Microwave ablation assembly for treating anal fistula

Abstract

The invention relates to a microwave ablation assembly for treating anal fistula, which comprises an outer tube, a cable, a guide head, a PTFE piece and a near-end connecting piece, a first channel, a second channel, a third channel and a fourth channel are formed in the outer tube, and the cable passes through the first channel; a liquid inlet and a liquid outlet are formed in the side wall of the outer pipe, and both the liquid inlet and the liquid outlet are communicated with the second channel; the near end of the outer tube is connected to the near-end connecting piece, a first cavity and a second cavity which are separated from each other are formed in the near-end connecting piece, the near end of the fourth channel penetrates through the near end of the outer tube, so that the fourth channel is communicated with the second cavity, and the far end of the third channel and the far end of the fourth channel are both communicated with a connecting cavity of the outer tube; a liquid return opening is formed in the outer pipe and located in the first cavity. The PTFE piece is inserted into the far end of the outer pipe, and an insertion channel is formed in the PTFE piece; the guide head is inserted into the insertion channel from the far end side, and the far end of the cable is connected with the guide head. Tissues around the fistula are denatured through microwaves, coagulative necrosis is formed, and the purpose of safely treating anal fistula is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a microwave ablation component for treating anal fistula. Background Art

[0002] Anal fistula is a common anorectal surgical condition, accounting for approximately 15%-20% of anorectal morbidity. Currently, the main clinical treatments include fistulotomy, seton therapy, bio-protein glue filling, and laser therapy. Fistulotomy creates a large incision and requires a long recovery period, which can affect the patient's anal function. Seton therapy has the disadvantage of a long treatment cycle; bio-protein glue filling has a high recurrence rate; and laser therapy has the disadvantages of expensive equipment and a high risk of carbonization of normal tissue. Summary of the Invention

[0003] In view of this, the present invention provides a microwave ablation component for treating anal fistula, which uses microwaves to denature the tissue around the fistula, forming coagulative necrosis, thereby achieving the purpose of safely treating anal fistula.

[0004] The technical solution adopted in the present invention is:

[0005] A microwave ablation assembly for treating anal fistula, comprising an outer tube, a cable, a guide head, a PTFE piece and a proximal connector.

[0006] A first channel, a second channel, a third channel and a fourth channel are formed in the outer tube, and the four channels all extend along the axial direction of the outer tube, and the cable passes through the first channel;

[0007] The proximal and distal ends of the second channel are both closed, and a liquid inlet and a liquid outlet are provided on the side wall of the outer tube. The liquid inlet and the liquid outlet are both connected to the second channel, the liquid inlet is located on the proximal side of the outer tube, and the liquid outlet is located on the distal side of the outer tube. The liquid inlet is connected to a liquid inlet pipe;

[0008] The proximal end of the outer tube is connected to the proximal connector. The proximal connector is provided with a first cavity and a second cavity separated from each other. The first cavity is located on the distal side of the second cavity. The proximal end of the outer tube extends into the second cavity. The proximal end of the third channel is closed. The proximal end of the fourth channel passes through the proximal end of the outer tube, so that the fourth channel is connected to the second cavity. The distal ends of the third channel and the fourth channel are both connected to the connecting cavity of the outer tube.

[0009] The outer tube is provided with a liquid return port, the liquid return port is communicated with the third channel, and the liquid return port is located in the first cavity;

[0010] The PTFE piece is an annular structure, and the PTFE piece is plugged into the distal end of the outer tube, with an insertion channel formed in the PTFE piece;

[0011] The guide head is plugged into the insertion channel from the distal end side, and the distal end of the cable is connected to the guide head.

[0012] Preferably, the outer tube includes a first tube segment and a second tube segment connected to each other, the second tube segment is located on the distal side of the first tube segment, the first channel, the second channel, the third channel and the fourth channel are all located in the first tube segment, the connecting cavity is formed in the second tube segment, and the PTFE part is inserted into the connecting cavity; the drain port is located in the first tube segment and is close to the second tube segment, and the length of the second tube segment is not more than 1 cm.

[0013] Preferably, the number of the fourth channels is two.

[0014] Preferably, a first partition and a second partition are provided in the first pipe section, both of which extend along the length direction of the first pipe section. In the radial direction of the first pipe section, the first partition is spaced apart from the second partition, dividing the first pipe section into a first space, a second space, and a third space. The first space and the third space are respectively located on either side of the second space. The first space constitutes the second channel, and the third space constitutes the third channel.

[0015] The first channel and the two fourth channels together constitute the second space.

[0016] Preferably, the first partition includes a first straight plate, a curved plate, and a second straight plate connected in sequence, and the curved plate is bent in a direction facing away from the second partition;

[0017] The first partition plate and the second partition plate have the same structure, and the curved plate on the second partition plate is bent in a direction facing away from the first partition plate, so that the first channel is formed between the two curved plates;

[0018] Two of the first straight plates are arranged opposite to each other, and two of the second straight plates are arranged opposite to each other, one of the fourth channels is formed between the two first straight plates, and another of the fourth channels is formed between the two second straight plates;

[0019] After the cable passes through the first channel, the outer wall of the cable is respectively fitted with the two arc-shaped plates to separate the two fourth channels through the cable.

[0020] Preferably, the cross sections of the second channel and the third channel are both fan-shaped, and the cross sections of the two are equal; the area of the cross section of the second channel is 4-5 times the area of the cross section of the fourth channel.

[0021] Preferably, it also includes a bushing, which includes a first annular segment and a second annular segment connected to each other, the outer diameter of the first annular segment matches the inner diameter of the connecting cavity, the outer diameter of the second annular segment is consistent with the outer diameter of the outer tube, the first annular segment is inserted into the connecting cavity, and the PTFE part is inserted into the second annular segment, so that the PTFE part is inserted into the connecting cavity through the bushing.

[0022] Preferably, the first annular segment is provided with two mounting openings which are arranged opposite to each other in the radial direction, each mounting opening is embedded with an LED lamp, and the wires of the LED lamp are led out through the fourth channel.

[0023] Preferably, a proximal space is formed in the proximal connector, a partition plate is provided in the proximal space, the partition plate divides the proximal space into the first cavity and the second cavity, a communicating hole is provided on the partition plate, and the proximal end of the outer tube is inserted into the second cavity through the first cavity and the communicating hole;

[0024] The proximal connecting member is provided with a first connecting port and a second connecting port, the first connecting port is communicated with the first cavity, the second connecting port is communicated with the second cavity, the first connecting port is externally connected to a first liquid pipe, and the second connecting port is externally connected to a second liquid pipe.

[0025] Beneficial effects of the present invention:

[0026] The proximal end of the cable is connected to a microwave generator. The microwaves emitted by the microwave generator propagate through the cable to the distal end and radiate outward through the PTFE component. During the operation, the distal end of the ablation component is inserted into the fistula tract and microwaves are emitted through the PTFE component, causing the temperature of the tissue at the PTFE component to rise, resulting in destruction of the cell structure and formation of coagulative necrosis, thereby achieving the purpose of treating anal fistula.

[0027] When treating anal fistula, normal saline is injected into the fourth channel through the second cavity. The normal saline enters the connecting cavity through the fourth channel and flows back into the first cavity from the third channel, thereby taking away the heat from the cable and distal components, and avoiding tissue burns caused by overheating of parts other than the PTFE parts.

[0028] Physiological saline is injected into the second channel through the liquid inlet tube, and the physiological saline is sprayed out from the drainage port. The drainage port is located on the distal side of the outer tube, so that the physiological saline can flush the fistula, remove secretions or necrotic tissue in the fistula, and improve the treatment effect and surgical safety.

[0029] During the procedure, the fistula tract is first flushed through the second channel (the PTFE component is not emitting microwaves at this time), and then microwave treatment is initiated (flushing is stopped). After treating a section of the fistula tract, the ablation assembly is pulled backward a predetermined distance (e.g., 1 cm), and the flushing and treatment steps are repeated. This step-by-step procedure helps ensure cleanliness within the fistula tract, reduces interference from secretions, and achieves uniform treatment throughout the entire tract.

[0030] In addition, the physiological saline used for flushing is transported through an independent and closed second channel, which is completely isolated from the channels used for cooling (the first, third, and fourth channels) and does not interfere with each other, thus ensuring the functionality and safety of each flow path. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0032] Figure 1 It is a schematic diagram of the structure of a microwave ablation component used to treat anal fistula;

[0033] Figure 2 is a first cross-sectional view of the ablation assembly;

[0034] Figure 3 is a second cross-sectional view of the ablation assembly;

[0035] Figure 4 is a third cross-sectional view of the ablation assembly;

[0036] Figure 5 It is a partial exploded view of the ablation component;

[0037] Figure 6 is a fourth cross-sectional view of the ablation assembly.

[0038] In the figure: 1, outer tube; 2, proximal connector; 3, guide head; 4, liquid inlet pipe; 5, first liquid pipe; 6, second liquid pipe; 7, cable; 8, PTFE part; 10, bushing;

[0039] 12, second channel; 13, third channel; 14, fourth channel; 121, liquid discharge port; 131, liquid return port;

[0040] 21. First cavity; 22. Second cavity;

[0041] 101. First annular segment; 102. Second annular segment; 103. Mounting opening. DETAILED DESCRIPTION

[0042] The present invention is described below based on the following embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. In order to avoid obscuring the essence of the present invention, well-known methods, processes, procedures, and components are not described in detail.

[0043] Furthermore, persons of ordinary skill in the art will appreciate that the figures provided herein are for illustration purposes only and are not necessarily drawn to scale.

[0044] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include," "comprising," and similar words should be construed in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to."

[0045] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0046] In the present invention, “distal” refers to the side closer to the patient's body during surgery; and “proximal” refers to the side closer to the operator during surgery.

[0047] See also Figures 1-6 The present invention provides a microwave ablation assembly for treating anal fistula (hereinafter referred to as "ablation assembly"), which includes an outer tube 1, a cable 7, a guide head 3, a PTFE piece 8 and a proximal connector 2.

[0048] A first channel, a second channel 12, a third channel 13 and a fourth channel 14 are formed in the outer tube 1. These four channels extend along the axial direction of the outer tube 1. The cable 7 passes through the first channel.

[0049] The proximal and distal ends of the second channel 12 are both closed, and a liquid inlet and a liquid outlet 121 are provided on the side wall of the outer tube 1. The liquid inlet and the liquid outlet 121 are both connected to the second channel 12. The liquid inlet is located on the proximal side of the outer tube 1, and the liquid outlet 121 is located on the distal side of the outer tube 1. The liquid inlet is connected to the liquid inlet pipe 4;

[0050] The proximal end of the outer tube 1 is connected to the proximal connector 2. The proximal connector 2 is provided with a first cavity 21 and a second cavity 22 separated from each other. The first cavity 21 is located on the distal side of the second cavity 22. The proximal end of the outer tube 1 extends into the second cavity 22. The proximal end of the third channel 13 is closed, and the proximal end of the fourth channel 14 passes through the proximal end of the outer tube 1, so that the fourth channel 14 is in communication with the second cavity 22. The distal ends of the third channel 13 and the fourth channel 14 are both in communication with the connecting cavity of the outer tube 1.

[0051] The outer tube 1 is provided with a liquid return port 131 , which is communicated with the third channel 13 , and is located in the first cavity 21 ;

[0052] The PTFE piece 8 is an annular structure and is plugged into the distal end of the outer tube 1 , with an insertion channel formed in the PTFE piece 8 ;

[0053] The guide head 3 is plugged into the insertion channel from the distal end side, and the distal end of the cable 7 is connected to the guide head 3 .

[0054] When treating anal fistula, the direction, length and other information of the fistula can be determined through a probe. Since there is often a certain amount of secretions in the fistula, the fistula is first flushed through a catheter to remove the secretions; then the ablation component is used for treatment.

[0055] Specifically, the distal end of the ablation component is extended into the fistula along the opening of the fistula, so that the distal end of the ablation component reaches the blind end of the fistula. For fistulas with an external opening and an internal opening, it can be extended along the external opening so that the distal end of the ablation component reaches the internal opening; the proximal end of the cable 7 is connected to the microwave generator, and the microwave generator emits microwaves, which are transmitted to the distal end of the cable 7 through the cable 7. Since the distal end of the cable 7 is connected to the guide head, the guide head is located at the distal end of the outer tube 1, so the microwaves can be transmitted along the cable 7 to the distal end of the outer tube 1. The PTFE part 8 is inserted into the distal end of the outer tube 1, and the microwaves are emitted outward through the PTFE part 8, thereby acting on the tissue at the fistula, causing the temperature of the tissue at the PTFE part 8 to rise, thereby destroying the cell structure there, and forming coagulative necrosis. In this way, the entire ablation component is pulled backward, so that the PTFE part 8 can be gradually pulled to the opening, so that the PTFE part 8 will move along the entire fistula, thereby destroying the overall internal cell structure of the fistula, thereby achieving the purpose of treating anal fistula.

[0056] During treatment, the temperature of the cell structure affected by microwaves will rise, causing the cell structure with high temperature to die, and the heat conduction performance will destroy the deeper cell structure, thus causing excessive damage.

[0057] The proximal end of the fourth channel 14 is connected to the second cavity 22, so that physiological saline can be injected into the fourth channel 14 through the second cavity 22, and the physiological saline flows out from the distal end of the fourth channel 14 into the connecting cavity. The connecting cavity is located at the distal end of the ablation component, so the connecting cavity can absorb the heat at the distal end of the ablation component. The distal end of the third channel 13 is connected to the connecting cavity, so the physiological saline with increased temperature in the connecting cavity can flow from far to near through the third channel 13, and finally flow into the first cavity 21 through the return liquid port 131. In this way, the second cavity 22 continuously outputs physiological saline, and the first cavity 21 continuously recovers physiological saline, which can continuously take away the heat at the distal end of the ablation component, avoid the aforementioned excessive damage, and improve the safety of the operation.

[0058] In addition, as mentioned above, there are secretions in the fistula. Although it is flushed through the catheter first, some secretions will still remain. The secretions will affect the therapeutic effect of microwaves. A second channel 12 is provided in the outer tube 1 of the present invention, and the distal and proximal ends of the second channel 12 are closed, so that the second channel 12 will not be connected to the connecting cavity, that is, the second channel 12 is completely independent of the first channel, the third channel 13 and the fourth channel 14. When used, physiological saline is injected into the second channel 12 through the liquid inlet tube 4, and the physiological saline passes through the second channel 12 and is discharged from the drain port 121. The drain port 121 is located on the distal side of the outer tube 1, that is, the drain port 121 is also located on the distal side of the ablation component as a whole. After the physiological saline is discharged from the drain port 121, it will immediately enter the fistula, thereby cleaning the excrement in the fistula, ensuring that there is basically no secretion in the fistula, and ensuring the therapeutic effect.

[0059] During use, the fistula can be cleaned through the second channel 12 first (the PTFE part 8 does not emit microwaves at this time), and then microwaves are emitted through the PTFE part 8 (the drainage port 121 no longer sprays saline) for treatment, and then the ablation component is pulled to the rear for a predetermined distance (for example, 1 cm), and the above process is repeated. In this way, the fistula is flushed once without pulling the predetermined distance, and then microwave treatment is performed once, which ensures that there will be no secretions in the fistula and the treatment effect is ensured.

[0060] In addition, the physiological saline for flushing the fistula is transported through the second channel 12, and the second channel 12 will never be connected to the first channel, the third channel 13 and the fourth channel 14. That is to say, the cable 7 will not affect the physiological saline passing through the second channel 12, ensuring the safety of the physiological saline and improving the safety of the operation.

[0061] The outer tube 1 includes a first tube segment and a second tube segment connected to each other, the second tube segment is located on the distal side of the first tube segment, the first channel, the second channel 12, the third channel 13 and the fourth channel 14 are all located in the first tube segment, the connecting cavity is formed in the second tube segment, and the PTFE part 8 is inserted into the connecting cavity; the drain port 121 is located in the first tube segment and close to the second tube segment, and the length of the second tube segment is not more than 1 cm.

[0062] The length of the first pipe section is much greater than that of the second pipe section. The first channel, the second channel 12, the third channel 13 and the fourth channel 14 all extend in the first pipe section. A connecting cavity is formed in the second pipe section. The distal end of the first channel is connected, so that the cable 7 can pass through the first channel into the connecting cavity. The distal ends of the third channel 13 and the fourth channel 14 are connected, so that the distal ends of the third channel 13 and the fourth channel 14 are connected to the connecting cavity, so that the two are connected.

[0063] The position of the liquid discharge port 121 is close to the second tube section, so that the liquid discharge port 121 is located entirely at the distal end of the ablation assembly.

[0064] The number of the fourth channels 14 is two.

[0065] A first baffle and a second baffle are provided in the first pipe section. Both the first baffle and the second baffle extend along the length direction of the first pipe section. In the radial direction of the first pipe section, the first baffle is spaced apart from the second baffle, dividing the first pipe section into a first space, a second space, and a third space. The first space and the third space are located on either side of the second space, respectively. The first space constitutes the second channel 12, and the third space constitutes the third channel 13.

[0066] The first channel and the two fourth channels 14 together constitute the second space.

[0067] At any point along the axis of the first tube segment, the cross-section of the first and second baffles remains constant, thus dividing the space within the first tube segment into three independent spaces. This simplifies the structure of the first, second, third, and fourth channels 12, 13, and 14, eliminating the need for separate catheters to form four channels. This allows the outer diameter of the ablation assembly's outer tube 1 to be kept small (less than 5 mm), facilitating passage through the fistula tract and facilitating surgical procedures.

[0068] The first partition includes a first straight plate, a curved plate, and a second straight plate connected in sequence, and the curved plate is bent in a direction facing away from the second partition;

[0069] The first partition plate and the second partition plate have the same structure, and the curved plate on the second partition plate is bent in a direction facing away from the first partition plate, so that the first channel is formed between the two curved plates;

[0070] The two first straight plates are arranged opposite to each other, and the two second straight plates are arranged opposite to each other, one fourth channel 14 is formed between the two first straight plates, and another fourth channel 14 is formed between the two second straight plates;

[0071] After the cable 7 passes through the first channel, the outer wall of the cable 7 is respectively fitted with the two arc-shaped plates to separate the two fourth channels 14 through the cable 7 .

[0072] The cross-sections of the first straight plate and the second straight plate are both rectangular, and the cross-section of the curved plate is fan-shaped. The center of the curved plate (cross-section) overlaps with the center of the first pipe section (cross-section), so that a circular space (cross-section) is formed between the two curved plates. The circular space corresponds to the first channel, and two rectangular spaces (corresponding to the two fourth channels 14) are respectively formed between the two first straight plates and between the two second straight plates.

[0073] It can be seen that the first channel is directly connected to the two fourth channels 14 , and the cable 7 passes through the first channel. Therefore, the physiological saline flowing through the fourth channels 14 can directly contact the cable 7 , thereby better removing heat from the cable 7 .

[0074] In addition, when the cable 7 passes through the first channel, the cable 7 (the cross section of the cable 7 is circular) substantially completely fills the first channel, so that the two fourth channels 14 are completely separated by the cable 7 .

[0075] Of course, even if there is a clearance fit between the cable 7 and the first channel, the first channel can also serve as the fourth channel 14 for the physiological saline in the second cavity 22 to flow into the connecting cavity.

[0076] The cross sections of the second channel 12 and the third channel 13 are both fan-shaped, and the cross sections of the two are equal; the area of the cross section of the second channel 12 is 4-5 times the area of the cross section of the fourth channel 14 .

[0077] The second channel 12 is for passing saline solution for flushing the fistula. The cross-sectional area of the second channel 12 is larger, which facilitates the flow of a larger amount of saline solution to improve the flushing effect of the secretions in the fistula and ensure the surgical effect. There are two fourth channels 14. The fourth channels 14 are for passing cooled saline solution and returning to the first cavity 21 through the third channel 13. The cross-sectional area of the third channel 13 is larger than twice the cross-sectional area of the fourth channel 14, so that the flow rate of saline solution in the fourth channel 14 is higher. Therefore, when the saline solution enters the connecting cavity from the fourth channel 14, it can fully disturb the saline solution in the connecting cavity, thereby fully cooling the distal part of the ablation component. At the same time, the cross-sectional area of the third channel 13 is larger, which facilitates the return of the heated saline solution and ensures the cooling effect.

[0078] The ablation assembly also includes a sleeve 10, which includes a first annular segment 101 and a second annular segment 102 connected to each other. The outer diameter of the first annular segment 101 matches the inner diameter of the connecting cavity, and the outer diameter of the second annular segment 102 is consistent with the outer diameter of the outer tube 1. The first annular segment 101 is inserted into the connecting cavity, and the PTFE part 8 is inserted into the second annular segment 102, so that the PTFE part 8 is inserted into the connecting cavity through the sleeve 10.

[0079] The first annular segment 101 is provided with two mounting openings 103 that are arranged opposite to each other in the radial direction. An LED lamp is embedded in each mounting opening 103 , and the wires of the LED lamp are led out through the fourth channel 14 .

[0080] The setting of the sleeve 10 facilitates the installation of the LED lamp. During the operation, the LED lamp can emit bright light to illuminate the distal end of the ablation component and be directly seen by medical staff through the tissue, making it convenient for medical staff to understand the position of the distal end of the ablation component and facilitate the smooth progress of the operation.

[0081] In addition, one of the two LED lamps is a cold white light LED, which is used for conventional lighting, and the other LED lamp can emit light with a wavelength of 240-280nm, using the ultraviolet sterilization principle to destroy the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in bacteria and viruses, causing growth cell death and (or) regenerative cell death, thereby achieving the effect of sterilization and disinfection.

[0082] Of course, a temperature sensor may also be provided in the connecting cavity to detect the temperature at the distal end of the ablation assembly, so as to facilitate control of the flow of physiological saline in the fourth channel 14 and ensure smooth operation.

[0083] A proximal space is formed in the proximal connector 2. A partition plate is provided in the proximal space. The partition plate divides the proximal space into the first cavity 21 and the second cavity 22. A communicating hole is provided on the partition plate. The proximal end of the outer tube 1 is inserted into the second cavity 22 through the first cavity 21 and the communicating hole.

[0084] The proximal connecting member 2 is provided with a first connecting port and a second connecting port. The first connecting port is communicated with the first cavity 21 , and the second connecting port is communicated with the second cavity 22 . The first connecting port is externally connected to a first liquid pipe 5 , and the second connecting port is externally connected to a second liquid pipe 6 .

[0085] The first liquid tube 5 is connected to the first cavity 21, and the second liquid tube 6 is connected to the second cavity 22. Physiological saline is pumped into the second cavity 22 through the second liquid tube 6. The physiological saline flows into the connecting cavity through the fourth channel 14, and flows back to the first cavity 21 through the third channel 13, and flows out through the first liquid tube 5, forming a closed-loop cooling circuit, thereby achieving continuous cooling of the front end of the ablation component.

[0086] It should be understood that the above-mentioned embodiments are merely illustrative and non-restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will be included in the scope of the claims of the present invention.

Claims

1. A microwave ablation assembly for treating anal fistula, characterized in that: Including outer tube, cable, guide head, PTFE parts and proximal connector, A first channel, a second channel, a third channel and a fourth channel are formed in the outer tube, and the four channels all extend along the axial direction of the outer tube, and the cable passes through the first channel; The proximal and distal ends of the second channel are both closed, and a liquid inlet and a liquid outlet are provided on the side wall of the outer tube. The liquid inlet and the liquid outlet are both connected to the second channel, the liquid inlet is located on the proximal side of the outer tube, and the liquid outlet is located on the distal side of the outer tube. The liquid inlet is connected to a liquid inlet pipe; The proximal end of the outer tube is connected to the proximal connector. The proximal connector is provided with a first cavity and a second cavity separated from each other. The first cavity is located on the distal side of the second cavity. The proximal end of the outer tube extends into the second cavity. The proximal end of the third channel is closed. The proximal end of the fourth channel passes through the proximal end of the outer tube, so that the fourth channel is connected to the second cavity. The distal ends of the third channel and the fourth channel are both connected to the connecting cavity of the outer tube. The outer tube is provided with a liquid return port, the liquid return port is communicated with the third channel, and the liquid return port is located in the first cavity; The PTFE piece is an annular structure, and the PTFE piece is plugged into the distal end of the outer tube, with an insertion channel formed in the PTFE piece; The guide head is plugged into the insertion channel from the distal end side, and the distal end of the cable is connected to the guide head.

2. The microwave ablation assembly for treating anal fistula according to claim 1, characterized in that: The outer tube includes a first tube segment and a second tube segment connected to each other, the second tube segment is located on the distal side of the first tube segment, the first channel, the second channel, the third channel and the fourth channel are all located in the first tube segment, the connecting cavity is formed in the second tube segment, and the PTFE part is inserted into the connecting cavity; the drain port is located in the first tube segment and is close to the second tube segment, and the length of the second tube segment is not more than 1 cm.

3. The microwave ablation assembly for treating anal fistula according to claim 2, characterized in that: The number of the fourth channels is two.

4. The microwave ablation assembly for treating anal fistula according to claim 3, characterized in that: A first baffle and a second baffle are provided in the first pipe section. Both the first baffle and the second baffle extend along the length direction of the first pipe section. In the radial direction of the first pipe section, the first baffle and the second baffle are spaced apart from each other to divide the first pipe section into a first space, a second space, and a third space. The first space and the third space are located on either side of the second space, respectively. The first space constitutes the second channel, and the third space constitutes the third channel. The first channel and the two fourth channels together constitute the second space.

5. The microwave ablation assembly for treating anal fistula according to claim 4, characterized in that: The first partition includes a first straight plate, a curved plate, and a second straight plate connected in sequence, and the curved plate is bent in a direction facing away from the second partition; The first partition plate and the second partition plate have the same structure, and the curved plate on the second partition plate is bent in a direction facing away from the first partition plate, so that the first channel is formed between the two curved plates; Two of the first straight plates are arranged opposite to each other, and two of the second straight plates are arranged opposite to each other, one of the fourth channels is formed between the two first straight plates, and another of the fourth channels is formed between the two second straight plates; After the cable passes through the first channel, the outer wall of the cable is respectively fitted with the two arc-shaped plates to separate the two fourth channels through the cable.

6. The microwave ablation assembly for treating anal fistula according to claim 5, characterized in that: The cross sections of the second channel and the third channel are both fan-shaped, and the cross sections of the two are equal; the area of the cross section of the second channel is 4-5 times the area of the cross section of the fourth channel.

7. The microwave ablation assembly for treating anal fistula according to any one of claims 1 to 6, characterized in that: It also includes a sleeve, which includes a first annular segment and a second annular segment connected to each other, the outer diameter of the first annular segment matches the inner diameter of the connecting cavity, the outer diameter of the second annular segment is consistent with the outer diameter of the outer tube, the first annular segment is inserted into the connecting cavity, and the PTFE part is inserted into the second annular segment, so that the PTFE part is inserted into the connecting cavity through the sleeve.

8. The microwave ablation assembly for treating anal fistula according to claim 7, characterized in that: The first annular segment is provided with two mounting openings which are arranged opposite to each other in the radial direction. An LED lamp is embedded in each mounting opening, and the wires of the LED lamp are led out through the fourth channel.

9. The microwave ablation assembly for treating anal fistula according to any one of claims 1 to 6, characterized in that: A proximal space is formed in the proximal connector, a partition plate is provided in the proximal space, the partition plate divides the proximal space into the first cavity and the second cavity, a communication hole is provided on the partition plate, and the proximal end of the outer tube is inserted into the second cavity through the first cavity and the communication hole; The proximal connecting member is provided with a first connecting port and a second connecting port, the first connecting port is communicated with the first cavity, the second connecting port is communicated with the second cavity, the first connecting port is externally connected to a first liquid pipe, and the second connecting port is externally connected to a second liquid pipe.

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