CN115501456A

CN115501456A - Guiding device

Info

Publication number: CN115501456A
Application number: CN202110688913.7A
Authority: CN
Inventors: 孙权权; 叶萍; 张一�
Original assignee: Shanghai Achieva Medical Suzhou Co ltd
Current assignee: Shanghai Achieva Medical Suzhou Co ltd
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2022-12-23
Anticipated expiration: 2041-06-22
Also published as: CN115501456B

Abstract

The invention provides a guiding device, which comprises an inner tube, an outer tube and an expandable part, wherein the outer tube is sleeved outside the inner tube, a fluid channel is formed between the outer tube and the inner tube, the expandable part is arranged outside the far end of the outer tube, the far end of the outer tube is provided with at least one through hole, when the expandable part injects fluid in an expansion state, a fluid cavity is formed between the outer tube and the expandable part, the through hole is communicated with the fluid channel and the fluid cavity, the far end of the outer tube is also provided with at least two concave parts, each concave part is sunken towards the inner tube and fixed on the inner tube, and each through hole is arranged between two adjacent concave parts in the circumferential direction of the outer tube. The at least two concave parts of the outer pipe are respectively sunk towards the inner pipe and fixed on the inner pipe, the concave parts and the inner pipe can provide supporting force for the part between the two adjacent concave parts of the outer pipe, so that the part between the two adjacent concave parts of the outer pipe is arched, and when fluid in the fluid cavity is pumped out, the situation that the part of the outer pipe around the through hole is tightly attached to the wall of the inner pipe to block the through hole is avoided.

Description

Guiding device

Technical Field

The invention relates to a vessel intervention medical instrument, in particular to a guiding device.

Background

Cerebral thrombosis is mainly caused by cerebrovascular thrombosis, and is the most common lethal and disabling disease of the central nervous system. Cerebral thrombosis has the characteristics of high morbidity, high disability rate, high mortality and high recurrence rate.

The recanalization of blood vessels is the key for treating cerebral thrombosis, one treatment method of the cerebral thrombosis at present is mechanical thrombus extraction, and the mechanical thrombus extraction is completed by adopting interventional medical equipment, the thrombus extraction device is pushed to the position of a target thrombus through an inner cavity of a balloon guide catheter, then fluid is injected between an inner tube and an outer tube of the balloon guide catheter, the fluid flows into a balloon tube coated on the periphery of the outer tube through a through hole on the outer tube, so that the balloon tube is expanded and attached to the inner wall of the blood vessel, the blood flow is temporarily blocked, then the thrombus extraction device is cut into the target thrombus to hang the whole thrombus, then the thrombus extraction device is withdrawn to extract the thrombus, the fluid in the balloon tube is sucked to enable the balloon tube to contract to the outer surface of the attached outer tube, and the blood flow returns to normal flow.

However, when fluid is sucked, the flow rate of the fluid at the through hole is the largest, and the negative pressure borne by the part of the outer tube around the through hole is far greater than that borne by other parts of the outer tube, so that the part of the outer tube around the through hole is easily sunk towards the inner tube, the distance between the outer tube and the inner tube is reduced, the time required by the contraction of the balloon tube is increased, and even the part of the outer tube around the through hole is tightly attached to the wall of the inner tube to block the through hole, so that the fluid is remained in the balloon tube to prevent the balloon tube from being continuously contracted, the time for blocking the blood flow is increased, and the operation risk is increased.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a guiding device to solve the problem that when fluid is pumped, the portion of the outer tube around the through hole is easily sunk to the inner tube or even tightly attached to the inner tube wall to block the through hole, so that the fluid in the balloon cannot be smoothly discharged.

In order to achieve one of the above objects, an embodiment of the present invention provides a guiding device, including an inner tube, an outer tube, and an expandable member, where the outer tube is sleeved outside the inner tube, and a fluid channel is formed between the outer tube and the inner tube, the expandable member is disposed outside a distal end of the outer tube, a distal end of the outer tube is provided with at least one through hole, when the expandable member injects a fluid to an expanded state, a fluid cavity is formed between the outer tube and the expandable member, the through hole communicates the fluid channel and the fluid cavity, a distal end of the outer tube further has at least two recesses, each recess is recessed toward the inner tube and fixed to the inner tube, and each through hole is disposed between two adjacent recesses in a circumferential direction of the outer tube, and the through hole is located in the balloon tube.

As a further improvement of an embodiment of the present invention, in a circumferential direction of the outer tube, a distance between each of the through holes and two of the recesses adjacent thereto is equal.

As a further improvement of an embodiment of the present invention, two of the recesses adjacent to the through hole are located on the same circumference of the outer tube and are arranged at an interval of 180 °.

As a further refinement of an embodiment of the present invention, the expandable member is a balloon.

As a further improvement of an embodiment of the present invention, both ends of the expandable member are fixed to the outer tube, respectively, in an axial direction of the outer tube, and the recess is located outside the expandable member.

As a further improvement of an embodiment of the present invention, the recess is located on a side of the expandable member near the proximal end of the outer tube.

As a further improvement of an embodiment of the present invention, the outer tube includes a first section and a second section which are arranged in sequence from the proximal end to the distal end thereof, the expandable member is arranged outside the second section, the through hole is arranged in the second section, and the outer diameter of the second section is not greater than the maximum diameter of the first section.

As a further improvement of an embodiment of the present invention, the recess extends in an axial direction of the outer tube.

As a further improvement of an embodiment of the present invention, the recess is fixed to the inner pipe by welding, adhesion, or fusion.

As a further improvement of an embodiment of the present invention, the hardness of the outer tube is gradually decreased from the proximal end to the distal end, and/or the hardness of the inner tube is gradually decreased from the proximal end to the distal end.

Compared with the prior art, the invention has the following beneficial effects: the guiding device of the invention is characterized in that at least two concave parts of the outer pipe are respectively sunk towards the inner pipe and fixed on the inner pipe, the concave parts and the inner pipe can provide supporting force for the part between two adjacent concave parts of the outer pipe, so that the part between two adjacent concave parts of the outer pipe is arched, the radial distance from the highest point of the arch to the inner pipe is increased, when the bolt is taken out, the fluid in the fluid cavity is pumped out from the through hole arranged between two adjacent concave parts, under the supporting force action of the concave parts and the inner pipe, even if the flow velocity of the fluid at the through hole is the maximum, the negative pressure born by the part of the outer pipe around the through hole is far larger than the negative pressure born by other parts of the outer pipe, the part of the outer tube around the through hole can not be excessively sunk towards the inner tube, a certain space is still formed between the part of the outer tube around the through hole and the inner tube, so that fluid can smoothly flow out of a fluid cavity, the situation that the part of the outer tube around the through hole is tightly attached to the wall of the inner tube to block the through hole is avoided under the condition that the diameter of the outer tube is not increased, the expandable part can be restored to the contracted state from the expanded state as soon as possible, the expandable part is separated from the inner wall of the blood vessel, the blocked blood flow is restored to flow, meanwhile, the guiding device is convenient to take out, and the operation risk is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic cross-sectional view of a guide device according to an embodiment of the present invention, showing a balloon in a deflated state;

FIG. 2 is a cross-sectional view of a guide device according to an embodiment of the invention, showing the balloon in an inflated state;

fig. 3 is a schematic cross-sectional view of a guide device illustrating a cross-section of a balloon in an inflated state and at a maximum diameter in accordance with an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the various illustrations of the present invention, certain dimensions of structures or portions are exaggerated relative to other structures or portions for ease of illustration and, thus, are merely provided to illustrate the basic structure of the subject matter of the present invention.

It is to be understood that, unless otherwise expressly specified or limited, in the description of the invention, the terms "inner", "outer", and the like refer to an orientation or positional relationship based on that shown in the drawings, which is for convenience in describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Referring to fig. 1, the present invention provides a guiding device 100, which comprises an inner tube 1, an outer tube 2, a connecting tube 3 and an expandable member, wherein the outer tube 2 is sleeved outside the inner tube 1 and coaxially disposed, a fluid channel 6 is formed between the outer tube 2 and the inner tube 1, and a sealing portion 5 extending from the distal end of the outer tube 2 to the inner tube 1 along the radial direction of the outer tube 2 is further disposed at the distal end of the guiding device 100, so as to prevent fluid from flowing out of the guiding device 100 and entering into a blood vessel. One end of the connecting pipe 3 is connected to the outer pipe 2, and the pipe cavity of the connecting pipe 3 is communicated with the fluid channel 6, but the pipe cavity of the connecting pipe 3 is isolated from the pipe cavity of the inner pipe 1, so that the fluid can be conveniently injected into the fluid channel 6 from the connecting pipe 3, and the fluid can not enter the pipe cavity of the inner pipe 1.

Referring to fig. 1 to 2, the expandable member is disposed outside the distal end of the outer tube 2, the distal end of the outer tube 2 is provided with at least one through hole 21, the expandable member has an expanded state and a contracted state abutting against the outer surface of the outer tube 2, when the expandable member injects a fluid in the expanded state, a fluid cavity 41 is formed between the outer tube 2 and the expandable member, the through hole 21 communicates the fluid channel 6 and the fluid cavity 41, at this time, the fluid flows into the fluid cavity 41 from the fluid channel 6 and fills the fluid cavity 41, and the expandable member expands along the axial direction thereof to abut against the inner wall of the blood vessel, thereby playing a role of temporarily blocking blood flow and avoiding the influence of blood flow on the thrombus removal process. The fluid here is a mixed solution of contrast agent and saline to facilitate viewing of the inflated state of the inflatable member.

Specifically, in this embodiment, the expandable member is a balloon 4, the balloon 4 is disposed at the periphery of the outer tube 2, the outer tube 2 is provided with a through hole 21 communicating the fluid channel 6 with the balloon 4, the balloon 4 has an expanded state and a contracted state attached to the outer surface of the outer tube 2, when the balloon 4 injects a fluid in the expanded state, a fluid cavity 41 is formed between the outer tube 2 and the balloon 4, the fluid flows into the fluid cavity 41 from the fluid channel 6 and fills the fluid cavity 41, and the balloon 4 expands along the axial direction thereof to the inner wall attached to the blood vessel, thereby playing a role of temporarily blocking the blood flow and avoiding the influence of the blood flow on the embolectomy process. The fluid here is a mixed solution of contrast agent and saline to facilitate observation of the inflated state of the balloon 4.

Referring to fig. 3, the outer tube 2 further has at least two recesses 22, each recess 22 being recessed toward the inner tube 1 and fixed to the inner tube 1, the recesses 22 being disposed adjacent to the through holes 21, and each through hole 21 being disposed between two adjacent recesses 22 in the circumferential direction of the outer tube 2, the through holes 21 being located within the balloon 4. Thus, the concave portions 22 and the inner tube 1 will provide a supporting force to the portion between two adjacent concave portions 22 of the outer tube 2, so that the portion between two adjacent concave portions 22 of the outer tube 2 is arched, and the radial distance from the highest point of the arch to the inner tube 1 is increased, so that the radial distance from the through hole 21 to the inner tube 1 is increased, when the fluid in the fluid cavity 41 is sucked out of the fluid cavity 41 after the embolectomy is completed, even if the fluid flow rate at the through hole 21 is the largest, the negative pressure borne by the portion of the outer tube 2 around the through hole 21 is much larger than the negative pressure borne by other portions of the outer tube 2, under the supporting force of the concave portions 22 and the inner tube 1, the portion of the outer tube 2 around the through hole 21 will not be excessively sunk towards the inner tube 1, and a certain space is still reserved between the portion of the outer tube 2 around the through hole 21 and the inner tube 1 so that the fluid can smoothly flow out of the fluid cavity 41, under the condition that the diameter of the outer tube 2 is not increased, the situation that the portion of the outer tube 2 around the through hole 21 clings to the wall of the inner tube 1 to block the through hole 21 is avoided, so that the balloon 4 can be quickly brought from the contracted state, the inner wall of the balloon 4 can be separated, and the balloon, and the blood flow guiding device can be easily recovered, and the blood flow guiding device 100 can be conveniently taken out, and the blood flow can be conveniently, and the surgery can be conveniently reduced, and the surgery can be conveniently taken out.

Specifically, in the present embodiment, the balloon 4 is disposed outside the distal end of the outer tube 2, and the through hole 21 and the at least two recesses 22 are also disposed at the distal end of the outer tube 2, so that it can block the blood flow near the location of the target thrombus and prevent the debris embolus generated during the embolectomy from flowing to the distal end of the blood vessel along with the blood flow.

In the present invention, the terms "distal" and "proximal" are to be understood as meaning, viewed from the direction of the operator, the proximal end being the end closer to the operator and the distal end being the end further away from the operator during operation, the direction indicated by the arrow in the figure being the direction from the proximal end to the distal end.

Preferably, the through holes 21 are formed between every two adjacent concave portions 22, so that the fluid in the fluid cavity 41 can be divided by the through holes 21, the negative pressure at each through hole 21 is reduced, the speed can be increased, the time for the fluid cavity 41 to move from the expanded state to the contracted state is shortened, the blood can be restored to flow as soon as possible, and the surgical risk is reduced.

Referring to fig. 3, in the present embodiment, the outer tube 2 has two recesses 22, and the recesses 22 and the through holes 21 are alternately arranged in the circumferential direction of the outer tube 2, that is, the through holes 21 are arranged between two adjacent recesses 22, and the recesses 22 are also arranged between two adjacent through holes 21. Of course, the number of the outer tube 2 and the recesses 22 is not limited thereto, and in other embodiments, the recesses 22 and the through holes 21 may be each provided in plural and alternately arranged in the circumferential direction of the outer tube 2.

Further, at least two recesses 22 are arranged at intervals in the circumferential direction of the outer tube 2. In this way, each concave portion 22 provides a supporting force to the other part of the outer tube 2 along the tangential direction of the position thereof, under the action of the supporting force, the part between two adjacent concave portions 22 of the outer tube 2 arches outwards along the circumferential direction, the negative pressure that can be borne by the part between two adjacent concave portions 22 becomes larger, when the fluid in the fluid cavity 41 is pumped out of the fluid cavity 41, the supporting force can provide a radial inward pressure that is generated to the outer tube 2 by the fluid flowing from the fluid cavity 41 into the outer tube 2, so as to reduce the collapse amplitude of the outer tube 2 towards the inner tube 1, so that the outer tube 2 does not collapse until clinging to the inner tube 1 to block the through holes 21, in addition, the part between two adjacent concave portions 22 of the outer tube 2 arches outwards along the circumferential direction, and also increases the distance between the part between two adjacent concave portions 22 and the inner tube 1, that is, the space for the outer tube 2 to move towards the inner tube 1 is increased, and the possibility that the outer tube 2 collapses until clinging to the inner tube 1 to block the through holes 21 is reduced.

Preferably, the distance between each through hole 21 and its adjacent two recesses 22 is equal in the circumferential direction of the outer tube 2. As can be seen from the above analysis, each concave portion 22 provides a supporting force to the other portion of the outer tube 2 along the tangential direction of the position thereof, and under the supporting force, the portion between two adjacent concave portions 22 of the outer tube 2 is arched outward along the circumferential direction, so that the distance from the middle point of the two adjacent concave portions 22 of the outer tube 2 to the inner tube 1 is the largest, and the component of the supporting force provided by the two adjacent concave portions 22 to the inner tube is the largest, so that the negative pressure can be borne by the outer tube is the largest, the collapse amplitude is the smallest when the fluid flows from the fluid chamber 41 to the outer tube 2 through the through hole 21, and the space for collapsing the outer tube 2 is the largest, so that the influence on the fluid flowing from the fluid chamber 41 to the fluid channel 6 through the through hole 21 is the smallest, and the occurrence of the situation that the outer tube 2 collapses to the inner tube 1 to block the through hole 21 is avoided.

Referring to fig. 3, taking the present example as an example, two recesses 22 are arranged at 180 ° intervals on the same circumference of the outer tube 2, and the through-hole 21 and two recesses 22 adjacent thereto are respectively arranged at 90 ° intervals in the circumferential direction of the outer tube 2, so that the distance from the through-hole 21 to the inner tube 1 is maximized, and the component of the supporting force applied to the outer tube 2 around the through-hole 21 by the adjacent two recesses 22 is also maximized.

In the axial direction of the outer tube 2, both ends of the expandable member are fixed to the outer tube 2, respectively, and the recess 22 is located outside the expandable member, and the portion between both ends of the expandable member is expanded when injecting the fluid, so that it is possible to prevent the outer diameter of the distal end of the guide device 100 from being excessively large because the recess 22 and the expandable member are located on the same circumference of the outer tube 2. Preferably, the recess 22 is located on the side of the expandable member near the proximal end of the outer tube 2.

In other embodiments, at least part of the through hole 21 and two adjacent recesses 22 may be located on the same circumference of the outer tube 2, so that the space between the outer tube 2 and the inner tube 1 around the through hole 21 is maximized, and the supported force provided by the inner tube 1 and the two adjacent recesses 22 is maximized, so that the negative pressure can be maximized, the collapse amplitude is minimized when the fluid flows from the fluid chamber 41 to the outer tube 2 through the through hole 21, and the outer tube 2 is prevented from collapsing to be close to the inner tube 1 to block the through hole 21. Preferably, the recess 22 is at least partially provided at the intersection of the cross section of the axial center of the expandable member and the outer tube 2, so that the supporting force of the inner tube 1 and the recess 22 on the rest of the outer tube 2 is mainly concentrated on the cross section of the axial center of the expandable member, the outer tube 2 is arched outwards along the cross section and has the largest amplitude at the cross section, and the arched amplitude has a gradually decreasing trend from the cross section to the two ends of the expandable member along the axial direction of the outer tube 2, and the trend is consistent with the trend of the expansion amplitude of the expandable member, thereby facilitating the fluid to flow from the fluid chamber 41 to the fluid channel 6 through the through hole 21.

Preferably, the through hole 21 is provided at the intersection of the cross section of the axial center of the expandable member and the outer tube 2, such that the through hole 21 also arches outwardly with the outer tube 2 along the cross section, which increases the distance between the through hole 21 and the inner tube 1, which facilitates the smooth flow of fluid from the fluid chamber 41 through the through hole 21 to the fluid channel 6, and avoids the risk of the through hole 21 being blocked.

Further, the concave portion 22 extends along the axial direction of the outer tube 2, so that the arched area of the outer tube 2, especially the area extending along the axial direction of the outer tube 2, can be further increased, and the area of the through hole 21 can be enlarged, or a plurality of through holes 21 can be arranged along the axial direction, so as to increase the speed of the fluid flowing from the fluid chamber 41 to the fluid channel 6, shorten the time, and further to remove the blockage of the blood flow and withdraw the guiding device 100 as soon as possible, complete the surgical procedure as soon as possible, and reduce the surgical risk.

Referring to fig. 1 to 2, further, at least two through holes 21 are arranged between two adjacent recesses 22 at intervals along the axial direction of the outer tube 2, so as to disperse the fluid pressure in the fluid chamber 41, and avoid that the fluid pressure in the fluid chamber 41 is totally concentrated on the outer tube 2 near one through hole 21 when the fluid flows out from the one through hole 21, so that the pressure of the part of the outer tube 2 is too high to be tightly attached to the inner tube 1.

The inner tube 1 and the outer tube 2 can adopt a single-layer structure prepared from nylon elastomer, nylon, polyurethane, polyimide or polytetrafluoroethylene, so that the inner tube 1 and the outer tube 2 have certain flexibility and strength so as to be convenient to intervene in a blood vessel; the inner tube 1 and the outer tube 2 can also be formed by compounding a multilayer structure, specifically, the inner tube comprises an outer layer, an inner layer and a reinforcing layer arranged between the outer layer and the inner layer, the flexibility of the inner tube 1 and the flexibility of the outer tube 2 are kept, the strength of the inner tube 1 and the strength of the outer tube 2 are improved, preferably, the outer layer adopts nylon elastomer, nylon or polyurethane, the inner layer adopts nylon elastomer, nylon, polyurethane or polytetrafluoroethylene, and the reinforcing layer is a woven mesh or a spring mesh prepared by stainless steel, nickel titanium or high polymer materials; of course, the inner tube 1 and the outer tube 2 may include only an outer layer and a reinforcing layer, and the strength of the inner tube 1 and the outer tube 2 may be increased.

Further, the concave portion 22 is fixed to the inner tube 1 by welding, bonding or welding, so that the outer tube 2 can be supported by the inner tube 1 to reduce the collapse range of the outer tube 2 and even prevent the collapse of the outer tube 2, the welding or welding mode is selected based on the materials of the outer tube 2 and the inner tube 1 and the limitation of the sizes of the outer tube 2 and the inner tube 1 by the diameter of the blood vessel, the concave portion 22 of the outer tube 2 is favorably fixed to the inner tube 1, the outer tube 2 and the inner tube 1 cannot be damaged, the inner diameter of the inner tube 1 cannot be reduced, and the thrombus taking device can be ensured to smoothly pass through the guiding device 100 to reach the target thrombus.

Referring to fig. 1 to 2, further, the outer tube 2 includes a first section 23 and a second section 24 arranged in sequence from the proximal end to the distal end thereof, the expandable member is arranged outside the second section 24, the through hole 21 is arranged in the second section 24, the recess 22 is arranged at one end of the first section 23 close to the expandable member to ensure that the blood flow near the target thrombus is blocked, and the outer diameter of the second section 24 is not larger than the maximum diameter of the first section 23, so as to avoid the size increase of the distal end of the guiding device 100 caused by the arrangement of the expandable member, and to ensure that the inner diameter of the inner tube 1 is as large as possible in the case of being limited by the inner diameter of the blood vessel, thereby facilitating the insertion of the thrombus taking device.

Further, the stiffness of the outer tube 2 tapers from the proximal end to the distal end and/or the stiffness of the inner tube 1 tapers from the proximal end to the distal end, thereby increasing the flexibility of the distal end of the guiding device 100 to avoid damage to the vessel during insertion of the guiding device 100 into the vessel and during expansion of the expandable member.

In addition, visualization rings may be mounted at both the distal end of the inner tube 1 and the proximal end of the expandable member to facilitate determination of the target thrombus location and the state of the expandable member.

In summary, in the guiding device 100 proposed in the present invention, at least two recesses 22 of the outer tube 2 are respectively recessed toward the inner tube 1 and fixed to the inner tube 1, and the recesses 22 and the inner tube 1 provide a supporting force for a portion between two adjacent recesses 22 of the outer tube 2, so that the portion between two adjacent recesses 22 of the outer tube 2 is arched, and the radial distance from the highest point of the arch to the inner tube 1 is increased, when the embolectomy is completed, the fluid in the fluid chamber 41 is drawn out from the through hole 21 disposed between two adjacent recesses 22, under the supporting force of the recesses 22 and the inner tube 1, even if the fluid flow speed in the through hole 21 is the largest, the negative pressure borne by the portion of the outer tube 2 around the through hole 21 is much larger than the negative pressure borne by other portions of the outer tube 2, the portion of the outer tube 2 around the through hole 21 does not sink much toward the inner tube 1, and a certain space is still left between the portion of the outer tube 2 around the through hole 21 and the inner tube 1 for the fluid to smoothly flow out of the outer tube 41, so that the expandable fluid can be recovered from the expandable state to the inner wall of the inner tube 21, and the expandable guiding device 100, thereby reducing the risk of blood flow and the expandable state of the expandable guiding device, and the expandable blood flow.

It should be understood that although the specification describes embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and it will be appreciated by those skilled in the art that the specification as a whole may be appropriately combined to form other embodiments as will be apparent to those skilled in the art.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications are all within the scope of the present invention.

Claims

1. A guiding device comprises an inner tube, an outer tube and an expandable part, wherein the outer tube is sleeved outside the inner tube, a fluid channel is formed between the outer tube and the inner tube, the expandable part is arranged outside the far end of the outer tube, the far end of the outer tube is provided with at least one through hole, when the expandable part is injected with fluid in an expansion state, a fluid cavity is formed between the outer tube and the expandable part, and the through hole is communicated with the fluid channel and the fluid cavity.

2. The guide device of claim 1, wherein the distance between each through hole and two adjacent recesses is equal in the circumferential direction of the outer tube.

3. The guide device of claim 2, wherein two of said recesses adjacent to said through hole are located on the same circumference of said outer tube and are spaced 180 ° apart.

4. The guide device of claim 1, wherein the expandable member is a balloon.

5. The guide device according to claim 1, wherein both ends of the expandable member are fixed to the outer tube, respectively, in an axial direction of the outer tube, and the recess is located outside the expandable member.

6. The guide device of claim 5, wherein the recess is located on a side of the expandable member proximate the proximal end of the outer tube.

7. The guide device of claim 1, wherein the outer tube comprises a first section and a second section sequentially arranged from the proximal end to the distal end thereof, the expandable member is arranged outside the second section, the through hole is arranged in the second section, and the outer diameter of the second section is not larger than the maximum diameter of the first section.

8. The guide device of claim 1, wherein the recess extends in an axial direction of the outer tube.

9. The guide device of claim 1 wherein the recess is secured to the inner tube by welding, gluing or fusing.

10. The guide device of claim 1, wherein the stiffness of the outer tube tapers from the proximal end to the distal end and/or the stiffness of the inner tube tapers from the proximal end to the distal end.