrombus aspiration catheter, and belongs to the technical field of thrombus treatment instruments, the broken thrombus aspiration catheter comprises a rotation driving handle, a catheter, a twist control bourdon tube and a broken thrombus cutting head, the twist control bourdon tube is arranged in the catheter in a penetrating manner, the broken thrombus cutting head is mounted at the far end of the twist control bourdon tube, and the output end of the rotation driving handle is connected with the near end of the twist control bourdon tube; an annular clamp is fixedly installed on the inner side wall of the far end of the catheter, the near end of the thrombus breaking cutting head rotationally abuts against the end face of the far end of the clamp, and the twisting control spring tube is pulled and tensioned between the thrombus breaking cutting head and the rotation driving handle. Due to the limitation of the annular hoop, the broken thrombus cutting head cannot move in the direction away from the thrombus under the traction effect of the twisting control spring tube and the extrusion effect of the broken thrombus, and it is guaranteed that the broken thrombus cutting head makes contact with the thrombus all the time; the twisting control spring tube is in a traction tensioning state, so that the thrombus breaking cutting head is always abutted against the far end of the annular hoop, the thrombus breaking cutting head cannot move out of the far end of the catheter, and the risk that the thrombus breaking cutting head is in contact with the blood vessel wall and damages the blood vessel is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of thrombus treatment devices, and more specifically, relates to a thrombus fragmentation and aspiration catheter. Background Art

[0002] Thrombi are small masses of blood that form within cardiovascular vessels. They are typically composed of insoluble fibrin, deposited platelets, accumulated white blood cells, and trapped red blood cells. Smaller thrombi can be dissolved and absorbed. However, larger and harder thrombi often require mechanical aspiration.

[0003] In the prior art, patent application CN111031943A discloses a fluid-dynamic vortex suction catheter, which uses a motor to drive the rotation and vibration of a flexible shaft. A sharp-edged tip at the distal end of the flexible shaft cuts thrombi, and the cut thrombi are expelled through the catheter via negative pressure to treat large-volume thrombi. In this patent application, because the sharp-edged tip of the flexible shaft is free within the catheter, and the catheter also requires negative pressure suction to break up the thrombi, the thrombi can be squeezed into the catheter lumen during movement, causing the tip to move away from the thrombus, affecting its efficiency. Alternatively, the tip can move axially beyond the catheter tip and into the blood vessel, causing damage to the vessel. Summary of the Invention

[0004] In order to address the deficiencies of the prior art, the present application provides a thrombus crusher aspiration catheter, which can limit the axial position of the thrombus crusher cutting head by applying a certain tension to the torsion-controlled spring tube, thereby preventing the thrombus crusher cutting head from moving away from the thrombus under the squeezing action of the thrombus crusher or causing the thrombus crusher cutting head to move out of the head end of the catheter into the blood vessel and cause vascular damage.

[0005] To achieve the above-mentioned purpose, the technical solution of the present application provides a thrombus crushing and aspiration catheter, comprising a rotary drive handle, a catheter, a torsion-controlled spring tube and a thrombus crushing cutting head. The torsion-controlled spring tube is passed through the interior of the catheter, and the thrombus crushing cutting head is installed at the distal end of the torsion-controlled spring tube. The output end of the rotary drive handle is fixedly connected to the proximal end of the torsion-controlled spring tube. The end of the catheter is connected to a negative pressure aspiration tube, and a guide wire guide channel is arranged in parallel with the catheter. An annular clamp is fixedly installed on the inner side wall of the distal end of the catheter, and the proximal end of the thrombus crushing cutting head is rotatably abutted against the distal end face of the clamp. The torsion-controlled spring tube is pulled and tensioned between the thrombus crushing cutting head and the rotary drive handle.

[0006] Rotating the drive handle rotates the torsion-controlled spring tube, which in turn drives the clot-breaking head to perform the clot-breaking operation. Due to the restraint of the annular clamp, the clot-breaking head will not move away from the clot due to the pulling action of the torsion-controlled spring tube and the squeezing action of the clot-breaking device. This ensures that the clot-breaking head remains in contact with the clot, ensuring efficient and effective clot-breaking. Furthermore, because the torsion-controlled spring tube is in a tensioned state, the clot-breaking head remains in contact with the distal end of the annular clamp and will not separate from it. This prevents the clot-breaking head from moving out of the distal end of the catheter, avoiding the risk of contact with the vessel wall and damaging the vessel, thereby improving surgical safety.

[0007] Optionally, the torsion-controlled spring tube is a hollow spring tube formed by spirally winding a single or multiple layers of metal wire. This allows the torsion-controlled spring tube to have a certain degree of stretching capability in addition to its ability to flexibly deform and transmit torque. The torsion-controlled spring tube, when stretched, can generate a certain internal tension, thereby pulling the bolt cutter head and ensuring that the support wings on the bolt cutter head are always in contact with the annular clamp.

[0008] Optionally, a Y-shaped connector is included. The Y-shaped connector comprises a main tube and a branch tube, with the branch tube serving as a negative pressure suction tube. The distal end of the main tube is fixedly connected to the catheter, while the proximal end of the main tube is fitted with a locking connector and a check valve, with the locking connector located on one side of the distal end of the check valve. A torque-controlled spring tube passes through the interior of the main tube, and the proximal end of the torque-controlled spring tube passes through the locking connector and the check valve. The portion of the torque-controlled spring tube extending beyond the proximal end of the main tube is connected to the output end of the rotary drive handle. The negative pressure suction tube is used to connect to a suction pump or syringe to achieve negative pressure suction. The check valve is designed to prevent blood and emboli from leaking from the proximal end of the main tube, thereby reducing bleeding.

[0009] Optionally, the proximal end of the torsion control spring tube is fused with a nylon barrier material by thermo-rheological means, and the output end of the rotating drive handle has a locking Luer. The end of the torsion control spring tube fused with the nylon barrier material passes through the check valve and is fixedly inserted into the interior of the locking Luer. Due to the limitations of the structure of the torsion control spring tube itself, there will be gaps inside it. The nylon barrier material is melted and embedded between the spring wires of the torsion control spring tube to form a closed structure. Sealing and filling the internal gaps at the proximal end of the torsion control spring tube with nylon barrier material can increase the airtightness between it and the check valve and reduce the amount of bleeding. At the same time, the hardness of the proximal end of the torsion control spring tube can be guaranteed, and when connected to the locking Luer, the connection will not be loose due to the plasticity of the torsion control spring tube itself.

[0010] Optionally, the rotary drive handle includes a housing, within which a reduction motor, a driving gear, and a driven gear are mounted. The driving gear is connected to the output end of the reduction motor, and the driven gear meshes with the driving gear. The driven gear is fixedly sleeved on the outside of the locking Luer. A switch for controlling the reduction motor is provided on the outside of the housing. The main pipe is fixedly mounted inside the housing, and the branch pipe extends out of the housing. By gripping the housing and turning the switch, the reduction motor can be used to control the bolt-breaking head to perform the bolt-breaking operation, resulting in a simple and convenient structure.

[0011] Optionally, a plurality of support wings are circumferentially distributed around the proximal end of the bolt-crushing head. These support wings include arcuate cylindrical projections, the proximal ends of which abut against the distal ends of the annular clamp, and the arcuate surfaces of which circumferentially abut against the inner wall of the catheter. In this case, the entire bolt-crushing head abuts not only against the annular clamp but also against the inner wall of the catheter, preventing radial movement of the bolt-crushing head and further ensuring the stability of its position. The arcuate cylindrical projections make smooth linear contact with the inner wall of the catheter, reducing the contact area with the inner wall during rapid rotation, resulting in smoother rotation.

[0012] Optionally, the embolism removal head comprises a central axis and a plurality of spiral blades distributed circumferentially around the central axis. Support wings are located proximal to the spiral blades, and an embolism removal channel is formed between any two adjacent spiral blades. The rotation of the spiral blades guides the removal of emboli, allowing for better embolism removal. Thin blades minimize the cross-sectional area of the embolism removal head, maximizing the cross-sectional area of the embolism removal channel, improving embolism removal efficiency, reducing surgical time, and indirectly reducing blood loss.

[0013] Optionally, each arc-surface cylindrical projection is provided with edge blades on both sides. When the broken bolts pass through the bolt discharge channel, they come into contact with the edge blades, which perform secondary cutting on the broken bolts that are partially chopped and accumulated between the ring clamps of the broken bolt cutting head, thereby improving the efficiency of the broken bolt transfer.

[0014] Optionally, the distal end of the torsion-controlled spring tube is fixedly connected with a connecting wire, the proximal end of the central axis is a hollow structure, and the distal end of the connecting wire is passed through the interior of the central axis and fixed to the central axis by laser welding. The connecting wire, which serves as the connecting part between the torsion-controlled spring tube and the thrombus-crushing cutting head, can be made very thin, for example, the wire diameter is between 0.016 inches and 0.020 inches, and can be made of nickel-titanium alloy or SST316 stainless steel, and can also have a certain degree of flexibility. A thinner wire diameter can significantly reduce the cross-sectional size of the central axis, increase the cross-sectional area of the thrombus-removal channel, and improve the efficiency of thrombus-removal, thereby reducing the amount of bleeding by reducing the surgical time. At the same time, the flexible connecting wire root can be flexibly deformed and will not affect the adjustment of the position of the thrombus-crushing cutting head.

[0015] Optionally, the distal end of the catheter is connected to a guidewire guide tube, which serves as a guidewire guide channel. Unlike the prior art, the guidewire guide tube for threading the guidewire is not located inside the torsion-controlled spring tube, but on the catheter. When the thrombus-crushing head and the torsion-controlled spring tube catheter enter the thrombus along the guidewire, if the guidewire is inside the torsion-controlled spring tube, the rotation of the torsion-controlled spring tube cannot be started, and the guidewire needs to be pulled out, otherwise the guidewire will follow the rotation and easily pierce the blood vessel. By setting the guidewire guide tube on the catheter, there is no need to pull out the guidewire when the thrombus-crushing head is working, and there is no need to repeatedly thread the guidewire when the direction of the catheter needs to be adjusted, thereby reducing the number of surgical steps.

[0016] Optionally, the catheter includes a first PTFE sleeve layer, a first metal braided layer wrapped around the outside of the first PTFE sleeve layer, and a first polymer material layer heat-melted onto the outside of the first metal braided layer, and the flexibility of the first polymer material layer gradually increases from the proximal end to the distal end; the guidewire guide tube includes a second PTFE sleeve layer, a second metal braided layer wrapped around the outside of the second PTFE sleeve layer, and a second polymer material layer heat-melted onto the outside of the second metal braided layer, and the flexibility of the second polymer material layer gradually increases from the proximal end to the distal end.

[0017] The first and second PTFE lining layers increase internal lubricity. A sufficiently lubricated first PTFE lining layer prevents the accumulation of broken plugs, facilitating rapid transport. A sufficiently lubricated second PTFE lining layer facilitates sliding along the guidewire. The first and second metal braid layers enhance torque control, facilitating position adjustment. The first and second polymer layers, with increasing flexibility from the proximal end to the distal end, facilitate position adjustment at the distal end.

[0018] Optionally, the materials of the first polymer material layer from the distal end to the proximal end are selected in sequence from at least two materials of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 and are fused to each other through thermorheological means; the material flexibility of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 gradually decreases, thereby achieving a gradual flexibility effect of the first polymer material layer.

[0019] The materials of the second polymer material layer from the distal end to the proximal end are selected in sequence from at least two materials of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 and are fused to each other through thermorheological means; the material flexibility of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 gradually decreases, thereby achieving a gradual flexibility effect of the second polymer material layer.

[0020] The first polymer material layer and the second polymer material layer are connected by heat melting to connect the catheter and the guide wire guide tube into a whole.

[0021] Optionally, the proximal end of the guidewire guide tube is a bevel structure. The guidewire guide tube generally covers the entire path of the atrium and ventricle, and the proximal end of the guidewire guide tube with a bevel structure can prevent the sharp end from getting caught on the blood vessels or the inner wall of the heart.

[0022] The technical solution of this application has the following advantages over the prior art:

[0023] Rotating the drive handle rotates the torsion-controlled spring tube, which in turn drives the clot-breaking head to perform the clot-breaking operation. Due to the restraint of the annular clamp, the clot-breaking head will not move away from the clot due to the pulling action of the torsion-controlled spring tube and the squeezing action of the clot-breaking device. This ensures that the clot-breaking head remains in contact with the clot, ensuring efficient and effective clot-breaking. Furthermore, because the torsion-controlled spring tube is in a tensioned state, the clot-breaking head remains in contact with the distal end of the annular clamp and will not separate from it. This prevents the clot-breaking head from moving out of the distal end of the catheter, avoiding the risk of contact with the vessel wall and damaging the vessel, thereby improving surgical safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 This is a schematic diagram of the overall structure of the thrombus fragmentation and aspiration catheter;

[0026] Figure 2 This is a schematic diagram of the internal structure of the distal end of the thrombus fragmentation and aspiration catheter;

[0027] Figure 3 Schematic diagram of the conduit structure connected with an annular clamp and a Y-shaped structure;

[0028] Figure 4 It is a schematic diagram of the structure of the rotating drive handle;

[0029] Figure 5 Schematic diagram of the structure of a torsion-controlled spring tube connected to a bolt-breaking cutter;

[0030] Figure 6 This is a cross-sectional view of the catheter structure at the guidewire guide tube;

[0031] Figure 7 Schematic diagram of a high-load old thrombus in the pulmonary artery used for in vitro simulation;

[0032] Figure 8 Schematic diagram of pushing a catheter for removing old pulmonary artery thrombus in a cardiovascular model;

[0033] Figure 9 Schematic diagram of the process of fragmenting old thrombus.

[0034] Icons: 1. Rotating drive handle; 101. Locking Luer; 102. Housing; 103. Reduction motor; 104. Driving gear; 105. Driven gear; 106. Switch; 2. Catheter; 201. First PTFE bushing layer; 202. First metal braiding layer; 203. First polymer material layer; 3. Torsion control spring tube; 301. Barrier material; 302. Connecting wire; 4. Plug cutting head; 401. Support wing; 402. Arc cylindrical protrusion; 403. Central axis; 404. Spiral blade; 405. Plug removal channel; 406. Edge blade; 407. Slotted structure; 5. Ring clamp; 6. Y-shaped connector; 601. Main pipe; 602. Branch pipe; 7. Locking connector; 8. Check valve; 9. Guide wire guide tube; 901. Second PTFE bushing layer; 902. Second metal braiding layer; 903. Second polymer material layer. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0036] Example 1:

[0037] This embodiment provides a thrombus fragmentation and aspiration catheter. In this embodiment, unless otherwise specified, the distal end refers to the end facing the thrombus, and the proximal end refers to the end facing away from the thrombus.

[0038] based on Figure 1 and Figure 2As shown, the thrombus-crushing and aspiration catheter includes a rotating drive handle 1, a catheter 2, a torsion-controlled spring tube 3, and a thrombus-crushing cutting head 4. The torsion-controlled spring tube 3 is passed through the interior of the catheter 2, and the thrombus-crushing cutting head 4 is installed at the distal end of the torsion-controlled spring tube 3. The output end of the rotating drive handle 1 is fixedly connected to the proximal end of the torsion-controlled spring tube 3, and the distal end of the catheter 2 is connected to a negative pressure suction tube. A guidewire guide channel is provided in parallel with the catheter 2. Under the guidance of the guidewire, the distal end of the thrombus-crushing and aspiration catheter is used to penetrate along the vascular pathway to the site of thrombus occurrence, and the rotating drive handle 1 drives the thrombus-crushing cutting head 4 to rotate through the torsion-controlled spring tube 3 to perform the thrombus-crushing operation. The negative pressure suction tube is used to connect a suction pump or a syringe. By starting the suction pump or pulling the syringe, negative pressure is generated in the catheter 2 to aspirate the thrombus.

[0039] Based on the above structure, an annular clamp 5 is fixedly mounted on the inner sidewall of the distal end of the catheter 2. The proximal end of the thrombus-crushing head 4 is rotatably abutted against the distal end face of the clamp. The torsion-controlled spring tube 3 is pulled and tensioned between the thrombus-crushing head 4 and the rotating drive handle 1. Due to the restraint of the annular clamp 5, the thrombus-crushing head 4 will not move away from the thrombus due to the pulling action of the torsion-controlled spring tube 3 and the squeezing action of the thrombus-crushing device. This ensures that the thrombus-crushing head 4 remains in contact with the thrombus, ensuring efficient and effective thrombus-crushing. Furthermore, because the torsion-controlled spring tube 3 is in a tensioned state, the thrombus-crushing head 4 remains in contact with the distal end of the annular clamp 5 and will not separate from it. This ensures that the thrombus-crushing head 4 will not move out of the distal end of the catheter 2, avoiding the risk of the thrombus-crushing head 4 contacting and damaging the vessel wall, thereby improving surgical safety.

[0040] In this embodiment, the annular clamp 5 is preferably an annular stainless steel ring with a wall thickness of 0.2 mm to 0.3 mm. Its outer diameter is 0.2 mm to 0.6 mm larger than the inner diameter of the distal end of the catheter 2. It is inserted into the distal end of the catheter 2 through an interference fit to ensure stable positioning. The edges of the annular clamp 5 are rounded to prevent damage to the inner lumen of the catheter 2 during installation. It is contemplated that the annular clamp 5 can also be made of hard plastic or other materials such as titanium alloy. Alternatively, the annular clamp 5 can be formed as part of the inner wall structure of the catheter 2, protruding from the inner wall of the catheter 2, as long as it blocks the proximal end of the plug-breaking head 4.

[0041] Furthermore, the torsion-controlled spring tube 3 is a hollow spring tube formed by spirally winding a single layer or multiple layers of metal wire, and the diameter of the filaments is between 0.05 mm and 0.1 mm. The number of strands is 18 or 24. The material is SUS304 stainless steel or MP35N. The torsion-controlled spring tube 3 in this embodiment is a hollow spring tube formed by rotating and winding 18 strands of 0.08 mm filaments of three-layer stainless steel SUS304. After assembly, the overlapping positions are laser welded under the conditions of a current of 45 A, a pulse width of 2.5 ms, a frequency of 1.0 Hz, and a spot diameter of 0.1 mm to form a torsion-controlled spring tube 3 with an outer diameter of 1.45 mm, an inner diameter of 0.95 mm, and a length of 1.2 meters. In addition to having the ability to flexibly deform and transmit torque, the torsion-controlled spring tube 3 also has a certain tensile strength. The torsion-controlled spring tube 3 is stretched and elongated to achieve a certain internal tension, thereby pulling the bolt-crushing cutter 4 and ensuring that the support wings 401 on the bolt-crushing cutter 4 are always in contact with the annular clamp 5. It is contemplated that the torsion-controlled spring tube 3 can also be formed by spirally winding metal wire in other layers, such as a single layer or a double layer, and the rotational winding method can be selected to be clockwise or counterclockwise. The size, specifications, and number of fine wire strands in each layer can be adjusted according to actual conditions.

[0042] Further, based on Figures 1 to 4 As shown, a Y-shaped connector 6 is also included, and the Y-shaped connector 6 has a main pipe 601 and a branch pipe 602. The branch pipe 602 serves as a negative pressure suction tube and is used to connect a suction pump or a syringe. The distal end of the main pipe 601 is fixedly connected to the catheter 2, and the proximal end of the main pipe 601 is installed with a locking connector 7 and a check valve 8 to prevent blood and broken emboli from flowing out from the proximal end of the main pipe 601 and reduce the amount of bleeding. The locking connector 7 is located on one side of the distal end of the check valve 8, the torsion control spring tube 3 passes through the interior of the main pipe 601, and the proximal end of the torsion control spring tube 3 passes through the locking connector 7 and the check valve 8. The part of the torsion control spring tube 3 that passes through the proximal end of the main pipe 601 is connected to the output end of the rotation drive handle 1.

[0043] Among them, based on Figure 4 and Figure 5As shown, the proximal end of the torque-controlled spring tube 3 is thermorheologically fused with a nylon barrier material 301. The output end of the rotary drive handle 1 features a locking luer 101. The end of the torque-controlled spring tube 3, fused with the nylon barrier material 301, passes through the check valve 8 and is fixedly inserted into the interior of the locking luer 101. The nylon barrier material 301 can be made of PA12 or Pebax, such as Pebax 72D. In this embodiment, PA12 is used. Specifically, during manufacturing, a PA12 tube is placed over the proximal end of the torque-controlled spring tube 3, covering a length of 10 to 20 cm. The tube is thermorheologically bonded in a high-temperature air box at 300°C and an air flow rate of 40 SCFH. Due to structural limitations of the torque-controlled spring tube 3, there are gaps within it. The nylon barrier material 301 is melted and embedded between the spring wires of the torque-controlled spring tube 3, forming a sealed structure. Sealing and filling the internal gap at the proximal end of the torsion control spring tube 3 with nylon barrier material 301 can increase the airtightness between it and the check valve 8, reduce the amount of bleeding, and ensure the hardness of the proximal end of the torsion control spring tube 3. When connected to the locking Luer 101, the connection will not be loose due to the plasticity of the torsion control spring tube 3 itself.

[0044] Further, based on Figure 4 As shown, the rotary drive handle 1 includes a housing 102, in which a reduction motor 103, a driving gear 104 and a driven gear 105 are installed. The driving gear 104 is connected to the output end of the reduction motor 103, and the driven gear 105 is meshed with the driving gear 104. The driven gear 105 is fixedly sleeved on the outside of the locking Luer 101. A switch 106 for controlling the reduction motor 103 is provided on the outside of the housing 102. The main pipe 601 is fixedly installed inside the housing 102, and the branch pipe 602 extends out of the housing 102 so as to be docked with a suction pump or a syringe. When in use, the housing 102 can be held by hand and the toggle switch 106 can be used to control the plug-breaking cutting head 4 through the reduction motor 103 to perform the plug-breaking operation. The structure is simple and convenient. It can be imagined that the housing 102 is also provided with a corresponding circuit board and conventional components such as a battery or an external power cord used as a power supply end, which will not be repeated.

[0045] Further, based on Figure 2As shown, in this embodiment, several groups of support wings 401 are circumferentially distributed around the proximal end of the bolt-crushing head 4, i.e., at least two groups of support wings 401. In this embodiment, the number of support wings 401 is three. The support wings 401 include arc-surface cylindrical protrusions 402, the proximal ends of which abut against the distal ends of the annular clamp 5, thereby achieving abutment between the bolt-crushing head 4 and the annular clamp 5. The arc surface of the arc-surface cylindrical protrusions 402 abuts circumferentially against the inner wall of the catheter 2. At this time, the entire bolt-crushing head 4 abuts against the annular clamp 5 while also abutting against the inner side wall of the catheter 2, preventing radial movement of the bolt-crushing head 4 and ensuring the stability of the position of the bolt-crushing head 4. The arc-surface cylindrical protrusions 402 are in line contact with the inner wall of the catheter 2, and the contact area is smooth. During rapid rotation, the contact area with the inner wall of the catheter 2 is reduced, making the rotation smoother and preventing the bolt-crushing head 4 from getting stuck. If the thrombus-breaking head 4 is stuck and the torsion-controlled spring tube 3 continues to rotate, stress will accumulate inside the torsion-controlled spring tube 3. If the stress accumulates to a certain extent and is suddenly released, the thrombus-breaking head 4 may suddenly shake and rotate to a high degree and impact the inner wall of the catheter 2, causing impact on the blood vessel and causing danger. The thrombus is discharged from the gap between the two support wings 401. It can be imagined that the number of support wings 401 can also be set to two groups or four groups, etc. The more support wings 401 there are, the larger the area they occupy on the cross-section of the catheter 2, and the increased contact area with the inner wall of the catheter 2 leads to increased friction, but the support stability will also be better. Designers can make reasonable settings based on actual conditions.

[0046] based on Figure 2 As shown, the embolism cutting head 4 includes a central axis 403 and a plurality of spiral blades 404 distributed circumferentially around the central axis 403. In this embodiment, the number of spiral blades 404 is three. The support wings 401 are located at the proximal ends of the spiral blades 404, and a bolt removal channel 405 is formed between any two adjacent spiral blades 404. Under the rotational guidance of the spiral blades 404, the embolism can be better removed. The thin blade structure can minimize the cross-sectional area occupied by the embolism cutting head 4, thereby maximizing the cross-sectional area of the bolt removal channel 405, improving the efficiency of bolt removal, reducing surgical time, and indirectly reducing the amount of bleeding. Supported by the arc-shaped cylindrical protrusion 402, the radial position of the entire embolism cutting head 4 will not wobble relative to the catheter 2, ensuring that the spiral blades 404 will not contact the inner wall of the catheter 2. When the embolism cutting head 4 rotates at high speed, the spiral blades 404 will not cut the inner wall of the catheter 2 to produce debris particles of the catheter 2 material, completely avoiding the possibility of debris particles entering the human body and ensuring safety.

[0047] Each arc-shaped cylindrical protrusion 402 is provided with an edge blade 406 on both sides. When the thrombus is passed through the thrombus removal channel 405, the edge blade 406 contacts the thrombus. The edge blade 406 cuts the thrombus that is partially chopped and accumulated between the annular clamp 5 of the thrombus cutting head 4 for a second time, thereby improving the efficiency of thrombus transfer. It can be imagined that the number of spiral blades 404 can also be set to two groups or four groups, etc. The more spiral blades 404 there are, the larger the area they occupy on the cross-section of the catheter 2, and the thrombus removal efficiency will be reduced accordingly. However, increasing the number of spiral blades 404 can also improve the efficiency of contact with the thrombus and improve the cutting efficiency. Designers can make reasonable settings based on actual conditions.

[0048] In this embodiment, the thrombus-crushing cutting head 4 is made of SST316 stainless steel, with an outer diameter of 2-4 mm and a length of 5-10 mm. The channel area between the support wings 401 accounts for 50%-70% of the cross-sectional area of the thrombus-crushing cutting head 4. Sufficient channel area facilitates the rapid aspiration and transfer of shredded plaque. The increase in transfer speed can reduce the time required for thrombus removal, indirectly reducing the amount of bleeding. The spiral blade 404 is oriented in a unified clockwise or counterclockwise direction, and the thickness of the thinnest part of the sharp edge of the spiral blade 404 is 0.1 mm-0.5 mm. During actual production, the blade thickness can gradually increase from the distal end to the proximal end. The distal blade has sufficient contact with the thrombus, and the thin thickness can improve sharpness and enhance the thrombus-crushing effect. The proximal blade has less contact with the thrombus, and the increased thickness can improve strength.

[0049] Further, based on Figure 2As shown, the distal end of the torsion spring tube 3 is fixedly connected to a connecting wire 302. The proximal end of the central shaft 403 is hollow, and the distal end of the connecting wire 302 is inserted into the interior of the central shaft 403 and laser welded to the central shaft 403. The connecting wire 302, which serves as the connection between the torsion spring tube 3 and the thrombus-crushing head 4, can be made very thin, for example, with a wire diameter between 0.016 inches and 0.020 inches. Specifically, it can be made of materials such as nickel-titanium alloy or SST316 stainless steel, and it also has a certain degree of flexibility. The thinner wire diameter significantly reduces the cross-sectional dimensions of the central shaft 403. It essentially eliminates the area of the thrombus aspiration channel after the thrombus-crushing head 4 and the annular clamp 5 are assembled, greatly increasing the effective cross-sectional area of the lumen, facilitating the rapid aspiration and transfer of thrombi, eliminating the risk of thrombus blockage, shortening surgical time, and reducing the risk of blood loss. Furthermore, the flexible root of the connecting wire 302, exposed outside the central shaft 403, can flexibly deform, reducing stiffness and improving bending ability within blood vessels and the heart. To facilitate laser welding, a slotted structure 407 can be provided on the proximal sidewall of the central axis 403. In this embodiment, the proximal end of the connecting wire 302 is inserted into the distal end of the torsion spring tube 3, with an overlap length of approximately 0.5 cm to 1.0 cm. The exposed length of the connecting wire 302 is 5 cm to 20 cm. After assembly, the overlapping position is laser welded under the laser welding parameters of 40A to 50A current, 2.0ms to 3.0ms pulse width, 0.7Hz to 1.0Hz frequency, and 0.1mm to 0.3mm spot diameter. Simultaneously, the connecting wire 302 is inserted into the interior of the central axis 403, and the laser focuses on the edge of the overlapping area of the slotted structure 407 of the crushing bolt cutting head 4 and the connecting wire 302. After assembly, the overlapping position is laser welded under the laser welding parameters of 40A to 50A current, 2.0ms to 3.0ms pulse width, 0.7Hz to 1.0Hz frequency, and 0.1mm to 0.3mm spot diameter. The slotted structure 407 can not only provide a laser welding area but also reduce the cross-sectional area occupied by the central axis 403 and increase the cross-sectional area of the bolt removal channel 405 .

[0050] Further, based on Figure 1 and Figure 3As shown, the distal end of the catheter 2 is connected to a guidewire guide tube 9, which serves as a guidewire guiding channel. Unlike the prior art, the guidewire guide tube 9 for inserting the guidewire is not located inside the torsion-controlled spring tube 3, but on the catheter 2. When the thrombus-breaking cutting head 4, the torsion-controlled spring tube 3 and the catheter 2 enter the thrombus along the guidewire, if the guidewire is inside the torsion-controlled spring tube 3, the torsion-controlled spring tube 3 cannot be started to rotate, and the guidewire needs to be pulled out, otherwise the guidewire will follow the rotation and easily pierce the blood vessel. The guidewire guide tube 9 is set on the catheter 2, and the guidewire does not need to be pulled out when the thrombus-breaking cutting head 4 is working. When the direction of the catheter 2 needs to be adjusted, there is no need to repeatedly insert the guidewire, which reduces the number of surgical steps. The distal end of the guidewire guide tube 9 is flush with the distal end of the catheter 2, and the total length is about 25cm-35cm, to ensure that the entire guidewire cavity covers the entire path of the atria and ventricles when clearing the pulmonary artery thrombus, to avoid the guidewire bifurcation in the heart, which affects the pushing of the catheter 2 into place.

[0051] Further, based on Figure 6 As shown, the catheter 2 includes a first PTFE sleeve layer 201, a first metal braided layer 202 wrapped around the outside of the first PTFE sleeve layer 201, and a first polymer material layer 203 heat-melted to the outside of the first metal braided layer 202. The flexibility of the first polymer material layer 203 gradually increases from the proximal end to the distal end. The guidewire guide tube 9 includes a second PTFE sleeve layer 901, a second metal braided layer 902 wrapped around the outside of the second PTFE sleeve layer 901, and a second polymer material layer 903 heat-melted to the outside of the second metal braided layer 902. The flexibility of the second polymer material layer 903 gradually increases from the proximal end to the distal end. The first PTFE sleeve layer 201 and the second PTFE sleeve layer 901 can increase the internal lubricity. The first PTFE sleeve layer 201 with sufficient lubricity can prevent the deposition of broken plugs and facilitate rapid transportation. The second PTFE sleeve layer 901 with sufficient lubricity facilitates sliding along the guidewire. The first metal braided layer 202 and the second metal braided layer 902 can increase the torsion control and facilitate azimuth adjustment. The first polymer material layer 203 and the second polymer material layer 903 , which have gradually increasing flexibility from the proximal end to the distal end, make the position of the distal end easier to adjust.

[0052] The first metal braided layer 202 and the second metal braided layer 902 can both be made of stainless steel braided layers or titanium alloy braided layers. The first polymer material layer 203 is made of at least two materials selected from the group consisting of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, in order from distal to proximal, and fused to each other through thermorheological methods. The first polymer material layer 203 is made of at least two of the above materials. Since the flexibility of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 gradually decreases, they must be arranged in the above order from distal to proximal, and the order must not be reversed, in order to achieve a gradual change in the flexibility of the first polymer material layer 203. Similarly, the materials for the second polymer layer 903 are selected from TPU45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, in order from distal to proximal, and are fused together via thermorheological methods. The second polymer layer 903 uses at least two of the aforementioned materials. Since the flexibility of TPU45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 decreases gradually, they must be arranged in the aforementioned order from distal to proximal, and the order must not be reversed, to achieve the effect of a gradual change in the flexibility of the second polymer layer 903. The first polymer layer 203 and the second polymer layer 903 are heat-fused together to connect the catheter 2 and the guidewire guide tube 9 as a single entity.

[0053] In this embodiment, the materials of the first polymer material layer 203 from distal to proximal end are, in order, TPU 45A, Pebax 35D, Pebax 55D, Pebax 72D, and PA12. The materials of the second polymer material layer 903 from distal to proximal end are, in order, TPU 45A and Pebax 35D. It is contemplated that in other embodiments, the number and types of materials for the first polymer material layer 203 and the second polymer material layer 903 can be reasonably selected within the above-defined ranges. For example, the materials of the first polymer material layer 203 from distal to proximal end are, in order, TPU 1074A, Pebax 35D, Pebax 45D, Pebax 63D, Pebax 72D, and PA12. The materials of the first polymer material layer 203 from distal to proximal end are, in order, TPU 45A, TPU 1074A, and Pebax 45D. Specific permutations and combinations are not exhaustive.

[0054] In this embodiment, the manufacturing process of the catheter 2 is as follows:

[0055] The PTFE bushing tube is fixed on the lubricating coating core shaft, a stainless steel braid is installed on the PTFE bushing tube and tightened to form a middle layer, and TPU 45A, Pebax35D, Pebax55D, Pebax72D, and PA12 polymer tubes are respectively put on the stainless steel braid to form an outer layer, and a heat shrink tube is put on the surface. The thermorheological coating is carried out at a temperature of 250℃-400℃, an air flow rate of 30SCFH-40SCFH, and a moving speed of 1.0mm / s-2.5mm / s.

[0056] The preparation process of the guide wire guide tube 9 is as follows:

[0057] By fixing the PTFE bushing tube on the lubricating coating core shaft, TPU 45A and Pebax35D polymer material tubes are put on the PTFE bushing tube one by one to form an outer layer, and a heat shrink tube is put on the surface. The thermorheological coating is carried out under the parameters of temperature of 250℃-400℃, air flow rate of 30SCFH-40SCFH, and moving speed of 1.0mm / s-2.5mm / s.

[0058] After the catheter 2 and the guidewire guide tube 9 are manufactured, the distal ends of the catheter 2 and the guidewire guide tube 9 are fitted together and covered with a heat shrink tube. The outer layers of the two are thermo-rheologically melted and bonded together at a temperature of 250°C-400°C, an air flow rate of 30SCFH-40SCFH, and a moving speed of 1.0mm / s-2.5mm / s, and a hydrophilic lubricating coating is coated on the surface.

[0059] Optionally, the proximal end of the guidewire guide tube 9 is a bevel structure. The guidewire guide tube 9 generally covers the entire path of the atrium and ventricle, and the proximal end of the guidewire guide tube 9 with a bevel structure will prevent the sharp end from getting caught on the blood vessels or the inner wall of the heart.

[0060] The clinical use of the thrombus fragmentation and aspiration catheter of this embodiment for clearing old pulmonary artery thrombus is as follows:

[0061] Step 1: Preoperative preparation and anesthesia: Prepare the patient for surgery and administer anesthesia according to the medical association guidelines or relevant guidelines.

[0062] Step 2: Puncture and establishment of vascular access: Under the guidance of imaging equipment (such as X-ray, CT, or angiography), puncture is performed through the femoral vein and a 13F or 14F catheter sheath is inserted. The pigtail catheter 2 and a 0.035-inch guide wire are inserted into the catheter sheath. The guide wire is passed along the pigtail catheter to the location of the pulmonary artery thrombus, thereby establishing a guidewire pathway from the right femoral vein to the external iliac vein, the common iliac vein, the inferior vena cava, the right atrium, the right ventricle, and the pulmonary artery.

[0063] Step 3: Place catheter 2 for pulmonary artery old thrombus removal: Insert the proximal end of the 0.035-inch guide wire into the guide wire guide tube 9 and advance catheter 2 along the guide wire. Under imaging equipment and angiography, advance catheter 2 to the thrombus location, and ensure that the distal end of catheter 2 contacts the thrombus.

[0064] Step 4: Connect branch tube 602 to a suction pump or syringe. Start the suction pump or pull the syringe to initiate negative pressure aspiration. This will draw the old thrombus to the distal end of catheter 2 and cause it to become lodged. Flip switch 106 to activate the rotation of the thrombus-breaking head 4, which begins fragmenting the thrombus. Simultaneously, with the aid of negative pressure aspiration, the fragmented thrombus is rapidly drawn into the suction pump or syringe. Multiple angiography procedures may be required during the fragmentation process to confirm vascular recanalization.

[0065] Step 5: After confirming that the blood vessels are recanalized, the switch 106 is turned off to close the thrombus-breaking cutting head 4, and the negative pressure suction state is ended. The catheter 2 is withdrawn from the body along the 0.035-inch guide wire for postoperative treatment.

[0066] Comparative Example 1:

[0067] A mesh-disc thrombectomy catheter was prepared based on the invention patent publication number CN113855164A, entitled "A Mesh-Disc Mechanical Thrombectomy Catheter Device." The thrombectomy mechanism involves releasing the mesh disk within the catheter, allowing it to embed within the thrombus. The thrombus is then pulled into the catheter by negative pressure suction, thereby removing the thrombus from the body.

[0068] Comparative Example 2:

[0069] Use only catheter 2 and connect it to a negative pressure pump for suction.

[0070] Comparative Example 3:

[0071] According to the invention patent of publication number CN111031943A, entitled Fluid Dynamic Vortex Suction Catheter, a suction catheter was prepared, specifically using the invention patent of the publication number CN111031943A. Figure 8 The flexible shaft shown in Figure C and the shaft tip shown in Figure 11A were tested. The thrombus removal principle is to use the sharp-edged shaft tip at the distal end of the flexible shaft to rotate and cut the thrombus, and then use vacuum suction to aspirate the thrombus along the catheter under negative pressure.

[0072] The experimental models and methods used in the in vitro simulations of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are as follows:

[0073] Reference Figure 7 、 Figure 8 and Figure 9As shown, a pulmonary artery model was used to place an old thrombus prepared with fresh porcine blood. A 0.035-inch guide wire was used to establish access. The devices of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 were advanced along the guide wire to the site of the thrombus in the model. A negative pressure vacuum pump was used for suction.

[0074] In Example 1, the switch 106 is turned on, the clot-breaking head 4 begins to rotate and break up the clot, and the negative pressure vacuum pump is turned on to aspirate and expel the clot until the clot is completely removed. The time taken for this process and the amount of blood in the negative pressure vacuum pump are recorded.

[0075] For Comparative Example 1, the mesh disc holder was released at the thrombus location using the handle. After 2 minutes, the handle was used to drag the mesh disc into the lumen of catheter 2, and suction was initiated simultaneously. After a single operation, the device was withdrawn, and the lumen of catheter 2 was flushed until no residual thrombus remained. The suction was repeated multiple times until the thrombus was completely removed. The duration of this process and the amount of blood in the negative pressure vacuum pump were recorded.

[0076] For Comparative Example 2, after the tip of catheter 2 was placed close to the thrombus, the negative pressure vacuum pump was turned on to aspirate until the thrombus was completely removed. The time taken for this process and the amount of blood in the negative pressure vacuum pump were recorded.

[0077] For Comparative Example 3, the switch was turned on, and the shaft tip began to rotate to break the clot. Simultaneously, the negative pressure vacuum pump was turned on to aspirate and expel the clot until the clot was completely cleared. The time taken for this process and the amount of blood in the negative pressure vacuum pump were recorded.

[0078] Test results:

[0079]

[0080]

[0081] Test conclusion:

[0082] The above test results show that under the test model and method used in the above in vitro simulation:

[0083] In Example 1, the method of repeatedly pulling and aspirating the thrombus through the net disk to remove the thrombus took a long time to remove old and heavy thrombi. The multiple aspirations during the removal process resulted in a large amount of blood loss.

[0084] In contrast to Example 2, the method of simple negative pressure aspiration is prone to clogging the tip of the catheter 2 for old, large-load thrombi, resulting in aspiration failure.

[0085] In Comparative Example 3, a fluid-dynamic vortex suction catheter was used. A motor drove the flexible shaft to rotate and vibrate, and the sharp-edged tip at the distal end of the flexible shaft cut the thrombus. The cut thrombus fragments were then expelled through the catheter using negative pressure. During thrombus aspiration, the thrombus fragments were entrained with the tip and, under the negative pressure, retreated into the catheter, losing contact with the thrombus and resulting in thrombus fragmentation failure. Repeated testing also occasionally revealed that the tip of the shaft exposed the distal end of the catheter during delivery, posing a risk of vascular damage.

[0086] The thrombus crushing and aspiration catheter of the present invention has significantly better clearance time and blood loss than the technical solutions of Comparative Examples 1 and 2, and the stability of the thrombus crushing and cutting head is significantly better than the technical solution of Comparative Example 3.

[0087] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A thrombus fragmentation and aspiration catheter, comprising a rotary drive handle, a catheter, a torsion-controlled spring tube, and a thrombus fragmentation cutting head, wherein the torsion-controlled spring tube is inserted into the catheter, the thrombus fragmentation cutting head is mounted at the distal end of the torsion-controlled spring tube, the output end of the rotary drive handle is fixedly connected to the proximal end of the torsion-controlled spring tube, the distal end of the catheter is connected to a negative pressure aspiration tube, and a guidewire guide channel is provided in parallel with the catheter; Its characteristics are: An annular clamp is fixedly installed on the inner wall of the distal end of the catheter, the proximal end of the bolt-breaking cutting head is rotationally abutted against the distal end face of the clamp, and the torsion-controlled spring tube is pulled and tensioned between the bolt-breaking cutting head and the rotation drive handle.

2. The thrombus fragmentation and aspiration catheter according to claim 1, characterized in that: The torsion control spring tube is a hollow spring tube formed by spirally winding single or multiple layers of metal wire.

3. The thrombus fragmentation and aspiration catheter according to claim 1 or 2, characterized in that: It also includes a Y-shaped connector, which has a main pipe and a branch pipe. The branch pipe serves as the negative pressure suction pipe. The distal end of the main pipe is fixedly connected to the catheter. The proximal end of the main pipe is installed with a locking connector and a check valve. The locking connector is located on one side of the distal end of the check valve. The torsion-controlled spring tube passes through the interior of the main pipe, and the proximal end of the torsion-controlled spring tube passes through the locking connector and the check valve. The part of the torsion-controlled spring tube that passes through the proximal end of the main pipe is connected to the output end of the rotation drive handle.

4. The thrombus fragmentation and aspiration catheter according to claim 3, characterized in that: The proximal end of the torsion control spring tube is fused with nylon barrier material by thermo-rheological means, the output end of the rotation drive handle has a locking Luer, and the end of the torsion control spring tube fused with nylon barrier material passes through the check valve and is fixedly inserted into the interior of the locking Luer.

5. The thrombus fragmentation and aspiration catheter according to claim 4, characterized in that: The rotation drive handle includes a shell, in which a reduction motor, a driving gear and a driven gear are installed. The driving gear is connected to the output end of the reduction motor, and the driven gear is engaged with the driving gear. The driven gear is fixedly sleeved on the outside of the locking Luer. A switch for controlling the reduction motor is provided on the outside of the shell, the main pipe is fixedly installed inside the shell, and the branch pipe extends out of the shell.

6. The thrombus fragmentation and aspiration catheter according to claim 1, characterized in that: A plurality of support wings are distributed circumferentially around the proximal end of the bolt cutting head, and the support wings include an arc-surface cylindrical protrusion, the proximal end of the arc-surface cylindrical protrusion abuts against the distal end of the annular clamp, and the arc surface of the arc-surface cylindrical protrusion abuts against the inner wall of the catheter circumferentially.

7. The thrombus fragmentation and aspiration catheter according to claim 6, characterized in that: The bolt-breaking cutting head includes a central axis and a plurality of spiral blades distributed circumferentially around the central axis. The supporting wings are located at the proximal ends of the spiral blades. A bolt-discharging channel is formed between any two adjacent spiral blades.

8. The thrombus fragmentation and aspiration catheter according to claim 6 or 7, characterized in that: Edge cutting edges are provided on both sides of each of the arc-surface cylindrical protrusions.

9. The thrombus fragmentation and aspiration catheter according to claim 7, characterized in that: The distal end of the torsion control spring tube is fixedly connected with a connecting wire, the proximal end of the central shaft is a hollow structure, and the distal end of the connecting wire is inserted into the interior of the central shaft and fixed to the central shaft by laser welding.

10. The thrombus fragmentation and aspiration catheter according to claim 1, characterized in that: The distal end of the catheter is connected to a guidewire guide tube, which serves as the guidewire guiding channel.

11. The thrombus fragmentation and aspiration catheter according to claim 10, characterized in that: The catheter comprises a first PTFE liner layer, a first metal braided layer wrapped around the outside of the first PTFE liner layer, and a first polymer material layer heat-melted and bonded to the outside of the first metal braided layer, wherein the flexibility of the first polymer material layer gradually increases from the proximal end to the distal end; The guidewire guide tube includes a second PTFE sleeve layer, a second metal braided layer wrapped around the outside of the second PTFE sleeve layer, and a second polymer material layer heat-melted and bonded to the outside of the second metal braided layer. The flexibility of the second polymer material layer gradually increases from the proximal end to the distal end.

12. The thrombus fragmentation and aspiration catheter according to claim 11, characterized in that: The materials of the first polymer material layer from the distal end to the proximal end are selected in sequence from at least two materials selected from TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 and are fused to each other by thermorheological means; The second polymer material layer is made of at least two materials selected from the group consisting of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 from the distal end to the proximal end, and the materials are fused to each other by thermorheological means; The first polymer material layer and the second polymer material layer are connected by thermal melting.

13. The thrombus fragmentation and aspiration catheter according to claim 10, 11 or 12, characterized in that: The proximal end of the guidewire guiding tube is a bevel structure.

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