Cryoablation catheter with telescopic head end and system

Abstract

The utility model relates to a cryoablation catheter with a telescopic head end and a system. The cryoablation catheter comprises a sheath tube, an air inlet tube, an air return tube, an inner tube, a balloon, the head end and a handle, the far end of the sheath tube is fixedly connected with the near end of the balloon, and the air inlet tube, the air return tube and the inner tube are all located in the sheath tube; the far end of the air inlet pipe and the far end of the air return pipe extend out of the far end of the sheathing canal, are arranged in the balloon and are in fluid communication with the balloon, and the far end of the inner pipe and the far end of the balloon are fixedly connected with the head end. The handle is connected to the near end of the sheath tube and provided with an air inlet connector, an air return connector and an adjusting mechanism, the air inlet connector and the air return connector are communicated with the air inlet tube and the air return tube respectively, and the adjusting mechanism is fixedly connected with the near end of the inner tube and can drive the inner tube to move front and back relative to the sheath tube so as to drive the head end to move towards the near end of the balloon. According to the embodiment of the invention, the distance between the ablation part of the balloon and the head end can be shortened, and the mapping position is close to the target position as far as possible during electric signal monitoring, so that the electric signal is more accurate.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a cryoablation catheter and system with a retractable tip. Background Technology

[0002] Cryoablation uses a cryo-medium to lower the temperature of the target ablation site (the diseased tissue), destroying its tissue cells and thus achieving the therapeutic goal. Currently, cryoablation is widely used not only in the field of atrial fibrillation (AF), but also in areas such as renal artery sympathetic nerves, tumors, arterial blood vessels, and pulmonary hypertension.

[0003] In the clinical treatment of atrial fibrillation using cryoballoon ablation to isolate the pulmonary veins, an irreversible ablation focus is created at the pulmonary vein orifice through cryoablation, preventing abnormal electrical signals from being conducted to the left atrium. To monitor in real time whether the abnormal electrical signals between the pulmonary veins and the left atrium are completely isolated, electrical signal monitoring at the pulmonary vein orifice is necessary.

[0004] Currently, during cryoablation of pulmonary veins, the mapping catheter extends beyond the tip of the cryoballoon. When the balloon is placed against the target location for ablation, there is a distance between the ablation portion of the balloon and the tip of the balloon catheter. This means the mapping catheter also needs to extend a distance into the blood vessel. Not only is the mapping location far from the target location, but sometimes the mapping catheter may also become kinked or entangled in the pulmonary vein. This results in poor contact between the mapping electrode and the pulmonary vein, significantly reducing the acquisition of electrical signals and making it impossible to accurately determine the treatment effect. Summary of the Invention

[0005] Based on this, this application provides a cryoablation catheter and system with a retractable tip.

[0006] One embodiment of this application provides a cryoablation catheter with a retractable tip, including a sheath, an inlet tube, a return tube, an inner tube, a balloon, a tip, and a handle; the distal end of the sheath is fixedly connected to the proximal end of the balloon, and the inlet tube, return tube, and inner tube are all located inside the sheath; the distal ends of the inlet tube and the return tube extend beyond the distal end of the sheath and are disposed inside the balloon and in fluid communication with the balloon, and the distal ends of the inner tube and the distal ends of the balloon are fixedly connected to the tip;

[0007] The handle is connected to the proximal end of the sheath. The handle is provided with an air inlet connector, an air return connector, and an adjustment mechanism. The air inlet connector and the air return connector are respectively connected to the air inlet pipe and the air return pipe. The adjustment mechanism is fixedly connected to the proximal end of the inner tube, and the adjustment mechanism can drive the inner tube to move back and forth relative to the sheath, thereby driving the head end to move towards the proximal end of the balloon.

[0008] In an alternative embodiment, as the head end moves toward the proximal end of the balloon, the head end is recessed into the balloon, and the distal surface of the balloon is annular.

[0009] In one alternative embodiment, the portion of the air intake pipe located inside the balloon has a plurality of jet holes.

[0010] In an alternative embodiment, the cryoablation catheter further includes an electrode catheter that extends from the tip of the inner tube.

[0011] In one alternative embodiment, the electrode conduit is one or more of a mapping conduit, a radio frequency conduit, and a pulsed electric field conduit.

[0012] In one alternative embodiment, the balloon is a compliant balloon or a semi-compliant balloon.

[0013] In one alternative embodiment, the balloon is a single-layer balloon or a double-layer balloon.

[0014] In an optional embodiment, the cryoablation catheter further includes a bending wire fixed inside the wall of the sheath, the distal end of the bending wire being connected to the distal end of the sheath, and the proximal end of the bending wire being connected to the bending unit of the handle.

[0015] Another embodiment of this application provides a cryoablation system, including a cryoablation device and the aforementioned cryoablation catheter. The cryoablation catheter is connected to the cryoablation device via a connector, and is used to deliver the refrigerant in the cryoablation device to the balloon through the air inlet connector, and to perform cryoablation.

[0016] Compared with the prior art, the advantages of the embodiments of this application are as follows:

[0017] 1. In this embodiment, the adjusting mechanism can move the inner tube back and forth relative to the sheath. When the inner tube moves towards the handle, it moves the tip towards the proximal end of the balloon, shortening the distance between the ablation site of the balloon and the tip. Therefore, during electrical signal monitoring, the mapping position can be as close as possible to the target position, resulting in more accurate electrical signals. Simultaneously, the shorter distance the mapping catheter extends into the blood vessel avoids problems such as kinking or entanglement in the pulmonary vein, allowing the mapping catheter to be completely close to the pulmonary vein opening, reducing electrical signal errors and making the electrical signals more accurate.

[0018] 2. When the tip of the ablation catheter in this embodiment is recessed into the balloon, the distal surface of the balloon can be annular. Therefore, the ablation catheter in this embodiment is suitable for ablation of the atrial wall, and can also be used to monitor the electrical signals of the atrial wall by the mapping catheter.

[0019] 3. The cryoablation catheter in this embodiment can be used in conjunction with mapping catheters, radiofrequency catheters, and pulsed electric field catheters. The annular structure on the distal end of the balloon can press against the working section of the mapping catheter, radiofrequency catheter, and pulsed electric field catheter, making it fit the target position more closely. It can not only realize cryoablation technology, but also combine mapping technology, radiofrequency ablation technology, and pulsed electric field ablation technology to realize multimodal ablation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a balloon catheter in the prior art.

[0021] Figure 2 This is a schematic diagram of another balloon catheter in the prior art.

[0022] Figure 3 This is a schematic diagram of the structure of a cryoablation catheter according to an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of a balloon with a toroidal distal surface according to an embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the cryoablation catheter according to another embodiment of this application.

[0025] Figure 6 This is a schematic diagram of the structure of a cryoablation system according to an embodiment of this application.

[0026] Figure label:

[0027] 100 - Cryoablation catheter; 200 - Cryoablation equipment;

[0028] 1-Sheath; 2-Inlet tube; 3-Return tube; 4-Inner tube; 5-Balloon; 6-Head end; 7-Handle; 8-Electrode catheter; 11-Inlet connector; 12-Return connector; 13-Adjustment mechanism; 14-Bending unit;

[0029] 201 - Human-computer interaction module; 202 - Control module; 203 - Pneumatic circuit module; Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0036] In existing cryoablation techniques for pulmonary veins, the mapping catheter extends beyond the tip of the cryoballoon. When the balloon is placed against the target location for ablation, a distance exists between the ablation portion of the balloon and the tip of the catheter. This means the mapping catheter must also extend a considerable distance into the blood vessel. Not only is the mapping location far from the target location, but problems such as kinking and entanglement of the mapping catheter within the pulmonary vein can also occur. Figure 1 , Figure 2 As shown, poor adhesion between the mapping electrode and the pulmonary vein significantly reduces the acquisition of electrical signals, making it impossible to accurately determine the treatment effect. Therefore, this application provides a cryoablation catheter and system with a retractable tip, which can shorten the distance between the balloon ablation section and the tip.

[0037] The technical solutions provided by the embodiments of this application are described below with reference to the accompanying drawings.

[0038] The proximal end, as described in this application, refers to the end closer to the surgical operator, while the distal end refers to the end farther away from the surgical operator.

[0039] like Figures 3-6 As shown, this application provides a cryoablation catheter 100 with a retractable tip, including a sheath 1, an inlet tube 2, a return tube 3, an inner tube 4, a balloon 5, a tip 6, and a handle 7; the distal end of the sheath 1 is fixedly connected to the proximal end of the balloon 5, and the inlet tube 2, the return tube 3, and the inner tube 4 are all located inside the sheath 1; the distal ends of the inlet tube 2 and the return tube 3 extend out of the distal end of the sheath 1 and are disposed inside the balloon 5 and in fluid communication with the balloon 5, and the distal ends of the inner tube 4 and the distal ends of the balloon 5 are fixedly connected to the tip 6;

[0040] The handle 7 is connected to the proximal end of the sheath 1. The handle 7 is provided with an air inlet connector 11, an air return connector 12, and an adjustment mechanism 13. The air inlet connector 11 and the air return connector 12 are respectively connected to the air inlet pipe 2 and the air return pipe 3. The adjustment mechanism 13 is fixedly connected to the proximal end of the inner tube 4, and the adjustment mechanism 13 can drive the inner tube 4 to move back and forth relative to the sheath 1, thereby driving the head end 6 to move towards the proximal end of the balloon 5.

[0041] In this embodiment, both the inlet connector 11 and the return connector 12 are connected to the cryoablation device to deliver or recover refrigerant (such as N2, N2O, liquid nitrogen, etc.) to the cryoablation conduit 100. The refrigerant in the cryoablation device enters the balloon 5 through the inlet pipe 2 via the inlet connector 11. After cryoablation is performed, the refrigerant is discharged from the return connector 12 via the return pipe 3.

[0042] In this embodiment, since the adjusting mechanism 13 can move the inner tube 4 back and forth relative to the sheath 1, when the inner tube 4 moves towards the handle 7, it moves the head end 6 towards the proximal end of the balloon 5, thereby shortening the distance between the ablation portion of the balloon 5 and the head end 6. Therefore, during electrical signal monitoring, the measured position can be as close as possible to the target position, resulting in more accurate electrical signals. Figure 3 As shown. At the same time, the distance the mapping catheter extends into the blood vessel is shortened, avoiding problems such as kinking or entanglement of the mapping catheter in the pulmonary vein. This allows the mapping catheter to be completely close to the pulmonary vein orifice, reducing errors in the electrical signal and making the electrical signal more accurate.

[0043] In an optional embodiment, as the head end 6 moves proximally to the balloon 5, the head end 6 is recessed into the balloon 5, and the distal surface of the balloon 5 is annular, such as... Figure 4 As shown. In this embodiment, since the tip 6 is retractable, when the tip 6 moves towards the proximal end of the balloon 5, the distal end of the balloon 5 is tucked in under the force, and the tip 6 is recessed into the balloon 5, making the distal surface of the balloon 5 annular. Therefore, the ablation catheter of this embodiment is also suitable for ablation of large-area lesions such as the atrial wall.

[0044] In this embodiment, the cryoablation catheter 100 further includes an electrode catheter 8, which extends from the inner tube 4 to its tip 6. Specifically, the electrode catheter 8 in this embodiment can be a mapping catheter, a radiofrequency catheter, or a pulsed electric field catheter. The tip 6 in this embodiment is also the TIP tip of the cryoballoon 5. During cryoablation of the pulmonary vein, when the electrode catheter 8 is a mapping catheter, since the mapping catheter needs to be deployed at a suitable position to monitor electrical signals, the distance between the ablation site of the balloon 5 and the tip 6 is shortened, making the mapping position as close to the target position as possible. Therefore, this embodiment can also achieve monitoring of the electrical signals of the atrial wall by the mapping catheter. When the electrode catheter 8 in this embodiment is a radiofrequency catheter or a pulsed electric field catheter, cryoablation plus radiofrequency ablation or a composite ablation of cryoablation plus pulsed electric field ablation can be achieved. Since the annular structure of the distal end of the balloon 5 can press against the working section of the mapping catheter, radiofrequency catheter, and pulsed electric field catheter, making it fit the target position better, there is no need to adjust the contact position significantly when performing composite ablation, thus improving ablation efficiency.

[0045] Optionally, the balloon 5 is a compliant balloon or a semi-compliant balloon. The balloon 5 can be a single-layer balloon or a double-layer balloon.

[0046] In another alternative embodiment, the portion of the air inlet pipe 2 located inside the balloon 5 has several jet holes. The jet holes allow for more even injection of refrigerant into the balloon, improving freezing efficiency.

[0047] In another alternative embodiment, the cryoablation catheter further includes a bending wire (not shown in the figure), which is fixed inside the wall of the sheath 1. The distal end of the bending wire is connected to the distal end of the sheath 1, and the proximal end of the bending wire is connected to the bending unit 14 of the handle 7. Figure 5 As shown. By setting the bending wires, the curvature of the sheath 1 can be adjusted, thereby adjusting the curvature of the balloon 5 for better fit with the target tissue. Furthermore, there are two bending wires, and the two bending wires are symmetrically located on both sides of the sheath 1. This allows for bidirectional bending of the balloon 5, making it more flexible to use.

[0048] Another aspect of this application provides a cryoablation system, referencing... Figure 6 The device includes a cryoablation device 200 and the aforementioned cryoablation catheter 100. The cryoablation catheter 100 is connected to the cryoablation device 200 via a connector and is used to deliver the refrigerant in the cryoablation device 200 to the balloon 5 through the air inlet connector 11 and perform cryoablation.

[0049] Specifically, in this embodiment, the cryoablation device 200 includes a human-machine interface module 201, a control module 202, and a gas path module 203. The human-machine interface module 201 is electrically connected to the control module 202, and the control module 202 is electrically connected to the gas path module 203. The gas path module 203 can be connected to the handle 7 of the cryoablation catheter 100 via a connector. Specifically, the gas path module 203 is connected to the inlet connector 11 and the return connector 12 on the handle 7 via connectors, respectively, for delivering or recovering refrigerant to the cryoablation catheter 100. During operation, the cryoablation device 200 is first started, and the cryoablation catheter 100 is inserted into the patient's body. The mapping catheter is pushed to the distal end of the cryoablation catheter 100 through the inner tube 4. Then, the control module 202 controls the gas path module 203 to start delivering refrigerant to the balloon 5. After the balloon 5 is filled with refrigerant, it expands inside the patient's body. Pull the bending unit 14 to adjust the bending angle of the sheath 1, then adjust the retraction degree of the tip 6 through the adjustment mechanism 13, so that the balloon 5 and the mapping catheter are close to the lesion, and then start the ablation operation. The ablation parameters are returned to the control module 202, processed by the control module 202 and finally fed back to the human-machine interaction module 201. After the ablation is completed, the operation control module 202 causes the gas circuit module 203 to stop the delivery of refrigerant and recover the refrigerant through the return gas pipe 3. Then the cryoablation catheter 100 is withdrawn from the human body.

[0050] The above is an exemplary description of a cryoablation system. In practical applications, the cryoablation device 200 may also employ other existing technologies, which will not be elaborated upon here.

[0051] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A head-extendable cryoablation catheter, comprising: The sheath tube, the air inlet tube, the air return tube, the inner tube, the balloon, the head end and the handle are included. The distal end of the sheath tube is fixedly connected with the proximal end of the balloon, the air inlet tube, the air return tube and the inner tube are located in the sheath tube, the distal ends of the air inlet tube and the air return tube extend out of the distal end of the sheath tube and are arranged in the balloon and in fluid communication with the balloon, the distal end of the inner tube and the distal end of the balloon are fixedly connected with the head end. The handle is connected with the proximal end of the sheath tube, the handle is provided with an air inlet connector, an air return connector and an adjusting mechanism, the air inlet connector and the air return connector are in communication with the air inlet tube and the air return tube respectively, the adjusting mechanism is fixedly connected with the proximal end of the inner tube, and the adjusting mechanism can drive the inner tube to move forward and backward relative to the sheath tube, thereby driving the head end to move towards the proximal end of the balloon.

2. The cryoablation catheter of claim 1, wherein, When the head end moves towards the proximal end of the balloon, the head end is recessed in the balloon, and the distal end face of the balloon is in the shape of a torus.

3. The cryoablation catheter of claim 1, wherein, The part of the air inlet tube located in the balloon has a plurality of air injection holes.

4. The cryoablation catheter of claim 1, wherein, The cryoablation catheter further comprises an electrode catheter which extends out of the head end through the inner tube.

5. The cryoablation catheter of claim 4, wherein, The electrode catheter is one or a combination of a mapping catheter, a radiofrequency catheter and a pulsed electric field catheter.

6. The cryoablation catheter of claim 1, wherein, The balloon is a conformable balloon or a semi-conformable balloon.

7. The cryoablation catheter of claim 1, wherein, The balloon is a single-layer balloon or a double-layer balloon.

8. The cryoablation catheter of claim 1, wherein, The cryoablation catheter further comprises a bending wire which is fixed in the tube wall of the sheath tube, the distal end of the bending wire is connected with the distal end of the sheath tube, and the proximal end of the bending wire is connected to a bending unit of the handle.

9. A cryoablation system, comprising: The cryoablation catheter is connected to the cryoablation device through a connector for conveying refrigerant in the cryoablation device to the balloon through the air inlet connector and performing cryoablation.

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