CN113974766A

CN113974766A - thrombectomy catheter

Info

Publication number: CN113974766A
Application number: CN202111270425.0A
Authority: CN
Inventors: 葛泉波; 陆信武; 叶开创; 吴常生; 裴强; 张壮利
Original assignee: Shanghai Weiyu Medical Technology Co ltd
Current assignee: Shanghai Weiyu Medical Technology Co ltd
Priority date: 2018-01-19
Filing date: 2018-01-19
Publication date: 2022-01-28
Anticipated expiration: 2038-01-19
Also published as: CN113974766B; CN108143464A

Abstract

The invention provides a thrombus removal catheter, which comprises: a blocking sheath, a dilator and a thrombus extractor; the blocking sheath comprises a sheath tube, the distal end of the sheath tube is provided with a balloon, the proximal end of the sheath tube is provided with an opening part, at least two cavities are arranged in the sheath tube, the distal end of the first cavity is communicated with the inner cavity of the balloon, and the second cavity is axially communicated with the opening part; the dilator can extend into the second cavity of the sheath from the opening part; the thrombus taking device can extend into the second cavity from the opening part of the handle and comprises an outer pipe, an inner pipe and a dense mesh thrombus taking piece, wherein the outer pipe and the inner pipe are coaxially sleeved with each other, one end of the dense mesh thrombus taking piece is connected with the far end of the inner pipe, the other end of the dense mesh thrombus taking piece is connected with the far end of the outer pipe, and the dense mesh thrombus taking piece can be expanded or loosened by pulling the inner pipe. The thrombus removal catheter can effectively improve the thrombus removal rate and reduce the blood loss.

Description

Thrombus-taking catheter

The patent application of the divisional application has the application date of 2018, 1 and 19, and the application number of 201810052511.6, and the invention is named as an embolectomy catheter and an embolectomy device for the embolectomy catheter.

Technical Field

The invention relates to the technical field of thrombus removal, in particular to a thrombus removal catheter.

Background

The existing treatment methods mainly comprise vascular incision embolectomy, catheter contact thrombolysis and percutaneous mechanical puncture embolectomy, the incision embolectomy needs to be dissected and separated and blood vessels are incised, such as femoral artery, femoral vein or brachial artery incision, and with the development of intracavity interventional techniques and the innovation of materials, the open surgical mode is gradually replaced by minimally invasive intracavity therapy, namely catheter contact thrombolysis and percutaneous mechanical puncture embolectomy, the catheter contact thrombolysis is extremely strict due to high risk of thrombolysis medicine bleeding, and most patients have contraindications of catheter contact thrombolysis, so many patients cannot benefit from the open surgical mode.

The stent-type embolectomy is a newly appeared mechanical embolectomy method, and the mechanical embolectomy method is that under the assistance of medical imaging technology, a stent-type embolectomy device is sent to a vascular embolism position through a catheter and released, the stent-type embolectomy device is unfolded automatically, is embedded with thrombus by means of the self expansion force, and then is recovered to carry out the thrombus.

The Chinese patent CN103417257B discloses an intracranial vascular thrombus removal catheter, the distribution density of spiral mesh ring units of the thrombus removal catheter is different, the distribution of the spiral mesh ring units is dense at the far end, the distribution of the spiral mesh ring units is relatively sparse at the near end, and therefore, the thrombus can be effectively prevented from falling off. Chinese patent application CN103997976A discloses an embolectomy cage having an elongated axis and a circumference, comprising elongated members that collectively define a plurality of open cells, which is effective in removing emboli. Chinese patent CN105726088A discloses a thrombus extraction device, which comprises a reticular self-expanding stent and a core wire, wherein the stent is in a cylindrical expansion state, the proximal end of the stent is provided with an opening, and the distal end of the stent is closed.

As mentioned above, the current stent-type thrombus extractor or thrombus extraction catheter is limited by the structure, the sparse stent rod is used for capturing thrombus or sucking the thrombus under negative pressure, and the thrombus is pulled out of the body, but when the thrombus is extracted, the force of the stent-type thrombus extractor or thrombus extraction catheter acting on the thrombus is not uniform, the thrombus is easy to fall off from the thrombus extractor, or thrombus fragments are generated to block a far-end blood vessel or enter other blood vessels, and the blood loss amount is too large due to the long-time negative pressure. In addition, current stent-type embolisers or embolisers do not work well for old thrombi and for extensive embolization. Based on the existing medical cognition, the deep venous thrombosis is often large in capacity, and the acute-phase thrombosis is soft and fragile in texture; arterial thrombosis often has small volume, acute-stage thrombosis is soft in texture, and old thrombosis often adheres to the vessel wall. At present, the stent type thrombus taking catheter with a sparse structure is generally developed aiming at arterial thrombus, and the effect is not ideal for large-capacity venous thrombosis. Therefore, there is a need for an easy-to-embolise embolectomy catheter.

Disclosure of Invention

In view of the above disadvantages of the prior art, the present invention is directed to an embolectomy catheter, which is used to solve the problems of the prior art that the thrombus falls off and overflows and the blood loss is too high when the stent embolectomy device is used.

To achieve the above and other related objects, the present invention provides an embolectomy catheter, comprising:

the blocking sheath comprises a sheath tube, the distal end of the sheath tube is provided with a balloon, and the proximal end of the sheath tube is provided with an opening part; at least two axially extending cavities are arranged in the sheath tube, the far end of the first cavity is communicated with the inner cavity of the balloon, and the second cavity is axially communicated with the opening part;

a dilator extendable from the opening into the second lumen, a distal end of the dilator extending out of the second lumen and occluding the same;

the thrombus taking device comprises an outer pipe, an inner pipe and an expandable dense-mesh thrombus taking piece, wherein the outer pipe and the inner pipe are coaxially sleeved with each other, the inner pipe can move axially relative to the outer pipe, one end of the dense-mesh thrombus taking piece is connected with the far end of the inner pipe, the other end of the dense-mesh thrombus taking piece is connected with the far end of the outer pipe, and the dense-mesh thrombus taking piece can be expanded or loosened by drawing the inner pipe; the thrombus remover can extend into the second cavity from the opening part, the far end of the outer tube penetrates out of the second cavity, and the near end of the outer tube is exposed out of the opening part.

Preferably, the proximal end of the sheath tube is connected with a handle, and the opening part is arranged on the handle; the first cavity is used for communicating the inner cavity of the balloon with a balloon filling joint connected with the handle; the proximal end of the second cavity is communicated with a negative pressure suction device which is connected with the handle.

Preferably, the opening part of the handle is provided with a connecting buckle, the proximal end of the dilator is connected with a handheld part, and the handheld part is provided with a connecting part which is matched and fixed with the connecting buckle.

Preferably, the outer diameter of the dilator matches the inner diameter of the second lumen.

Preferably, the dilator is made of a thermoplastic elastomer, and barium sulfate, bismuth oxide or bismuth oxychloride containing a developer material is filled in the thermoplastic elastomer.

Preferably, the dense mesh-shaped plug taking piece is formed by weaving a superelastic memory nickel-titanium alloy wire mixed with a platinum-iridium alloy wire, a gold wire or a stainless steel wire, and the platinum-iridium alloy wire, the gold wire or the stainless steel wire is used for developing under an X-ray machine.

Preferably, the proximal end of the outer tube is connected with a hand piece, and the hand piece is provided with a positioning part for locking the inner tube.

Preferably, both ends of the inner tube are exposed out of both ends of the outer tube, and the near end of the inner tube is connected with a pulling handle.

Preferably, the sheath tube, the inner tube and the outer tube are all made of polyamide-based thermoplastic elastomer.

Preferably, the distal ends of the sheath tube and the inner tube are tapered.

As mentioned above, the thrombus removal catheter of the invention has the following beneficial effects: the blood flow is blocked by the filling of the saccule at the far end of the sheath tube, so that thrombus is enclosed between the dense mesh-shaped thrombus taking piece and the saccule, thrombus taking is easy, the dense mesh-shaped thrombus taking piece can enable blood to pass through meshes on the dense mesh-shaped thrombus taking piece, thrombus can be effectively prevented from overflowing to blood vessels at other parts in the thrombus taking process when thrombus taking operation is carried out, and the amount of blood loss is reduced to the minimum by matching with negative pressure suction while the dense mesh-shaped thrombus taking piece and the blocking saccule take thrombus; the thrombus remover is provided with an inner tube with a thinner tip and an outer tube with a thinner tube body, and can reach the deeper position of thrombus; the thrombus extraction device is suitable for extracting thrombus from large and medium blood vessels, comprises relatively old lesion, and is particularly suitable for absorbing thrombus on limbs, such as thrombus with large volume in veins; the thrombus removal catheter is a passive thrombus removal instrument, is low in cost and simple to operate, and can greatly reduce the cost of thrombus removal operation.

Drawings

Fig. 1 shows a schematic view of the dilator of the present invention inserted within an occlusion sheath.

Fig. 2 is a cross-sectional view taken along line AA in fig. 1.

Fig. 3 shows a schematic view of the blocking sheath of the present invention.

Fig. 4 shows a schematic view of the dilator of the present invention.

FIG. 5 is a schematic view of the embolectomy device of the present invention.

Fig. 6 is a cross-sectional view taken along line BB in fig. 5.

Fig. 7 is a schematic view of the thrombus remover of the present invention inserted into the blocking sheath and in a relaxed state.

FIG. 8 is a schematic view of the embolectomy device of the present invention inserted into an occlusion sheath and in an expanded state.

Element number description:

1 dilator

2 developing mark

3 saccule

4 sheath pipe

5 negative pressure suction device

6 handle

7 balloon filling joint

8 hand-held part

9 two-way

10 connecting pipe

11 connecting fastener

12 connecting part

121 notch

13 dense net-shaped bolt taking piece

14 outer tube

15 handpiece

16 inner pipe

17 drawing handle

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Please refer to fig. 1 to 8. It should be understood that the structures, ratios, sizes, and the like shown in the drawings are only used for matching the disclosure of the present disclosure, and are not used for limiting the conditions that the present disclosure can be implemented, so that the present disclosure is not limited to the technical essence, and any structural modifications, ratio changes, or size adjustments should still fall within the scope of the present disclosure without affecting the efficacy and the achievable purpose of the present disclosure. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

For convenience of description, the embolic catheter is defined herein along its length, in use, the end distal to the operator is defined as the distal end, and the end held by the operator is the proximal end.

As shown in fig. 1 to 8, the present invention provides an embolectomy catheter, which includes:

the blocking sheath is shown in fig. 3 and comprises a sheath tube 4, a balloon 3 is arranged at the far end of the sheath tube 4, and preferably, a handle 6 is connected with the near end of the sheath tube 4; at least two axially extending cavities are arranged in the sheath tube 4, the far end of the first cavity is communicated with the inner cavity of the saccule 3, preferably, the near end of the first cavity is communicated with a saccule filling joint 7 which is connected with the handle 6, and preferably, the sheath tube 4 at two sides of the saccule 3 is provided with the developing marks 2; preferably, the proximal end of the second cavity is communicated with a negative pressure suction device 5 connected to a handle 6, and the handle 6 is further provided with an opening part axially communicated with the second cavity;

a dilator 1, preferably, the outer diameter of the dilator 1 is matched with the inner diameter of the second cavity of the sheath 4, the dilator can extend into the second cavity of the sheath 4 from the opening part of the handle 6, and the distal end of the dilator 1 passes out of the second cavity of the sheath 4 and seals the second cavity of the sheath 4;

the embolectomy device, as shown in fig. 5, comprises an outer tube 14 and an inner tube 16 which are coaxially sleeved, and an expandable dense-mesh embolectomy member 13, wherein both ends of the inner tube 16 are exposed out of both ends of the outer tube 14, the inner tube 16 can move axially relative to the outer tube 14 and can also be positioned and fixed with each other, one end of the dense-mesh embolectomy member 13 is connected with the distal end of the inner tube 16, the other end of the dense-mesh embolectomy member 13 is connected with the distal end of the outer tube 16, and the reticular embolectomy member 13 can be expanded or loosened by pulling the inner tube 16; the embolectomy device may extend into the second cavity from the opening of the handle 6, and the distal end of the outer tube 14 may pass out of the second cavity, as shown in fig. 7 and 8, and the proximal end of the outer tube 14 is exposed outside the opening of the handle 6.

The thrombus taking catheter comprises three components, namely the blocking sheath, the dilator 1 and the thrombus taking device, the balloon 3 at the far end of the sheath tube 4 is inflated to be used as the blocking of the near end of thrombus, so that the blood flow is blocked, the thrombus is enclosed between the dense mesh-shaped thrombus taking piece 13 and the balloon 3, the thrombus is easy to take, the dense mesh-shaped thrombus taking piece 13 can enable the blood to pass through meshes of the dense mesh-shaped thrombus taking piece 13, due to the compactness of the dense mesh-shaped thrombus taking piece 13, a stopping film is easily formed on the surface of the dense mesh-shaped thrombus taking piece 13 during thrombus taking operation, the thrombus can be effectively prevented from overflowing to other parts of blood vessels beyond the dense mesh-shaped thrombus taking piece in the process of taking, the dense mesh-shaped thrombus taking piece and the blocking balloon are matched with negative pressure suction at the same time of thrombus taking, the blood loss is reduced to the minimum, and the thrombus taking catheter is particularly suitable for absorbing large-capacity thrombus in veins.

The connecting buckle 11 is arranged at the opening part of the handle 6, the dilator 1 is provided with a connecting part 12 which is matched and fixed with the connecting buckle 11, and the dilator 1 is fixed with the blocking sheath through the fixing of the connecting part 12 and the connecting buckle 11, so that the dilator can conveniently penetrate into the blood vessel. In this embodiment, the connection buckle 11 is provided with a protruding portion, the connection portion 12 is provided with a notch 121, when the dilator 1 penetrates into the second cavity of the sheath tube 4 from the opening portion of the handle 6, the dilator 1 is connected to the blocking sheath by the protruding portion being clamped in the notch 121, and the dilator 1 is separated from the blocking sheath by the matching of the protruding portion and the notch 121, so that the dilator 1 is easily pulled out from the blocking sheath.

The positioning connection between the handle 6 and the dilator 1 is not limited to the engagement between the connection buckle 12 and the connection portion 11, but may be achieved by providing a rotatable positioning portion that locks the dilator after the positioning portion is tightened. The handle 6 may also lock the bolt remover by a rotatable detent.

To facilitate insertion of the dilator 1, a handle 8 is connected to the proximal end of the dilator 1, and the operator can insert the dilator 1 into the sheath 4 through the opening of the handle 6 by holding the handle 8 with his hand. For medical imaging, the dilator 1 in this embodiment is made of a thermoplastic elastomer such as polyethylene or polyurethane, and barium sulfate, bismuth oxide or bismuth oxychloride containing a developer is filled in the thermoplastic elastomer.

In this embodiment, the sheath tube 4 in the blocking sheath has a dual-lumen structure or a multi-lumen structure, wherein one lumen, i.e., the first lumen, is used as a passage for filling the balloon 3, and the other lumen, i.e., the second lumen, is used as a working lumen for passing the dilator 1 or the embolectomy device or other medical devices into and out of the blood vessel, and the sheath tube 4 is made of polyurethane or polyamide thermoplastic elastomer. In this embodiment, the balloon 3 is made of thermoplastic elastomer such as natural latex, synthetic rubber, silica gel or polyurethane, and contrast agent is injected through the balloon filling cavity joint 7 on the handle 6 to inflate and expand the compliant balloon, so as to block blood circulation. In order to extract thrombus, the negative pressure suction device 5 is connected with the handle 6 through a connecting pipe 10, and the negative pressure suction device 5 is further connected with a two-way 9, so that the negative pressure suction device can be conveniently connected with an electric negative pressure aspirator to form suction negative pressure, and the thrombus can more efficiently flow into a collecting device of the negative pressure suction device 5 from the blocking sheath.

In the thrombus taking device in the embodiment, the dense mesh thrombus taking piece 13 is woven by the superelastic memory nickel-titanium alloy wire, and a certain amount of platinum-iridium alloy wires, gold wires or stainless steel wires are mixed and woven for developing under an X-ray machine, so that blood can be allowed to flow through the dense mesh thrombus taking piece during thrombus taking, and the thrombus can be effectively prevented from overflowing to blood vessels at other parts during thrombus taking; when the dense-mesh embolectomy piece is used for embolectomy, negative pressure suction is matched, so that the amount of blood loss can be effectively reduced, and the thrombus suction effect can be effectively improved. The super elastic memory nickel titanium alloy wires used by the dense mesh-shaped embolectomy piece in the embodiment are very thin, and the pore diameter of the woven meshes is about 0.3-1.0mm, namely, the dense mesh-shaped embolectomy piece is a dense mesh-shaped member, so that blood can pass through the dense mesh-shaped embolectomy piece, and the passage of thrombus blocks can be prevented. The outer tube 14 and the inner tube 16 are both made of a polyamide-based thermoplastic elastomer. The whole thrombus taking device is soft, and the injury of the blood vessel intima is reduced in the thrombus taking process.

In order to facilitate the expansion and loosening of the dense mesh-like plug member, a handle member 15 is attached to the proximal end of the outer tube 14 in this embodiment, and as shown in fig. 5, a positioning portion for locking the inner tube 16 is provided at the proximal end of the handle member 15. In this embodiment, the handle 15 can be used as a handle to facilitate the operator to take the bolt device. The positioning portion in the hand piece 15 positions the inner tube 16 and the outer tube 14, and the mesh-like embolectomy member 13 is maintained in an expanded state, thereby facilitating drawing of the thrombus into the occlusion sheath. The positioning part can be a rotary or switch type locking piece, and the inner pipe and the outer pipe are locked through rotation or switch.

Referring to fig. 5 and 6, in the embodiment, the inner tube 16 is inserted into the outer tube 14, the length of the inner tube 16 is longer than that of the outer tube 14, both ends of the inner tube 16 are located outside the outer tube 14, one end of the dense mesh-shaped bolt-taking member 13 is connected to the distal end of the inner tube 16, the other end of the dense mesh-shaped bolt-taking member 13 is connected to the distal end of the outer tube 14, the relative distance between the distal end of the inner tube 16 and the distal end of the outer tube is changed by pulling the inner tube 16, so that the dense mesh-shaped bolt-taking member 13 is expanded and loosened, and the dense mesh-shaped bolt-taking member is expanded if the inner tube is pulled in the direction of the arrow in fig. 5, and is loosened otherwise.

To facilitate withdrawal of the inner tube, in this embodiment a withdrawal handle 17 is attached to the proximal end of the inner tube 16, as shown in figure 5. To facilitate passage of the embolectomy device through the thrombus, and to the distal end of the thrombus, the distal end of the inner tube 16 in this embodiment is rounded and tapered, i.e., the end is tapered.

The specific process of extracting thrombus in the blood vessel by adopting the thrombus extraction catheter is as follows:

after a blood vessel is punctured and cannulated, and the position of a thrombus and the condition of surrounding blood vessels are known through arterial or venous angiography, firstly, the dilator 1 is arranged in a second cavity of the sheath tube 4 in a penetrating way, as shown in fig. 1 and 2, the dilator 1 is arranged in a blocking sheath in a penetrating way, and then, the sheath tube 4 is guided to the proximal end of the thrombus under the guide of a guide wire; connecting a balloon cavity joint 7 with normal saline or other appropriate liquid medicine to fill the balloon 3 to the inner diameter of the blood vessel, so that the balloon blocks the blood vessel at the proximal end of the thrombus and blocks the blood flow; withdrawing the dilator 1 from the blocking sheath, and placing an embolectomy device along the guide wire, wherein a dense mesh-shaped embolectomy piece 13 in the embolectomy device passes through the thrombus and is placed at the far end of the thrombus as shown in fig. 7; pulling the inner tube 16 of the embolectomy device outwards, as shown in fig. 8, the dense mesh embolectomy member 13 expands, locking the inner tube 16 and the outer tube 14, and keeping the dense mesh embolectomy member 13 in an expanded state; the outer tube 14 is pulled outwards to take the thrombus into the sheath tube 4 of the blocking sheath, the thrombus is synchronously discharged into the negative pressure suction device 5 through negative pressure suction, and when the thrombus is pulled, the blood can pass through the dense mesh thrombus taking piece 13 to reduce the blood loss, but the massive thrombus can be sucked out along with the suction force; after the thrombus is taken out from a certain section of blood vessel, the balloon on the blocking sheath is inflated and placed, and the blood vessel is moved to the next section of thrombus for thrombus taking out. The thinner tip and the tube body of the embolectomy device can reach the deeper position of the thrombus.

In conclusion, the thrombus taking catheter and the thrombus taking device for the same provided by the invention block the blood flow by blocking the filling of the balloon at the distal end of the sheath, and the soft thrombus taking device reduces the damage of the blood vessel intima in the thrombus taking process; the dense mesh-shaped embolectomy piece can enable blood to pass through the mesh openings of the dense mesh-shaped embolectomy piece, so that the embolus of the thrombus can be effectively prevented from overflowing to blood vessels of other parts in the embolectomy operation, the dense mesh-shaped embolectomy piece is matched with negative pressure suction while embolectomy is performed, the thrombus can be removed, and the blood loss is reduced to the minimum; the inner tube of the thrombus remover is provided with a thinner tip and a tube body, and can reach the deeper position of thrombus; is suitable for removing embolus from large and medium sized blood vessels, including relatively old lesions; the invention is a passive embolectomy instrument, has low cost and simple operation, and can greatly reduce the expense of embolectomy; can efficiently take out large-capacity thrombus, reduce valve injury, reduce the application of thrombolytic drugs, reduce blood loss, reduce wound and accelerate recovery. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. a thrombectomy catheter, is characterized in that, comprises:

The blocking sheath includes a sheath tube, the distal end of the sheath tube is provided with a balloon, and the proximal end of the sheath tube is provided with an opening; at least two axially extending cavities are arranged in the sheath tube, the first The distal end of the cavity is communicated with the inner cavity of the balloon, and the second cavity is communicated axially with the opening;

a dilator, the dilator can extend into the second cavity from the opening, and the distal end of the dilator passes through the second cavity and seals it;

The thrombus removal device includes an outer tube and an inner tube that are coaxially sleeved, and an expandable dense mesh-shaped thrombus removal piece, the inner tube can move in the axial direction relative to the outer tube, and one end of the dense mesh-shaped thrombus removal piece is connected to the outer tube. The distal end of the inner tube is connected, and the other end of the dense mesh-shaped thrombus removal member is connected to the distal end of the outer tube, and pulling the inner tube can make the dense mesh-shaped thrombus removal member expand or relax; The thrombectomy device can be inserted into the second cavity from the opening, the distal end of the outer tube passes through the second cavity, and the proximal end of the outer tube is exposed at the opening of the opening. outside.

2. The thrombectomy catheter according to claim 1, wherein a handle is connected to the proximal end of the sheath, and the opening is arranged on the handle; The inner cavity of the second cavity is communicated with the balloon filling joint connected on the handle, and the proximal end of the second cavity is communicated with the negative pressure suction device connected on the handle.

3. The thrombectomy catheter according to claim 2, characterized in that, the handle is provided with a connection buckle, the proximal end of the dilator is connected with a handle, and the handle is provided with the connection card Snap-fit secure connection.

4. The thrombectomy catheter according to claim 1, wherein the outer diameter of the dilator matches the inner diameter of the second cavity.

5 . The thrombectomy catheter according to claim 1 , wherein the dilator is made of thermoplastic elastomer, and the thermoplastic elastomer is filled with developer-containing materials such as barium sulfate, bismuth oxide or bismuth oxychloride. 6 .

6 . The thrombectomy catheter according to claim 1 , wherein the dense mesh-shaped thrombectomy member is woven from superelastic memory nickel-titanium alloy wire mixed with platinum-iridium alloy wire, gold wire or stainless steel wire. 7 .

7 . The thrombectomy catheter according to claim 1 , wherein a hand piece is connected to the proximal end of the outer tube, and the hand piece is provided with a positioning portion for locking the inner tube. 8 .

8. The thrombectomy catheter according to claim 7, wherein both ends of the inner tube are exposed outside the two ends of the outer tube, and the proximal end of the inner tube is connected with a pulling handle .

9 . The thrombectomy catheter according to claim 1 , wherein the sheath tube, the inner tube and the outer tube are all made of polyurethane or polyamide thermoplastic elastomer. 10 .

10. The thrombectomy catheter of claim 1, wherein the distal ends of the sheath tube and the inner tube are tapered.