Intravascular thrombus suction catheter

Abstract

The utility model provides an intravascular thrombus aspiration catheter. The intravascular thrombus aspiration catheter comprises an internal flow channel, a far-end aspiration catheter section, a middle catheter section and a near-end driving catheter section, and the internal flow channel is sequentially communicated with the far-end aspiration catheter section, the middle catheter section and the near-end driving catheter section from the far end of the intravascular thrombus aspiration catheter to the near end of the intravascular thrombus aspiration catheter. Wherein the intravascular thrombus aspiration catheter further comprises an aspiration inlet and an outflow window, and the internal flow channel is communicated with the aspiration inlet and the outflow window; a filter screen is arranged in an inner flow channel of the middle guide pipe section and is positioned between the suction inlet and the outflow window; at least one of the far-end suction catheter section, the middle catheter section and the near-end driving catheter section is detachably connected, and the suction inlet is formed in the far-end suction catheter section. According to the intravascular thrombus aspiration catheter provided by the invention, due to the segmented detachable design, the use convenience is facilitated.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 2024103744017, filed on March 29, 2024, entitled “An Intravascular Thrombus Aspiration Catheter,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of medical device technology, specifically to an intravascular thrombus aspiration catheter. Background Technology

[0004] Currently, the main treatments for thrombotic diseases include: anticoagulation, antithrombotic, and thrombolytic drug therapy, surgical treatment, and interventional therapy. Anticoagulation, antithrombotic, and thrombolytic drug therapy requires medication throughout the entire circulatory system, resulting in large doses, slow onset of action, and a high risk of complications such as organ bleeding. For old thrombi that do not respond well to medical treatment and show poor collateral circulation, surgical treatment may be considered, involving surgical removal of the thrombus or resection and reanastomosis of the embolic vessel segment. Interventional therapy involves local thrombolysis via catheter, low-pressure thrombus aspiration via catheter, and mechanical thrombectomy using instruments such as balloons and stents.

[0005] Current treatment methods for thrombosis still need improvement. Utility Model Content

[0006] According to an example embodiment of this disclosure, an intravascular thrombus aspiration catheter is provided. It has a small overall size and can be inserted into the patient's body to collect thrombi directly without relying on extracorporeal circulation equipment. In addition, the segmented and detachable design facilitates the selection of interventional specifications that are more favorable to the patient, the replacement of thrombus accumulation segments, and the modular assembly and use of other components.

[0007] In a first aspect of this disclosure, an intravascular thrombus aspiration catheter is provided, comprising: an inflow channel, a distal aspiration catheter segment, an intermediate catheter segment, and a proximal driving catheter segment. The inflow channel connects the distal aspiration catheter segment, the intermediate catheter segment, and the proximal driving catheter segment sequentially from the distal end to the proximal end of the intravascular thrombus aspiration catheter. The intravascular thrombus aspiration catheter also includes an aspiration inlet and an outflow window, with the inflow channel connecting the aspiration inlet and the outflow window. The inflow channel of the intermediate catheter segment is provided with a filter screen located between the aspiration inlet and the outflow window. At least one connection between the distal aspiration catheter segment, the intermediate catheter segment, and the proximal driving catheter segment is detachable, with the aspiration inlet located in the distal aspiration catheter segment.

[0008] In some embodiments of this application, the intermediate catheter segment is detachably connected to both the distal aspiration catheter segment and the proximal driving catheter segment.

[0009] In some embodiments of this application, the inner flow channel of the proximal drive duct section is provided with an impeller, which is arranged radially opposite to the outlet window along the inner flow channel, or, along the axial direction of the inner flow channel, the impeller is placed between the filter screen and the outlet window.

[0010] In some embodiments of this application, the intermediate catheter segment and the distal aspiration catheter segment are detachably connected, and the distal aspiration catheter segment and the intermediate catheter segment are press-fitted for sealing.

[0011] In some embodiments of this application, the distal aspiration catheter segment is threadedly connected to the intermediate catheter segment.

[0012] In some embodiments of this application, the outer diameter of the distal aspiration catheter segment gradually increases from the distal end to the proximal end, and the distal aspiration catheter segment is constructed as a cone-shaped structure.

[0013] In some embodiments of this application, the hardness of the distal aspiration catheter segment changes in a stepwise manner from the distal end to the proximal end, wherein the distal end of the distal aspiration catheter segment is less hard than its proximal end.

[0014] In some embodiments of this application, the distal aspiration catheter segment includes a distal aspiration segment, an intermediate aspiration segment, and a proximal aspiration segment. The distal aspiration segment, the intermediate aspiration segment, and the proximal aspiration segment are connected sequentially from the distal end to the proximal end of the distal aspiration catheter segment. The distal aspiration segment has a hardness of 25D, the intermediate aspiration segment has a hardness of 35D to 55D, and the proximal aspiration segment has a hardness of 63D.

[0015] In some embodiments of this application, the distal aspiration catheter segment is configured as a multilayer composite structure, wherein the multilayer composite structure includes an outer layer, a middle layer and an inner layer, the outer layer is configured to be made of a medical polymer material, the inner layer is configured to be made of a material with a friction coefficient of 0.01 to 0.1, and the middle layer is configured to be made of a metallic material.

[0016] In some embodiments of this application, the outer layer is configured to be made of one or more of Pebax, TPU, and nylon, the inner layer is configured to be made of PTFE, and the middle layer is configured to be made of nickel-titanium alloy or stainless steel.

[0017] In some embodiments of this application, the surfaces of the outer layer and inner layer that are in contact with the intermediate layer are formed with etched layers.

[0018] In some embodiments of this application, the intermediate layer is configured as a spiral or braided structure, and the intermediate layer is fixed between the inner and outer layers by a reflow process.

[0019] In some embodiments of this application, the intravascular thrombus aspiration catheter further includes a contrast ring, which is positioned 1 to 10 mm distal to the distal end of the distal aspiration catheter segment.

[0020] In some embodiments of this application, a one-way valve is provided in the internal flow channel of the intermediate conduit section, and the one-way valve is placed between the filter screen and the suction inlet.

[0021] In a second aspect of this disclosure, an intravascular thrombus aspiration catheter is provided, comprising: an inflow channel, a distal aspiration catheter segment, an intermediate catheter segment, and a proximal driving catheter segment. The inflow channel sequentially connects the distal aspiration catheter segment, the intermediate catheter segment, and the proximal driving catheter segment from the distal end to the proximal end of the intravascular thrombus aspiration catheter. The intravascular thrombus aspiration catheter further includes an aspiration inlet and an outflow window, and the inflow channel connects the aspiration inlet and the outflow window. In the intermediate catheter... The aforementioned internal flow channel of the segment is provided with a filter screen; the aforementioned internal flow channel of the aforementioned proximal driving catheter segment is provided with an impeller; the aforementioned suction inlet, the aforementioned filter screen, and the aforementioned outflow window are sequentially provided from the distal end to the proximal end of the aforementioned intravascular thrombus aspiration catheter; the aforementioned impeller is located at the aforementioned outflow window, or the aforementioned outflow window is located closer to the proximal end of the aforementioned intravascular thrombus aspiration catheter than the aforementioned impeller; the aforementioned distal aspiration catheter segment is detachably connected to the aforementioned intermediate catheter segment, and the aforementioned suction inlet is located on the aforementioned distal aspiration catheter segment.

[0022] Furthermore, in some embodiments, the aforementioned one-way valve is a biological valve or a mechanical valve.

[0023] Furthermore, in some embodiments, the filter screen is made of metal or polymer material, and the filter screen is configured as a dense mesh structure or a claw-like structure.

[0024] Compared with the prior art, this utility model has the following advantages:

[0025] (1) The distal aspiration catheter segment is replaceable. For example, in some embodiments, the distal aspiration catheter segment is detachably connected to the intermediate catheter segment. Thus, by switching the distal aspiration catheter segment, for example, changing the distal diameter and length, it is possible to accommodate thrombus aspiration of different blood vessel diameters in different patients.

[0026] (2) Further, the distal end of the catheter is thin and the proximal end is thick, forming a tapered design. For example, in some embodiments, the distal aspiration catheter segment is constructed as a tapered structure that is thin at the distal end and gradually becomes thick at the proximal end, thereby facilitating the entry and exit of instruments into blood vessels, reducing frictional resistance, reducing vascular damage, and improving the flexibility of the distal end, which is beneficial for entering tortuous small blood vessels.

[0027] (3) Furthermore, the tube body adopts a multi-segment hardness design, with the distal end being soft, the proximal end being hard, and the intermediate hardness transitioning stepwise. In some embodiments, this manifests as a stepwise change in hardness between the distal aspiration catheter segment, the intermediate catheter segment, and the proximal driving catheter segment, with the distal aspiration catheter segment being the softest, the intermediate catheter segment being the second softest, and the proximal driving catheter segment being the hardest. Preferably, the hardness of the distal aspiration catheter segment is 25D, the hardness of the intermediate catheter segment is 35D to 55D, and the hardness of the proximal driving catheter segment is 63D. This ensures that the intravascular thrombus aspiration catheter as a whole has good pushability, flexural strength, support, and torsion control, while also taking into account flexibility.

[0028] (4) Further, the detachable connection between the distal aspiration catheter segment and the intermediate catheter segment is an interference fit sealed connection, that is, the connection part is fixed and sealed by interference fit; more preferably, the fixation and sealing between the two segments can be strengthened by additional threads. Replaceable structure, such as detachable connection, makes it convenient for doctors to replace distal aspiration catheters of different lengths, inner diameters and hardness according to actual clinical needs.

[0029] (5) Further, in some embodiments, the distal aspiration catheter segment adopts a multi-layer composite structure, which includes an outer layer, a middle layer, and an inner layer. The inner layer is made of a material with a low coefficient of friction, such as PTFE, to reduce friction with blood and prevent thrombus formation on the inner surface of the catheter. For example, it is made of a material with a coefficient of friction of 0.01 to 0.1. The middle layer is a metal reinforcing layer to improve the maneuverability and support of the distal catheter and prevent catheter collapse due to excessive negative pressure. It can be made of nickel-titanium alloy or stainless steel and processed into a spiral or braided shape. The outer layer is made of common medical polymer materials, and the outer surface of the outer layer has a hydrophilic coating, such as PVP, which can reduce pushing friction and prevent thrombus adhesion to the catheter body. Preferably, the outer layer is constructed to be made of one or more of Pebax, TPU, and nylon, the inner layer is constructed to be made of PTFE, and the middle layer is constructed to be made of nickel-titanium alloy or stainless steel.

[0030] (6) Furthermore, the intravascular thrombus aspiration catheter also includes a contrast ring, which is set at a position of 1 mm to 10 mm from the farthest end of the distal aspiration catheter segment. The contrast ring support structure is made of platinum alloy, which facilitates the doctor to determine the position of the catheter outside the body and increases the radial support force of the end face to prevent the tube opening from collapsing due to excessive negative pressure suction.

[0031] (7) Furthermore, the middle catheter is replaceable. In some embodiments, the middle catheter segment is detachably connected to the proximal drive catheter segment, which facilitates the replacement of the filter during the operation without having to completely remove the thrombus aspiration system, reducing the time required to replace the entire aspiration system, and allowing some components to be reused, thus reducing costs.

[0032] (8) In some embodiments, the one-way valve is set at the front end of the filter screen, i.e., the distal end. That is, the one-way valve is set at the distal end of the thrombus aspiration catheter closer to the blood vessel than the filter screen, which can effectively prevent the blood aspiration from stopping suddenly, such as when the impeller suddenly stops turning and the collected and accumulated thrombus flows back into the blood vessel with the backflow of blood. Attached Figure Description

[0033] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings:

[0034] Figure 1 A schematic diagram of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown;

[0035] Figure 2 Another schematic diagram of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown;

[0036] Figure 3 A schematic diagram of the distal aspiration catheter segment of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown;

[0037] Figure 4 A schematic diagram of a filter structure for an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown;

[0038] Figure 5 A schematic diagram of another filter structure for an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown.

[0039] In the various figures, the same or corresponding reference numerals indicate the same or corresponding parts; wherein the reference numerals are: intravascular thrombus aspiration catheter 100; distal aspiration catheter segments 110, 210; distal aspiration catheter segment wall 111; aspiration inlet 112; interference fit sealing connection 116; aspiration segment sealing connection 116-1; intermediate segment sealing connection 116-2; threaded connection 117; aspiration segment threaded connection 117-1; intermediate segment threaded connection 117-2; intermediate catheter segment 120; intermediate catheter segment wall 121; one-way valve 122; filter screen 123; proximal drive catheter segment 130; impeller 132; outflow window 133; transmission catheter 134; distal aspiration segment 210-1; intermediate aspiration segment 210-2; proximal aspiration segment 210-3; inner layer 211-1; intermediate layer 211-2; outer layer 211-3. Detailed Implementation

[0040] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0041] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0042] Furthermore, it should be noted that in the description of the embodiments of this application, unless otherwise explicitly defined, "in vivo" means inside the patient's tissues and organs, and "outside the body" means outside the patient's tissues and organs. Also, in the embodiments of this application, "distal" refers to the direction away from the physician, and "proximal" refers to the direction closer to the physician.

[0043] Generally, thrombi, especially fresh thrombi, resemble jelly in the body, lacking mechanical strength and easily rupturing. Balloon thrombectomy requires blocking distal blood flow; to ensure complete thrombectomy, the balloon needs to be positioned close to the vessel wall, which can easily scratch the blood vessel during movement. Stent thrombectomy is prone to thrombus rupture and incomplete thrombectomy. Catheter-assisted negative pressure thrombectomy includes manual aspiration and Bernoulli's effect to remove the thrombus. Manual aspiration is unstable and has weak suction force, offering almost no clinical efficacy. Bernoulli's effect aspiration works by driving a pump to generate pulsed pressure, injecting saline through the catheter and then jetting it back through a side orifice at the catheter tip to flush the thrombus. The high-speed saline simultaneously creates a local low-pressure area, causing fragmented thrombus particles to be aspirated through the catheter's exit port. The drawback of this method is that while removing the thrombus, blood is also aspirated, leading to a reduction in blood volume. In such cases, physicians need to operate cautiously to ensure that the thrombus is removed without excessively affecting the patient's blood supply. Additional measures may be needed to replenish blood or other bodily fluids to maintain the patient's blood circulation and vital signs. Therefore, an interventional thrombectomy device has been proposed. However, filtering blood within the patient's body (removing thrombi) and directly returning blood to the vessel avoids the problems associated with extracorporeal circulation. However, this introduces additional issues, such as the need to customize different types of interventional heads for different vascular branches. A one-piece design inevitably leads to higher costs for patients and is a waste of medical resources. Designing the interventional part as detachable also presents sealing and securing challenges. Similarly, because it is an interventional filtering thrombectomy, when there are too many thrombi, the device inevitably faces the problem of replacing the filter to remove accumulated thrombi. A one-piece design also faces higher costs and a waste of medical resources. Furthermore, if the thrombectomy device is placed inside the patient's body, such as inside a blood vessel, for thrombectomy, meaning the patient's blood does not flow outside the body—both blood aspiration and outflow occur within the patient's body, such as within a segment of a blood vessel—further thrombectomy issues arise. For example, if the internal impeller or external aspiration device suddenly stops, such as abruptly stopping aspiration, the blood in the patient's blood vessels may experience a certain degree of backflow, which could cause the collected or aggregated thrombus to return to the blood vessels along with the backflow of blood.

[0044] To address at least one of the aforementioned problems, and one or more other potential problems, exemplary embodiments of this disclosure provide an intravascular thrombus aspiration catheter comprising: an internal flow channel, a distal aspiration catheter segment, an intermediate catheter segment, and a proximal driving catheter segment. A more detailed explanation follows with reference to the accompanying drawings.

[0045] Figure 1 A schematic diagram of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown.

[0046] In such Figure 1In the illustrated embodiment, the intravascular thrombus aspiration catheter 100 includes: an internal flow channel, a distal aspiration catheter segment 110, an intermediate catheter segment 120, and a proximal driving catheter segment 130. The internal flow channel connects the distal aspiration catheter segment 110, the intermediate catheter segment 120, and the proximal driving catheter segment 130 sequentially from the distal end to the proximal end of the intravascular thrombus aspiration catheter 100. The intravascular thrombus aspiration catheter 100 also includes an aspiration inlet 112 and an outflow window 133, with the internal flow channel connecting the aspiration inlet 112 and the outflow window 133. A filter 123 is provided in the internal flow channel of the intermediate catheter segment 120; an impeller 132 is provided in the internal flow channel of the proximal driving catheter segment 130; and the aspiration inlet 112, the filter 123, and the outflow window 133 are sequentially provided from the distal end to the proximal end of the intravascular thrombus aspiration catheter 100. Impeller 132 is located at outflow window 133, or outflow window 133 is located closer to the proximal end of intravascular thrombus aspiration catheter 100 than impeller 132; distal aspiration catheter segment 110 is detachably connected to intermediate catheter segment 120, and aspiration inlet 112 is located on distal aspiration catheter segment 110.

[0047] Exemplarily, filter 123 is used to filter substances, such as blood clots, from the liquid entering the internal flow channel through suction inlet 112. In some implementations, filter 123 is located between suction inlet 112 and outflow window 133; in other alternative implementations, filter 123 is located at suction inlet 112; and in still other alternative implementations, filter 123 is located at outflow window 133. The following description will use the example of filter 123 being located between suction inlet 112 and outflow window 133.

[0048] In some embodiments, the suction inlet 112 is located at the distal suction catheter segment 110.

[0049] For example, the suction inlet 112 is located at one end of the distal suction conduit segment 110 facing away from the intermediate conduit segment 120, and the intermediate conduit segment 120 has a suction outlet at one end facing away from the distal suction conduit segment 110, which communicates with the proximal drive conduit segment 130. Exemplarily, the internal flow channel includes a communicating outflow channel and a suction channel, the suction channel passing through the distal suction conduit segment 110 and the intermediate conduit segment 120, and the outflow channel passing through the proximal drive conduit segment 130. The suction outlet communicates with the outflow channel within the proximal drive conduit segment 130.

[0050] The suction conduit can be configured as a detachable structure consisting of one or more segments. For example, the distal suction conduit segment 110 and the intermediate conduit segment 120 are detachably connected, while the intermediate conduit segment 120 is fixedly connected to the proximal drive conduit segment 130. Alternatively, the distal suction conduit segment 110 and the intermediate conduit segment 120 are integrally formed and detachably connected to the proximal drive conduit segment 130; that is, the distal suction conduit segment 110 and the intermediate conduit segment 120 are either integrally formed or fixedly connected, while the intermediate conduit segment 120 is detachably connected to the proximal drive conduit segment 130. Alternatively, the distal suction conduit segment 110 and the intermediate conduit segment 120 are detachably connected, while the intermediate conduit segment 120 is detachably connected to the proximal drive conduit segment 130. For example, the proximal drive conduit segment 130 can generate negative pressure on the suction conduit through external power suction or impeller 132, etc.

[0051] Exemplarily, the distal aspiration conduit segment 110 and the intermediate conduit segment 120 form a suction tube, and the filter 123 may be disposed within the suction tube or within the proximal drive conduit segment 130. In one example, the filter 123 is disposed within the suction channel and located between the suction inlet 112 and the suction outlet. For example, the filter 123 is disposed within the internal flow channel corresponding to the distal aspiration conduit segment 110, or the filter 123 is disposed within the internal flow channel corresponding to the intermediate conduit segment 120. Alternatively, the filter 123 is disposed between the distal aspiration conduit segment 110 and the intermediate conduit segment 120.

[0052] The filter 123 can be arranged in various ways within the internal flow channel in this application. In one example, the filter 123 is provided in the internal flow channel of the intermediate duct section.

[0053] It can be understood that the filter 123 is set in the inner flow channel corresponding to the intermediate conduit section, which means that the connection position of the filter 123 on the wall of the inner flow channel is located on the inner flow channel corresponding to the intermediate conduit section 120. The filter 123 can be arranged only in the intermediate conduit section 120 along the axial direction, or it can be extended from the intermediate conduit section 120 to the proximal drive conduit section 130.

[0054] To prevent blood backflow during thrombectomy from carrying the thrombus accumulated on the filter back into the blood vessel and endangering the patient's health, a one-way valve 122 is installed in the internal flow channel. The one-way valve 122 is located at the distal end of the filter 123, meaning it is closer to the suction inlet 112 than the filter 123. For example, in some embodiments, the suction inlet 112, one-way valve 122, filter 123, and outflow window 133 are sequentially arranged from the distal end to the proximal end of the intravascular thrombus aspiration catheter 100. This arrangement allows the thrombus to be effectively collected at the filter 123, and the one-way valve 122's proximity to the suction inlet 112 effectively intercepts any thrombus that might flow back into the blood vessel.

[0055] It should be noted that, in the exemplary embodiment, the impeller 132, which performs the function of aspirating blood, can also be disposed within the internal flow channel of the proximal drive catheter segment 130 of the intravascular thrombus aspiration catheter 100. Generally, the outflow window 133 is disposed precisely at the tail end of the impeller 132, that is, the outflow window 133 is disposed near the impeller 132 capable of generating the aspiration function. This allows for more effective utilization of the impeller 132 to aspirate blood from the internal flow channel of the intravascular thrombus aspiration catheter 100 and to discharge blood through the outflow window 133.

[0056] In some alternative embodiments, the outflow window 133 is positioned closer to the proximal end of the intravascular thrombus aspiration catheter 100 than the impeller 132. It should be noted that positioning the outflow window 133 at the impeller 132 or closer to the proximal end of the intravascular thrombus aspiration catheter 100 than the impeller 132 allows the impeller 132 to more effectively perform its aspiration function at the same power. Conversely, positioning the outflow window 133 more distally to the intravascular thrombus aspiration catheter 100 than the impeller 132 will prevent blood from draining from the section between the outflow window 133 and the impeller 132, leading to a blood stagnation zone and subsequent thrombus formation.

[0057] It should be noted that the aforementioned one-way valve 122 can effectively prevent thrombus from flowing back into the human body. When the impeller 132 stops rotating or in other special circumstances, the one-way valve 122 can effectively prevent the appearance of blood, especially the reverse flow of thrombus, inside the internal flow channel of the intravascular thrombus aspiration catheter 100.

[0058] The following describes how the impeller 132 drives the intravascular thrombus aspiration catheter 100 to perform aspiration. In some embodiments, the proximal driving catheter segment 130 of the intravascular thrombus aspiration catheter 100 further includes a flexible drive shaft and a sheath. The flexible drive shaft is disposed inside the proximal driving catheter segment 130, and the sheath is disposed outside the flexible drive shaft. The proximal driving catheter segment 130 is connected to an external motor via the flexible drive shaft and the sheath. The external motor can drive the impeller 132 to rotate, for example, at high speed, so that blood and thrombi in the internal flow channel of the intravascular thrombus aspiration catheter 100 enter the internal flow channel through the aspiration inlet 112 and flow towards the outflow window 133, and finally flow out through the outflow window 133.

[0059] In some embodiments, the intravascular thrombus aspiration catheter 100 may be configured to be detachable into one or more segments. In some embodiments, one or more segments of the internal flow channel of the intermediate catheter segment 120 are configured to be detachable.

[0060] Furthermore, in some embodiments, the detachable connection between the distal aspiration catheter segment 110 and the intermediate catheter segment 120 is an interference-fit sealed connection. Figure 1 In the illustrated embodiment, the interference fit sealing connection is manifested as the interference fit sealing connection portion 116.

[0061] Furthermore, in some embodiments, the detachable connection between the distal aspiration catheter segment 110 and the intermediate catheter segment 120 also includes a threaded connection. Figure 1 In the illustrated embodiment, the threaded connection is represented by the threaded connection portion 117. Thus, the detachable connection between the distal aspiration catheter segment 110 and the intermediate catheter segment 120 is an interference-fit sealed connection, meaning the connection is fixed and sealed through an interference fit; furthermore, the additional thread enhances the fixation and sealing between the two segments. The replaceable structure, i.e., the detachable connection method, allows physicians to easily replace distal aspiration catheters of different lengths, inner diameters, and hardnesses according to actual clinical needs.

[0062] Figure 2 Another schematic diagram of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown.

[0063] In such Figure 2 The example shown details the interference fit sealing connection and reinforcement fastening method between the distal aspiration catheter segment 110 and the intermediate catheter segment 120. The distal aspiration catheter segment 110 and the intermediate catheter segment 120 of the intravascular thrombus aspiration catheter 100 are detachable. The proximal end of the distal aspiration catheter segment 110 includes a detachable aspiration segment, which includes a sealing connection portion 116-1 and a threaded connection portion 117-1. The distal end of the intermediate catheter segment 120 includes an intermediate detachable segment, which includes a sealing connection portion 116-2 and a threaded connection portion 117-2.

[0064] The sealing connection 116-1 of the suction section and the sealing connection 116-2 of the intermediate section are fitted together to form an interference fit sealing connection 116 between the distal suction guide tube section 110 and the intermediate guide tube section 120. The threaded connection 117-1 of the suction section and the threaded connection 117-2 of the intermediate section are fitted together to form a threaded connection 117.

[0065] In one example, the suction section sealing connection 116-1 is located between the suction inlet 112 and the suction section threaded connection 117-1. The suction section sealing connection 116-1 includes an inner bore that gradually widens from the distal end to the proximal end, and the suction section threaded connection 117-1 includes internal threads. The intermediate section threaded connection 117-2 is located between the intermediate section sealing connection 116-2 and the one-way valve 122. The intermediate section sealing connection 116-2 includes a tube body whose outer diameter gradually widens from the distal end to the proximal end, and the intermediate section threaded connection 117-2 includes external threads.

[0066] The angle between the outer diameter of the tube and the axis of the suction conduit is greater than the angle between the inner bore and the axis of the suction conduit to achieve an interference seal.

[0067] In another example, a sealing ring is provided between the threaded connection 117-1 of the suction section and the threaded connection 117-2 of the intermediate section, and the sealing ring is located on the side of the threaded connection 117 away from the sealing connection 116.

[0068] In some examples, the distal suction catheter segment 110 includes a first body segment, a suction segment sealing connection 116-1 and a suction segment threaded connection 117-1 arranged sequentially along the axial direction X; the intermediate catheter segment 120 includes a second body segment, an intermediate segment sealing connection 116-2 and an intermediate segment threaded connection 117-2 arranged sequentially along the axial direction X.

[0069] In other embodiments, the outer diameter of the first body segment of the distal aspiration catheter segment 110 tends to be thinner at the distal end and thicker at the proximal end, which facilitates the aspiration catheter entering the blood vessel.

[0070] In some examples, the entire length of the first body segment or a portion thereof from the suction inlet 112 toward the intermediate conduit segment 120 has a tapering tendency.

[0071] For example, the inner diameter of the first body segment can be variable or constant. In one example, the inner diameter of the first body segment is constant, reducing resistance to thrombus entry.

[0072] Furthermore, in some alternative embodiments, the intermediate catheter segment 120 is detachably connected to the proximal drive catheter segment 130. This facilitates intraoperative replacement of the filter 123, eliminates the need to completely remove the thrombus aspiration system, reduces the time required to replace the entire aspiration system, and allows for the reuse of some components, thus lowering costs.

[0073] Furthermore, in some embodiments, the filter 123 is made of a metallic or polymeric material, wherein the filter 123 is configured as a dense mesh structure or a claw-like structure, for example, by laser cutting or weaving to form a dense mesh structure or a claw-like structure, such as... Figure 4 The diagram shows a dense mesh structure, as shown below. Figure 5The structure shown is claw-shaped, and the filter 123 includes multiple claws that are spaced apart circumferentially and tend to taper from the distal end to the proximal end.

[0074] Furthermore, in some embodiments, the one-way valve 122 is a biological valve or a mechanical valve. The one-way valve 122 can be a biological valve, such as a 2-valve or 3-valve type, a mechanical valve, or other structures that only allow unidirectional flow. The valve's opening and closing threshold is between blood pressure and the negative pressure generated by the rotation of the impeller 132; that is, the valve opens when the impeller rotates and closes when the impeller 132 stops, preventing blood pressure from pushing it open. The one-way valve 122 is fixed to the internal flow channel of the intermediate catheter segment 12 by mechanical connection or adhesive bonding. The connection method in the above example embodiments solves the problem of detachability between the distal aspiration catheter segment 110 and the intermediate catheter segment 120 under sealed and secure conditions. Further, regarding the intervention problem of the distal aspiration catheter segment, the following detailed description is provided in conjunction with the accompanying drawings.

[0075] Figure 3 A schematic diagram of the distal aspiration catheter segment of an intravascular thrombus aspiration catheter according to some embodiments of the present disclosure is shown.

[0076] In such Figure 3 In the illustrated embodiment, the distal aspiration catheter segment 210 is configured as a tapered structure that tapers from a thin distal end to a thicker proximal end. This facilitates instrument entry and exit from the blood vessel, reduces frictional resistance, minimizes vascular injury, and improves distal flexibility, which is beneficial for accessing tortuous small blood vessels.

[0077] Furthermore, in some embodiments, the distal end of the distal aspiration catheter segment 210 exhibits a step-like change in hardness from the distal end to the proximal end, wherein the distal end of the distal aspiration catheter segment 210 is more flexible than the proximal end of the distal aspiration catheter segment 210.

[0078] Furthermore, in some embodiments, the distal aspiration catheter segment 210 is divided into three segments, namely, a distal aspiration segment 210-1, an intermediate aspiration segment 210-2, and a proximal aspiration segment 210-3. The distal aspiration segment 210-1, the intermediate aspiration segment 210-2, and the proximal aspiration segment 210-3 are sequentially connected from the distal end to the proximal end of the distal aspiration catheter segment 210.

[0079] Preferably, in some embodiments, the hardness of the distal aspiration segment 210-1 is 25D, the hardness of the intermediate aspiration segment 210-2 is 35D to 55D, and the hardness of the proximal aspiration segment 210-3 is 63D. Specifically, in some embodiments, the tolerance of the above hardness values ​​is 5D. This ensures that the intravascular thrombus aspiration catheter as a whole has good pushability, flexural strength, support, and torsion control, while also taking into account flexibility.

[0080] Furthermore, in Figure 3 In the illustrated embodiment, the distal aspiration catheter segment 210 is constructed as a multi-layer composite structure, comprising an outer layer 211-3, a middle layer 211-2, and an inner layer 211-1. The outer layer 211-3 is made of a medical-grade polymer material, the inner layer 211-1 is made of a material with a coefficient of friction of 0.01 to 0.1, and the middle layer 211-2 is made of a metallic reinforcing material. Regarding the multi-layer composite structure, the inner layer uses a material with a low coefficient of friction to reduce friction with blood and prevent thrombus formation on the inner surface of the catheter; for example, it can be made of a material with a coefficient of friction of 0.01 to 0.1. The middle layer is a metallic reinforcing layer that improves the maneuverability and support of the distal catheter, preventing catheter collapse due to excessive negative pressure; it can be made of nickel-titanium alloy or stainless steel and processed into a spiral or braided shape. The outer surface of the outer layer has a hydrophilic coating, such as PVP, which reduces pushing friction and prevents thrombus adhesion to the catheter body.

[0081] Furthermore, in some embodiments, the outer layer 211-3 is configured to be made of one or more of pebax, TPU, and nylon. The inner layer 211-1 is configured to be made of PTFE. The intermediate layer 211-2 is configured to be made of nickel-titanium alloy or stainless steel. Here, pebax stands for polyether block polyamide; TPU stands for Thermoplastic Polyurethane; and PTFE stands for Polytetrafluoroethylene.

[0082] Furthermore, in some embodiments, the surfaces of the outer layer 211-3 and the inner layer 211-1 that contact the intermediate layer 211-2 are formed with etched layers. For example, since the inner layer 211-1 needs to facilitate the entry of thrombi, the material of the inner layer 211-1 is relatively smooth. In order to improve the connection stability between the inner layer 211-1 and other layers, the surface of the inner layer 211-1 facing away from the internal flow channel is etched to form an etched layer, thereby increasing the connection tightness between the inner layer 211-1 and the intermediate layer 211-2.

[0083] Furthermore, in some embodiments, the intermediate layer 211-2 is configured in a spiral or braided shape, and the intermediate layer 211-2 is fixed between the inner layer 211-1 and the outer layer 211-3 by a reflow process. The reflow process is a reflow soldering process.

[0084] Furthermore, in Figure 3In the illustrated embodiment, the distal end of the distal aspiration catheter segment 210 further includes a contrast ring 215, which is positioned 1 mm to 10 mm from the farthest end of the distal aspiration catheter segment 210. The support structure of the contrast ring 215 is made of platinum alloy, which facilitates the doctor's external assessment of the catheter position and increases the radial support force on the end face, preventing the catheter opening from collapsing due to excessive negative pressure suction.

[0085] Furthermore, regarding the placement of the contrast ring 215, if it is positioned less than 1 mm from the distal end of the distal aspiration catheter segment 210, the tip of the distal aspiration catheter segment 210 will be too rigid, posing a risk of damaging blood vessels or tissues; if it is positioned more than 10 mm from the distal end of the distal aspiration catheter segment 210, the contrast ring 215 will be too far from the tip of the distal aspiration catheter segment 210, making it difficult for the physician to accurately position the catheter.

[0086] In one embodiment of this application, an intravascular thrombus aspiration catheter includes: an internal flow channel, a distal aspiration catheter segment, an intermediate catheter segment, and a proximal driving catheter segment. The internal flow channel connects the distal aspiration catheter segment, the intermediate catheter segment, and the proximal driving catheter segment sequentially from the distal end to the proximal end of the intravascular thrombus aspiration catheter. The intravascular thrombus aspiration catheter also includes an aspiration inlet and an outflow window, and the internal flow channel connects the aspiration inlet and the outflow window. A filter screen is provided in the internal flow channel of the intermediate catheter segment. An aspiration inlet, a filter screen, and an outflow window are sequentially provided from the distal end to the proximal end of the intravascular thrombus aspiration catheter. One or more segments of the internal flow channel of the intermediate catheter segment are configured as a detachable structure, and the aspiration inlet is located on the distal aspiration catheter segment.

[0087] In one embodiment, an impeller is provided in the flow channel of the proximal drive catheter segment; the impeller is located at the outflow window, or the outflow window is located closer to the proximal end of the intravascular thrombus aspiration catheter than the impeller.

[0088] In one embodiment, one or more segments of the internal flow channel of the intermediate catheter segment are configured as detachable junctions, including: a distal aspiration catheter segment being detachably connected to the intermediate catheter segment, and / or the intermediate catheter segment being detachably connected to a proximal drive catheter segment.

[0089] In one embodiment, the detachable connection between the distal aspiration catheter segment and the intermediate catheter segment is an interference-fit sealed connection.

[0090] In one embodiment, the detachable connection between the distal aspiration catheter segment and the intermediate catheter segment also includes a threaded connection.

[0091] In one embodiment, the distal aspiration catheter segment is configured as a cone-shaped structure that is thinner at the distal end and gradually thicker at the proximal end.

[0092] In one embodiment, the distal aspiration catheter segment exhibits a stepwise change in hardness from distal to proximal, wherein the distal end of the distal aspiration catheter segment is softer than its proximal end.

[0093] In one embodiment, the distal aspiration catheter segment further includes a distal aspiration segment, an intermediate aspiration segment, and a proximal aspiration segment, which are connected sequentially from the distal end to the proximal end of the distal aspiration catheter segment. The distal aspiration segment has a hardness of 25D, the intermediate aspiration segment has a hardness of 35D to 55D, and the proximal aspiration segment has a hardness of 63D.

[0094] In one embodiment, the distal aspiration catheter segment is configured as a multilayer composite structure, wherein the multilayer composite structure includes an outer layer, a middle layer and an inner layer, the outer layer is configured to be made of a medical polymer material, the inner layer is configured to be made of a material with a coefficient of friction of 0.01 to 0.1, and the middle layer is configured to be made of a metallic reinforcing material.

[0095] In one embodiment, the outer layer is configured to be made of one or more of pebax, TPU, and nylon, the inner layer is configured to be made of PTFE, and the middle layer is configured to be made of nickel-titanium alloy or stainless steel.

[0096] In one embodiment, the surfaces of the outer and inner layers that contact the intermediate layer are formed with an etched layer.

[0097] In one embodiment, the intermediate layer is configured as a spiral or braided structure, and the intermediate layer is fixed between the inner and outer layers by a reflow process.

[0098] In one embodiment, the intravascular thrombus aspiration catheter further includes a contrast ring, which is positioned 1 to 10 mm from the distal end of the distal aspiration catheter segment.

[0099] In one embodiment, a one-way valve is provided in the internal flow channel of the intermediate conduit section, and the one-way valve is closer to the suction inlet than the filter screen.

[0100] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0101] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An intravascular thrombus aspiration catheter, characterized by, The catheter comprises: an inner flow channel, a distal suction catheter segment, an intermediate catheter segment and a proximal driving catheter segment, the inner flow channel sequentially communicates the distal suction catheter segment, the intermediate catheter segment and the proximal driving catheter segment from the distal end of the intravascular thrombus suction catheter to its proximal end; the intravascular thrombus suction catheter further comprises a suction inlet and an outflow window, the inner flow channel communicates the suction inlet and the outflow window; the inner flow channel of the intermediate catheter segment is provided with a filter screen, the filter screen is located between the suction inlet and the outflow window; at least one of the distal suction catheter segment, the intermediate catheter segment and the proximal driving catheter segment is detachably connected, and the suction inlet is arranged in the distal suction catheter segment.

2. The intravascular thrombus aspiration catheter of claim 1, wherein, The intermediate catheter segment is detachably connected with the distal suction catheter segment and the proximal driving catheter segment.

3. The intravascular thrombus suction catheter according to claim 1, wherein: the inner flow channel of the proximal driving catheter segment is provided with an impeller, the impeller is arranged opposite to the outflow window along the radial direction of the inner flow channel, or along the axial direction of the inner flow channel, the impeller is located between the filter screen and the outflow window.

4. The intravascular thrombus aspiration catheter of claim 1, wherein, The intermediate catheter segment is detachably connected with the distal suction catheter segment, and the distal suction catheter segment and the intermediate catheter segment are interference fit for sealing.

5. The intravascular thrombus aspiration catheter of claim 1, wherein, The distal suction catheter segment is threadedly connected with the intermediate catheter segment.

6. The intravascular thrombus aspiration catheter of claim 1, wherein, The outer diameter of the distal suction catheter segment gradually expands from the distal end to the proximal end, and the distal suction catheter segment is configured as a conical structure.

7. The intravascular thrombus aspiration catheter of claim 1, wherein, The hardness of the distal suction catheter segment gradually changes from the distal end to the proximal end, wherein the hardness of the distal end of the distal suction catheter segment is lower than that of the proximal end.

8. The intravascular thrombus suction catheter according to claim 7, wherein: the distal suction catheter segment comprises a suction distal segment, a suction intermediate segment and a suction proximal segment, the suction distal segment, the suction intermediate segment and the suction proximal segment are sequentially connected from the distal end to the proximal end of the distal suction catheter segment, wherein: the hardness of the suction distal segment is 25D, the hardness of the suction intermediate segment is 35D to 55D, and the hardness of the suction proximal segment is 63D.

9. The intravascular thrombus suction catheter according to claim 1, wherein: the distal suction catheter segment is configured as a multi-layer composite structure, wherein the multi-layer composite structure comprises an outer layer, an intermediate layer and an inner layer, the outer layer is configured to be made of a medical polymer material, the inner layer is configured to be made of a material with a friction coefficient of 0.01-0.1, and the intermediate layer is configured to be made of a metal material.

10. The intravascular thrombus suction catheter according to claim 9, wherein: the outer layer is configured to be made of one or more of pebax, tpu and nylon, the inner layer is configured to be made of PTFE, and the intermediate layer is configured to be made of nickel-titanium alloy or stainless steel.

11. The intravascular thrombus aspiration catheter of claim 9, wherein, The surfaces of the outer layer, the inner layer and the intermediate layer in contact with each other are configured with etching layers.

12. The intravascular thrombus aspiration catheter of claim 9, wherein, The intermediate layer is configured in a spiral or braided shape, and is fixed between the inner layer and the outer layer by a reflow process.

13. The intravascular thrombus aspiration catheter of claim 1, wherein, Also included are: a visualization loop disposed 1 to 10 mm from a distal end of the distal aspiration catheter segment.

14. The intravascular thrombus aspiration catheter of claim 1, wherein: A one-way valve is disposed in the inner flow passage of the intermediate catheter segment, between the strainer and the aspiration inlet.

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