Radiofrequency ablation balloon catheter for biliary ablation

Abstract

This invention discloses a radiofrequency ablation balloon catheter for biliary ablation, comprising a catheter body, a radiofrequency electrode head, an ablation balloon, a tissue cleaning balloon, and a connector. The radiofrequency electrode head is mounted on the ablation balloon, the ablation balloon is located at one end of the catheter body, and the tissue cleaning balloon is located at both ends of the ablation balloon. The tissue cleaning balloon assists in cleaning up ablated tissue. Advantages include: controlling the adhesion between the catheter and the diseased tissue through inflation and deflation of the ablation balloon; fully ablating the diseased tissue using the radiofrequency electrode on the ablation balloon; and achieving temperature-controlled ablation by real-time monitoring of the ablation temperature. The tissue cleaning balloon allows for direct cleaning of necrotic tissue after ablation without the need to change instruments, significantly improving surgical efficiency. Multiple annular radiofrequency electrodes arranged in an array structure on the treatment head ensure uniform ablation, guaranteeing effectiveness while effectively controlling the ablation depth, reducing the risk of delayed bile duct perforation due to excessive ablation depth.

Description

Technical Field

[0001] This invention specifically relates to a radiofrequency ablation balloon catheter for biliary ablation. Background Technology

[0002] Malignant biliary stricture (MBS) is an obstructive disease of the biliary tract caused by various primary or secondary malignant tumors, accounting for about 3% of malignant tumors of the digestive system. At present, surgical resection is still the only radical treatment for MBS, but only a small number of patients can have the opportunity for radical surgery in clinical practice. The median survival of patients who do not undergo surgical resection is less than 1 year.

[0003] Radiofrequency ablation (RFA) of tumors is a mature treatment. Published literature and expert consensus at home and abroad indicate that endoscopic RFA can be used for palliative treatment of inoperable extrahepatic cholangiocarcinoma. Compared with simple bile duct stent drainage, it can improve the overall survival and quality of life of patients.

[0004] Currently available radiofrequency ablation catheters have two spaced-apart ring electrodes at the catheter tip, which are used to ablate tissues during gastrointestinal and digestive tract (including bile and pancreatic duct) surgeries.

[0005] However, existing products have the following problems when treating malignant biliary strictures:

[0006] (1) Bile duct stenosis is mostly non-uniform stenosis, and conventional catheters cannot be closely attached to the lesion, and cannot fully ablate the diseased tissue;

[0007] (2) Existing ablation catheters lack temperature control systems, making it difficult to determine whether ablation has been completed. This necessitates repeat angiography or insertion of a transoral cholangioscope to assess the ablation effect of the stenotic segment, increasing the risk of radiation exposure and the operation time.

[0008] (3) The necrotic tissue after ablation needs to be replaced with a stone removal balloon for bile duct cleaning. For long-stage stenosis, ablation and necrotic tissue cleaning need to be performed multiple times. The repeated replacement of instruments greatly increases the operation time and the operation risk.

[0009] Therefore, finding a suitable biliary ablation catheter to solve the aforementioned problems of existing catheters has become a focus of attention for many front-line researchers in this field.

[0010] Chinese patent 201710077036.3, entitled "Catheter with both balloon dilation and radiofrequency ablation functions and ablation method thereof", describes a catheter including an expandable balloon located at the front end of the catheter and an ablation component located on the outer wall or inside of the balloon. While the balloon is gradually dilated, the ablation component ablates the proliferating tissue or nerve.

[0011] As shown in the attached figure of patent 201710077036.3, this patent mainly utilizes a radiofrequency ablation catheter to combine the expansion effect of an expandable balloon with the ablation effect of the radiofrequency ablation catheter, achieving simultaneous expansion and ablation. While the patent can achieve the ablation effect in terms of structure, the ablation electrodes in this patent are distributed in a "W" shape. As the balloon expands, this structure means that when the ablation electrodes are not fully expanded, the ablation shape of the "W"-shaped ablation electrodes is also "W"-shaped, making it difficult to ablate the gaps in the middle, resulting in a poor ablation effect. In addition, the necrotic and sloughed tissue after ablation needs to be removed by changing instruments, which is inconvenient to use. Summary of the Invention

[0012] The technical problem to be solved by the present invention is that, as mentioned in the background art, existing radiofrequency ablation catheters used for biliary tract treatment do not ablate sufficiently, and it is difficult to clean up the sloughed tissue after ablation and to determine whether the ablation has been completed.

[0013] To address the aforementioned technical problems, a radiofrequency ablation balloon catheter for biliary ablation is proposed. This is achieved through the following technical solution: A radiofrequency ablation balloon catheter for biliary ablation, comprising a catheter body, characterized in that it further comprises a radiofrequency electrode head, an ablation balloon, a tissue cleaning balloon, and a connector. The radiofrequency electrode head for tissue ablation is mounted on the ablation balloon, which is located at one end of the catheter body. The ablation balloon is controllably inflated and expands to conform to the diseased tissue. The radiofrequency electrode head expands with the ablation balloon, ablating the diseased tissue, and the ablation temperature is controllable. The tissue cleaning balloon is located at both ends of the ablation balloon and is controllably inflated and expands to assist in cleaning necrotic tissue ablated by the radiofrequency electrode head. The connector is detachably located at one end of the catheter body. An inflation pipe for controlling the inflation and deflation of the ablation balloon and the tissue cleaning balloon is connected to the ablation balloon and the tissue cleaning balloon through the connector.

[0014] In a preferred embodiment of the present invention, the radiofrequency electrode head includes multiple radiofrequency electrodes arranged at intervals, which are connected by wires. Each radiofrequency electrode includes four electrode plates and an extension plate. The four electrode plates are arranged in a ring on the ablation balloon, and two adjacent electrode plates are connected by the extension plate. The extension plate allows the radiofrequency electrodes to expand as the ablation balloon expands, facilitating the ablation of lesions.

[0015] In a preferred embodiment of the present invention, an annular pull ring is provided at one end of the electrode sheet, one end of the extension piece is connected to the electrode sheet, and the other end passes through the pull ring and is connected to an adjacent electrode sheet. This arrangement facilitates the expansion of the radiofrequency electrode after the ablation balloon expands, thus enabling better ablation.

[0016] In a preferred embodiment of the present invention, the electrode sheet and the extension sheet are made of conductive material with certain strength and toughness. The extension sheet expands and contracts with the expansion and contraction of the ablation balloon, and is adaptively pulled out and retracted by the pull ring. This arrangement facilitates the electrode sheet to expand and contract accordingly with the expansion of the ablation balloon, ensuring the ablation effect and making it convenient to use.

[0017] In a preferred embodiment of the present invention, the ablation balloon includes a fixed section and an inflation section. The fixed section is located at both ends of the inflation section. The ablation balloon is fixed to the catheter body through the fixed section. The inflation section can be controlled to expand and contract. The ablation balloon is designed to facilitate inflation, so that the radiofrequency electrode set on the ablation balloon fits tightly with the lesion, thereby improving the ablation effect.

[0018] In a preferred embodiment of the present invention, the tissue cleaning balloon includes a fixed end and an umbrella-shaped support end. The tissue cleaning balloon is fixed to the catheter body through the fixed end. The umbrella-shaped support end is connected to the fixed end and communicates with the inflation pipe. The umbrella-shaped support end is inflated and unfolded through the inflation pipe, and the unfolding port of the umbrella-shaped support end corresponds to the external outlet. This arrangement facilitates the umbrella-shaped support end to remove tissue detached after ablation.

[0019] In a preferred embodiment of the present invention, two sets of tissue cleaning balloons are provided on the catheter body. The umbrella-shaped supporting ends of the two sets of tissue cleaning balloons are of different sizes. The size of the umbrella-shaped supporting end near the external outlet is smaller than that of the other umbrella-shaped supporting end. This arrangement allows the tissue cleaning balloon at one end to clean up a portion of the detached tissue while the other end can clean up the remaining part, facilitating the removal of detached tissue and improving the cleaning effect.

[0020] In a preferred embodiment of the present invention, the inflation conduit includes a tissue cleaning balloon inflation tube and an ablation balloon inflation tube. One end of the tissue cleaning balloon inflation tube is connected to the tissue cleaning balloon, and the other end is connected to a connector. One end of the ablation balloon inflation tube is connected to the ablation balloon, and the other end is connected to a connector. The inflation conduit facilitates the control of inflation and deflation of the ablation balloon and the tissue cleaning balloon, making it convenient to use.

[0021] In a preferred embodiment of the present invention, the connector includes an inflation interface and a cable interface. A wire for powering the radio frequency electrode head passes through the cable interface and connects to the radio frequency electrode head. A double valve is provided on the inflation interface. The double valve is connected to the inflation tube of the cleaning balloon and the inflation tube of the ablation balloon, respectively. The inflation and deflation of the cleaning balloon inflation tube and the ablation balloon inflation tube are respectively controlled through the inflation port on the double valve. The double valve facilitates the separate control of inflation and deflation of the ablation balloon and the tissue cleaning balloon, making it convenient to use.

[0022] The beneficial effects of this invention compared to the prior art are:

[0023] The technical solution of this invention involves placing the catheter body into the lesion site using a guidewire, controlling the adhesion between the catheter and the diseased tissue by inflating and deflating the ablation balloon, and then fully ablating the diseased tissue using the radiofrequency electrode on the ablation balloon. Furthermore, a temperature sensor is added to the ablation balloon to achieve real-time monitoring of the ablation temperature, reducing the risk of eschar and carbonization caused by excessive tissue ablation, thus achieving temperature-controlled ablation. Additionally, a tissue cleaning balloon on the catheter body allows for direct cleaning of necrotic tissue after ablation without the need to change instruments, significantly improving surgical efficiency, reducing the use of additional consumables, and lowering surgical costs. Furthermore, the radiofrequency electrode head itself is designed as an array electrode, with multiple ring-shaped radiofrequency electrodes closely arranged on the treatment head to form an array structure, ensuring uniform ablation and effective control of the ablation depth, reducing the risk of delayed bile duct perforation due to excessive ablation depth. Attached Figure Description

[0024] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0025] Figure 2 A three-dimensional schematic diagram of the radiofrequency electrode head (including the ablation balloon);

[0026] Figure 3 This is a three-dimensional schematic diagram of the radio frequency electrode;

[0027] Figure 4 This is a partial cross-sectional view of the radio frequency electrode head;

[0028] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0029] Figure 6 This is a schematic diagram of the connection between the electrode plate and the extension plate in the radio frequency electrode.

[0030] Figure 7 This is a three-dimensional schematic diagram of the ablation balloon after inflation.

[0031] Figure 8 Diagram showing the balloon after it has been opened for tissue clearance;

[0032] Figure 9 This is a 3D schematic diagram of the connector;

[0033] Figure 10 This is a partial sectional view of a double valve;

[0034] Figure 11 This is a partial cross-sectional view of the present invention;

[0035] Figure 12 for Figure 11 Enlarged view at point B in the middle;

[0036] Explanation of reference numerals in the attached diagram: 1-RF electrode head, 11-RF electrode, 12-electrode plate, 13-extension plate, 14-pull ring, 15-lead wire, 16-fixation block, 2-catheter body, 3-ablation balloon, 31-fixation section, 32-inflation section, 33-temperature sensor, 4-tissue removal balloon, 41-fixation end, 42-umbrella-shaped support end, 43-pull strap, 5-inflation tube, 51-cleaning balloon inflation tube, 52-ablation balloon inflation tube, 6-connector, 61-inflation interface, 62-cable interface, 63-guidewire cavity interface, 64-double valve, 65-ablation balloon valve, 66-cleaning balloon valve, 67-inflation port. Detailed Implementation

[0037] The following will refer to the appendices in the embodiments of the present invention. Figure 1-12 The technical solutions in the embodiments of the present invention will be described in detail below. Example

[0038] like Figure 1 and 11 As shown, a radiofrequency ablation balloon catheter for biliary ablation includes a radiofrequency electrode head 1, a catheter body 2, an ablation balloon 3, a tissue cleaning balloon 4, an inflation tube 5, and a connector 6.

[0039] The ablation balloon 3 and the tissue cleaning balloon 4 are installed at the treatment end of the catheter body 2. The radiofrequency electrode head 1 is installed on the ablation balloon 3. The ablation balloon 3 and the tissue cleaning balloon 4 are connected to the inflation pipe 5. The connector 6 is located at the other end of the catheter body 2. The inflation and deflation of the ablation balloon 3 and the tissue cleaning balloon 4 can be controlled by the double valve 64 on the connector 6 and the inflation pipe 5. When the ablation balloon 3 is inflated, the radiofrequency electrode head 1 will expand accordingly to ablate the tissue at the lesion site.

[0040] The main function of the radio frequency electrode head 1 is to generate radio frequency current to ablate the tissue at the contact point of the radio frequency electrode head 1. Radio frequency ablation technology is an existing technology and can be used directly.

[0041] The function of the catheter body 2 is to serve as a carrier for the radiofrequency electrode head 1, ablation balloon 3, tissue cleaning balloon 4, inflation tube 5, and connector 6. As an existing device, the diameter of the catheter body 2 is preferably controlled within 1.2 mm. The advantage of this is that it can be used with a cholangioscope, allowing for direct visualization and ablation under the cholangioscope, which facilitates the doctor's intuitive judgment of the ablation degree and reduces the risks of blind ablation. The connection between the catheter body 2 and the cholangioscope is existing technology and is well known to those skilled in the art, so it will not be described in detail here.

[0042] The ablation balloon 3 is installed at the treatment end of the catheter body 2. Within a certain size range, the ablation balloon 3 can be inflated to the required size as needed, so that the radiofrequency electrode head 1 on the ablation balloon 3 fits tightly with the lesion, which facilitates the full ablation of the diseased tissue.

[0043] The tissue cleaning balloon 4 is installed on the catheter body 2, near both ends of the ablation balloon 3. The main function of the tissue cleaning balloon 4 is to help clean up necrotic and sloughed tissue after ablation, avoiding frequent instrument changes and improving efficiency.

[0044] like Figure 1 , 2 As shown in Figures 4 and 7, the ablation balloon 3 is made of plastic with a certain degree of elasticity and meets medical standards. The ablation balloon 3 is sleeved on the outside of the catheter body 2. The ablation balloon 3 can be medical-grade silicone rubber or medical-grade TPE soft rubber material. In this embodiment, medical-grade silicone rubber is preferred.

[0045] The ablation balloon 3 consists of two circular tubes nested together. The two ends of the two tubes are fixedly connected, and a chamber for inflation is formed in the middle. The fixed ends of the ablation balloon 3 are named the fixed section 31, and the inflatable chamber in the middle is named the inflation section 32. The fixed section 31 is fixedly connected to the outer surface of the catheter body 2, and the inflation section 32 can expand when inflated.

[0046] To facilitate inflation of the inflation section 32, a circular through hole is provided on the main body 2 near the inflation section 32. An ablation balloon inflation tube 52 is also inserted into the circular through hole. The ablation balloon inflation tube 52 passes through the inner wall of the inflation section 32 and is fixedly connected to the ablation balloon 3. Inflation and deflation of the ablation balloon 3 can be achieved through the ablation balloon inflation tube 52, controlling the expansion and contraction of the ablation balloon 3, so that the radiofrequency electrode head 1 on the ablation balloon 3 fits closely to the lesion, facilitating the full ablation of the diseased tissue.

[0047] Definition: In this embodiment, with the catheter body 2 as the reference, one end of the ablation balloon 3 is installed as the treatment end (treatment head), and the other end is the open end. After the catheter body 2 is inserted into the body, the treatment head is located inside and the open end is located outside.

[0048] To facilitate control of the ablation process, determine whether the ablation is complete, and prevent over-ablation that could cause eschar and carbonization, a temperature sensor 33 is fixed to the surface of the ablation balloon 3. The temperature sensor 33 is connected to external equipment via a control line passing through the catheter body 2. The temperature sensor 33 allows for real-time monitoring of the ablation temperature, determining whether the ablation is complete, and preventing over-ablation that could cause eschar and carbonization. To ensure measurement accuracy, multiple temperature sensors 33 can be installed, either on the fixed section 31 or on the inflation section 32. However, care must be taken to avoid the radiofrequency electrode head 1 to prevent damage to the temperature sensor 33.

[0049] like Figure 2 , 3 As shown in Figures 4, 5, 6 and 7, the radio frequency electrode head 1 is composed of multiple arrays of radio frequency electrodes 11. The multiple sets of radio frequency electrodes 11 are connected to each other through wires 15, forming a radio frequency electrode head 1 that can expand and contract as the ablation balloon 3 expands and contracts.

[0050] In this embodiment, the advantage of the radiofrequency electrode 11 over existing electrodes capable of ablation balloon changes is that the radiofrequency electrode 11 in this embodiment is always ring-shaped. The expansion or contraction of the ablation balloon 3 does not affect the shape of the radiofrequency electrode 11. Existing electrodes are distributed in a "W" shape, so when the balloon expands, the electrodes will unfold, and the degree of unfolding depends entirely on the size of the balloon expansion. Theoretically, the electrodes can only be ring-shaped when the balloon expands to a sufficiently large size. When the balloon is in a semi-expanded state, the electrodes are still "W"-shaped, so the ablation shape of the electrodes is also "W"-shaped, resulting in gaps that cannot be ablated. At the same time, the shape of the existing electrodes determines the distance between two sets of adjacent electrodes. After the electrodes unfold, the distance between two sets of adjacent electrodes... The distance between electrodes is relatively large, which may result in some areas that cannot be ablated. However, the radiofrequency electrode 11 in this embodiment does not have these two problems. In this embodiment, the radiofrequency electrode 11 is annular and is expanded and contracted by pulling out and retracting the extension piece 13. Therefore, no matter whether the ablation balloon 3 expands or contracts, the radiofrequency electrode 11 is always annular. The change of the radiofrequency electrode 11 is only a change in radial diameter, while there is no change in axial diameter. This setting allows two adjacent radiofrequency electrodes 11 to be closer together, and more radiofrequency electrodes 11 can be installed on the ablation balloon 3 of the same size. There are no areas that cannot be ablated between adjacent radiofrequency electrodes 11, which significantly improves the ablation speed, increases efficiency, and reduces operation time.

[0051] The radio frequency electrode 11 includes an electrode sheet 12 and an extension sheet 13. The electrode sheet 12 and the extension sheet 13 are made of a conductive metal material with certain toughness and elasticity, such as stainless steel or platinum-iridium alloy. Each radio frequency electrode 11 is composed of multiple electrode sheets 12 and extension sheets 13 connected to each other. In this embodiment, each radio frequency electrode 11 preferably consists of four electrode sheets 12 and extension sheets 13. The four electrode sheets 12 are evenly distributed along the circle of the ablation balloon 3, and every two electrode sheets 12 are connected by an extension sheet 13.

[0052] Electrode 12 is a rectangular thin sheet, and the electrode 12 is generally arc-shaped. A rectangular block made of insulating material is fixed on the inner arc surface of electrode 12. This block is named fixing block 16. Fixing block 16 has a certain thickness. One end of fixing block 16 is connected to the inner arc surface of electrode 12, and the other end is connected to ablation balloon 3 (the connection method of fixing block 16 can be adhesive or other existing methods). After fixing, fixing block 16 will not fall off ablation balloon 3. Since fixing block 16 is located between electrode 12 and ablation balloon 3, there is a certain gap between ablation balloon 3 and electrode 12. Extension piece 13 is placed in this gap. In order to facilitate the installation of extension piece 13, there is a certain interval between multiple electrode pieces 12 in a group of radio frequency electrodes 11.

[0053] To facilitate the extension and retraction of the extension piece 13, a rectangular piece is integrally fixed to one end of the electrode piece 12. A rectangular through hole is provided in the rectangular piece, which is named the pull ring 14. The width of the pull ring 14 is slightly larger than the width of the electrode piece 12. One end of the extension piece 13 is fixedly connected to the electrode piece 12, and the other end passes through the rectangular hole on the pull ring 14 from the inner side of the pull ring 14 and is fixedly connected to the end of the adjacent electrode piece 12 that does not have a pull ring 14. When the ablation balloon 3 is inflated, the radiofrequency electrode 11 unfolds accordingly, and the extension piece 13 located between the ablation balloon 3 and the electrode piece 12 is pulled out along the pull ring 14.

[0054] The extension piece 13 is a rectangular metal sheet. The width of the extension piece 13 is the same as the width of the electrode piece 12, and the flexibility of the extension piece 13 is higher than that of the electrode piece 12 to ensure that the extension piece 13 can be pulled out from the pull ring 14. In addition, in order to ensure that the extension piece 13 has a certain elasticity, the extension piece 13 is in a "C" shape when it is not under force. One end of the extension piece 13 is fixedly connected to the electrode piece 12 with the pull ring 14 installed, and the other end is fixedly connected to the end of the adjacent electrode piece 12 without the pull ring 14. In this way, the four electrode pieces 12 in a group of radiofrequency electrodes 11 are connected to each other through the extension piece 13 to form a final ring. When the ablation balloon 3 expands, the extension piece 13 will be pulled out, and the radiofrequency electrode 11 will be fully deployed. At this time, the extension piece 13 is under force. When the ablation balloon 3 contracts, the extension piece 13 pulls the electrode piece 12 back to its original position under its own elasticity, thus completing the reset of the radiofrequency electrode 11.

[0055] like Figure 1 , 7 As shown in Figures 8 and 11, the tissue cleaning balloon 4 is an inflatable balloon made of a plastic film that meets medical standards. The tissue cleaning balloon 4 is not elastic. The tissue cleaning balloon 4 includes a fixed end 41 and an umbrella-shaped support end 42. The umbrella-shaped support end 42 can be inflated into an umbrella shape, and the opening of the unfolded umbrella-shaped support end 42 corresponds to the external outlet (the external outlet is the opening when the catheter body 2 is inserted into the patient's body). The necrotic tissue that has been sloughed off after ablation can be cleaned out through the umbrella-shaped support end 42.

[0056] The fixed end 41 and the umbrella-shaped support end 42 are integrally connected to each other. In order to facilitate the installation of the fixed end 41 and the umbrella-shaped support end 42, the fixed end 41 and the umbrella-shaped support end 42 are installed on a circular sleeve. The inner diameter of the sleeve is the same as the outer diameter of the catheter body 2. The sleeve is fitted on the catheter body 2 near the ablation balloon 3 and is fixedly connected to the catheter body 2. The fixed end 41 is annular and is fitted on the outside of the sleeve and is fixedly connected to the sleeve.

[0057] After the umbrella-shaped support end 42 is opened, it takes the shape of an umbrella. The smaller diameter end of the umbrella-shaped support end 42 is connected to the fixed end 41. In order to make the outer diameter of the umbrella-shaped support end 42 the same as that of the fixed end 41 when it is not inflated, and at the same time to ensure that the umbrella-shaped support end 42 is inflated and unfolded, there are folds on the outer wall of the umbrella-shaped support end 42. When the tissue cleaning balloon 4 is inflated, the folds are opened, and the umbrella-shaped support end 42 is unfolded. In order to clean up the detached tissue, the unfolded opening of the umbrella-shaped support end 42 corresponds to the external outlet.

[0058] To prevent the umbrella-shaped support end 42 from flipping over during cleaning, a pull strap 43 is fixed between the inner side of the umbrella-shaped support end 42 and the sleeve. Multiple pull straps 43 are circularly distributed on the sleeve. One end of the pull strap 43 is fixedly connected to the sleeve, and the other end is fixedly connected to the umbrella-shaped support end 42. The pull strap 43 is a bent flexible strip, and the pull strap 43 is made of the same material as the tissue cleaning balloon 4. When the umbrella-shaped support end 42 is deployed, the length of the pull strap 43 can limit the size of the deployment of the umbrella-shaped support end 42. At the same time, when cleaning the detached tissue, the umbrella-shaped support end 42 acts like a net to scrape the detached tissue out, while the pull strap 43 provides support for the umbrella-shaped support end 42, preventing the umbrella-shaped support end 42 from flipping over and ensuring the normal cleaning of the detached tissue.

[0059] The tissue cleaning balloon 4 is provided at both ends of the ablation balloon 3, and the umbrella-shaped support end 42 of the tissue cleaning balloon 4 closer to the external outlet is slightly smaller than the size of the other one. This arrangement allows the umbrella-shaped support end 42 closer to the external outlet to clean up a portion of the detached tissue first when cleaning up the detached tissue, while the umbrella-shaped support end 42 on the other tissue cleaning balloon 4 cleans up the remaining detached tissue, relieving the pressure of cleaning with a single umbrella-shaped support end 42 and ensuring the cleaning effect.

[0060] like Figure 5 and 12 As shown, in order to facilitate the inflation and deflation of the ablation balloon 3 and the tissue cleaning balloon 4, an inflation pipe 5 is also provided in the catheter body 2. The inflation pipe 5 enters the catheter body 2 from one end and is connected to the connector 6 on the catheter body 2 at the other end.

[0061] The inflation conduit 5 includes a cleaning balloon inflation tube 51 and an ablation balloon inflation tube 52. Both the cleaning balloon inflation tube 51 and the ablation balloon inflation tube 52 are commonly used hollow flexible tubes. One end of the cleaning balloon inflation tube 51 is connected to two tissue cleaning balloons 4, and the ablation balloon inflation tube 52 is connected to the ablation balloon 3. The other ends of the cleaning balloon inflation tube 51 and the ablation balloon inflation tube 52 pass through the inside of the catheter body 2 and are connected to the double valve 64 at the inflation port 61 on the connector 6. Air can be injected into or extracted into the ablation balloon 3 and the tissue cleaning balloon 4 through the syringe and the double valve 64, thereby controlling the expansion and contraction of the ablation balloon 3 and the tissue cleaning balloon 4. The connection between the cleaning balloon inflation tube 51 and the ablation balloon inflation tube 52 and the ablation balloon 3 and the tissue cleaning balloon 4 can be selected by thermocompression connection or other existing mature connection technologies.

[0062] like Figure 1 , 9As shown in Figures 10 and 11, the main function of connector 6 is to connect the catheter body 2 and external equipment. Connector 6 consists of a main pipe and two branch pipes. One end of the main pipe is inserted into the outlet end of the catheter body 2 (the insertion method is the prior art). The other two branch pipes are distributed in a "Y" shape on both sides of the main pipe. One of the branch pipes is named inflation connector 61, and the other branch pipe is named cable connector 62. Inflation connector 61 and cable connector 62 are connected to the main pipe, and the other end of the main pipe near the two branch rods is guidewire lumen connector 63.

[0063] The function of the inflation connector 61 is to install the double valve 64. The cleaning balloon inflation tube 51 and the ablation balloon inflation tube 52 in the inflation pipeline 5 are connected to the double valve 64 at the end of the inflation connector 61.

[0064] The main function of the cable connector 62 is to connect the wires 15 inside the catheter body 2 to the outside world. The wires 15 connected to the radio frequency electrode head 1 and the wires 15 connected to the temperature sensor 33 pass through the inside of the catheter body 2 and extend out from the cable connector 62 to connect to the external control equipment and radio frequency ablation equipment to output radio frequency energy.

[0065] The function of the guidewire lumen connector 63 is to facilitate the insertion of the guidewire and the placement of the catheter body 2 through the guidewire, which is existing technology.

[0066] The double valve 64 is a large valve with two small valves connected in parallel. The double valve 64 includes a circular main shaft with an external thread at one end. The main shaft is screwed onto the inflation tube 61 through this external thread. On the circular end face of the main shaft with the external thread, there are two circular cavities of different depths that are recessed perpendicular to the end face. The port of the cleaning balloon inflation tube 51 is inserted into the deeper circular cavity, and the port of the ablation balloon inflation tube 52 is inserted into the other, slightly shallower circular cavity.

[0067] Two small valves are installed at intervals on the side of the main shaft. One end of one of the small valves is connected to a circular cavity connected to the inflation tube 51 of the cleaning balloon. This valve is named the cleaning balloon valve 66. The other interface of the cleaning balloon valve 66 is the inflation port 67. Through the inflation port 67, air can be injected or deflated into the tissue cleaning balloon 4 using a syringe. One end of the other small valve is connected to a circular cavity connected to the inflation tube 52 of the ablation balloon. This valve is named the ablation balloon valve 65. The other interface of the ablation balloon valve 65 is the inflation port 67. Through the inflation port 67, air can be injected or deflated into the ablation balloon 3 using a syringe. At the same time, by using the valves on the ablation balloon valve 65 and the cleaning balloon valve 66, the air intake or exhaust into the ablation balloon 3 and the tissue cleaning balloon 4 can be controlled.

[0068] The usage process of this embodiment:

[0069] Ablation process: When ablation is required, first install the connector 6 to the outlet end of the catheter body 2, then connect the wire 15 at the cable connector 62 to the power supply and control equipment, then connect the catheter body 2 to the existing tubular endoscope, and then use the guide wire to place the catheter body 2 into the lesion.

[0070] During ablation, simply turn on the control switch of the radiofrequency electrode head 1 to activate it and perform ablation on the lesion. The ablation temperature is monitored by the temperature sensor 33 to prevent over-ablation that could cause eschar and carbonization. When encountering irregularly distributed tumors within the bile duct, where the radiofrequency electrode head 1 cannot closely adhere to the lesion's inner wall, insert the syringe into the inflation port of the ablation balloon valve 65, then open the valve and inject air into the ablation balloon 3 until it inflates and resonates with the lesion. The ablation balloon is tightly fitted. At this time, the radiofrequency electrode head 1 expands as the ablation balloon 3 expands. Then, the ablation balloon valve 65 is closed, the syringe is removed, and ablation continues. After this section of ablation is completed, the syringe is inserted into the inflation port on the ablation balloon valve 65, and then the ablation balloon valve 65 is opened. The air inside the ablation balloon 3 is then drawn out using the syringe until the ablation balloon 3 contracts and resets. At this time, the radiofrequency electrode head 1 resets as the ablation balloon 3 resets. Then, the ablation balloon valve 65 is closed, the syringe is removed, and ablation of the remaining parts can continue.

[0071] Cleaning process: When it is necessary to clean up the necrotic tissue that has been ablated, first empty the gas in the ablation balloon 3 (see above for the emptying method), then insert the syringe into the inflation port of the cleaning balloon valve 66, then open the cleaning balloon valve 66, and use the syringe to inject air into the tissue cleaning balloon 4. At this time, the umbrella-shaped support ends 42 on the two tissue cleaning balloons 4 will inflate and expand. Then close the cleaning balloon valve 66, remove the syringe, and pull the catheter body 2 outward. At this time, the umbrella-shaped support ends 42 will clean up the tissue that has been ablated like a net, and the pull strap 43 can prevent the umbrella-shaped support ends 42 from folding over during the cleaning process, making the cleaning more thorough. The tissue cleaning balloon 4 can be cleaned after ablation, reducing the number of instrument exchanges and improving surgical efficiency.

[0072] The above embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solutions based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A radiofrequency ablation balloon catheter for biliary ablation, comprising a catheter body (2), characterized in that: It also includes a radiofrequency electrode head (1), an ablation balloon (3), a tissue cleaning balloon (4), and a connector (6). The radiofrequency electrode head (1) for tissue ablation is set on the ablation balloon (3). The ablation balloon (3) is set at one end of the catheter body (2). The ablation balloon (3) can be controlled to expand and fit the lesion tissue. The radiofrequency electrode head (1) expands with the ablation balloon (3) to ablate the lesion tissue, and the ablation temperature is controllable. The tissue cleaning balloon (4) is set at both ends of the ablation balloon (3). The tissue cleaning balloon (4) can be controlled to expand and assist in cleaning the necrotic tissue ablated by the radiofrequency electrode head (1). The connector (6) is detachably set at one end of the catheter body (2). The inflation pipe (5) for controlling the inflation and deflation of the ablation balloon (3) and the tissue cleaning balloon (4) is connected to the ablation balloon (3) and the tissue cleaning balloon (4) through the connector (6). The radio frequency electrode head (1) includes multiple radio frequency electrodes (11) arranged at intervals. Each radio frequency electrode (11) includes multiple electrode pieces (12) and extension pieces (13). Adjacent electrode pieces (12) are connected by extension pieces (13), and the extension pieces (13) are adaptively pulled out and extended as the ablation balloon (3) expands. The tissue cleaning balloon (4) includes a fixed end (41) and an umbrella-shaped support end (42). The tissue cleaning balloon (4) is fixed to the catheter body (2) through the fixed end (41). The umbrella-shaped support end (42) is connected to the fixed end (41) and communicates with the inflation pipe (5). The umbrella-shaped support end (42) is inflated and unfolded through the inflation pipe (5), and the unfolding port of the umbrella-shaped support end (42) corresponds to the external outlet. Two sets of tissue cleaning balloons (4) are provided on the catheter body (2). The umbrella-shaped support ends (42) of the two sets of tissue cleaning balloons (4) are different in size. The umbrella-shaped support end (42) on the side closer to the external outlet is smaller than the other umbrella-shaped support end (42). A double valve (64) is provided on the connector (6), and an independent pipe is provided on the inflation pipe (5) to connect to the ablation balloon (3) and the tissue cleaning balloon (4) respectively. The double valve (64) controls the inflation and deflation of the ablation balloon (3) and the tissue cleaning balloon (4).

2. The radiofrequency ablation balloon catheter for biliary ablation according to claim 1, characterized in that: Multiple radio frequency electrodes (11) are connected by wires, and the electrode pads (12) on each radio frequency electrode (11) are arranged in a ring on the ablation balloon (3).

3. The radiofrequency ablation balloon catheter for biliary ablation according to claim 2, characterized in that: An annular pull ring (14) is provided at one end of the electrode sheet (12). One end of the extension piece (13) is connected to the electrode sheet (12), and the other end passes through the pull ring (14) and is connected to an adjacent electrode sheet (12).

4. The radiofrequency ablation balloon catheter for biliary ablation according to claim 3, characterized in that: The electrode sheet (12) and the extension sheet (13) are made of conductive materials with certain strength and toughness.

5. The radiofrequency ablation balloon catheter for biliary ablation according to claim 1, characterized in that: The ablation balloon (3) includes a fixed section (31) and an inflation section (32). The fixed section (31) is located at both ends of the inflation section (32). The ablation balloon (3) is fixed to the catheter body (2) through the fixed section (31). The inflation section (32) can expand and contract in a controlled manner.

6. The radiofrequency ablation balloon catheter for biliary ablation according to claim 1, characterized in that: The inflation tube (5) includes a cleaning balloon inflation tube (51) and an ablation balloon inflation tube (52). One end of the cleaning balloon inflation tube (51) is connected to the tissue cleaning balloon (4), and the other end is connected to the connector (6). One end of the ablation balloon inflation tube (52) is connected to the ablation balloon (3), and the other end is connected to the connector (6).

7. The radiofrequency ablation balloon catheter for biliary ablation according to claim 1, characterized in that: The connector (6) includes an inflation port (61) and a cable port (62), through which a wire (15) for powering the RF electrode head (1) passes and connects to the RF electrode head (1).

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