Cryoablation catheter and ablation system

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a cryoablation catheter and an ablation system.The cryoablation catheter comprises an inner catheter body and an outer catheter body, the outer catheter body is coaxially arranged on the outer side of the inner catheter body in a sleeving mode, and the inner catheter body is configured to be of a multi-cavity structure; the multiple plugging assemblies are arranged on the outer side of the inner catheter; wherein in the initial state, the multiple plugging assemblies and the inner catheter are located in the outer catheter, and in the working state, the multiple plugging assemblies and the inner wall of the intestinal tract jointly form an ablation closed space. The cryoablation catheter is guided to a target position through the guide wire, the closed ablation space is formed through cooperation of the plugging assembly and the inner wall of the cavity, a freezing medium is input into the closed ablation space to conduct cryoablation on the inner wall of the cavity, an available treatment scheme is provided for patients suffering from type 2 diabetes, obesity or other cavity lesions, and meanwhile the treatment effect is improved. The device has the advantages of small trauma, less pain of patients, low surgical risk and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a cryoablation catheter and an ablation system. Background Art

[0002] For patients with type II diabetes and obesity, the more commonly used treatment methods are drug treatment and surgical treatment. When treating type II diabetes with drugs, some patients do not respond well to traditional drug treatment. When treating obesity with drugs, it often causes some adverse reactions in patients, affecting their lives. Using surgical treatment, such as gastric bypass surgery and sleeve gastrectomy; the risks of surgery and postoperative complications are relatively high, and generally speaking, the surgical cost is relatively expensive. Some studies have shown that duodenal mucosal surface replacement (DMR) as a new minimally invasive treatment method can effectively treat type 2 diabetes and obesity in some cases, which provides an option for many patients with poor effects of traditional drugs or who are unable to undergo traditional surgical treatment. Currently, related products using hydrothermal method, hot steam method and IRE method have been disclosed for DMR. This patent proposes a cryoablation catheter for mucosal remodeling, aiming to perform DMR surgery by freezing, so as to give patients one more treatment option. Summary of the Invention

[0003] The purpose of the present invention is to provide a cryoablation catheter. The cryoablation catheter is guided to the target position through a guide wire. An ablation closed space is formed by the cooperation of a sealing component and the inner wall of the cavity. A cryogenic medium is input into the ablation closed space to perform cryoablation on the inner wall of the cavity, providing a viable treatment plan for patients with type 2 diabetes, obesity or other cavity lesions. At the same time, it has the advantages of less trauma, less pain for patients and low surgical risk.

[0004] The technical solution adopted by the present invention is specifically as follows:

[0005] A cryoablation catheter includes an inner catheter and an outer catheter. The outer catheter is coaxially sleeved outside the inner catheter. The inner catheter is configured as a multi-channel structure, and further includes:

[0006] A plurality of sealing components, and a plurality of the sealing components are all arranged outside the inner catheter;

[0007] Wherein, in the initial state, a plurality of the sealing components and the inner catheter are both located inside the outer catheter. In the working state, a plurality of the sealing components and the intestinal inner wall jointly form an ablation closed space. The sealing component is configured to limit the action range of the cryogenic medium when the ablation instrument inputs the cooling medium into the ablation closed space.

[0008] In a preferred embodiment, a plurality of first medium delivery holes are formed on the outer side of the inner catheter, and at least one channel inside the ablation sealed space and the inner catheter communicates with each other through the first medium delivery holes.

[0009] In a preferred embodiment, a plurality of negative pressure through holes are formed on the outer side of the inner catheter, and at least one channel inside the ablation sealed space and the inner catheter communicates with each other through the negative pressure through holes.

[0010] In a preferred embodiment, the plugging assembly includes a plurality of support frames and a plugging film. The plurality of support frames are annularly arrayed on the outer side of the inner catheter, and adjacent support frames do not contact each other. The plugging film is fixed to the outer sides of the plurality of support frames, and the plugging film is fixedly connected to the inner catheter.

[0011] In a preferred embodiment, the material of the plugging film is one of the following materials: polyurethane, silicone.

[0012] In a preferred embodiment, a plurality of avoidance notches are formed on the outer side of the plugging film and between adjacent support frames.

[0013] In a preferred embodiment, the plugging assembly includes a positioning ring, a plurality of support rods and a plugging airbag. The positioning ring is sleeved on the outer side of the inner catheter. The plurality of support rods are all fixed to the outer side of the positioning ring, and the plurality of support rods are annularly arrayed on the outer side of the positioning ring. The plugging airbag is arranged between the inner catheter and the positioning ring, and the plugging airbag is fixedly connected to both the inner catheter and the positioning ring. In the initial state, the support rods are in a straight segment form, and in the working state, the support rods undergo elastic deformation.

[0014] In a preferred embodiment, second medium delivery holes are formed on the outer side of the inner catheter. Avoidance through holes are formed on both the positioning ring and the plugging airbag. At least one channel inside the plugging airbag and the inner catheter communicates with each other through the second medium delivery holes.

[0015] In a preferred embodiment, the material of the plugging airbag is polytetrafluoroethylene.

[0016] In a preferred embodiment, the cryogenic medium can be one of the following substances: gaseous CO2, gaseous N2, liquid nitrogen, liquid CO2.

[0017] A cryoablation system includes a cryoablation catheter as described in any one of the above and an ablation instrument. The ablation instrument includes a control module, a display module, an input module, a working medium module, a constant pressure module, a negative pressure module, and an impedance test module;

[0018] The control module can receive, process relevant data and send corresponding instructions;

[0019] The display module can display relevant data and information;

[0020] The input module can input relevant parameters and instructions;

[0021] The working fluid module can deliver or withdraw the working fluid to / from the cryoablation catheter, and the working fluid includes a cryogenic medium and a gas medium;

[0022] The constant pressure module can regulate the flow rates of the cryogenic medium and the gas medium;

[0023] The negative pressure module can regulate the pressure inside the ablation sealed space and / or inside the plugging module;

[0024] The impedance test module can test the impedance value of the support frame.

[0025] The technical effects achieved by the present invention are:

[0026] After the inner catheter and the outer catheter are delivered to the target position inside the duodenal lumen, the ablation sealed space is formed by the cooperation of the expanded plugging component and the lumen inner wall. After the cryogenic medium is input into the ablation sealed space, the cryogenic medium is used to perform cryoablation on the lumen inner wall. Multiple segments of ablation are repeated, and finally, the ablation of the tissues in the entire duodenal lumen is completed, providing a viable treatment plan for patients with type 2 diabetes, obesity, or other human natural lumen lesions for whom traditional drug treatment has poor effects or who cannot undergo traditional surgery. At the same time, minimally invasive techniques are used during the treatment process, which have the advantages of small trauma, less pain for the patient, low surgical risk, rapid postoperative recovery, and few complications;

[0027] During the process of performing cryoablation on the duodenal inner wall, by opening negative pressure through holes on the outer side of the inner catheter and providing stable negative pressure by the ablation instrument, the pressure inside the ablation sealed space is regulated, so that the expanded cryogenic medium can quickly be discharged through the negative pressure through holes, avoiding damage and breakage to the lumen inner wall caused by excessive volume expansion of the vaporized cryogenic medium, and improving the safety performance of the device. Description of the Drawings

[0028] Figure 1 is the overall structural schematic diagram in the first embodiment of the present invention;

[0029] Figure 2 is the axial sectional view of the overall structure in the first embodiment of the present invention;

[0030] Figure 3 is the radial sectional view of the overall structure in the first embodiment of the present invention;

[0031] Figure 4 is the structural schematic diagram of the plugging component in the first embodiment of the present invention;

[0032] Figure 5 It is a schematic structural diagram of the plugging component in the second embodiment of the present invention;

[0033] Figure 6 It is a structural sectional view of the plugging component in the second embodiment of the present invention;

[0034] Figure 7 It is an exploded view of the structure of the plugging component in the second embodiment of the present invention;

[0035] Figure 8 It is a structural block diagram of the cryoablation system in the third embodiment of the present invention.

[0036] In the drawings, the list of components represented by each reference numeral is as follows:

[0037] 10. Inner catheter; 11. Outer catheter; 12. First medium delivery hole; 13. Negative pressure through hole; 14. Second medium delivery hole;

[0038] 21. Support frame; 22. Plugging film; 23. Avoidance notch;

[0039] 31. Positioning ring; 32. Support rod; 33. Plugging airbag. Detailed implementation manners

[0040] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given in conjunction with the drawings of the specification.

[0041] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0042] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The "in a preferred embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that mutually excludes other embodiments.

[0043] Furthermore, the present invention is described in detail in conjunction with schematic diagrams. When detailing the embodiments of the present invention, for the sake of explanation, the sectional views showing the device structure will be enlarged locally not in accordance with the general ratio, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0044] Embodiment 1

[0045] Please refer to the attached Figures 1 to 4As shown, this is the first embodiment of the present invention. This embodiment provides a cryoablation catheter, which is mainly used for reconstructing the duodenal mucosa to treat type 2 diabetes and obesity, and can also be used for the treatment of other lumen tissue diseases, such as Barrett's esophageal cancer, biliary tract stenosis, etc. It includes an inner catheter 10 and an outer catheter 11. The outer catheter 11 is coaxially sleeved outside the inner catheter 10. The inner catheter 10 is configured as a multi-lumen structure, and further includes:

[0046] Two blocking components, both of which are arranged outside the inner catheter 10;

[0047] Among them, in the initial state, multiple blocking components and the inner catheter 10 are both located inside the outer catheter 11, and the blocking components are in a retracted state. In the working state, the blocking components are in an extended state. The two blocking components and the intestinal wall jointly form an ablation sealed space. The blocking components are configured to limit the action range of the cryogenic medium when the cryoablation instrument inputs the cooling medium into the ablation sealed space.

[0048] It should be noted that there is also a cryoablation instrument and a guide wire used in conjunction with the device. There is a lumen inside the inner catheter 10 that is adapted to the guide wire. The above-mentioned lumen is denoted as the first lumen. The first lumen is coaxially arranged with the inner catheter 10 and penetrates through the inside of the inner catheter 10. And other lumens inside the inner catheter 10 except the first lumen are non-penetrating lumens. The cryoablation instrument can input the cryogenic medium into the ablation sealed space. The guide wire can slide inside the inner catheter 10. Under the guidance of the imaging device, the guide wire is transported to the lesion location. Through the guide wire, the inner catheter 10 and the outer catheter 11 can be guided to the lesion location. The initial state is the state of the device before the cryoablation catheter enters the target position in the patient's body. The working state refers to the state of the device when the cryoablation catheter has reached the lesion tissue and is about to or has already started cryoablation of the lesion tissue.

[0049] Furthermore, in order to describe the working process of the device in more detail, in the following text, the ablation of the mucosa of the duodenal inner wall is taken as an example. Of course, the device can also be used for the treatment of other lumen tissue diseases, such as Barrett's esophageal cancer, biliary tract stenosis, etc. Here, it does not constitute a specific limitation.

[0050] In this embodiment, the device is connected to an ablation instrument. Under the guidance of an imaging device, a guide wire is delivered into the interior of the duodenum. Under the guidance of the guide wire, the inner catheter 10 and the outer catheter 11 are pushed to the target position in the duodenum. The outer catheter 11 is kept stationary, and the inner catheter 10 is pushed. The inner catheter 10 drives the occlusion assembly to move outside the outer catheter 11. After the occlusion assembly slides out of the inner part of the outer catheter 11, it changes from the stored form to the extended form, and the outer side of the occlusion assembly is completely attached to the inner wall of the duodenum. An ablation sealed space is jointly formed by the two occlusion assemblies and the intestinal wall. The ablation instrument is started, and a cryogenic medium is input into the ablation sealed space through the ablation instrument. After the cryogenic medium enters the ablation sealed space, it can cause the water in the inner wall tissue cells of the ablation area to quickly condense into ice cones or ice crystals, pierce the cell wall, thereby killing the tissue of the inner wall of the cavity, and then performing cryoablation on the mucosa of the inner wall of the duodenum, which is the target tissue. Then, the cooling medium inside the ablation sealed space is evacuated, and the inner catheter 10 is pulled back, so that the inner catheter 10 and the occlusion assembly move back into the inner part of the outer catheter 11 again, and the occlusion assembly changes from the extended form to the stored form. Multiple segments of ablation are repeated, and finally, cryoablation of the entire tissue in the duodenal cavity is completed. Then, the device can be removed from the patient's body. Through the above solution, through the cryoablation technology, not only a new treatment option is provided for diseases such as diabetes and obesity that can be treated by reconstructing the digestive tract mucosa, but also a minimally invasive technique is adopted during the treatment process, which has the advantages of small trauma, less pain for the patient, low surgical risk, rapid postoperative recovery, and few complications. This provides a viable treatment option for patients with type 2 diabetes, obesity, or other cavity lesions who have poor effects with traditional drug treatment or cannot accept traditional surgery.

[0051] Specifically, the cryogenic medium can be one of the following substances: high-pressure gaseous CO2, high-pressure gaseous N2, liquid nitrogen, liquid CO2, or other media with a cryogenic function. According to the Joule-Thomson effect, when high-pressure gases such as high-pressure gaseous CO2 and high-pressure gaseous N2 change from the high-pressure state to the low-pressure state, the gas expands and cools rapidly, causing the water in the inner wall tissue cells of the ablation area to quickly condense into ice cones or ice crystals, piercing the cell wall, thereby killing the tissue of the inner wall of the cavity and completing the treatment. For media such as liquid nitrogen and liquid CO2, on the one hand, their own temperature is very low. After vaporizing in the catheter lumen, they enter the ablation area in the form of low-temperature gas, which can cause the water in the inner wall tissue cells of the ablation area to quickly condense into ice cones or ice crystals, pierce the cell wall, thereby killing the tissue of the inner wall of the cavity and completing the treatment. Preferably, in this embodiment, the cryogenic medium is liquid CO2.

[0052] Secondly, please refer to again Figures 1 to 2, a plurality of first medium delivery holes 12 are formed on the outer side of the inner catheter 10, and at least one cavity inside the ablation sealed space and the inner catheter 10 communicates with each other through the first medium delivery holes 12. Among them, the above-mentioned cavity is denoted as the second cavity, and the second cavity is connected to the ablation instrument.

[0053] In this embodiment, through the above scheme, the cryogenic medium can be delivered into the ablation sealed space through the second cavity. Under the restrictive action of the sealing assembly, the cryogenic medium contacts the inner wall of the duodenum located between the sealing assemblies. The water in the inner wall tissue cells of the cryogenic medium can be quickly condensed into ice cones or ice crystals, piercing the cell wall, thereby killing the tissue on the inner wall of the cavity, and then performing cryoablation on the target tissue.

[0054] Thirdly, please refer to again Figures 1 to 2 , a plurality of negative pressure through holes 13 are formed on the outer side of the inner catheter 10, and at least one cavity inside the ablation sealed space and the inner catheter 10 communicates with each other through the negative pressure through holes 13. Among them, the above-mentioned cavity is denoted as the third cavity; at least one cavity inside the inner catheter 10 is provided with a power supply wire, and the support frame 21 is connected to the power supply wire. Among them, the above-mentioned cavity is denoted as the fourth cavity, and the third cavity, the fourth cavity and the power supply wire are all connected to the ablation instrument.

[0055] In this embodiment, when the inner wall of the duodenum is ablated by the cryogenic medium, after the cryogenic medium vaporizes, its volume will inevitably expand rapidly. By forming negative pressure through holes 13 on the outer side of the inner catheter 10 and between the two sealing assemblies, and the negative pressure through holes 13 are connected to the ablation instrument, a stable negative pressure is provided by the ablation instrument, so that the expanded gas can quickly be discharged through the negative pressure through holes 13, avoiding the over-rapid expansion of the gas volume and causing damage to the cavity.

[0056] Secondly, please refer to again Figures 2 to 4 , the sealing assembly includes a plurality of support frames 21 and a sealing film 22. The plurality of support frames 21 are annularly arranged on the outer side of the inner catheter 10, and the support frames 21 are fixedly connected to the inner catheter 10. Adjacent two support frames 21 do not contact each other. The sealing film 22 is fixed on the outer side of the plurality of support frames 21, and the sealing film 22 is fixedly connected to the inner catheter 10. The material of the sealing film 22 is one of the following materials: polyurethane, silica gel, polytetrafluoroethylene or other high molecular materials with good ductility. Preferably, in this example, the material of the sealing film 22 is preferably polyurethane.

[0057] It should be noted that the material of the support frame 21 is shape memory alloy. When the sealing assembly is located inside the outer catheter 11 and in the storage state, the support frame 21 undergoes elastic bending. After the external force is withdrawn (such as: after the sealing assembly moves out of the outer catheter 11), the storage-state sealing assembly changes to the extended state under the action of the support frame 21.

[0058] Further, in this embodiment, the blocking component in the extended form is frustum-shaped, and the opening directions of the two blocking components are close to each other.

[0059] In this embodiment, when performing cryoablation on the patient's duodenum, the inner catheter 10 and the outer catheter 11 are pushed to the target position in the duodenum through a guide wire. The outer catheter 11 is kept stationary, and the inner catheter 10 is pushed. The blocking component is driven by the inner catheter 10 to move outside the outer catheter 11. After the support frame 21 elastically bends and moves out of the inner part of the outer catheter 11, the support frame 21 that has elastically bent resumes its free shape, and the blocking membrane 22 is driven by the support frame 21 to unfold, so that the support frame 21 and the blocking membrane 22 are transformed from the storage form to the extended form. Since the blocking component in the extended form is frustum-shaped, an ablation closed space is formed by the cooperation of the two blocking membranes 22 and the inner wall of the duodenum. The cryogenic medium is input into the ablation closed space through an ablation instrument, and the inner wall of the duodenum located between the two blocking components can be cryoablated. After the ablation is completed, the inner catheter 10 is pulled in the direction close to the outer catheter 11, and the support frame 21 and the blocking membrane 22 are driven by the inner catheter 10 to move synchronously. When the support frame 21 and the blocking membrane 22 come into contact with the outer catheter 11, the outer catheter 11 squeezes the support frame 21 and the blocking membrane 22, so that the support frame 21 drives the blocking membrane 22 to elastically bend again and move into the inner part of the outer catheter 11. Furthermore, the blocking component is transformed from the extended form to the storage form. The inner catheter 10 and the outer catheter 11 are pushed to move the blocking component to the next target position for repeated multi-segment ablation, and finally the cryoablation of the tissues in the entire duodenal lumen is completed, and the device can be taken out of the patient's body.

[0060] It should be noted that the inner diameter of the outer catheter 11 is larger than the outer diameter of the inner catheter 10 to ensure that the bent support frame 21 and the blocking membrane 22 can completely move into the inner part of the outer catheter 11.

[0061] Please refer to again Figure 3 and Figure 4 As shown, a plurality of avoiding notches 23 are formed on the outer side of the blocking membrane 22 and between two adjacent support frames 21.

[0062] Here, Figure 3 and Figure 4The size of the avoidance notch 23 is for illustration only. Its specific size is small, only to ensure that the support frame 21 can be partially exposed (not completely wrapped by the sealing film 22), so that a part of the support frame 21 can be in direct contact with the inner wall of the duodenum. Here, it does not constitute a specific limitation. Of course, the avoidance notch 23 will cause the ablation closed space not to be completely airtight. After the cryogenic medium is input into the ablation closed space, it will overflow through the avoidance notch 23. The overflow amount is small and will not affect the cryoablation operation. At the same time, multiple segments of ablation need to be performed on the inner wall of the duodenum. Here, the amount of the cryogenic medium overflowing through the avoidance notch 23 can be ignored.

[0063] In this embodiment, during the actual production process, the support frame 21 is composed of multiple round rods made of shape memory alloy. To prevent the separation between the support frame 21 and the sealing film 22, the edge of the sealing film 22 and the outermost round rod are fixedly connected in a winding manner (that is, the edge of the sealing film 22 is wound around the outside of the outermost round rod). At this time, the outside of the sealing film 22 cannot be in direct contact with the inner wall of the rectum. To measure the impedance value of the support frame 21 and determine whether the support frame 21 is completely attached to the inner wall of the duodenum subsequently, the setting of the avoidance notch 23 enables the outermost round rod to be exposed (that is, the part of the outermost sealing film 22 overlapping with the avoidance notch 23 is in an exposed state), so as to be in direct contact with the inner wall of the duodenum for subsequent measurement of the impedance value of the support frame 21.

[0064] Embodiment Two

[0065] This embodiment is a further adjustment based on Embodiment One. Specifically:

[0066] Please refer to again Figures 5 to 7 , the plugging assembly includes a positioning ring 31, a plurality of support rods 32 and a plugging airbag 33. The positioning ring 31 is sleeved outside the inner catheter 10. A plurality of support rods 32 are all fixed outside the positioning ring 31, and the plurality of support rods 32 are annularly arrayed outside the positioning ring 31. The plugging airbag 33 is arranged between the inner catheter 10 and the positioning ring 31, and both between the plugging airbag 33 and the inner catheter 10 and between the plugging airbag 33 and the positioning ring 31 are fixedly connected. In the initial state, the support rods 32 are in a straight segment shape. In the working state, the support rods 32 undergo elastic deformation. The second medium delivery hole 14 is opened on the outside of the inner catheter 10. Avoidance through holes are opened on both the positioning ring 31 and the plugging airbag 33. At least one cavity inside the plugging airbag 33 and the inner catheter 10 is interconnected through the second medium delivery hole 14. Among them, the above-mentioned cavity is denoted as the fifth cavity, and the fifth cavity is connected to the ablation instrument.

[0067] Furthermore, the material of the plugging airbag 33 is one of the following materials: polytetrafluoroethylene or other non-ductile polymer materials. Preferably, in this embodiment, the material of the plugging airbag 33 is polytetrafluoroethylene.

[0068] It should be noted that in this instance, when the device is in the initial state, the plugging component is in the retracted form. When the device is in the working state, the plugging component is in the extended form. After the plugging airbag 33 is inflated with a gas medium and transforms into the extended form, the surface area of the plugging airbag 33 does not change, and its material essence does not expand. It only changes from a deflated state to a full state. The change process can be referred to as an inflatable castle for children's entertainment. Moreover, the plugging airbag 33 in the extended form can be fully attached to the inner wall of the cavity.

[0069] Here, the first cavity, the second cavity, the third cavity, the fourth cavity, and the fifth cavity respectively correspond to different cavities inside the inner catheter 10, and the number of the first cavity, the second cavity, the third cavity, the fourth cavity, and the fifth cavity is at least one. The specific number can be adjusted according to actual clinical needs and will not be further limited here. In this instance, the plugging component in the extended form is in the shape of a frustum of a cone, and the opening directions of the two plugging components are close to each other.

[0070] In this embodiment, when cryoablation is performed on the patient's duodenum, the inner catheter 10 and the outer catheter 11 are pushed to the target position in the duodenum through a guide wire. The outer catheter 11 is kept stationary, and the inner catheter 10 is pushed. The inner catheter 10 drives the sealing assembly to move outside the outer catheter 11. A gas medium is input into the device through an ablation instrument. The gas medium is injected into the inside of the sealing balloon 33 through the fifth channel and the second medium delivery hole 14, causing the sealing balloon 33 to expand. The expanded sealing balloon 33 changes from the storage form to the extended form. Under the action of the gas medium, the expanded sealing balloon 33 will automatically adjust the position of the eccentric inner catheter 10 until the inner catheter 10 is located at the center of the duodenal inner wall. At the same time, the sealing balloon 33 drives the support rod 32 to undergo elastic deformation and forms a limit on the support rod 32. When the outer side of the sealing balloon 33 is in contact with the duodenal inner wall, an ablation closed space is formed through the cooperation of the two sealing balloons 33 and the duodenal inner wall. A cryoablation medium is input into the ablation closed space through an ablation instrument, and the duodenal inner wall located between the two sealing balloons 33 can be cryoablated. After the ablation is completed, the cryoablation medium and the gas medium inside the sealing balloon 33 in the ablation closed space are withdrawn through the ablation instrument, so that the sealing balloon 33 releases the limit on the support rod 32. The support rod 32 that has undergone elastic deformation will return to its original state and drive the sealing balloon 33 to closely fit outside the inner catheter 10. Furthermore, the support rod 32 and the sealing balloon 33 change from the extended form to the storage form. The inner catheter 10 and the outer catheter 11 are pushed, so that the sealing assembly moves to the next target position for repeated multi-segment ablation, and finally the cryoablation of the tissue in the entire duodenal cavity is completed, and the device can be taken out of the patient's body.

[0071] Embodiment Three

[0072] Please refer to again Figure 8 , a cryoablation system, including a cryoablation catheter according to any one of Embodiment One and an ablation instrument. The ablation instrument is connected to the cryoablation catheter. The ablation instrument includes a control module, a display module, an input module, a working medium module, a constant pressure module, a negative pressure module, and an impedance test module;

[0073] The control module can receive, process relevant data and send corresponding instructions;

[0074] The display module can display relevant data and information;

[0075] The input module can input relevant parameters and instructions;

[0076] The working medium module can deliver or withdraw the working medium to the cryoablation catheter. The working medium includes a cryoablation medium and a gas medium;

[0077] The constant pressure module can independently regulate the flow rates of the cryoablation medium and the gas medium respectively;

[0078] The negative pressure module can independently regulate the pressure inside the ablation sealed space and the plugging module respectively;

[0079] The impedance test module can test the impedance value of the support frame 21 in the first embodiment.

[0080] In a specific embodiment, when performing cryoablation on the inner wall of the patient's duodenum, the cryoablation catheter is reliably connected to the ablation instrument, the system is powered on and self-checked. After the self-check passes, the impedance test module starts to work. The cryoablation catheter is placed at the target position along with the guide wire. With the aid of medical auxiliary vision technology, it is judged whether the catheter reaches the target position, and then the outer catheter 11 is withdrawn, the plugging component is released, and it is judged by the impedance test module whether the plugging component is completely attached to the inner wall of the cavity. After the plugging component is completely attached to the inner wall of the cavity and an ablation sealed space is formed, the working medium module is started to input the cryogenic medium into the ablation sealed space. At the same time, the negative pressure module is turned on to ensure the stability of the cryoablation process. The flow rate of the cryogenic medium is controlled by the constant pressure module to avoid damage to the cavity by the cryogenic medium. After the cryogenic medium is used up and after a certain interval of time, hot steam is introduced for a period of time. The temperature of the hot steam can be adjusted according to requirements, and the adjustment range is 35°C to 85°C to facilitate the rewarming of the cavity tissue. Even a thermal ablation can be performed. Multiple segments of ablation are repeated. The length of the single ablation area can be set to 1 cm to 10 cm according to different cavity tissues and different ablation requirements. After multiple segments of ablation, the ablation of the entire cavity tissue is finally completed. The device is powered off to prevent the negative pressure module or the working medium module from continuing to work. The inner catheter 10 is pulled to move the plugging component into the outer catheter 11 and change from the extended form to the retracted form, and the device is withdrawn to complete the cryoablation of the inner wall of the duodenum.

[0081] Embodiment 4

[0082] An impedance measurement method, applicable to a cryoablation catheter according to any one of the first embodiments and a cryoablation system according to any one of the third embodiments, for judging whether the plugging component in the first embodiment is completely attached to the inner wall of the cavity, includes the following steps:

[0083] St1: The inner catheter 10 and the outer catheter 11 are transported to the target position in the duodenum, and the inner catheter 10 is pushed to change the support frame 21 and the plugging membrane 22 from the retracted form to the extended form;

[0084] St2: During a shorter time slice, a high-frequency micro-voltage signal is sequentially applied to the support frames 21 in different regions in a time-sharing manner. The impedance of each regional loop in the current time sequence is calculated by measuring the current on the loop within the current time slice. Among them, when the plugging assembly is in the retracted state, the support frames 21 (the regions not wrapped by the plugging film 22) are not in contact with the tissue, and the impedance of the support frames 21 is relatively high. When the plugging assembly is in the extended state, if the support frames 21 (the regions not wrapped by the plugging film 22) are in contact with the inner wall of the cavity, the impedance of the support frames 21 will decrease significantly.

[0085] It should be noted that if the preoperative preparation has been completed during the operation and the outer catheter 11 has completely withdrawn from the working area, the following judgments can be made by comparing the changes in impedance:

[0086] 1. If the impedance of all regions is significantly less than the initial impedance, then each support frame 21 and the inner wall of the cavity are in mutual contact, indicating that everything is going well and the ablation can be successfully performed;

[0087] 2. If, in the same plugging assembly, the impedance of several support frames 21 is significantly less than that of the other support frames 21, it indicates that the position of the inner catheter 10 has shifted, and the operator needs to slightly adjust the current catheter position to ensure that the impedance of all support frames 21 does not deviate significantly;

[0088] 3. If the impedance of all support frames 21 has not decreased or only the impedance of a small number of support frames 21 has decreased, it is considered that the selected model (size) of the plugging assembly may be too small to be applicable to cavity ablation.

[0089] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. The structures, devices, and operation methods not specifically described and explained in the present invention are implemented according to the conventional means in the art without special instructions and limitations.

Claims

1. A cryoablation catheter, characterized in that: The invention comprises an inner catheter (10) and an outer catheter (11), wherein the outer catheter (11) is coaxially sleeved on the outer side of the inner catheter (10), and the inner catheter (10) is configured as a multi-lumen structure, and further comprises: A plurality of blocking components, each of which is arranged on the outside of the inner catheter (10); Among them, in the initial state, the multiple blocking components and the inner catheter (10) are all located inside the outer catheter (11), and in the working state, the multiple blocking components and the inner wall of the intestine together form an ablation closed space, and the blocking components are configured so that when the ablation device inputs cooling medium into the ablation closed space, the blocking components can limit the scope of action of the freezing medium.

2. A cryoablation catheter according to claim 1, characterized in that: A plurality of first medium delivery holes (12) are provided on the outer side of the inner catheter (10), and the ablation closed space and at least one cavity inside the inner catheter (10) are connected to each other through the first medium delivery holes (12).

3. A cryoablation catheter according to claim 1, characterized in that: A plurality of negative pressure through holes (13) are provided on the outer side of the inner catheter (10), and the ablation closed space and at least one cavity inside the inner catheter (10) are connected to each other via the negative pressure through holes (13).

4. The cryoablation catheter according to claim 1, characterized in that: The blocking assembly comprises a plurality of support frames (21) and a blocking membrane (22); the plurality of support frames (21) are arranged in a circular array on the outside of the inner catheter (10), and no two adjacent support frames (21) are in contact with each other; the blocking membrane (22) is fixed to the outside of the plurality of support frames (21), and the blocking membrane (22) and the inner catheter (10) are fixedly connected.

5. A cryoablation catheter according to claim 4, characterized in that: The material of the blocking film (22) is one of the following materials: polyurethane and silica gel.

6. A cryoablation catheter according to claim 4, characterized in that: A plurality of avoidance notches (23) are provided on the outer side of the blocking film (22) and between two adjacent support frames (21).

7. The cryoablation catheter according to claim 1, characterized in that: The blocking assembly comprises a positioning ring (31), a plurality of support rods (32) and a blocking airbag (33); the positioning ring (31) is sleeved on the outer side of the inner catheter (10); the plurality of support rods (32) are fixed on the outer side of the positioning ring (31), and the plurality of support rods (32) are arranged in a circular array on the outer side of the positioning ring (31); the blocking airbag (33) is arranged between the inner catheter (10) and the positioning ring (31); and the blocking airbag (33) and the inner catheter (10) as well as the blocking airbag (33) and the positioning ring (31) are fixedly connected; in an initial state, the support rod (32) is in the form of a straight segment; in a working state, the support rod (32) undergoes elastic deformation.

8. A cryoablation catheter according to claim 7, characterized in that: A second medium delivery hole (14) is provided on the outer side of the inner catheter (10), and avoidance holes are provided on the positioning ring (31) and the blocking airbag (33), and the blocking airbag (33) and at least one cavity inside the inner catheter (10) are connected to each other through the second medium delivery hole (14).

9. The cryoablation catheter according to claim 7, characterized in that: The material of the blocking airbag (33) is polytetrafluoroethylene.

10. A cryoablation system, characterized in that: A cryoablation catheter and ablation device according to any one of claims 1 to 9, wherein the ablation device comprises a control module, a display module, an input module, a working fluid module, a constant pressure module, a negative pressure module and an impedance test module; The control module is capable of receiving and processing relevant data and sending corresponding instructions; The display module is capable of displaying relevant data and information; The input module is capable of inputting relevant parameters and instructions; The working medium module can deliver or extract working medium to the cryoablation catheter, and the working medium includes a freezing medium and a gas medium; The constant pressure module can regulate the flow rate of the freezing medium and the gas medium; The negative pressure module can regulate the pressure inside the ablation closed space and / or the blocking module; The impedance testing module is capable of testing the impedance value of the support frame (21).

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