Thrombus breaking suction catheter

Abstract

The utility model 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] This application belongs to the field of thrombosis treatment device technology, and more specifically, relates to a thrombus fragmentation and aspiration catheter. Background Technology

[0002] A thrombus is a small blood clot that forms within the blood vessels of the cardiovascular system. It is 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, more rigid thrombi often require mechanical aspiration for treatment.

[0003] In the prior art, invention patent CN111031943A discloses a hydrodynamic vortex aspiration catheter, which uses a motor to drive the rotation and vibration of a flexible shaft. The thrombus is cut through a sharp-edged tip at the distal end of the flexible shaft, and the fragmented thrombus is discharged along the catheter under negative pressure to treat large thrombi. In this patent, because the sharp-edged tip of the flexible shaft is free within the catheter, and the catheter requires negative pressure aspiration to fragment the thrombus, the fragmented thrombus may be squeezed into the catheter lumen during movement. This could cause the tip to move away from the thrombus, affecting fragmentation efficiency, or the tip might move axially out of the catheter tip and into the blood vessel, causing damage. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application provides a thrombus fragmentation and aspiration catheter that can limit the axial position of the fragmentation head by applying a certain tension to the torsion-controlled spring tube, thereby preventing the fragmentation head from moving away from the thrombus under the squeezing action of the fragments or causing the fragmentation head to move out of the catheter tip and enter the blood vessel, resulting in vascular damage.

[0005] To achieve the above objectives, the technical solution of this application provides a thrombus fragmentation and aspiration catheter, including a rotation drive handle, a catheter, a torsion control spring tube, and a fragmentation cutter. The torsion control spring tube is inserted inside the catheter, and the fragmentation cutter is installed at the distal end of the torsion control spring tube. The output end of the rotation drive handle is fixedly connected to the proximal end of the torsion control spring tube. A negative pressure aspiration tube is connected to the end of the catheter, and a guidewire guiding channel is provided in parallel with the catheter. An annular clamp is fixedly installed on the inner wall of the distal end of the catheter, and the proximal end of the fragmentation cutter rotatably abuts against the distal end face of the clamp. The torsion control spring tube is pulled and tensioned between the fragmentation cutter and the rotation drive handle.

[0006] Rotating the drive handle causes the torsion-controlled spring tube to rotate, thereby actuating the thrombectomy head for thrombectomy. Due to the restriction of the annular clamp, the thrombectomy head will not move away from the thrombus under the pulling force of the torsion-controlled spring tube and the squeezing force of the thrombus fragments, ensuring that the thrombectomy head remains in contact with the thrombus, thus guaranteeing thrombectomy efficiency and effectiveness. Simultaneously, because the torsion-controlled spring tube is under tension, the thrombectomy head remains in contact with the distal end of the annular clamp and will not separate from it. This prevents the thrombectomy head from slipping out of the distal end of the catheter, avoiding the risk of the thrombectomy head contacting and damaging the vessel wall, and improving the safety of the procedure.

[0007] Optionally, the torsion control spring tube is a hollow spring tube formed by spirally winding single or multiple layers of metal wire, which gives the torsion control spring tube flexible deformation ability and torque transmission ability, as well as a certain tensile capacity. By stretching the torsion control spring tube, a certain tension force can be achieved inside, realizing the pulling of the broken bolt cutter head and ensuring that the support wing on the broken bolt cutter head always abuts against the annular clamp.

[0008] Optionally, it also includes a Y-shaped connector, which has a main tube and a branch tube. The branch tube serves as a negative pressure suction tube. The distal end of the main tube is fixedly connected to a catheter, and the proximal end of the main tube is equipped with a locking connector and a check valve. The locking connector is located on one side of the distal end of the check valve. A torsion control spring tube passes through the interior of the main tube, with its proximal end passing through the locking connector and the check valve. The portion of the torsion control 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 prevents blood and thrombus fragments 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 nylon barrier material via thermorheological means. The output end of the rotating drive handle has a locking lug. The end of the torsion control spring tube with the nylon barrier material passes through the check valve and is fixedly inserted into the interior of the locking lug. Due to the inherent structural limitations of the torsion control spring tube, there will be gaps inside. The nylon barrier material is fused and embedded between the spring wires of the torsion control spring tube, forming a sealed structure. Sealing and filling the internal gaps at the proximal end of the torsion control spring tube with nylon barrier material can increase the sealing performance between it and the check valve, reducing bleeding. At the same time, it can ensure the rigidity of the proximal end of the torsion control spring tube, preventing the connection from being weak due to the plasticity of the torsion control spring tube itself when connected to the locking lug.

[0010] Optionally, the rotating drive handle includes a housing, within which a reduction motor, a drive gear, and a driven gear are installed. The drive gear is connected to the output end of the reduction motor, and the driven gear meshes with the drive gear. The driven gear is fixedly sleeved on the outside of the locking lug. A switch for controlling the reduction motor is provided on the outside of the housing. The main pipe is fixedly installed inside the housing, and the branch pipe extends out of the housing. By holding the housing and controlling the switch, the reduction motor can be used to control the bolt breaking cutter for bolt breaking operations. The structure is simple and convenient.

[0011] Optionally, several support wings are distributed circumferentially around the proximal end of the thrombectomy head. Each support wing includes an arc-shaped cylindrical protrusion. The proximal end of the arc-shaped cylindrical protrusion abuts against the distal end of the annular clamp, and the arc surface of the arc-shaped cylindrical protrusion abuts circumferentially against the inner wall of the catheter. In this case, the entire thrombectomy head abuts against both the annular clamp and the inner wall of the catheter circumferentially, preventing radial movement of the thrombectomy head and further ensuring its positional stability. The arc-shaped cylindrical protrusion has line contact with the inner wall of the catheter, and the contact area is smooth. During rapid rotation, this reduces the contact area with the inner wall of the catheter, resulting in smoother rotation.

[0012] Optionally, the thrombectomy head includes a central axis and several helical blades circumferentially distributed around the central axis. Support wings are located near the proximal ends of the helical blades, and a thrombectomy channel is formed between any two adjacent helical blades. The thrombectomy head can better remove thrombi under the rotational guidance of the helical blades. Thinner blades minimize the area occupied by the thrombectomy head's cross-section, thereby maximizing the cross-sectional area of ​​the thrombectomy channel, improving thrombectomy efficiency, reducing operative time, and indirectly reducing bleeding.

[0013] Optionally, each arc-shaped cylindrical protrusion has edge cutting edges on both sides. When the broken bolts pass through the bolt removal channel, they come into contact with the edge cutting edges, which partially cut the broken bolts that accumulate between the bolt cutting head annular clamps for secondary cutting, thus improving the bolt transfer efficiency.

[0014] Optionally, a connecting wire is fixedly connected to the distal end of the torsion-controlled spring tube, and the proximal end of the central axis is a hollow structure. The distal end of the connecting wire passes through the interior of the central axis and is laser-welded to it. The connecting wire, serving as the connection between the torsion-controlled spring tube and the thrombectomy head, can be made very thin, for example, with a diameter between 0.016 inches and 0.020 inches. It can be made of materials such as nickel-titanium alloy or SST316 stainless steel, and also possesses a certain degree of flexibility. The thinner wire diameter significantly reduces the cross-sectional size of the central axis, increases the cross-sectional area of ​​the thrombectomy channel, and improves thrombectomy efficiency, thereby reducing bleeding by shortening the operation time. Simultaneously, the flexible connecting wire can deform flexibly without affecting the adjustment of the thrombectomy head's orientation.

[0015] Optionally, a guidewire guide tube is connected to the distal end of the catheter, serving as a guidewire guidance channel. Unlike existing technologies, the guidewire guide tube is not located inside the torsion-controlled tube, but rather on the catheter itself. When the thrombectomy head and the torsion-controlled tube catheter are inserted along the guidewire to the thrombus site, if the guidewire is inside the torsion-controlled tube, the tube cannot be activated, requiring the guidewire to be withdrawn. Otherwise, the guidewire will rotate and potentially puncture the vessel. By placing the guidewire guide tube on the catheter, the guidewire does not need to be withdrawn during thrombectomy, and the catheter's direction cannot be adjusted repeatedly, reducing surgical steps.

[0016] Optionally, the catheter includes a first PTFE liner, a first metal braided layer wrapped around the outside of the first PTFE liner, and a first polymer material layer thermally bonded to the outside of the first metal braid, wherein the flexibility of the first polymer material layer gradually increases from the proximal end to the distal end; the guidewire includes a second PTFE liner, a second metal braided layer wrapped around the outside of the second PTFE liner, and a second polymer material layer thermally bonded to the outside of the second metal braid, wherein the flexibility of the second polymer material layer gradually increases from the proximal end to the distal end.

[0017] The first and second PTFE bushing layers increase internal lubrication. Sufficient lubrication in the first PTFE bushing layer prevents the accumulation of loose plugs and facilitates rapid transfer. Sufficient lubrication in the second PTFE bushing layer facilitates sliding along the guidewire. The first and second metal braided layers increase torsional control, facilitating orientation adjustment. The gradually increasing flexibility of the first and second polymer material layers from proximal to distal makes distal orientation adjustment easier.

[0018] Optionally, the materials of the first polymer material layer from the distal end to the proximal end are selected sequentially from TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, and fused together by thermorheological means; the flexibility of the materials of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 gradually decreases, so as to achieve the effect of gradual change in the flexibility 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 sequentially from at least two of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, and fused together by thermorheological means; the flexibility of the materials TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 gradually decreases, achieving the effect of gradual change in the flexibility of the second polymer material layer.

[0020] The first polymer material layer and the second polymer material layer are thermally fused together to connect the catheter and guidewire into a whole.

[0021] Optionally, the proximal end of the guidewire cannula has a beveled structure. The guidewire cannula typically covers the entire path of the atrium and ventricle, and a beveled proximal end prevents the sharp tip from snagging on blood vessels or the heart wall.

[0022] The advantages of the technical solution in this application compared to the prior art are as follows:

[0023] Rotating the drive handle causes the torsion-controlled spring tube to rotate, thereby actuating the thrombectomy head for thrombectomy. Due to the restriction of the annular clamp, the thrombectomy head will not move away from the thrombus under the pulling force of the torsion-controlled spring tube and the squeezing force of the thrombus fragments, ensuring that the thrombectomy head remains in contact with the thrombus, thus guaranteeing thrombectomy efficiency and effectiveness. Simultaneously, because the torsion-controlled spring tube is under tension, the thrombectomy head remains in contact with the distal end of the annular clamp and will not separate from it. This prevents the thrombectomy head from slipping out of the distal end of the catheter, avoiding the risk of the thrombectomy head contacting and damaging the vessel wall, and improving the safety of the procedure. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

[0027] Figure 3 This is a schematic diagram of a conduit structure connected by an annular clamp and a Y-shaped structure;

[0028] Figure 4 A schematic diagram of the rotating drive handle structure;

[0029] Figure 5 A schematic diagram of a torsion control spring tube structure connected to a break-bolt cutter;

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

[0031] Figure 7 A schematic diagram of a pulmonary artery with a high load of old thrombus used in an in vitro simulation.

[0032] Figure 8 A schematic diagram illustrating the insertion of a pulmonary artery thrombus removal catheter into a cardiac vascular model;

[0033] Figure 9 This is a schematic diagram of the process of breaking up old thrombi.

[0034] Icons: 1. Rotating drive handle; 101. Locking Luer; 102. Housing; 103. Gear reducer motor; 104. Drive gear; 105. Driven gear; 106. Switch; 2. Conduit; 201. First PTFE bushing layer; 202. First metal braided layer; 203. First polymer material layer; 3. Torque control spring tube; 301. Barrier material; 302. Connecting metal wire; 4. Plug cutter head; 401. Support wing; 402. Arc-shaped cylindrical protrusion; 403. Central shaft; 404. Spiral blade; 405. Plug removal channel; 406. Edge blade; 407. Slotted structure; 5. Annular 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 braided layer; 903. Second polymer material layer. Detailed Implementation

[0035] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of 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 away from the thrombus.

[0038] based on Figure 1 and Figure 2As shown, the thrombus fragmentation and aspiration catheter includes a rotation drive handle 1, a catheter 2, a torsion-controlled spring tube 3, and a fragmentation cutter 4. The torsion-controlled spring tube 3 is inserted inside the catheter 2, and the fragmentation cutter 4 is installed at the distal end of the torsion-controlled spring tube 3. The output end of the rotation drive handle 1 is fixedly connected to the proximal end of the torsion-controlled spring tube 3. The distal end of the catheter 2 is connected to a negative pressure aspiration tube. A guidewire guidance channel is provided parallel to the catheter 2. Under the guidance of the guidewire, the distal end of the thrombus fragmentation and aspiration catheter is used to penetrate along the vascular pathway to the site of thrombus occurrence. The rotation drive handle 1 drives the fragmentation cutter 4 to rotate via the torsion-controlled spring tube 3 to perform the fragmentation operation. The negative pressure aspiration tube is used to connect to an aspiration pump or syringe. By activating the aspiration pump or pulling the syringe, negative pressure is generated within the catheter 2 to aspirate the fragmented thrombi.

[0039] Based on the above structure, an annular clamp 5 is fixedly installed on the distal inner wall of catheter 2. The proximal end of the fragmentation head 4 rotates and abuts against the distal end face of the clamp. The torsion control spring tube 3 is pulled and tensioned between the fragmentation head 4 and the rotating drive handle 1. Due to the restriction of the annular clamp 5, the fragmentation head 4 will not move away from the thrombus under the pulling action of the torsion control spring tube 3 and the squeezing action of the fragmented thrombus, ensuring that the fragmentation head 4 is always in contact with the thrombus, ensuring fragmentation efficiency and effect. At the same time, since the torsion control spring tube 3 is in a pulled and tensioned state, it can be ensured that the fragmentation head 4 is always abutting against the distal end of the annular clamp 5 and will not separate from the annular clamp 5. This ensures that the fragmentation head 4 will not move out from the distal end of catheter 2, avoiding the risk of the fragmentation head 4 contacting the blood vessel wall and damaging the blood vessel, thus improving the safety of the operation.

[0040] In this embodiment, the annular clamp 5 is preferably a ring-shaped stainless steel ring with a wall thickness of 0.2mm to 0.3mm. Its outer diameter is 0.2mm to 0.6mm larger than the inner diameter of the distal end of the conduit 2. It is inserted into the distal end of the conduit 2 by an interference fit to ensure stable positioning. The edges of the annular clamp 5 are rounded to prevent damage to the inner cavity of the conduit 2 during installation. It is conceivable that the annular clamp 5 could also be made of rigid plastic or other materials such as titanium alloy. Alternatively, the annular clamp 5 can protrude from the inner wall of the conduit 2 as part of the inner wall structure, simply to block the proximal end of the thrombus cut-off head 4.

[0041] Furthermore, the torsion-controlled spring tube 3 is a hollow spring tube formed by spirally winding single or multiple layers of metal wires, with the wire diameter ranging from 0.05mm to 0.1mm. The number of strands is 18 or 24. The material is SUS304 stainless steel or MP35N. In this embodiment, the torsion-controlled spring tube 3 is a hollow spring tube formed by spirally winding 18 strands of 0.08mm fine wires of three-layer SUS304 stainless steel. After assembly, the overlapping positions are laser-welded under conditions of 45A current, 2.5ms pulse width, 1.0Hz frequency, and 0.1mm spot diameter to form a torsion-controlled spring tube 3 with an outer diameter of 1.45mm, an inner diameter of 0.95mm, and a length of 1.2 meters. The torsion-controlled spring tube 3, in addition to having flexible deformation capability and torque transmission capability, also possesses a certain tensile strength. The torsion-controlled spring tube 3 can achieve a certain internal tension through stretching, thereby pulling the bolt cutter head 4 and ensuring that the support wing 401 on the bolt cutter head 4 is always in contact with the annular clamp 5. It can be inferred that the torsion-controlled spring tube 3 can also be made of single or double layers of metal wire spirally wound, and the winding method can be clockwise or counterclockwise. The size and the number of fine wire strands in each layer can be adjusted according to the actual situation.

[0042] Furthermore, based on Figures 1 to 4 As shown, it also includes a Y-shaped connector 6, which has a main tube 601 and a branch tube 602. The branch tube 602 serves as a negative pressure suction tube for connecting a suction pump or syringe. The distal end of the main tube 601 is fixedly connected to the catheter 2, and the proximal end of the main tube 601 is equipped with a locking connector 7 and a check valve 8 to prevent blood and thrombus fragments from flowing out from the proximal end of the main tube 601, thereby reducing 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 tube 601, and the proximal end of the torsion control spring tube 3 is positioned through the locking connector 7 and the check valve 8. The portion of the torsion control spring tube 3 extending out of the proximal end of the main tube 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 torsion control spring tube 3 is fused with nylon barrier material 301 via thermorheological bonding. The output end of the rotating drive handle 1 has a locking lug 101. The end of the torsion control spring tube 3 with the nylon barrier material 301 passes through the check valve 8 and is fixedly inserted into the locking lug 101. The nylon barrier material 301 can be PA12 or Pebax, such as Pebax 72D. In this embodiment, PA12 is used. Specifically, during manufacturing, a PA12 material tube is sleeved on the proximal end of the torsion control spring tube 3, covering a length of 10cm to 20cm, and thermorheological bonding is performed in a high-temperature air chamber at a temperature of 300℃ and an air flow rate of 40SCFH. Due to the limitations of the torsion control spring tube 3's own structure, there will be gaps inside. The nylon barrier material 301 is fused and embedded between the spring wires of the torsion control spring tube 3 to form a sealed structure. By sealing and filling the internal gap at the proximal end of the torsion control spring tube 3 with nylon barrier material 301, the airtightness between it and the check valve 8 can be increased, the amount of bleeding can be reduced, and the rigidity of the proximal end of the torsion control spring tube 3 can be guaranteed, so that the connection will not be weak due to the plasticity of the torsion control spring tube 3 itself when it is connected to the locking Luer 101.

[0044] Furthermore, based on Figure 4 As shown, the rotating drive handle 1 includes a housing 102. A reduction motor 103, a drive gear 104, and a driven gear 105 are installed inside the housing 102. The drive gear 104 is connected to the output end of the reduction motor 103, and the driven gear 105 meshes with the drive gear 104. The driven gear 105 is fixedly sleeved on the outside of the locking lug 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 for connection to a suction pump or syringe. In use, by holding the housing 102 and toggling the switch 106, the reduction motor 103 controls the bolt-breaking head 4 to perform bolt-breaking operations. The structure is simple and convenient. It is conceivable that the housing 102 also contains a corresponding circuit board and conventional components such as a battery or external power cord for power supply, which will not be described in detail here.

[0045] Furthermore, based on Figure 2As shown, in this embodiment, several sets of support wings 401 are distributed circumferentially around the proximal end of the thrombectomy head 4, i.e., at least two sets of support wings 401. In this embodiment, the number of support wings 401 is three sets. The support wing 401 includes an arc-shaped cylindrical protrusion 402, the proximal end of which abuts against the distal end of the annular clamp 5, realizing the abutment between the thrombectomy head 4 and the annular clamp 5. The arc surface of the arc-shaped cylindrical protrusion 402 abuts circumferentially against the inner wall of the conduit 2. At this time, the entire thrombectomy head 4 abuts against the annular clamp 5 and also abuts circumferentially against the inner wall of the conduit 2, avoiding radial movement of the thrombectomy head 4 and ensuring the stability of the position of the thrombectomy head 4. The arc-shaped cylindrical protrusion 402 has line contact with the inner wall of the conduit 2 and the contact area is smooth. When rotating rapidly, the contact area with the inner wall of the conduit 2 is reduced, making the rotation smoother and preventing the thrombectomy head 4 from getting stuck. If the thrombectomy head 4 becomes stuck while the torsion control spring tube 3 continues to rotate, stress will accumulate inside the torsion control spring tube 3. If the stress is suddenly released after accumulating to a certain level, the thrombectomy head 4 may suddenly vibrate and rotate violently, impacting the inner wall of the catheter 2, causing damage to the blood vessel and leading to danger. The thrombectomy pieces are discharged through the gap between the two support wings 401. It is conceivable that the number of support wings 401 could also be set to two or four sets, 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 set them reasonably according to the actual situation.

[0046] based on Figure 2 As shown, the thrombectomy head 4 includes a central axis 403 and a plurality of helical blades 404 circumferentially distributed around the central axis 403. In this embodiment, there are three helical blades 404. A support wing 401 is located at the proximal end of the helical blades 404, and a thrombectomy channel 405 is formed between any two adjacent helical blades 404. The thrombectomy head can be better discharged under the rotational guidance of the helical blades 404. The thin blade structure can minimize the occupation of the cross section of the thrombectomy head 4, so as to maximize the cross-sectional area of ​​the thrombectomy channel 405, improve the thrombectomy efficiency, reduce the operation time, and indirectly reduce the amount of bleeding. With the support of the arc-shaped cylindrical protrusion 402, the radial position of the entire thrombectomy head 4 will not wobble relative to the catheter 2, ensuring that the helical blades 404 will not contact the inner wall of the catheter 2. When the thrombectomy head 4 rotates at high speed, the helical blades 404 will not cut the inner wall of the catheter 2 to generate 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 has an edge blade 406 on both sides. When the fragmented thrombus passes through the thrombus removal channel 405, it contacts the edge blade 406, which partially shreds the fragmented thrombus that accumulates between the annular clamps 5 of the fragmentation head 4 for secondary cutting, thus improving the thrombus transfer efficiency. It is conceivable that the number of spiral blades 404 could also be set to two or four sets, etc. The more spiral blades 404 there are, the larger the area they occupy on the cross-section of the catheter 2, and the lower the thrombus removal efficiency will be. 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 set them reasonably according to actual conditions.

[0048] In this embodiment, the thrombectomy 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 thrombectomy head 4. Sufficient channel area helps to rapidly aspirate and transfer the fragmented plaque. Increased transfer speed can reduce thrombus removal time and indirectly reduce bleeding. The spiral blade 404 is uniformly oriented clockwise or counterclockwise, and the thickness of the thinnest part of the spiral blade 404 is 0.1 mm-0.5 mm. In actual manufacturing, the blade thickness can gradually increase from the distal end to the proximal end. The distal blade has sufficient contact with the thrombus, and its thinner thickness can improve sharpness and enhance the thrombectomy effect. The proximal blade has less contact with the thrombus, and its thicker thickness can improve strength.

[0049] Furthermore, based on Figure 2As shown, a connecting wire 302 is fixedly connected to the distal end of the torsion-controlled spring tube 3. The proximal end of the central axis 403 is a hollow structure, and the distal end of the connecting wire 302 passes through the interior of the central axis 403 and is laser-welded to the central axis 403. The connecting wire 302, as the connection part between the torsion-controlled spring tube 3 and the thrombectomy 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 nickel-titanium alloy or SST316 stainless steel, etc., and also has a certain degree of flexibility. The thinner wire diameter can significantly reduce the cross-sectional size of the central axis 403. It basically does not occupy the thrombus aspiration channel area after the thrombectomy head 4 and the annular clamp 5 are assembled, which greatly increases the effective cross-sectional area of ​​the cavity, which is conducive to the rapid aspiration and transfer of the fragmented thrombus, eliminating the risk of thrombus blockage, shortening the operation time, and reducing the risk of blood loss. At the same time, the flexible connecting wire 302 exposed at the root on the outside of the central axis 403 can deform flexibly, reducing rigidity and having better bending ability in blood vessels and the heart. To facilitate laser welding, a slotted structure 407 can be provided on the proximal sidewall of the central shaft 403. In this embodiment, the proximal end of the connecting wire 302 is inserted into the distal end of the torsion control spring tube 3, with an overlap length of approximately 0.5cm-1.0cm. The exposed length of the connecting wire 302 is 5cm-20cm. After assembly, laser welding is performed on the overlapping area using laser welding parameters of 40A-50A current, 2.0ms-3.0ms pulse width, 0.7Hz-1.0Hz frequency, and 0.1mm-0.3mm spot diameter. Simultaneously, the connecting wire 302 is inserted into the interior of the central shaft 403, and the laser is focused on the edge of the overlap area between the slotted structure 407 of the bolt cutter head 4 and the connecting wire 302. After assembly, laser welding is performed on the overlapping area using laser welding parameters of 40A-50A current, 2.0ms-3.0ms pulse width, 0.7Hz-1.0Hz frequency, and 0.1mm-0.3mm spot diameter. The slotted structure 407 serves to provide a laser welding area while also reducing the cross-sectional area occupied by the central shaft 403 and increasing the cross-sectional area of ​​the bolt channel 405.

[0050] Furthermore, based on Figure 1 and Figure 3As shown, the distal end of catheter 2 is connected to a guidewire guide tube 9, which serves as the guidewire guiding channel. Unlike existing technologies, the guidewire guide tube 9, where the guidewire is inserted, is not located inside the torsion-controlled spring tube 3, but rather on catheter 2. When the thrombectomy head 4, torsion-controlled spring tube 3, and catheter 2 enter the thrombus site along the guidewire, if the guidewire is inside the torsion-controlled spring tube 3, the torsion-controlled spring tube 3 cannot be activated to rotate, requiring the guidewire to be withdrawn; otherwise, the guidewire will rotate and easily puncture the blood vessel. By placing the guidewire guide tube 9 on catheter 2, the guidewire does not need to be withdrawn when the thrombectomy head 4 is working, and the guidewire does not need to be repeatedly inserted when the direction of catheter 2 needs to be adjusted, reducing surgical steps. The distal end of the guidewire guide tube 9 is flush with the distal end of catheter 2, with a total length of approximately 25cm-35cm, ensuring that the entire guidewire lumen covers the entire path of the atrium and ventricle when clearing pulmonary thrombi, preventing the guidewire from branching within the heart and affecting the proper delivery of catheter 2.

[0051] Furthermore, based on Figure 6 As shown, the catheter 2 includes a first PTFE liner 201, a first metal braided layer 202 wrapped around the outside of the first PTFE liner 201, and a first polymer material layer 203 heat-fused 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 liner 901, a second metal braided layer 902 wrapped around the outside of the second PTFE liner 901, and a second polymer material layer 903 heat-fused 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 liner 201 and the second PTFE liner 901 can increase internal lubrication. Sufficiently lubricated first PTFE liner 201 can prevent the deposition of emboli and facilitate rapid transfer. Sufficiently lubricated second PTFE liner 901 facilitates sliding along the guidewire. The first metal braided layer 202 and the second metal braided layer 902 can increase torsional control and facilitate orientation adjustment. The first polymer material layer 203 and the second polymer material layer 903, which have gradually increased flexibility from the proximal end to the distal end, make the orientation 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 or titanium alloy. The materials of the first polymer material layer 203, from distal to proximal, are selected sequentially from TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, with at least two materials fused together via thermorheological means. Since the flexibility of the materials TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12 gradually decreases, they must be arranged sequentially from distal to proximal to achieve a gradual change in flexibility in the first polymer material layer 203. Similarly, the materials of the second polymer material layer 903, from distal to proximal, are selected sequentially from TPU45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, with at least two materials fused together via thermorheological means. Since the flexibility of the materials in the second polymer material layer 903 gradually decreases from TPU45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, to PA12, they must be arranged sequentially from distal to proximal without changing the order, in order to achieve a gradual change in flexibility in the second polymer material layer 903. The first polymer material layer 203 and the second polymer material layer 903 are thermally fused together to connect the conduit 2 and the guidewire guide tube 9 into a single unit.

[0053] In this embodiment, the materials of the first polymer material layer 203 from distal to proximal are TPU 45A, Pebax 35D, Pebax 55D, Pebax 72D, and PA12, respectively, and the materials of the second polymer material layer 903 from distal to proximal are TPU 45A and Pebax 35D, respectively. It is conceivable that in other embodiments, the quantity and type of materials of the first polymer material layer 203 and the second polymer material layer 903 can be reasonably selected and combined within the above-defined range. For example, the materials of the first polymer material layer 203 from distal to proximal are TPU1074A, Pebax 35D, Pebax 45D, Pebax 63D, Pebax 72D, and PA12, respectively, and the materials of the first polymer material layer 203 from distal to proximal are TPU 45A, TPU1074A, and Pebax 45D, respectively. Specific permutations and combinations are not exhaustively listed.

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

[0055] By fixing the PTFE bushing to the lubricated mandrel, installing stainless steel braid on the PTFE bushing and tightening it to form the middle layer, and then successively placing TPU 45A, Pebax35D, Pebax55D, Pebax72D, and PA12 polymer tubing onto the stainless steel braid to form the outer layer, and finally covering the surface with heat shrink tubing, thermorheological coating is performed under the parameters of temperature 250℃-400℃, air flow rate 30SCFH-40SCFH, and moving speed 1.0mm / s-2.5mm / s.

[0056] The fabrication process of the guidewire guide tube 9 is as follows:

[0057] By fixing the PTFE bushing to the lubricated mandrel, TPU 45A and Pebax 35D polymer material tubing are successively fitted onto the PTFE bushing to form an outer layer, and heat shrink tubing is applied to the surface. Thermorheological coating is performed under the following parameters: temperature 250℃-400℃, air flow rate 30SCFH-40SCFH, and moving speed 1.0mm / s-2.5mm / s.

[0058] After the catheter 2 and guidewire guide tube 9 are fabricated, their distal ends are attached together, covered with heat shrink tubing, and the outer layers of the two are thermorheologically melted and bonded together under the parameters of temperature 250℃-400℃, air flow rate 30SCFH-40SCFH, and moving speed 1.0mm / s-2.5mm / s, and a hydrophilic lubricating coating is applied to the surface.

[0059] Optionally, the proximal end of the guidewire cannula 9 has a beveled structure. The guidewire cannula 9 generally covers the entire path of the atrium and ventricle, and the beveled structure of the proximal end of the guidewire cannula 9 will prevent the sharp end from snagging on blood vessels or the inner wall of the heart.

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

[0061] Step 1, Preoperative preparation and anesthesia: Preoperative preparation and anesthesia are performed for the patient in accordance with medical association guidelines or relevant guidelines.

[0062] Step two, puncture and establishment of vascular access: Under the guidance of imaging equipment (such as X-ray, CT, or angiography machine), puncture is performed through the femoral vein, and a 13F or 14F catheter sheath is inserted. A pigtail catheter 2 and a 0.035in guidewire are inserted into the catheter sheath. The guidewire is followed along the pigtail catheter until the location of the pulmonary thrombus, thus establishing a guidewire access from the right femoral vein → external iliac vein → common iliac vein → inferior vena cava → right atrium → right ventricle → pulmonary artery.

[0063] Step 3: Deployment of Catheter 2 for Pulmonary Artery Old Thrombus Removal: Insert the proximal end of the 0.035-inch guidewire into the guidewire guide tube 9, and advance catheter 2 along the guidewire. Under imaging equipment and angiography, advance catheter 2 to the thrombus location, ensuring that the distal end of catheter 2 contacts the thrombus.

[0064] Step 4: Connect branch line 602 to the aspiration pump or syringe. Start the aspiration pump or pull the syringe to begin negative pressure aspiration. At this point, the old thrombus is drawn to the distal end of catheter 2 and becomes lodged. Turn on switch 106 to start the rotation of the thrombectomy head 4 to begin breaking up the thrombus. Simultaneously, with the help of negative pressure aspiration, the fragmented thrombus is quickly aspirated into the aspiration pump or syringe. Multiple angiography sessions may be required during the thrombectomy process to confirm whether the blood vessel is reopened.

[0065] Step 5: After confirming vascular recanalization, turn on switch 106 to close the thrombectomy head 4 and end the negative pressure aspiration state. Withdraw catheter 2 along the 0.035in guidewire from the body and perform postoperative care.

[0066] Comparative Example 1:

[0067] According to the invention patent CN113855164A entitled "A Mesh Disk Type Mechanical Thrombus Removal Catheter Device," a mesh disk type thrombus removal catheter was prepared. Its thrombus removal principle involves releasing a mesh disk within the catheter, embedding the disk inside the thrombus, and then using a combination of thrombus pulling and negative pressure suction to drag the thrombus into the catheter, thereby removing it from the body.

[0068] Comparative Example 2:

[0069] Use only conduit 2 to connect to a negative pressure pump for suction.

[0070] Comparative Example 3:

[0071] According to the invention patent CN111031943A entitled "Fluorodynamic Vortex Suction Conduit", a suction conduit is prepared, specifically using the method described in that patent. Figure 8 The experiment was conducted using the flexible shaft shown in Figure C and the shaft tip shown in Figure 11A. The principle of thrombectomy is to rotate and cut the thrombus through the shaft tip with a sharp edge at the distal end of the flexible shaft, and then aspirate the thrombus out along the negative pressure of the catheter by vacuum source.

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

[0073] Reference Figure 7 , Figure 8 and Figure 9As shown, a pulmonary artery vascular model was used, and an old thrombus prepared with fresh pig blood was placed into the model. A pathway was established using a 0.035-inch guidewire. The devices of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 were pushed along the guidewire to the thrombus site in the model. A negative pressure vacuum pump was used for negative pressure aspiration.

[0074] In Example 1, switch 106 is turned on, and the thrombectomy head 4 begins to rotate and break up the thrombus. At the same time, the negative pressure vacuum pump is turned on to aspirate and remove the thrombus fragments until the thrombus is completely cleared. The time taken and the amount of blood in the negative pressure vacuum pump are recorded during this process.

[0075] For Comparative Example 1, the mesh tray support was released at the thrombus location using the handle. Two minutes later, the handle was used to drag the thrombus through the mesh tray into the lumen of catheter 2, while simultaneously initiating aspiration. After a single procedure, the device was removed, and the lumen of catheter 2 was flushed until no residual thrombus was found. This process was repeated multiple times until the thrombus was completely removed. The time taken and the amount of blood in the vacuum pump were recorded.

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

[0077] For Comparative Example 3, the switch was turned on, and the shaft tip began to rotate and break up the thrombus. At the same time, the negative pressure vacuum pump was turned on to suction out the broken thrombus until the thrombus was completely removed. The time taken and the amount of blood in the negative pressure vacuum pump were recorded during this process.

[0078] Experimental results:

[0079]

[0080]

[0081] Experimental conclusion:

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

[0083] In Comparative Example 1, the thrombus was removed by repeated thrombectomy and aspiration using a mesh tray. For old thrombi with a large thrombus load, the removal time was very long. The multiple aspiration processes resulted in significant blood loss.

[0084] In Comparative Example 2, the simple negative pressure aspiration method is prone to blocking the tip of catheter 2 for old, high-load thrombi, leading to aspiration failure.

[0085] In Comparative Example 3, a hydrodynamic vortex aspiration catheter was used. A motor-driven flexible shaft rotated and vibrated, cutting the thrombus through its sharp-edged distal end. The fragmented thrombus was then expelled through the catheter under negative pressure. During aspiration, the fragments, carrying the distal end of the shaft, were retracted into the catheter under the negative pressure, failing to maintain contact with the thrombus and resulting in fragmentation failure. In repeated trials, the distal end of the shaft was occasionally exposed during delivery, posing a risk of vascular damage.

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

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

Claims

1. A thrombus fragmentation and aspiration catheter, comprising a rotation drive handle, a catheter, a torsion control spring tube, and a fragmentation cutter, wherein the torsion control spring tube is inserted inside the catheter, the fragmentation cutter is installed at the distal end of the torsion control spring tube, the output end of the rotation drive handle is fixedly connected to the proximal end of the torsion control spring tube, the distal end of the catheter is connected to a negative pressure aspiration tube, and the catheter is provided with guidewire guidance channels in parallel. characterized in that An annular clamp is fixedly installed on the inner wall of the distal end of the catheter. The proximal end of the thrombectomy head rotatably abuts against the distal end face of the clamp. The torsion control spring tube is pulled and tensioned between the thrombectomy head and the rotation drive handle.

2. The thrombus fragmentation and aspiration catheter of claim 1, wherein: The torsion control spring tube is a hollow spring tube formed by spiral winding of single or multiple layers of metal wire.

3. The thrombus fragmentation and aspiration catheter of claim 1 or 2, wherein: 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 tube. The distal end of the main pipe is fixedly connected to the conduit. The proximal end of the main pipe is equipped 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 control spring tube passes through the interior of the main pipe, and the proximal end of the torsion control spring tube passes through the locking connector and the check valve. The portion of the torsion control spring tube extending out of the proximal end of the main pipe is connected to the output end of the rotary drive handle.

4. The thrombus fragmentation and aspiration catheter of claim 3, wherein: The proximal end of the torsion control spring tube is fused with nylon barrier material via thermorheological means. The output end of the rotary drive handle has a locking lug. The end of the torsion control spring tube with nylon barrier material is inserted through the check valve and fixedly inserted into the interior of the locking lug.

5. The thrombus fragmentation and aspiration catheter of claim 4, wherein: The rotary drive handle includes a housing, in which a reduction motor, a drive gear, and a driven gear are installed. The drive gear is connected to the output end of the reduction motor, and the driven gear meshes with the drive gear. The driven gear is fixedly sleeved on the outside of the locking lug. A switch for controlling the reduction motor is provided on the outside of the housing. The main pipe is fixedly installed inside the housing, and the branch pipe extends out of the housing.

6. The thrombus fragmentation and aspiration catheter of claim 1, wherein: A plurality of support wings are distributed circumferentially around the proximal end of the thrombus cutting head. Each support wing includes an arc-shaped cylindrical protrusion. The proximal end of the arc-shaped cylindrical protrusion abuts against the distal end of the annular clamp, and the arc surface of the arc-shaped cylindrical protrusion abuts against the inner wall of the catheter circumferentially.

7. The thrombus fragmentation and aspiration catheter of claim 6, wherein: The thrombus-breaking head includes a central axis and a plurality of spiral blades circumferentially distributed around the central axis. The support wing is located near the end of the spiral blades, and a thrombus-removing channel is formed between any two adjacent spiral blades.

8. The thrombus fragmentation and aspiration catheter of claim 6 or 7, wherein: Each of the aforementioned arc-shaped cylindrical protrusions is provided with edge cutting edges on both sides.

9. The thrombus fragmentation and aspiration catheter as described in claim 7, characterized in that: The distal end of the torsion control spring tube is fixedly connected to a connecting metal wire, the proximal end of the central shaft is a hollow structure, and the distal end of the connecting metal wire passes through the interior of the central shaft and is laser welded to the central shaft for fixation.

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

11. The thrombus fragmentation and aspiration catheter of claim 10, wherein: The catheter includes a first PTFE liner layer, a first metal braid layer wrapped around the outside of the first PTFE liner layer, and a first polymer material layer thermally bonded to the outside of the first metal braid layer. The flexibility of the first polymer material layer gradually increases from the proximal end to the distal end. The guide wire guide tube includes a second PTFE bushing layer, a second metal braided layer wrapped around the outside of the second PTFE bushing layer, and a second polymer material layer thermally 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 of claim 11, wherein: The materials of the first polymer material layer, from the distal end to the proximal end, are selected in sequence from at least two of TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, and are fused together by thermorheological means. The second polymer material layer consists of materials selected sequentially from TPU 45A, TPU1074A, Pebax35D, Pebax45D, Pebax55D, Pebax63D, Pebax72D, and PA12, from distal to proximal, and fused together by thermorheological means. The first polymer material layer and the second polymer material layer are thermally fused together.

13. The thrombus fragmentation and aspiration catheter of claim 10 or 11 or 12, wherein: The proximal end of the guidewire guide tube has a beveled structure.

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