Cryogenic ablation catheter and device

Abstract

The application relates to a kind of frozen ablation catheter and device, frozen ablation catheter includes outer tube, center tube and multiple deformable inner tubes, wherein: center tube is movably inserted in outer tube along its axial direction;Multiple inner tubes are inserted in outer tube and in first state, the distal end of inner tube is exposed to outer tube, and is connected to the distal end of center tube, and inner tube has ablation section, in response to the movement of center tube from distal end to proximal end relative to outer tube, multiple inner tubes can be switched from first state to second state, and multiple ablation sections form annular structure.The frozen ablation catheter provided by the application can form annular structure by multiple predetermined shape ablation sections, since multiple ablation sections forming annular structure have no fixed connection relationship, it can be suitable for the abutting of various shape blood vessel walls, and will not affect the flow of blood flow in blood vessel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a cryoablation catheter and device. BACKGROUND

[0002] Pulmonary artery is a blood vessel that transports blood from the heart to the lungs. Pulmonary hypertension (PH) is a chronic cardiovascular disease characterized by abnormal elevation of pulmonary arterial blood pressure (hypertension), which leads to changes in the hemodynamics of the patient's cardiopulmonary circulation, pulmonary arterial vascular remodeling, right heart hypertrophy, and functional failure. The gold standard for the diagnosis of pulmonary hypertension is the measurement of mean pulmonary arterial pressure ≥ 25 mmHg at sea level and at rest by right heart catheterization, while the pulmonary arteriolar wedge pressure is ≤ 15 mmHg and the pulmonary vascular resistance is > 3 Wbod units. Experimental data show that pulmonary hypertension is related to increased excitability of the sympathetic nerves around the pulmonary artery and abnormal activity of the pulmonary arterial pressure receptors. Blocking the sympathetic nerves around the pulmonary artery or permanently destroying the structure and function of the pressure receptors can lower the pulmonary arterial pressure, which will become a breakthrough technology for the treatment of pulmonary hypertension, such as pulmonary artery denervation (PADN), which is a method for reducing sympathetic nerve stimulation of the pulmonary vessels. Studies have shown that in patients with pulmonary hypertension, there is an increase in plasma norepinephrine levels, increased excitability of muscle sympathetic nerves, and an increase in vascular sympathetic nerve endings. Therefore, the neurohumoral axis has been recognized as a potential therapeutic target. The principle of PADN is to block the sympathetic nerves in the intima of the pulmonary vessels using energy ablation to reduce pulmonary arterial pressure and slow disease progression. This minimally invasive intervention will provide a new means for the treatment of pulmonary hypertension.

[0003] In the existing pulmonary artery denervation by cryoablation, low-temperature energy is usually generated by spraying and releasing a low-temperature medium in a balloon. During the release of the low-temperature medium, a large load will be generated inside the balloon, which cannot be withstood by ordinary balloons. Therefore, the existing cryoablation system has serious and uncontrollable risk factors. Moreover, the traditional balloon structure needs to be expanded to adhere to the tissue, so the traditional cryoballoon will directly block the blood flow during ablation, causing corresponding complications. SUMMARY

[0004] Therefore, it is necessary to provide a cryoablation catheter and device to solve the problems that the cryoballoon needs to withstand a large load during the release of the low-temperature medium and blocks the blood flow.

[0005] A cryoablation catheter, the cryoablation catheter comprising:

[0006] an outer tube having opposite distal and proximal ends in its axial direction;

[0007] a central tube movably inserted into the outer tube along its axial direction;

[0008] a plurality of deformable inner tubes, each of the inner tubes being inserted into the outer tube and in a first state, a distal end portion of the inner tube being exposed from the outer tube and connected to a distal end portion of the central tube, the inner tube having an ablation segment, wherein, in response to a movement of the central tube relative to the outer tube from a distal end toward a proximal end, the plurality of inner tubes can be switched from the first state to a second state in which the plurality of ablation segments form a ring structure.

[0009] In one of the embodiments, in the second state, in response to a movement of the central tube relative to the outer tube from the proximal end toward the distal end, the plurality of inner tubes can be switched from the second state to the first state.

[0010] In one of the embodiments, in the first state, a combined projection of the plurality of inner tubes along any cross section of the central tube in a radial direction is inside the outer tube.

[0011] In one of the embodiments, in the first state, the inner tube as a whole or at least partially abuts against an outer wall of the central tube.

[0012] In one of the embodiments, the inner tube further has a first support segment and a second support segment, the first support segment and the second support segment being connected to two end portions of the ablation segment respectively, the first support segment being inserted into the outer tube, and the second support segment being connected to a distal end portion of the central tube away from the end portion of the ablation segment.

[0013] In the second state, the plurality of first support segments are distributed in a circumferential direction of the central tube and form a first corner with the ablation segment, and the plurality of second support segments are distributed inside the ring structure formed by the plurality of ablation segments and form a second corner with the ablation segment.

[0014] In one of the embodiments, the first corner and / or the second corner is an obtuse angle.

[0015] In one of the embodiments, the plurality of ablation segments are sequentially connected end to end to form the ring structure; or,

[0016] In the extension direction of the ablation segment, the plurality of ablation segments partially overlap, and the remaining portions of the plurality of ablation segments are connected to form the ring structure.

[0017] In one of the embodiments, the connection between the inner tube, the central tube and the outer tube is a sealed structure.

[0018] In one of the embodiments, the inner tube is made of a shape memory material and exhibits super-elasticity in a physiological environment.

[0019] In one of the embodiments, the distal end portion of the inner tube is connected to the end of the distal side of the central tube.

[0020] In one of the embodiments, the central tube has a reflux cavity, and the inner tube is in communication with the reflux cavity.

[0021] In one of the embodiments, the cryoablation catheter further comprises a handle connected to the proximal end of the outer tube, the handle is provided with an air inlet tube and an air outlet tube, the air inlet tube is in communication with the proximal end of the inner tube, and the air outlet tube is in communication with the reflux cavity.

[0022] In one of the embodiments, the handle has a receiving cavity for accommodating the inner tube and the outer tube, and a sliding knob is arranged on the handle, the sliding knob is connected to the proximal end portion of the central tube.

[0023] In one of the embodiments, the handle is provided with a connector, the connector is provided with at least one air inlet and at least one air outlet, the air inlet is connected to the air inlet tube, and the air outlet is connected to the proximal end of the inner tube.

[0024] In one of the embodiments, the connector is provided with a check valve arranged at the air inlet and / or the air outlet.

[0025] In one of the embodiments, the central tube further has a guide wire lumen for a guide wire to pass through.

[0026] In one of the embodiments, the cryoablation catheter further comprises a temperature sensor arranged at the ablation section for sensing the temperature of the refrigerant flowing in the ablation section.

[0027] In one of the embodiments, the cryoablation catheter further comprises a pressure sensor arranged at the end of the distal end portion of the central tube for sensing the pressure of the refrigerant flowing in the inner tube.

[0028] A cryoablation device, comprising:

[0029] a cold source;

[0030] The cryoablation catheter according to any one of the above technical solutions is connected to the cold source.

[0031] The above-mentioned cryoablation catheter and device, when the center tube is moved from the distal end to the proximal end relative to the outer tube, the center tube pulls the inner tube to bend according to the predetermined shape, and the plurality of ablation segments form a ring structure and abut against the blood vessel wall. The cryoablation catheter provided in the present application can form a ring structure through a plurality of ablation segments with a predetermined shape, and the inner tube does not need to be radially deformed and expanded during the flow of the refrigerant, so the inner tube bears less load, which can prevent the inner tube from rupturing due to excessive expansion deformation. At the same time, since the plurality of ablation segments forming the ring structure have no fixed connection relationship, the ablation segments have a large deformation / displacement space when subjected to external force, which can be suitable for abutting against blood vessel walls of various shapes. In addition, the hollow part in the ring structure can supply blood flow, so the blood flow in the blood vessel will not be affected during the ablation process, thereby avoiding the risk of blocking blood flow caused by the use of a balloon structure in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A structure schematic diagram of the cryoablation catheter provided in some embodiments in a second state.

[0033] Figure 2 A front view of the cryoablation catheter provided in some embodiments in a first state.

[0034] Figure 3 A Figure 2 A sectional view in A-A direction.

[0035] Figure 4 A front view of the handle provided in some embodiments.

[0036] Figure 5 A front view of the connector provided in some embodiments.

[0037] REFERENCE SIGNS:

[0038] 100, cryoablation catheter;

[0039] 110, outer tube;

[0040] 120, center tube; 121, backflow cavity; 122, guide wire cavity;

[0041] 130, inner tube; 131, ring structure; 132, ablation segment; 133, first support segment; 134, second support segment; 135, first corner; 136, second corner;

[0042] 140, handle; 141, air inlet tube; 142, air outlet tube; 143, accommodating cavity; 144, push block; 145, sliding groove; 146, connector; 1461, air inlet; 1462, air outlet; 147, guide wire inlet. DETAILED DESCRIPTION

[0043] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described herein and by one of ordinary skill in the art without departing from the spirit and scope of the present application, and therefore the present application is not limited to the following disclosed specific embodiments.

[0044] In the description of the present application, it should be understood that, if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0045] In addition, if these terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features referred to. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0046] In the present application, unless otherwise explicitly specified and limited, if the terms "mounting", "connecting", "connecting", "fixing" and the like appear, these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] In the present application, unless specifically defined and limited otherwise, if there is a description of a first feature "on" or "under" a second feature, it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "over", "above" and "on top of" the second feature can mean that the first feature is directly above or obliquely above the second feature, or only means that the first feature is horizontally higher than the second feature. The first feature "under", "below" and "underneath" the second feature can mean that the first feature is directly below or obliquely below the second feature, or only means that the first feature is horizontally lower than the second feature.

[0048] It should be noted that if an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or there can be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for illustrative purposes and do not mean the only implementation.

[0049] The technical solutions provided by the embodiments of the present application will be described below with reference to the drawings.

[0050] The proximal end described in the present application refers to the end close to the surgical operator, and the distal end refers to the end away from the surgical operator.

[0051] As Figure 1 With Figure 2 As shown in the drawings, the present application provides a cryoablation catheter 100, which comprises an outer tube 110, a center tube 120 and a plurality of deformable inner tubes 130, and is configured to ablate the pulmonary artery orifice. The outer tube 110 has opposite distal and proximal ends in its axial direction, in other words, the outer tube 110 has two opposite ends in its extension direction, one of which is the distal end of the outer tube 110, and the other is the proximal end of the outer tube 110. The center tube 120 is movably inserted into the outer tube 110 along its axial direction, as in the present embodiment, the proximal end of the center tube 120 is inserted into the outer tube 110, and the distal end of the center tube 120 is exposed from the distal end of the outer tube 110.

[0052] The inner tube 130 has a delivery cavity (not shown in the drawings) for the passage and flow of a refrigerant (such as N2O, N2 flow, etc. cooling medium), and the proximal end of the plurality of inner tubes 130 is inserted into the outer tube 110 and in a first state (see Figure 2), to achieve the fixed connection between the proximal end portions of the plurality of inner tubes 130 and the outer tube 110, the distal end portions of the plurality of inner tubes 130 are exposed from the distal end portion of the outer tube 110, and the distal end portions of the plurality of inner tubes 130 are connected to the distal end portion of the center tube 120. The inner tube 130 has an ablation section 132, and in this embodiment, the ablation section 132 is located in the middle section of the inner tube 130. Since the middle section of the inner tube 130 has a larger deformation amount than the two ends during bending of the inner tube 130, arranging the ablation section 132 in the middle section of the inner tube 130 can enable the ablation section 132 to better adapt to the lesion site during bending of the inner tube 130. In this embodiment, in the first state, the cryoablation catheter 100 is preferably in a long strip shape as a whole, i.e., the width of the cryoablation catheter 100 in the radial direction is minimized, facilitating insertion and withdrawal of the cryoablation catheter 100 at the lesion site. Of course, in other feasible embodiments, the cryoablation catheter 100 can also be in a tapered structure in the first state, as long as it can be inserted into or withdrawn from the lesion site.

[0053] In the above embodiment, when the cryoablation operation on the pulmonary artery orifice is required, the cryoablation catheter 100 is inserted into and positioned at the lesion site in the first state, the center tube 120 is moved from the distal end to the proximal end relative to the outer tube 110, i.e., the center tube 120 is moved towards the direction of being inserted into the inside of the outer tube 110, and the center tube 120 pulls the inner tube 130 to bend according to the predetermined shape. At this time, the plurality of inner tubes 130 can be switched from the first state to the second state in which the plurality of ablation sections 132 form the annular structure 131, as shown in Figure 1 , the plurality of ablation sections 132 form the annular structure 131 and abut against the blood vessel wall, the cryogen is delivered towards the inner tube 130, and the cryogen flowing in the ablation section 132 ablates the lesion site and forms a continuous ablation lesion. In this embodiment, the number of inner tubes 130 is preferably three, which can improve the stability of the ablation section 132 during ablation on the basis of ensuring a larger deformation amount of the ablation section 132. Of course, in other feasible embodiments, the number of inner tubes 130 can also be two, four or other numbers. For example, when the area of the lesion site to which the ablation section 132 abuts is large, the number of inner tubes 130 can be set to be larger, and for example, when the area of the lesion site to which the ablation section 132 abuts is small, the number of inner tubes 130 can be set to be smaller.

[0054] The researchers found that the existing cryoablation catheter sprays the refrigerant and expands the balloon to adhere to the lesion site to perform the cryoablation operation, but the refrigerant sprays the balloon to bear a large load, and the balloon is prone to rupture during the deformation process. Therefore, the existing cryoablation catheter has high requirements for the material of the balloon, and the deformation amount of the balloon is limited. When the balloon is adhered to the lesion site, the excessive pressure generated by the balloon on the lesion site will block the blood flow and cause corresponding complications. Based on the above reasons, the cryoablation catheter 100 provided by the application can form a ring structure 131 through a plurality of predetermined shape ablation segments 132. During the flow of the refrigerant, the inner tube 130 does not need to be radially deformed and expanded, so the inner tube 130 bears a smaller load and can prevent the inner tube 130 from rupturing due to excessive expansion and deformation. At the same time, since the plurality of ablation segments 132 forming the ring structure 131 have no fixed connection relationship, that is, there is no connection relationship between the adjacent two ablation segments 132, the ablation segment 132 has a larger deformation / displacement space when subjected to external force, and can be suitable for adhering to various shapes of blood vessel walls. The hollow part in the ring structure 131 can supply blood flow, so the ablation process will not affect the flow of blood in the blood vessel, preventing the inner tube 130 from blocking the blood flow during the cryoablation process, and avoiding the risk of blood flow obstruction caused by the use of the balloon structure in the prior art.

[0055] In an embodiment, as shown in Figure 1 and Figure 2 , when the plurality of ablation segments 132 are in the second state, the plurality of inner tubes 130 can be switched from the second state to the first state when the center tube 120 moves from the proximal end to the distal end relative to the outer tube 110. At this time, the cryoablation catheter 100 is in a long strip shape as a whole, which facilitates the withdrawal of the cryoablation catheter 100 from the lesion site of the patient after the completion of the cryoablation operation.

[0056] Further, as shown in Figure 1 and Figure 2 , in the first state, the combination of the plurality of inner tubes 130 is projected inside the outer tube 110 along any cross section of the center tube 120 in the radial direction, that is, during the process of inserting and withdrawing the cryoablation catheter 100 from the lesion site of the patient, the inner tube 130 and the center tube 120 are located inside the outer tube 110, and the cryoablation catheter 100 is in a long strip shape as a whole. To improve the smoothness of the insertion and withdrawal of the cryoablation catheter 100 from the lesion site of the patient, facilitate the operation of inserting and withdrawing the cryoablation catheter 100 from the lesion site of the patient.

[0057] In an embodiment, as shown in Figure 2As shown, in the first state, the inner tube 130 entirely or at least partially abuts against the outer wall of the center tube 120, i.e. the inner tube 130 partially or entirely abuts against the outer wall of the center tube 120, so that the combined inner tube 130 projects inside the outer tube 110 along any cross section of the center tube 120 in the radial direction, and the cryoablation catheter 100 as a whole has a long strip shape, facilitating the extension of the cryoablation catheter 100 to the lesion site of the patient, or facilitating the withdrawal of the cryoablation catheter 100 from the lesion site after the ablation operation is completed.

[0058] Further, as shown in Figure 2 the first state, the inner tube 130 entirely abuts against the outer wall of the center tube 120, i.e. the inner tube 130 abuts against the outer wall of the center tube 120 without gap in the axial direction, so that the outer diameter of the cryoablation catheter 100 as a whole is minimized in the first state, facilitating the extension of the cryoablation catheter 100 to the lesion site of the patient, or facilitating the withdrawal of the cryoablation catheter 100 from the lesion site of the patient after the ablation operation is completed.

[0059] In order to improve the stability of the ablation section 132 during the ablation process, in an embodiment, as shown in Figure 1 and Figure 2 the inner tube 130 further has a first support section 133 and a second support section 134. The first support section 133 and the second support section 134 are respectively connected to the two end portions of the ablation section 132, i.e. the inner tube 130 comprises the first support section 133, the ablation section 132 and the second support section 134 connected in sequence. The first support section 133 is inserted into the outer tube 110, and the distal end portion of the first support section 133 is exposed from the distal end portion of the outer tube 110, and the second support section 134 is connected to the distal end portion of the center tube 120 away from the end portion of the ablation section 132.

[0060] In the second state, the inner tube 130 is bent according to the predetermined shape by the center tube 120, and a plurality of first support sections 133 in the inner tube 130 after the predetermined shaping are distributed at intervals in the circumferential direction of the center tube 120, and first corners 135 are formed by bending between the first support sections 133 and the ablation sections 132. As in the present embodiment, the first support sections 133 on the same inner tube 130 are not coplanar with the ablation sections 132 after the predetermined shaping, and the plurality of first support sections 133 can form a conical structure to support the annular structure 131 formed by the plurality of ablation sections 132. Similarly, a plurality of second support sections 134 in the inner tube 130 after the predetermined shaping are distributed at intervals inside the annular structure 131 formed by the plurality of ablation sections 132, and second corners 136 are formed by bending between the second support sections 134 and the ablation sections 132, and the plurality of second support sections 134 and the annular structure 131 form a hub structure to support the annular structure 131 formed by the plurality of ablation sections 132. The above-mentioned cryoablation catheter 100, the plurality of first support sections 133 and the plurality of second support sections 134 can jointly support the annular structure 131 formed by the plurality of ablation sections 132, improve the stability of the ablation sections 132 during the ablation process, and further improve the reliability of the ablation sections 132 and the lesion position.

[0061] It should be noted that when the center tube 120 moves from the proximal end to the distal end relative to the outer tube 110, the first support section 133, the ablation section 132, and the second support section 134 can all abut against the outer wall of the center tube 120, facilitating the withdrawal operation of the cryoablation catheter 100 from the lesion position of the patient.

[0062] Further, as shown in Figure 1 , the first corner 135 and / or the second corner 136 is an obtuse angle, that is, in an embodiment, only the first corner 135 is an obtuse angle, in another embodiment, only the second corner 136 is an obtuse angle, and in still another embodiment, the first corner 135 and the second corner 136 are both obtuse angles. The above-mentioned cryoablation catheter 100, the first corner 135 formed by bending between the first support section 133 and the ablation section 132 and / or the second corner 136 formed by bending between the second support section 134 and the ablation section 132 is an obtuse angle, which can ensure that the overall smoothness of the bent inner tube 130 is high, improve the uniformity of the flow rate of the refrigerant in the inner tube 130, and facilitate the flow of the refrigerant into the reflux cavity of the center tube 120.

[0063] In an embodiment, as shown in Figure 1As shown, the plurality of ablation segments 132 are sequentially connected end to end to form the annular structure 131, i.e. when the inner tube 130 performs the cryoablation operation on the lesion site, the two ends of the ablation segment 132 are respectively adjacent to the ends of the two ablation segments 132 adjacent thereto, so that the annular structure 131 formed by the plurality of ablation segments 132 can completely ablate the lesion site. In another embodiment, in the extension direction of the ablation segment 132, the plurality of ablation segments 132 partially overlap, and the remaining part of the plurality of ablation segments 132 are connected to form the annular structure 131 to ablate the lesion site. As in the present embodiment, the two ends of the two adjacent ablation segments 132 overlap, and the other part of the plurality of ablation segments 132 are connected to form the annular structure 131.

[0064] In order to improve the ablation effect of the ablation segment 132 on the lesion site, in an embodiment, as shown in Figure 1 With Figure 2 As shown, the connection between the inner tube 130 and the center tube 120 inserted into the outer tube 110 is a sealing structure, which can improve the reliability of the fixed connection between the proximal end of the inner tube 130 and the outer tube 110, and prevent the blood flowing in the blood vessel from flowing back to the outer tube 110. As shown, a sealing ring can be provided at the connection between the inner tube 130 and the center tube 120 inserted into the outer tube 110, so that the inner tube 130 is fitted to the outer tube 110 without gaps, improving the stability of the inner tube 130 after being bent to a predetermined shape, and thus the annular structure 131 formed by the plurality of ablation segments 132 can better abut the lesion site, improving the ablation effect of the ablation segment 132 on the lesion site. It should be noted that when the sealing structure is provided at the connection between the inner tube 130 and the center tube 120 inserted into the outer tube 110, since the inner tube 130 is located outside the center tube 120, i.e. the outer wall of the inner tube 130 is close to the inner wall of the outer tube 110, and the center tube 120 does not contact the outer tube 110, the proximal end of the inner tube 130 is fixed to the outer tube 110 and cannot move, but the provided sealing structure does not affect the movement of the center tube 120 relative to the outer tube 110, so that the center tube 120 can switch the cryoablation catheter 100 between the first state and the second state during movement.

[0065] In order to make the plurality of ablation segments 132 be able to form the annular structure 131, in an embodiment, as shown in Figure 1 With Figure 2As shown, the distal end portion of the inner tube 130 is made of a shape memory material, and the inner tube 130 exhibits super-elasticity under a physiological environment. Such shape memory material can include shape memory alloy and / or shape memory polymer, such as the inner tube 130 is made of nickel-titanium alloy, copper-based alloy and / or other materials capable of controllable deformation, which allows the inner tube 130 to be deformed into different geometric configurations, shapes and / or sizes, etc. Due to the shape memory property of the inner tube 130, the ablation segments 132 can always maintain a predetermined shape during the bending and expansion of the inner tube 130, i.e. the ablation segments 132 can return to the predetermined annular structure 131 to perform ablation, and the inner tube 130 exhibits super-elasticity under a physiological temperature, so that the ablation segments 132 can better adhere to the lesion site after forming the annular structure 131, improving the ablation effect of the ablation segments 132 on the lesion site.

[0066] In an embodiment, as shown in Figure 1 With Figure 2 As shown, the distal end portion of the inner tube 130 is connected to the end of the distal side of the center tube 120. In this embodiment, the ablation segments 132 are located in the middle position of the inner tube 130, and the distal end portion of the inner tube 130 is connected to the end of the distal side of the center tube 120, so that the ablation segments 132 have more deformation / displacement space during the traction of the center tube 120, to improve the adaption of the ablation segments 132 to the different shape of the vessel wall.

[0067] In order to ablate the lesion site, in an embodiment, as shown in Figure 2 With Figure 3 As shown, the center tube 120 has a reflux cavity 121, and the inner tube 130 is connected to the reflux cavity 121, i.e. the inner tube 130 and the center tube 130 form a circulation loop for the refrigerant to flow, so that the refrigerant flows in the ablation segments 132 of the inner tube 130 to ablate the lesion site.

[0068] Continuing to refer to Figure 4The cryoablation catheter 100 further comprises a handle 140 connected to the proximal end of the outer tube 110, and the operator can hold the handle 140 to push or withdraw the cryoablation catheter 100 to the lesion site. The handle 140 is provided with an air inlet pipe 141 and an air outlet pipe 142 by screwing, inserting or the like, the air inlet pipe 141 is in communication with the proximal end of the plurality of inner tubes 130, for example, the plurality of inner tubes 130 can be directly inserted into the air inlet pipe 141, and the air outlet pipe 142 is in communication with the reflux cavity 121, that is, the air outlet pipe 142 is in communication with the proximal end of the central tube 120, for example, the central tube 120 can be directly inserted into the air outlet pipe 142. The refrigerant can be delivered to the inner tube 130 through the air inlet pipe 141, and the refrigerant flows in the inner tube 130 to ablate the lesion site, and the refrigerant continues to flow through the reflux cavity 121 to return to the air outlet pipe 142, that is, the air inlet pipe 141, the inner tube 130, the reflux cavity 121 and the air outlet pipe 142 can form a circulating loop for the refrigerant to flow, the air outlet pipe 142 can recycle the refrigerant after ablation, avoid the loss of refrigerant, improve the utilization rate of refrigerant, and continuously supplement the refrigerant to the inner tube 130 through the air inlet pipe 141, so as to ensure that the refrigerant in the ablation section 132 always maintains a lower temperature, and improve the ablation effect of the cryoablation catheter 100 on the lesion site.

[0069] Further, as shown in Figures 2-5 The handle 140 is provided with a connector 146, for example, in this embodiment, the connector 146 is arranged on one side of the handle 140 close to the outer tube 110. The connector 146 is provided with at least one air inlet 1461 and at least one air outlet 1462, the air inlet 1461 is connected to the air inlet pipe 141, for example, the air inlet pipe 141 is connected to the air inlet 1461 by screwing, inserting or the like, and the air outlet 1462 is connected to the proximal end of the inner tube 130, for example, the inner tube 130 is connected to the air outlet 1462 by screwing, inserting or the like. The air inlet 1461 is connected to the cold source (not shown in the figure) through the air inlet pipe 141, and the refrigerant in the cold source is delivered to the inner tube 130 through the air inlet pipe 141, the air inlet 1461 and the air outlet 1462 in turn to perform cryoablation treatment on the lesion site.

[0070] In this embodiment, the connector 146 can be a multi-way connector, for example, the connector 146 is a three-way connector, that is, the connector 146 has one air inlet 1461 and three air outlets 1462, one air inlet 1461 can be directly connected to the air inlet pipe 141, and three air outlets 1462 can be respectively connected to three inner tubes 130, the air inlet 1461 and the air outlet 1462 can allow the refrigerant to be delivered to the three inner tubes 130 to perform cryoablation treatment on the lesion site. When the connector 146 is other forms of multi-way connector, the connection can be made according to the above provided embodiments, which will not be described here.

[0071] To prevent the backflow of the refrigerant, in an embodiment, as shown in Figures 2-5 , a check valve (not shown in the figure) is arranged on the connecting head 146, which can be a one-way valve. The check valve is arranged at the air inlet 1461 and / or the air outlet 1462. The check valve can only allow the refrigerant in the air inlet pipe 141 to flow in the direction of being delivered to the inner tube 130. By arranging the check valve on the connecting head 146, the adverse phenomenon of backflow of the refrigerant during the flow can be prevented, so as to ensure that the refrigerant flows in the inner tube 130 at a certain flow rate, thereby ensuring the ablation effect of the refrigerant in the inner tube 130 on the lesion site.

[0072] In an embodiment, as shown in Figure 1 , Figure 2 and Figure 4 , the handle 140 has a receiving cavity 143 for receiving a plurality of inner tubes 130 and an outer tube 110, so that the plurality of inner tubes 130 and the outer tube 110 can be inserted and connected to the outer tube 110. A push block 144 is arranged on the handle 140 and is slidable on the handle 140. The push block 144 is connected to the proximal end portion of the central tube 120. In this embodiment, a sliding groove 145 is formed in the handle 140, and the push block 144 is arranged in the sliding groove 145 in the axial direction of the central tube 120. Since the proximal end portion of the central tube 120 is inserted into the outer tube 110, the cryoablation catheter 100 does not reserve the operation space of the central tube 120 for the operator. At this time, the operator can act on the push block 144 by pushing, pulling, and pushing, so that the push block 144 slides in the sliding groove 145 in the axial direction of the central tube 120 and drives the central tube 120 to move in the axial direction of the outer tube 110, that is, to switch the cryoablation catheter 100 between the first state and the second state, so as to drive the inner tube 130 to abut against the outer wall of the central tube 120, facilitate the insertion and withdrawal operation of the cryoablation catheter 100, or drive the plurality of ablation segments 132 to form the annular structure 131 for ablation treatment of the lesion site.

[0073] To facilitate the pushing of the cryoablation catheter 100, in an embodiment, as shown in Figure 2 and Figure 3 , the central tube 120 further has a guide wire cavity 122 for the passage of a guide wire (not shown in the figure). A guide wire inlet 147 is arranged on the handle 140, and the guide wire cavity 122 is in communication with the guide wire inlet 147. When the cryoablation catheter 100 needs to be pushed to the lesion site, the guide wire is inserted into the guide wire cavity 122 through the guide wire inlet 147, so that the cryoablation catheter 100 can follow the guide wire to reach the lesion site. The guide wire plays a guiding and positioning role in the pushing of the cryoablation catheter 100, and facilitates the pushing operation of the operator to the lesion site of the cryoablation catheter 100.

[0074] In an embodiment, as shown in Figure 1 The cryoablation catheter 100 further comprises a temperature sensor (not shown in the figure) in an embodiment. The temperature sensor is arranged at the ablation section 132, and is configured to sense the temperature of the refrigerant flowing in the ablation section 132. Since the ablation treatment of the lesion site is mainly performed by the refrigerant flowing in the ablation section 132, arranging the temperature sensor at the ablation section 132 can more accurately provide the real-time temperature of the ablation treatment of the lesion site, so that the cryogenic source can control the flow of the refrigerant delivered to the inner tube 130 based on the temperature of the refrigerant in the ablation section 132. It should be noted that the number of temperature sensors can be multiple, and the multiple temperature sensors are arranged at intervals in the ablation section 132 to obtain the refrigerant temperature parameters of each region of the ablation section 132, improve the control accuracy of the refrigerant flow, and further improve the ablation effect of the ablation section 132 on the lesion site.

[0075] In an embodiment, as shown in Figure 1 The cryoablation catheter 100 further comprises a pressure sensor (not shown in the figure) in an embodiment. The pressure sensor is arranged at the end of the distal end portion of the central tube 120, and is configured to sense the pressure of the refrigerant flowing in the inner tube 130. By monitoring the pressure of the refrigerant flowing in the inner tube 130 in real time through the pressure sensor, it can be prevented that the refrigerant flow pressure is too large to damage the inner tube 130 and affect the ablation effect. Specifically, when the pressure sensor senses that the pressure of the annular structure 131 formed by the ablation section 132 acting on the lesion site is too large, the delivery amount of the refrigerant to the inner tube 130 can be reduced or stopped, and thus the pressure of the ablation section 132 acting on the lesion site is reduced, and the ablation treatment effect of the cryoablation catheter 100 on the lesion site is improved.

[0076] In addition, as shown in Figure 1 and Figure 2 The present application provides a cryoablation device (not shown in the figure). The cryoablation device comprises a cryogenic source and the cryoablation catheter 100 according to any one of the above technical solutions, and the cryoablation catheter 100 is connected to the cryogenic source, such as the proximal end of the inner tube 130 being connected to the cryogenic source.

[0077] When the cryoablation device is needed to perform cryoablation treatment on the lesion site, the cryoablation catheter 100 is extended into and positioned at the lesion site in the first state, the central tube 120 is moved from the distal end to the proximal end relative to the outer tube 110, the central tube 120 pulls the inner tube 130 to bend according to the predetermined shape, the plurality of ablation segments 132 form the annular structure 131 and abut against the blood vessel wall in the second state, the cold source delivers the refrigerant to the inner tube 130, and the refrigerant flowing in the ablation segments 132 ablates the lesion site and forms a continuous lesion. When the cryoablation treatment on the lesion site is completed, the cold source stops the delivery of the refrigerant, the rewarming fluid is input into the inner tube 130, and then the central tube 120 is moved from the proximal end to the distal end relative to the outer tube 110, the central tube 120 pulls the inner tube 130 to extend to the distal end and abut against the outer wall of the central tube 120, and the cryoablation catheter 100 is switched from the second state to the first state, so as to facilitate the withdrawal of the cryoablation catheter 100 from the lesion site of the patient.

[0078] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0079] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, some modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A cryoablation catheter, characterized in that, The cryoablation catheter includes: An outer tube having a distal end and a proximal end opposite each other in its axial direction; A central tube, which is movably inserted into the outer tube along its axial direction; Multiple deformable inner tubes are inserted into an outer tube in a first state, with the distal ends of the inner tubes exposed above the outer tube and connected to the distal end of a central tube. Each inner tube has an ablation segment. In response to movement of the central tube relative to the outer tube from distal to proximal, the multiple inner tubes can switch from the first state to a second state where multiple ablation segments form a ring structure. The inner tubes also have a first support segment and a second support segment, respectively connected to the two ends of the ablation segment. The first support segment is inserted into the outer tube, and the second support segment is located away from the outer tube. The end of the ablation segment is connected to the distal portion of the central tube; in the second state, a plurality of first support segments are spaced apart in the circumferential direction of the central tube and form a first corner with the ablation segment, a plurality of second support segments are spaced apart inside the annular structure formed by the plurality of ablation segments and form a second corner with the ablation segment, the first corner and / or the second corner are obtuse angles, and the plurality of ablation segments are connected end to end to form the annular structure; or, in the extension direction of the ablation segment, a plurality of ablation segments partially overlap, and the remaining portions of the plurality of ablation segments are connected to form the annular structure.

2. The cryoablation catheter according to claim 1, characterized in that, When multiple ablation segments are in the second state, in response to the movement of the central tube relative to the outer tube from the proximal end to the distal end, multiple inner tubes can switch from the second state to the first state.

3. The cryoablation catheter according to claim 1 or 2, characterized in that, In the first state, the combination of the multiple inner tubes is projected onto the interior of the outer tube at any cross section along the radial direction of the central tube.

4. The cryoablation catheter according to claim 3, characterized in that, In the first state, the inner tube is entirely or at least partially abutted against the outer wall of the central tube.

5. The cryoablation catheter according to claim 1, characterized in that, The connection between the inner tube and the central tube and the outer tube is a sealed structure.

6. The cryoablation catheter according to claim 1, characterized in that, The distal portion of the inner tube is made of shape memory material and exhibits superelasticity under physiological conditions.

7. The cryoablation catheter according to claim 1, characterized in that, The distal portion of the inner tube is connected to the distal end of the central tube.

8. The cryoablation catheter according to claim 7, characterized in that, The central tube has a reflux cavity, and the inner tube is connected to the reflux cavity.

9. The cryoablation catheter according to claim 8, characterized in that, The cryoablation catheter also includes a handle connected to the proximal end of the outer tube. The handle is provided with an air inlet tube and an air outlet tube. The air inlet tube is connected to the proximal ends of the plurality of inner tubes, and the air outlet tube is connected to the reflux chamber.

10. The cryoablation catheter according to claim 9, characterized in that, The handle has a receiving cavity for accommodating the inner tube and the outer tube, and a lever is slidably disposed on the handle, the lever being connected to the proximal portion of the central tube.

11. The cryoablation catheter according to claim 9, characterized in that, The handle is provided with a connector, which has at least one air inlet and at least one air outlet. The air inlet is connected to the air inlet pipe, and the air outlet is connected to the proximal end of the inner pipe.

12. The cryoablation catheter according to claim 11, characterized in that, A check valve is provided on the connector, and the check valve is located at the air inlet and / or the air outlet.

13. The cryoablation catheter according to claim 1, characterized in that, The central tube also has a guide wire cavity for the guide wire to pass through.

14. The cryoablation catheter according to claim 1, characterized in that, The cryoablation conduit also includes a temperature sensor, which is disposed in the ablation section to sense the temperature of the refrigerant flowing within the ablation section.

15. The cryoablation catheter according to claim 1, characterized in that, The cryoablation conduit also includes a pressure sensor, which is located at the end of the distal portion of the central tube and is used to sense the pressure of the refrigerant flowing inside the inner tube.

16. A cryoablation device, characterized in that, The cryoablation device includes: Cold source; The cryoablation catheter as described in any one of claims 1-15, wherein the cryoablation catheter is connected to the cold source.

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