An intravascular rheolytic thrombectomy catheter and intravascular thrombectomy system

Abstract

The present application relates to the technical field of medical devices, and provides an intravascular rheological thrombus removing catheter and an intravascular thrombus removing system. The intravascular rheological thrombus removing catheter comprises a catheter body, a rheological thrombus removing assembly, an OCT imaging assembly and a balloon. The catheter body is internally provided with a guide wire lumen, an OCT optical fiber lumen, a suction lumen and a balloon pressurizing lumen. The rheological thrombus removing assembly is arranged at the distal end of the catheter, and negative pressure is generated by spraying high-pressure fluid through a spray hole to suck thrombus. The OCT imaging assembly is used to acquire blood vessel wall images. The balloon is arranged at the back side of the suction hole, and generates radial thrust when inflated to press the distal end of the catheter towards the target blood vessel wall, so that the suction hole and the OCT optical window are attached to the lesion area. The present application realizes the cooperative alignment of the suction hole and the OCT optical window by the directional attachment of the balloon, can distinguish thrombus from blood vessel wall in real time during the operation and perform targeted removal, can evaluate the removal effect in real time without withdrawing the catheter, shortens the operation time and improves the thoroughness and safety of thrombus removal.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an intravascular rheological thrombectomy catheter and an intravascular thrombus removal system. Background Technology

[0002] Deep vein thrombosis (DVT) of the lower extremities is a common and critical vascular emergency in clinical practice. Once a thrombus breaks off, it can travel through the bloodstream to the pulmonary artery, causing pulmonary embolism, which has an extremely high mortality rate. Simultaneously, severe obstruction of venous return in the lower extremities can lead to a sharp increase in tissue tension, compressing arteries and causing acute limb ischemia. If not treated promptly, this can rapidly develop into venous gangrene, posing a risk of amputation or even death. Currently, rheological thrombectomy catheters based on Bernoulli's principle are widely used in the endovascular interventional treatment of DVT in the lower extremities. These catheters utilize a high-pressure jet and aspiration port at the tip to generate local negative pressure (Venturi effect) at the catheter tip using high-speed jets of saline. This breaks up the thrombus, which is then aspirated into the catheter and removed from the body, offering minimally invasive advantages such as minimal trauma and rapid recovery.

[0003] However, existing rheology thrombectomy catheters still have the following technical problems in clinical application: First, it is impossible to distinguish between thrombi and vessel walls in real time during the procedure. Current rheology thrombectomy procedures rely entirely on DSA (Digital Subtraction Angiography) for navigation, but DSA can only show the overall filling defects of the lumen and cannot accurately distinguish the layered structure of thrombi, plaques, and vessel walls. Some mural thrombi closely attached to the vessel wall or organized old thrombi are difficult to identify in DSA angiography, making it difficult for the operator to determine whether the aspiration port is aligned with the target lesion, posing a risk of incomplete removal. Second, the circumferential orientation of the aspiration port cannot be actively controlled. Although the aspiration port of existing rheology thrombectomy catheters is located on one side of the catheter tip, the natural shape of the catheter within the lumen determines the orientation of the aspiration port. The operator cannot actively and precisely steer the aspiration port towards the location of residual thrombi. When the thrombus is unevenly distributed within the lumen or only exists in a specific direction of the vessel wall, the operator can only repeatedly rotate the catheter for blind aspiration, which not only reduces the removal efficiency but may also increase the risk of vascular damage due to repeated ineffective operations. Third, there is a time lag in assessing the effectiveness of aspiration. After completing one aspiration procedure, the operator usually needs to withdraw the thrombectomy catheter, inject contrast agent through a delivery sheath, and perform a DSA re-examination to assess whether the thrombus has been completely removed. If the angiography shows that there is still residue, the thrombectomy catheter needs to be delivered to the target location again for supplementary aspiration. This repeated cycle of aspiration, withdrawal, angiography, and reinsertion prolongs the operation time, increases the amount of contrast agent used, and raises the risk of vascular injury. Summary of the Invention

[0004] Therefore, the present invention aims to solve the problems of existing rheological thrombectomy catheters, such as the inability to distinguish between thrombi and the vessel wall in real time during the procedure, the inability to actively control the circumferential orientation of the aspiration port, and the operational time lag in the evaluation of aspiration effect. Thus, the present invention provides an intravascular rheological thrombectomy catheter and an intravascular thrombus removal system.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: On one hand, the present invention provides an intravascular rheological thrombectomy catheter, comprising: a catheter body having a proximal end and a distal end, wherein the catheter body is provided with a guidewire lumen, an OCT fiber lumen, an aspiration lumen, and a balloon inflator lumen extending axially; and a rheological thrombectomy assembly disposed at the distal end of the catheter body, including at least one aspiration port communicating with the aspiration lumen and at least one jet port communicating with a high-pressure fluid source, wherein the jet port is used to jet high-pressure fluid to the outside of the catheter body and generate negative pressure at the aspiration port, thereby drawing thrombi or plaque debris into the aspiration lumen. The catheter body includes a cavity; an OCT imaging component, comprising an optical fiber extending along the OCT fiber cavity and an optical component located at the distal end of the catheter body, the optical component being used to emit and receive imaging light signals; a balloon, located at the distal end of the catheter body and on the back side of the aspiration port, the balloon communicating with the balloon inflator cavity; the balloon generates radial thrust when inflated, pushing the distal end of the catheter body toward the blood vessel wall on the side facing the aspiration port, so that the aspiration port and the light outlet of the OCT imaging component are aligned with the target lesion area.

[0006] Furthermore, the balloon is disposed in the side wall of the catheter body; the catheter body is provided with a balloon hole at a position adapted to the balloon, and when the balloon is inflated, the balloon extends at least partially through the balloon hole from the side wall of the catheter body.

[0007] Furthermore, the side wall of the catheter body is provided with a receiving groove for accommodating a balloon, and the balloon is located in the receiving groove; the balloon pressurization chamber and the balloon orifice are both connected to the receiving groove.

[0008] Furthermore, the optical component includes a reflector and a lens group located at the distal end of the conduit body; the light outlet is located on the side wall of the conduit body, and the lens group is disposed at the light outlet; the reflector is adapted to the light outlet, and the light beam emitted from the optical fiber is guided by the reflector and then directed to the lens group, and then emitted through the light outlet.

[0009] Furthermore, the balloon is aligned with the light outlet along the radial direction of the catheter body.

[0010] Furthermore, the light outlet and the suction hole are located on the same circumferential side of the conduit body; and / or, along the axial direction of the conduit body, the light outlet is located between the suction hole and the jet hole.

[0011] Furthermore, the guidewire cavity, OCT fiber cavity, aspiration cavity, and balloon pressurization cavity are four independent axial cavities, and the OCT fiber cavity is sealed and isolated from the aspiration cavity and balloon pressurization cavity.

[0012] Furthermore, the balloon is made of compliant or semi-compliant medical polymer materials, and the balloon is inflated by injecting saline or contrast agent.

[0013] Furthermore, the OCT imaging component is used to acquire images of the target lesion area after the balloon is inflated and before the rheological thrombectomy component is activated.

[0014] On the other hand, the present invention also provides an intravascular thrombus removal system, including the intravascular rheological thrombectomy catheter described in any one of the above.

[0015] The technical solution of this invention has the following advantages: The intravascular rheological thrombectomy catheter provided by this invention integrates an OCT imaging component at the distal end of the catheter. Utilizing near-infrared light, it performs high-resolution cross-sectional imaging of the vessel wall tissue, clearly distinguishing the layered structure of thrombi, plaques, and normal vessel walls. This overcomes the limitation of existing technologies where DSA angiography can only display filling defects in the lumen but cannot differentiate tissue types. Operators can accurately determine the location and extent of residual lesions using OCT images before thrombectomy, providing precise navigation for subsequent targeted thrombectomy.

[0016] The intravascular rheological thrombectomy catheter provided by this invention features a balloon positioned at the distal end of the catheter, behind the aspiration port. When the balloon inflates, it generates radial thrust, pressing the distal end of the catheter, along with the aspiration port and the OCT optical window, against the target vessel wall. On one hand, the directional thrust of the balloon ensures close contact between the aspiration port and residual thrombus attached to the vessel wall, improving aspiration efficiency and overcoming the shortcomings of existing technologies where the aspiration port direction is uncontrollable and requires repeated blind aspiration. On the other hand, the balloon's adherence to the vessel wall ensures a stable relative position and good adhesion between the OCT optical window and the target tissue, effectively eliminating the impact of catheter vibration caused by fluid impact during rheological thrombectomy on image quality and ensuring the clarity and stability of the OCT images.

[0017] The intravascular rheological thrombectomy catheter provided by this invention, utilizing the high-resolution imaging capabilities of an OCT imaging component, allows the operator to instantly observe the cleanliness of the vessel wall in the target area via OCT imaging after completing the local thrombectomy procedure, without withdrawing the catheter or injecting additional contrast agent, thus determining whether residual thrombi have been completely removed. If residue is found, the catheter can be immediately adjusted at the same location for supplementary aspiration, avoiding the repeated cycles of aspiration, withdrawal, angiography, and re-insertion in existing technologies. This shortens the operation time, reduces the amount of contrast agent used and the patient's radiation exposure, and lowers the risk of vascular damage caused by repeated catheter advancements. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the intravascular rheological thrombectomy catheter provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the radial cross-sectional structure of the intravascular rheological thrombectomy catheter provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the axial cross-sectional structure of the intravascular rheological thrombectomy catheter provided in an embodiment of the present invention; Figure 4 for Figure 3 A magnified schematic diagram of a local structure; Figure 5 This is a schematic diagram of the intravascular rheological thrombectomy catheter in operation (without balloon inflation) provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the intravascular rheological thrombectomy catheter in operation (after balloon inflation) provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the intravascular thrombus removal system provided in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Catheter body; 101. Guidewire cavity; 102. OCT fiber cavity; 103. Aspiration cavity; 104. Balloon pressurization cavity; 105. Balloon orifice; 106. Receiving groove; 2. Aspiration port; 3. Jet port; 4. Optical fiber; 5. Reflector; 6. Lens group; 7. Light outlet; 8. Balloon; 9. Guidewire; 10. Water jet pipe; 11. Water jet ring; 12. High-pressure fluid source; 13. Balloon pressurization device; 14. OCT host; 15. Vessel wall; 16. Thrombus; 17. Debris. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and defined, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] like Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides an intravascular rheological thrombectomy catheter integrating optical coherence tomography and a directional balloon. This intravascular rheological thrombectomy catheter has an overall slender, flexible tubular structure, with a proximal end located on the operator's side (i.e.,...). Figure 1 The right end of the middle section) and the distal end used to extend into the blood vessel (i.e., the right end) and the distal end used to extend into the blood vessel. Figure 1 (Left end of the catheter). The catheter includes a catheter body 1, a rheology thrombectomy assembly, an OCT imaging assembly, and a balloon 8.

[0026] The catheter body 1 can be made of medical-grade polymer materials, such as polyurethane, polyether block amide, or nylon, which have good biocompatibility. This allows the catheter body 1 to have sufficient flexibility and delivery capability, enabling it to be smoothly delivered along the vascular pathway to the target location. The outer diameter of the catheter body 1 can be selected according to clinical needs. For example, in one optional implementation, the outer diameter of the catheter body 1 is 6 Fr to 10 Fr, and the length is 90 cm to 135 cm, to accommodate the vascular anatomy of patients in different locations and with different body types.

[0027] like Figure 2 As shown, the catheter body 1 has multiple independent cavities extending axially inside, specifically including a guidewire cavity 101, an OCT fiber cavity 102, an aspiration cavity 103, and a balloon inflator cavity 104. These four cavities are independently arranged and laid out in a predetermined manner on the cross-section of the catheter body 1. The guidewire cavity 101 is used to slidably accommodate the guidewire 9, the distal end of which extends beyond the distal end of the catheter body 1, for guiding the catheter to the target lesion location within the blood vessel. The diameter of the guidewire cavity 101 is adapted to clinically commonly used guidewire specifications, for example, guidewires with diameters ranging from 0.014 inches to 0.035 inches can be accommodated. The guidewire lumen 101 can adopt an integral exchangeable lumen structure, where the guidewire lumen 101 extends from the proximal end to the distal end of the catheter body 1, and the guidewire 9 extends the entire length of the catheter body 1, providing optimal push and torsion control performance; alternatively, it can adopt a quick-exchangeable lumen structure, where the guidewire lumen 101 exists only in the distal section of the catheter body 1, and the guidewire 9 exits from the guidewire outlet on the distal side of the catheter, shortening the coaxial length of the guidewire and catheter, facilitating single-person operation. The OCT fiber cavity 102 provides a dedicated passage for the fiber 4, and its inner diameter is slightly larger than the outer diameter of the fiber 4, allowing the fiber 4 to move freely within the OCT fiber cavity 102 without compression. The aspiration cavity 103 is used to transport thrombi or plaque fragments from the distal end of the catheter to the outside of the body; its inner diameter is relatively large to provide sufficient aspiration flow and drainage capacity. The balloon inflator chamber 104 is a long and narrow tube used to deliver the inflator medium (such as saline or contrast agent) provided by the external inflator device into the balloon 8, so that the balloon 8 inflates.

[0028] More importantly, the OCT fiber cavity 102 is sealed and isolated from the aspiration cavity 103 and the balloon inflator cavity 104. Specifically, the OCT fiber cavity 102 is not interconnected with the aspiration cavity 103 and the balloon inflator cavity 104 along the entire length of the catheter body 1, forming an independent sealed channel. This design effectively prevents high-speed flowing thrombi, debris, and blood in the aspiration cavity 103 from causing physical damage or optical interference to the optical fiber 4, and also prevents the high-pressure medium in the balloon inflator cavity 104 from seeping into the OCT fiber cavity 102 and affecting the normal operation of the optical devices. In a preferred embodiment, the wall of the OCT fiber cavity 102 is composed of a metal braided layer or a polymer reinforcement layer to provide additional pressure and kink resistance protection.

[0029] The proximal end of the catheter body 1 is provided with a connector or fitting assembly (not shown in the figure) for connecting each cavity to the corresponding external device. For example, the proximal end of the aspiration cavity 103 can be connected to a negative pressure aspiration device via a connector; the proximal end of the balloon inflator cavity 104 can be connected to the balloon compression device 13 via a connector and a pressurization line; the proximal end of the OCT fiber cavity 102 can be connected to the OCT host 14 via a fiber optic connector; and the proximal end of the guidewire cavity 101 is connected to the guidewire 9 via a connector or a sealing valve.

[0030] The proximal end of the catheter body 1 is equipped with a rotating actuator (not shown in the figure). This actuator can be a Y-valve connector or a rotary hemostatic valve, and it is fixedly connected to the proximal end of the catheter body 1. When the operator rotates this actuator, the entire catheter body 1 can rotate around its own axis, thereby adjusting the circumferential orientation of the distal ejection port 3, aspiration port 2, and light outlet 7 within the blood vessel. This rotating actuator allows the operator to achieve precise control of the distal orientation without having to completely twist the proximal extension of the catheter, improving the convenience and accuracy of the operation.

[0031] The rheology-based thrombectomy assembly is located at the distal end of the catheter body 1 and is used to break up and aspirate thrombi or plaques within the blood vessel through hydrodynamic effects. The rheology-based thrombectomy assembly includes at least one aspiration port 2 communicating with an aspiration chamber 103 and at least one jet port 3 communicating with a high-pressure fluid source 12. The aspiration port 2 is located on the distal sidewall of the catheter body 1, penetrating the wall thickness of the catheter body 1, thereby communicating the aspiration chamber 103 with the external space of the catheter. The shape of the aspiration port 2 can be circular, elliptical, or elongated, with a major diameter of approximately 2 mm to 5 mm; the specific size can be selected according to the catheter specifications and the expected thrombus load to be removed. Figure 3 In the alternative embodiment shown, the suction hole 2 is a generally elliptical opening with its long axis extending along the axial direction of the conduit body 1 to provide a longer suction area in the axial direction.

[0032] The injection hole 3 is also located on the distal side wall of the conduit body 1, communicating with the suction chamber 103, or communicating with the high-pressure fluid source 12 through a water-spraying steel pipe 10 installed in the suction chamber 103. The diameter of the injection hole 3 is smaller than that of the suction hole 2, approximately 0.5 mm to 3.5 mm, and is used to spray high-pressure fluid to the outside of the conduit in the form of a high-speed jet. Figure 3 In the optional embodiment shown, there are multiple injection holes 3, which are arranged circumferentially around the proximal side of the suction hole 2. For example, the injection direction of the injection holes 3 can be inclined toward the suction hole 2, that is, after the high-speed jet is ejected from the injection holes 3, it is obliquely directed toward the region where the suction hole 2 is located in the direction of the distal end of the conduit.

[0033] To achieve the aforementioned rheological thrombectomy function, a water-jet steel pipe 10 is installed inside the distal end of the catheter body 1. The water-jet steel pipe 10 is a slender metal tube extending axially along the catheter body 1 within the aspiration chamber 103. Its proximal end is connected to an external high-pressure fluid source 12, and its distal end extends to a position close to the distal end of the catheter body 1. A water-jet ring 11 is installed at the distal end of the water-jet steel pipe 10. The water-jet ring 11 is an annular component connected to the distal end of the water-jet steel pipe 10, and its sidewall has several micro-holes. The positions of these micro-holes correspond to the jet holes 3 on the sidewall of the catheter body 1. High-speed saline solution ejected through the micro-holes passes through the jet holes 3 and is projected towards the outside of the catheter. The diameter of the micro-holes on the water-jet ring 11 is approximately 0.05 mm to 0.2 mm, and the number of holes can be set to 2 to 8 as needed, allowing the high-pressure fluid to be ejected uniformly in the form of multiple jets, improving the efficiency and coverage of thrombus fragmentation. The water spray pipe 10 and the water spray ring 11 are made of medical-grade stainless steel (such as 304 or 316L stainless steel) and the surface is electrochemically polished with a roughness Ra of no more than 0.2μm to reduce fluid resistance and prevent thrombus adhesion.

[0034] In such Figure 3 In the embodiment shown, along the axial direction of the catheter body 1, the suction hole 2 is located on the distal side of the jet hole 3, that is, the jet hole 3 is closer to the proximal end of the catheter, while the suction hole 2 is closer to the distal end of the catheter.

[0035] The hydrodynamic principle of the rheological thrombectomy assembly is as follows: High-pressure saline solution (typically between 300 psi and 1200 psi) supplied by the high-pressure fluid source 12 is delivered to the spray ring 11 via the spray pipe 10. The solution is ejected at extremely high speeds (over 100 m / s) from tiny orifices on the spray ring 11, exiting through the spray holes 3 on the side wall of the catheter body 1. This jet impacts and breaks up thrombi or plaque tissue within the blood vessel, cutting and tearing them into tiny fragments. Simultaneously, as the high-speed jet exits from the spray holes 3 and flows near the aspiration holes, the static pressure at the aspiration holes decreases significantly, creating a local negative pressure (i.e., the Venturi effect). This local negative pressure draws the broken thrombus fragments, along with the surrounding blood, into the aspiration holes. The fragments can then be transported to an external collection container via the aspiration chamber 103. Throughout the process, thrombus breaking and aspiration occur almost simultaneously, achieving highly efficient rheological thrombectomy.

[0036] like Figure 4 As shown, the OCT imaging component is used to acquire cross-sectional or three-dimensional images of the vessel wall surrounding the distal end of the catheter. The OCT imaging component includes an optical fiber 4 extending along the OCT fiber cavity 102 and an optical component located at the distal end of the catheter body 1. The optical fiber 4 can be a single-mode fiber, extending from the proximal end to the distal end of the catheter body 1 within the OCT fiber cavity 102. The proximal end of the optical fiber 4 is connected to an external OCT host 14 for transmitting imaging light and receiving reflected light signals. The optical component is located inside the distal end of the catheter body 1, specifically at the light outlet 7 on the distal sidewall of the catheter. The optical component includes a reflector 5 and a lens group 6. The reflector 5 can be a miniature reflector, with its reflecting surface set at a 45° angle to the optical axis of the optical fiber 4, used to deflect the light beam propagating along the catheter axis from the distal end of the optical fiber 4 by 90°, causing it to exit in the radial direction of the catheter body 1. The lens group 6 is located in the reflected light path of the reflector 5, used to focus or collimate the outgoing light beam to optimize image quality. In an alternative embodiment, lens group 6 may be a miniature graded-index lens, which has the characteristics of short focal length and small size, making it suitable for installation in a limited space at the distal end of the conduit.

[0037] The light outlet 7 is located on the distal sidewall of the conduit body 1 and serves as a light-transmitting window. The light outlet 7 can be an opening on the sidewall of the conduit body 1, with a window made of a light-transmitting material (such as transparent polymer material or optical glass) embedded in the opening to maintain the smoothness and sealing of the outer surface of the conduit; alternatively, an area uncovered by opaque material can be left directly on the sidewall of the conduit body 1, allowing the light beam to pass through the conduit wall and exit. In such cases... Figure 3 In the embodiment shown, the lens group 6 is directly embedded in the light outlet 7, and the distal end of the lens group 6 is flush with the outer surface of the catheter body 1 to avoid damage to the blood vessel wall caused by the uneven surface structure.

[0038] The light beam emitted from fiber 4 is first reflected and guided by mirror 5, then passes through lens group 6, and finally exits the catheter body 1 through light outlet 7, irradiating the target blood vessel wall tissue. The signal light reflected back from the tissue is transmitted in the opposite direction along the same optical path, and is transmitted back to the OCT host 14 via fiber 4 for processing, thereby generating a high-resolution cross-sectional image of the blood vessel wall. The operating wavelength of the OCT imaging component is preferably 1200nm-1400nm. This wavelength band achieves a good balance between penetration depth and resolution in blood and biological tissues, and can clearly distinguish the intima, media, adventitia of the blood vessel wall, as well as attached thrombi or plaque tissue. The frequency-sweeping laser source in the OCT host 14 generates near-infrared light whose wavelength varies linearly with time. It is split into reference light and sample light by an interferometer. The sample light is transmitted to the distal end of the catheter via fiber 4 to irradiate the tissue. The signal light returning from the tissue interferes with the reference light. After processing, the interference signal is reconstructed into a two-dimensional cross-sectional image or a three-dimensional image of the blood vessel wall through algorithms such as Fourier transform. Because the scattering and absorption coefficients of near-infrared light differ in different tissues, OCT imaging can clearly distinguish the different layers of the blood vessel wall with a resolution of 10μm to 20μm, which is much higher than the resolution of DSA angiography.

[0039] The light-emitting port 7 of the OCT imaging component is positioned on the same circumferential side as the aspiration port 2 on the catheter body 1, meaning both face the vessel wall in the same direction. Along the axial direction of the catheter body 1, the light-emitting port 7 is located between the aspiration port 2 and the jet port 3, in the order from distal to proximal end of the catheter: aspiration port 2, light-emitting port 7, jet port 3. This arrangement ensures that the light-emitting port 7 is axially located within the working area of ​​the rheology thrombectomy component, guaranteeing that the observation area of ​​OCT imaging and the effective area of ​​rheology thrombectomy are spatially aligned.

[0040] The balloon 8 is located at the distal end of the catheter body 1 and is used to generate directional radial thrust upon inflating. The balloon 8 is located on the dorsal side of the aspiration port 2, that is, on the cross-section of the catheter body 1, the balloon 8 and the aspiration port 2 are located on opposite sides. More specifically, as... Figure 2 As shown, the balloon 8 is positioned approximately 180° opposite the suction port 2 and the light outlet 7 on the cross-section of the catheter body 1. In other words, if a coordinate system is established with the center of the cross-section of the catheter body 1 as the origin, and the suction port 2 and the light outlet 7 are located at the 12 o'clock position of the catheter body 1, then the balloon 8 is located at the 6 o'clock position; if the suction port 2 and the light outlet 7 are located at the 3 o'clock position, then the balloon 8 is located at the 9 o'clock position. Simultaneously, along the radial direction of the catheter body 1, the balloon 8 can be aligned with the position of the light outlet 7, meaning that the center of the balloon 8 and the center of the light outlet 7 are located on the same diameter direction but in opposite directions.

[0041] With this relative arrangement, when balloon 8 inflates, it expands towards the dorsal side of catheter body 1 and compresses the vessel wall 15. The increased volume of balloon 8 after inflation generates a reaction force on the vessel wall 15, which pushes catheter body 1 to move in the opposite direction. This causes the distal end of catheter body 1 to move towards the vessel wall on the side facing the suction port 2 and the light outlet 7. Since the suction port 2 and the light outlet 7 are located on the same circumferential side and axially adjacent, the unilateral thrust of balloon 8 acts simultaneously on two functional components: firstly, it brings the suction port 2 closer to the attached thrombus, improving the suction efficiency of the Venturi effect; secondly, it brings the light outlet 7 closer to the target tissue, enabling the OCT optical window to obtain a stable imaging distance and angle. Both functions are achieved synchronously in the same mechanical action, without the need for separate steps.

[0042] Balloon 8 is connected to balloon inflator 104, which can be connected to an external balloon inflation device 13 via a pressurization line. This device 13 can be a manual or electric pressure pump used to inject a pressurizing medium (such as saline or diluted contrast agent) into balloon 8, causing it to inflate. Balloon 8 is made of compliant or semi-compliant medical polymer materials, such as polyurethane or silicone rubber. A compliant balloon's diameter continuously increases with pressure during inflation, allowing it to adaptively conform to vessel walls of different diameters. A semi-compliant balloon's diameter decreases with pressure after inflating to its nominal diameter, providing more stable support. The operator can select the appropriate balloon type and inflation pressure based on the vessel diameter and the specific condition of the lesion.

[0043] The balloon 8 is installed as follows: The balloon 8 is located in the side wall of the catheter body 1. Specifically, a receiving groove 106 for accommodating the balloon 8 is provided on the side wall of the catheter body 1. The balloon 8 is completely contained within the receiving groove 106 in its uninflated state, ensuring that the outer surface of the catheter body 1 at the receiving groove 106 remains smooth and does not hinder the delivery of the catheter within the blood vessel. The receiving groove 106 is a recessed area on the outer surface of the side wall of the catheter body 1, and its shape and size match the shape and size of the balloon 8 in its inflated state. A balloon orifice 105 is also provided on the catheter body 1 at the position adapted to the balloon 8. The balloon orifice 105 penetrates the bottom wall of the receiving groove 106, allowing the receiving groove 106 to communicate with the internal space of the catheter body 1. The distal end of the balloon inflating chamber 104 is connected to the receiving groove 106. The pressurizing medium delivered through the balloon inflating chamber 104 flows into the receiving groove 106 and then enters the interior of the balloon 8, causing it to inflate. When balloon 8 inflates, its volume increases. Due to the constraint of the receiving groove 106, balloon 8 extends at least partially from the side wall of catheter body 1 through balloon orifice 105, thereby contacting the blood vessel wall and generating radial thrust. In an optional embodiment, multiple balloon orifices 105 are provided along the axial direction of catheter body 1, and the multiple balloon orifices 105 are evenly distributed on the bottom wall of receiving groove 106, so that balloon 8 can protrude outward evenly after inflation.

[0044] In this embodiment, the rheological thrombectomy component, the OCT imaging component, and the balloon 8 form a complete collaborative working relationship, and their spatial layout and timing coordination are as follows.

[0045] In terms of spatial layout, the aspiration port 2 and the light outlet 7 are located on the same circumferential side of the catheter body 1 (e.g., at the 12 o'clock position), while the balloon 8 is located on the opposite side (at the 6 o'clock position), and the light outlet 7 is axially positioned between the aspiration port 2 and the jet port 3. This layout ensures that when the balloon 8 inflates and presses the catheter against the opposite vessel wall, the aspiration port 2 and the light outlet 7 simultaneously come into contact with the target area, so that the tissue observed by OCT imaging is exactly the tissue that is about to be treated or has already been treated by rheological thrombectomy, achieving spatial consistency of what is seen is what is removed.

[0046] In terms of timing, the OCT imaging component is configured to acquire images of the target lesion area after balloon 8 inflates and before the rheology thrombectomy component is activated. Specifically, after balloon 8 inflates and presses the distal end of the catheter against the target vessel wall, the relative position of the distal end of the catheter and the vessel wall tends to stabilize. At this time, the OCT imaging component is activated to obtain clear, high-quality images without motion artifacts. The operator uses these images to determine the location, extent, thickness, and degree of adhesion to the vessel wall of any residual thrombus or plaque, thereby determining the specific operational parameters for rheology thrombectomy (such as jet pressure and aspiration time). After the rheology thrombectomy component completes one round of removal, images of the same area can be acquired again using the OCT imaging component to evaluate the removal effect. If images still show residual thrombi, the rheology thrombectomy operation can be repeated without withdrawing the catheter, maintaining the catheter position or finely adjusting the inflation degree of balloon 8, until OCT images confirm that the thrombus has been completely removed.

[0047] This sequential closed loop of balloon apposition, OCT positioning, rheological thrombectomy, and OCT assessment is achieved through the coordinated operation of three functional modules on the same catheter. It eliminates the need to remove the catheter or replace the device, avoiding the operational drawbacks of repeated angiography and push in existing technologies.

[0048] Based on the aforementioned intravascular rheological thrombectomy catheter, this embodiment also provides an intravascular thrombus removal system. For example... Figure 7 As shown, the system includes the intravascular rheological thrombectomy catheter in any of the above embodiments, and also includes external equipment used in conjunction with the catheter, specifically including a high-pressure fluid source 12, a balloon compression device 13, an OCT host 14, and a negative pressure aspiration device.

[0049] A high-pressure fluid source 12 is used to supply high-pressure fluid to the rheological thrombectomy assembly. The high-pressure fluid source 12 can be connected to the proximal end of the water jet tube 10 inside the catheter body 1 via a high-pressure line. The high-pressure fluid source 12 can be a medical high-pressure infusion pump or a dedicated fluid pressure pump, capable of pressurizing medical fluids such as saline to a predetermined pressure (e.g., 300 psi to 1200 psi) and delivering it to the distal end of the catheter at a set flow rate. The high-pressure fluid source 12 is also equipped with pressure and flow sensors for real-time monitoring and adjustment of the pressure and flow rate of the jet fluid, ensuring the safety and effectiveness of the rheological thrombectomy process.

[0050] The negative pressure aspiration device can be connected to the proximal end of the aspiration chamber 103 via a suction tubing to generate continuous negative pressure within the aspiration chamber 103, thereby aspirating thrombi and debris from the distal end of the catheter to the outside of the body. The negative pressure aspiration device can be a medical negative pressure suction pump or a syringe-type aspirator, capable of providing a stable negative pressure (e.g., -100 mmHg to -600 mmHg). In a preferred embodiment, the negative pressure aspiration device is linked to the high-pressure fluid source 12; that is, when the high-pressure fluid source 12 starts spraying, the negative pressure aspiration device simultaneously starts suction, ensuring that broken debris is promptly removed and preventing debris from drifting with the bloodstream and causing distal embolism.

[0051] The balloon inflator 13 is connected to the proximal end of the balloon inflator chamber 104 via a pressurization line, and is used to inject pressurizing medium into the balloon 8 to inflate the balloon 8. The balloon inflator 13 can be a manual screw pump or an electric pump, with a pressure output range typically from 0 atm to 20 atm, enabling precise control of the balloon 8's inflation degree. The balloon inflator 13 is also equipped with a pressure gauge and a volume indicator to display the current pressure and volume of the injected medium within the balloon 8, helping the operator accurately control the balloon 8's inflation diameter. In an optional implementation, the balloon inflator 13 is also equipped with a locking mechanism that maintains the pressure at the target pressure once the balloon 8 has inflated, eliminating the need for continuous force application by the operator.

[0052] The OCT host 14 is connected to the proximal end of fiber optic cable 4 via a fiber optic cable. The OCT host 14 includes a swept-frequency light source, an interferometer, a photodetector, a data acquisition card, and an image processing workstation. Its imaging speed is 100 to 200 frames per second, enabling it to obtain clear images of the vessel walls even amidst interference from heartbeats and respiratory movements. The OCT host 14 is also equipped with a monitor and operating interface for real-time display of OCT images and for allowing the operator to adjust imaging parameters (such as imaging depth and lateral scan range).

[0053] In an optional implementation, the intravascular thrombectomy system further includes an infusion device connected via an infusion line to an infusion lumen on the catheter body 1 or directly to a delivery sheath for injecting contrast agents or anticoagulants into the blood vessel. The infusion device can be an infusion pump or a manual syringe for injecting contrast agents into the blood vessel as needed for DSA-assisted positioning, or for continuously infusing heparinized saline during the procedure to prevent thrombus formation on the catheter surface.

[0054] This embodiment also provides a specific operation method for removing intravascular thrombi using the above-mentioned intravascular rheological thrombectomy catheter.

[0055] Step 1: Puncture and Establishment of Vascular Access. Puncture is performed at a suitable site, such as the femoral vein or internal jugular vein. A delivery sheath is inserted, and guidewire 9 and catheter are delivered into the blood vessel through the delivery sheath. With the assistance of short-term DSA angiography, guidewire 9 and catheter are maneuvered to the target location near the thrombus 16. Once the distal end of the catheter reaches the vicinity of the target location, DSA angiography is stopped to reduce contrast agent usage and radiation exposure. Guidewire 9 remains inserted through the guidewire lumen 101 throughout the procedure, providing stable track support for the catheter and preventing it from deviating from the target position during repeated adjustments.

[0056] like Figure 5 As shown, Step Two: Initial Thrombus Removal. The high-pressure fluid source 12 and negative pressure suction device are activated, and the rheological thrombectomy assembly begins operation. High-speed saline solution is ejected from the water jet tube 10 through tiny orifices on its distal water jet ring 11. The high-speed jet, after exiting through the jet hole 3, breaks the thrombus 16 or plaque into fragments 17. The local negative pressure generated at the suction hole 2 draws the fragments 17 into the suction chamber 103 and removes them from the body. During the removal process, the operator can rotate the entire catheter within the blood vessel around its axis by rotating the rotating manipulator (such as a Y-valve connector) at the proximal end of the catheter body 1, thereby adjusting the circumferential orientation of the jet hole 3 and the suction hole 2, allowing for comprehensive removal of the lumen in all directions. This step primarily removes the central region of the lumen and larger free thrombi.

[0057] like Figure 6As shown, step three: targeted removal of residual wall thrombi. After most of the thrombi in the lumen have been removed, the operation of the rheological thrombectomy assembly is paused. The balloon 8 is inflated by inflating or filling it with fluid using the balloon inflation device 13. After inflation, the balloon 8 extends from the receiving groove 106 through the balloon orifice 105, squeezing the vessel wall 15 outward. Since the balloon 8 is located on the back side of the suction port 2 and the light outlet 7, the reaction force generated by the inflation of the balloon 8 on the vessel wall 15 drives the distal end of the catheter body 1 to move towards the vessel wall area on the side facing the suction port 2 and the light outlet 7, so that the suction port 2 and the light outlet 7 are in close contact with the target vessel wall area. At this time, the OCT imaging assembly is activated, emitting near-infrared light from the light outlet 7 and receiving the reflected signal to obtain a clear image of the residual thrombus 16 or plaque tissue, determining its accurate location, size, and degree of adhesion to the vessel wall, and other detailed information.

[0058] Step Four: Targeted Removal of Residual Lesions. After determining the location and size of the residual lesion based on the OCT images, the operator uses the balloon depressurization device 13 to retract the balloon 8 back into the receiving groove 106. Then, based on the positional information provided by the OCT images, the axial position and circumferential angle of the catheter body 1 are finely adjusted by rotating the operating device, precisely aligning the aspiration port 2 with the area where the residual lesion is located. The high-pressure fluid source 12 and the negative pressure aspiration device are restarted to perform directional rheological thrombectomy. Because the OCT images have already provided precise location information, this removal can be targeted at the residual lesion, improving removal efficiency and reducing damage to the normal vessel wall.

[0059] Step 5: Immediate Assessment and Repeat Operation. After completing one round of targeted removal, pause the rheology thrombectomy unit again, allowing balloon 8 to re-inflate and press the distal end of the catheter towards the target area. Obtain images of the removed area using the OCT imaging unit to immediately assess the removal effect. If the OCT images show residual lesions, repeat steps 3 and 4 until OCT images confirm that the vessel wall in the target area has returned to normal and the thrombus has been completely removed.

[0060] Throughout the procedure, the OCT imaging unit can perform imaging at any time after balloon 8 inflates, without the need to remove the catheter or inject additional contrast agent. Operators can make real-time decisions based on the OCT images, reducing procedure time, contrast agent dosage, and patient radiation exposure.

[0061] In summary, the intravascular rheological thrombectomy catheter and intravascular thrombus removal system provided by this invention form a collaborative working closed loop among the rheological thrombectomy component, OCT imaging component, and balloon, enabling precise OCT positioning, directional balloon adhesion to the vessel wall, rheological targeted removal, and real-time OCT assessment.

[0062] By integrating an OCT imaging component, high-resolution cross-sectional images of the vessel wall can be acquired in real time during the procedure, clearly distinguishing the layered structure of thrombi, plaques, and normal vessel walls, overcoming the limitation of existing DSA angiography in distinguishing tissue types. By placing a directional, wall-adhering balloon on the dorsal side of the aspiration port, the radial thrust generated by balloon inflation presses the distal end of the catheter against the target vessel wall, ensuring close contact between the aspiration port and the attached thrombus. This simultaneously provides stable wall-adhering imaging conditions for the OCT optical window, effectively solving the dual problems of uncontrollable aspiration port orientation and catheter vibration affecting image quality. Through the real-time assessment function of OCT, the operator can determine the clearance effect without withdrawing the catheter, avoiding the cycle of repeated angiography and repeated pushing.

[0063] The rheological thrombectomy component, OCT imaging component, and balloon of this invention are not simply functional superpositions. Instead, they form a close synergy in terms of spatial layout (the aspiration port and the light outlet are on the same side, the balloon is 180° opposite each other on the dorsal side, and the light outlet is located between the aspiration port and the jet port) and working sequence (balloon inflation, OCT imaging, rheological thrombectomy, and OCT assessment). This systematically solves the technical problems of unclear visualization, inaccurate positioning, and slow assessment in existing rheological thrombectomy techniques, and has significant clinical practical value and prospects for widespread application.

[0064] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to cover all possible implementations. Those skilled in the art will recognize that various variations and modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations and modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An intravascular rheological thrombectomy catheter, characterized in that, include: The catheter body (1) has a proximal end and a distal end. The catheter body (1) is provided with a guidewire cavity (101), an OCT fiber cavity (102), an aspiration cavity (103) and a balloon inflator cavity (104) extending along the axial direction. The rheological thrombectomy assembly is located at the distal end of the catheter body (1) and includes at least one suction port (2) communicating with the suction chamber (103) and at least one jet port (3) communicating with a high-pressure fluid source (12). The jet port (3) is used to jet high-pressure fluid to the outside of the catheter body (1) and generate negative pressure at the suction port (2), thereby drawing thrombus (16) or plaque debris (17) into the suction chamber (103). The OCT imaging assembly includes an optical fiber (4) extending along the OCT fiber cavity (102) and an optical assembly located at the distal end of the catheter body (1), the optical assembly being used to transmit and receive imaging light signals. A balloon (8) is located at the distal end of the catheter body (1) and on the dorsal side of the aspiration port (2), and the balloon (8) is connected to the balloon pressurization chamber (104); When the balloon (8) expands, it generates radial thrust, pushing the distal end of the catheter body (1) toward the side of the blood vessel wall (15) facing the suction port (2), so that the suction port (2) and the light outlet (7) of the OCT imaging component fit into the target lesion area.

2. The intravascular rheological thrombectomy catheter according to claim 1, characterized in that, The balloon (8) is disposed in the side wall of the catheter body (1); The catheter body (1) is provided with a balloon hole (105) at a position adapted to the balloon (8). When the balloon (8) is inflated, the balloon (8) extends at least partially from the side wall of the catheter body (1) through the balloon hole (105).

3. The intravascular rheological thrombectomy catheter according to claim 2, characterized in that, The catheter body (1) has a receiving groove (106) on its side wall for accommodating a balloon (8), and the balloon (8) is located in the receiving groove (106); The balloon pressurization chamber (104) and the balloon orifice (105) are both connected to the receiving groove (106).

4. The intravascular rheological thrombectomy catheter according to claim 1, characterized in that, The optical components include a reflector (5) and a lens group (6) located at the distal end of the catheter body (1). The light outlet (7) is located on the side wall of the conduit body (1), and the lens group (6) is disposed at the light outlet (7); The reflector (5) is adapted to the light outlet (7). The light beam emitted from the optical fiber (4) is guided by the reflector (5) and then directed to the lens group (6), and then emitted through the light outlet (7).

5. The intravascular rheological thrombectomy catheter according to claim 4, characterized in that, The balloon (8) is aligned with the light outlet (7) along the radial direction of the catheter body (1).

6. The intravascular rheological thrombectomy catheter according to claim 4, characterized in that, The light outlet (7) and the suction hole (2) are located on the same circumferential side of the conduit body (1); And / or, the light outlet (7) is located between the suction hole (2) and the jet hole (3) along the axial direction of the conduit body (1).

7. The intravascular rheological thrombectomy catheter according to claim 1, characterized in that, The guidewire cavity (101), OCT fiber cavity (102), suction cavity (103) and balloon pressurization cavity (104) are four independent axial cavities, and the OCT fiber cavity (102) is sealed and isolated from the suction cavity (103) and balloon pressurization cavity (104).

8. The intravascular rheological thrombectomy catheter according to claim 1, characterized in that, The balloon (8) is made of compliant or semi-compliant medical polymer material, and the balloon (8) is inflated by injecting saline or contrast agent.

9. The intravascular rheological thrombectomy catheter according to claim 1, characterized in that, The OCT imaging component is used to acquire images of the target lesion area after the balloon (8) is inflated and before the rheological thrombectomy component is activated.

10. An intravascular thrombus removal system, characterized in that, Including the intravascular rheological thrombectomy catheter as described in any one of claims 1 to 9.

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