CN219940766U

CN219940766U - Cryoablation catheter and device

Info

Publication number: CN219940766U
Application number: CN202321551274.0U
Authority: CN
Inventors: 朱军
Original assignee: Cryofocus Medtech Shanghai Co Ltd
Current assignee: Cryofocus Medtech Shanghai Co Ltd
Priority date: 2023-06-16
Filing date: 2023-06-16
Publication date: 2023-11-03
Anticipated expiration: 2033-06-16

Abstract

The utility model relates to a cryoablation catheter and device, the cryoablation catheter comprises an outer tube, a central tube and a plurality of deformable inner tubes, wherein: the central tube is movably inserted into the outer tube along the axial direction of the central tube; the plurality of inner tubes are inserted into the outer tube and are in a first state, the distal end portions of the inner tubes are exposed out of the outer tube and are connected to the distal end portion of the central tube, the inner tubes are provided with ablation segments, and the plurality of inner tubes can be switched from the first state to a second state in which the plurality of ablation segments form an annular structure in response to movement of the central tube from the distal end to the proximal end relative to the outer tube. The cryoablation catheter provided by the utility model can form an annular structure through a plurality of preset ablation sections, and the plurality of ablation sections forming the annular structure have no fixed connection relation, so that the cryoablation catheter can be suitable for the adhesion of blood vessel walls with various shapes and can not influence the flow of blood flow in the blood vessel.

Description

Cryoablation catheter and device

Technical Field

The utility model relates to the technical field of medical appliances, in particular to a cryoablation catheter and a cryoablation device.

Background

Pulmonary arteries are the vessels that transport blood from the heart to the lungs. Pulmonary hypertension (pulmonary hypertension, PH) is a chronic cardiovascular disease characterized by abnormally elevated pulmonary blood pressure (hypertension) leading to altered hemodynamic circulation, pulmonary vascular remodeling, right heart hypertrophy, and failure of the patient. The gold standard for diagnosing pulmonary artery high pressure is that the average pulmonary artery pressure measured by the right heart catheter in the state of sea level is more than or equal to 25mmHg, and the pulmonary arteriole wedge pressure is less than or equal to 15mmHg and the pulmonary vascular resistance is more than 3Wood units. Experimental data demonstrate that pulmonary hypertension is associated with increased peripheral sympathetic excitability of the pulmonary artery and abnormal activation of pulmonary baroreceptors, and that blocking the peripheral sympathetic nerves of the pulmonary artery or permanently destroying the structure and function of baroreceptors can reduce pulmonary arterial depression, which would be a breakthrough technique for treating pulmonary hypertension, such as Pulmonary Artery Denervation (PADN), which is a method for reducing pulmonary vascular sympathetic nerve stimulation. Through research, symptoms such as increased plasma norepinephrine levels, increased muscle sympathetic excitability, increased vascular sympathetic nerve endings and the like have been shown in patients with pulmonary hypertension. Thus, the neurohormonal axis has been recognized as a potential therapeutic target. The principle of PADN is to block the sympathetic nerve of the intima of the pulmonary blood vessel by using energy ablation, thereby reducing the pulmonary artery pressure and delaying the disease progression. This minimally invasive intervention will provide a new means for pulmonary arterial hypertension intervention.

In the existing pulmonary artery denervation operation through cryoablation, low-temperature energy is usually generated based on the jet release of a low-temperature medium in a balloon, a large load is generated in the balloon during the release process of the low-temperature medium, and a common balloon cannot bear the high-temperature energy, so that the cryoablation system has serious and uncontrollable risk factors. And the traditional saccule structure needs to be expanded to be attached to tissues, so that the traditional freezing saccule can directly block blood flow in ablation to cause corresponding complications.

Disclosure of Invention

Based on this, it is necessary to provide a cryoablation catheter and device that address the problems of the cryoballoon that it is subjected to a large load during the release of the cryogenic medium and that it blocks blood flow.

A cryoablation catheter, the cryoablation catheter comprising:

an outer tube having opposite distal and proximal ends in an axial direction thereof;

the central tube is movably inserted into the outer tube along the axial direction of the central tube;

the inner tubes are inserted into the outer tube and are in a first state, the distal end portions of the inner tubes are exposed out of the outer tube and are connected to the distal end portion of the central tube, the inner tubes are provided with ablation sections, and the inner tubes can be switched from the first state to a second state in which the ablation sections form an annular structure in response to movement of the central tube relative to the outer tube from distal ends to proximal ends.

In one embodiment, in the second state, the plurality of inner tubes are switchable from the second state to the first state in response to proximal-to-distal movement of the central tube relative to the outer tube.

In one embodiment, in the first state, a combination of the plurality of inner tubes is projected inside the outer tube along any cross section of the central tube in the radial direction.

In one embodiment, in the first state, the inner tube is wholly or at least partially against the outer wall of the central tube.

In one embodiment, the inner tube further has a first support section and a second support section, the first support section and the second support section are respectively connected to two ends of the ablation section, the first support section is inserted into the outer tube, and an end of the second support section away from the ablation section is connected to a distal end portion of the central tube;

in the second state, a plurality of first support sections are distributed at intervals in the circumferential direction of the central tube, a first corner is formed between each first support section and each ablation section, and a plurality of second support sections are distributed at intervals inside an annular structure formed by the plurality of ablation sections, and a second corner is formed between each second support section and each ablation section.

In one embodiment, the first corner and/or the second corner is an obtuse angle.

In one embodiment, a plurality of ablation segments are sequentially connected end to form the annular structure; or alternatively, the first and second heat exchangers may be,

in the extending direction of the ablation segments, a plurality of the ablation segments are partially overlapped, and the rest parts of the plurality of the ablation segments are connected to form the annular structure.

In one embodiment, the joint of the inner tube and the central tube inserted in the outer tube is a sealing structure.

In one embodiment, the inner tube is made of a shape memory material and exhibits superelasticity in a physiological environment.

In one embodiment, the distal end portion of the inner tube is connected to the distal end portion of the center tube.

In one embodiment, the central tube has a return lumen, and the inner tube communicates with the return lumen.

In one embodiment, the cryoablation catheter further comprises a handle connected to the proximal end of the outer tube, the handle being provided with an air inlet tube in communication with the proximal ends of the plurality of inner tubes and an air outlet tube in communication with the flashback chamber.

In one embodiment, the handle is provided with a containing cavity for containing the inner tube and the outer tube, and a shifting block is slidably arranged on the handle and connected with the proximal end portion of the central tube.

In one embodiment, the handle is provided with a connector, at least one air inlet and at least one air outlet are arranged on the connector, the air inlet is connected with the air inlet pipe, and the air outlet is connected with the proximal end of the inner pipe.

In one embodiment, a check valve is arranged on the connector, and the check valve is arranged at the air inlet and/or the air outlet.

In one embodiment, the central tube further has a guidewire lumen for passage of a guidewire.

In one embodiment, the cryoablation catheter further comprises a temperature sensor disposed in the ablation segment for sensing a temperature of the refrigerant flowing within the ablation segment.

In one embodiment, the cryoablation catheter further comprises a pressure sensor disposed at an end of the distal portion of the central tube for sensing the pressure of the refrigerant flowing within the inner tube.

A cryoablation device, the cryoablation device comprising:

a cold source;

the cryoablation catheter as recited in any of the preceding claims wherein said cryoablation catheter is connected to said cold source.

According to the cryoablation catheter and the cryoablation device, when the central tube moves from the distal end to the proximal end relative to the outer tube, the central tube pulls the inner tube to bend according to the preset shape, the plurality of ablation sections form an annular structure and are abutted against the wall of the blood vessel, and the refrigerant flowing in the ablation sections ablates the focus position and forms continuous ablation damage. The cryoablation catheter provided by the utility model can form an annular structure through a plurality of preset ablation sections, and the inner tube does not need to be deformed and expanded radially in the flowing process of the refrigerant, so that the inner tube bears small load, the adverse phenomenon of cracking caused by overlarge expansion deformation of the inner tube can be prevented, meanwhile, the ablation sections forming the annular structure have larger deformation/displacement space when the ablation sections are subjected to external force due to no fixed connection relation, the cryoablation catheter can be suitable for the adhesion of blood vessel walls with various shapes, and the hollowed-out parts in the middle of the annular structure can be used for blood circulation, so that the flow of blood flow in the blood vessel cannot be influenced in the ablation process, and the risk of blocking the blood flow caused by using the balloon structure in the prior art is avoided.

Drawings

Fig. 1 is a schematic view of a cryoablation catheter provided in some embodiments in a second state.

Fig. 2 is an elevation view of a cryoablation catheter provided in some embodiments in a first state.

Fig. 3 is a cross-sectional view taken along A-A in fig. 2.

Fig. 4 is a front view of a handle provided in some embodiments.

Fig. 5 is a front view of the joint provided in some embodiments.

Reference numerals:

100. cryoablation catheters;

110. an outer tube;

120. a central tube; 121. a reflow chamber; 122. a guidewire lumen;

130. an inner tube; 131. a ring-shaped structure; 132. an ablation section; 133. a first support section; 134. a second support section; 135. a first corner; 136. a second corner;

140. a handle; 141. an air inlet pipe; 142. an air outlet pipe; 143. a receiving chamber; 144. a shifting block; 145 chute; 146. a connector; 1461. an air inlet; 1462. an air outlet; 147. a guidewire inlet.

Detailed Description

In order that the above objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. The present utility model may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the utility model, whereby the utility model is not limited to the specific embodiments disclosed below.

In the description of the present utility model, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the utility model.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present utility model, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

The following describes the technical scheme provided by the embodiment of the utility model with reference to the accompanying drawings.

The proximal end as used herein refers to the end proximal to the operator and the distal end refers to the end distal to the operator.

As shown in fig. 1 and 2, the present utility model provides a cryoablation catheter 100, the cryoablation catheter 100 comprising an outer tube 110, a central tube 120, and a plurality of deformable inner tubes 130, the cryoablation catheter 100 configured for ablating an ostium of a pulmonary artery. Wherein 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 direction of extension, one of which is the distal end of the outer tube 110 and the other of which is the proximal end of the outer tube 110. The central tube 120 is movably inserted into the outer tube 110 in the axial direction thereof, as in the present embodiment, a proximal end portion of the central tube 120 is inserted into the outer tube 110, and a distal end portion of the central tube 120 is exposed from a distal end portion of the outer tube 110.

The inner tube 130 has a supply of refrigerant (e.g., N ₂ O、N ₂ A flowing or like cooling medium) is introduced into a delivery lumen (not shown) and flows, the proximal end portions of the plurality of inner tubes 130 are each inserted into the outer tube 110 and are in a first state (see fig. 2) to achieve a 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 each exposed to the distal end portion of the outer tube 110, and the distal end portions of the plurality of inner tubes 130 are each connected to the distal end portion of the center tube 120. The inner tube 130 has the ablation section 132, such as in the present embodiment, the ablation section 132 is located at the middle section of the inner tube 130, and since the middle section of the inner tube 130 has a larger deformation amount than the two ends during the bending process of the inner tube 130, the ablation section 132 is disposed at the middle section of the inner tube 130, so that the ablation section 132 can be better adapted to be attached to the focus position during the bending process of the inner tube 130. In this embodiment, in the first state, the cryoablation catheter 100 is preferably elongated, i.e. the width of the cryoablation catheter 100 in the radial direction is the smallest, so as to facilitate the insertion and evacuation of the cryoablation catheter 100 at the lesion position. Of course, in other possible embodiments, the cryoablation catheter 100 may be tapered in the first state, so long as the cryoablation catheter 100 is capable of extending into or withdrawing from the lesion site。

In the above embodiment, when the cryoablation operation is to be performed on the pulmonary artery ostium, the cryoablation catheter 100 is extended into and positioned at the lesion position in the first state, the central tube 120 moves from the distal end toward the proximal end relative to the outer tube 110, that is, the central tube 120 moves toward the direction of inserting into the outer tube 110, the central 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 segments 132 form the annular structure 131, referring to fig. 1, the plurality of ablation segments 132 form the annular structure 131 and are abutted against the vessel wall, the refrigerant flowing in the ablation segments 132 ablates the lesion position and forms a continuous ablation lesion. In this embodiment, the number of the inner tubes 130 is preferably three, so that the stability of the ablation segment 132 in the ablation process is improved on the basis of ensuring that the ablation segment 132 has a larger deformation. Of course, in other possible embodiments, the number of inner tubes 130 may be two, four, or other numbers, such as when the area of the focal position on which the ablation segment 132 is to be placed is larger, the number of inner tubes 130 may be set to be larger, and such as when the area of the focal position on which the ablation segment 132 is to be placed is smaller, the number of inner tubes 130 may be set to be smaller.

Researchers find that in the using process of the conventional cryoablation catheter, the refrigerant sprays and expands the balloon to be attached to the focus position to execute the cryoablation operation, but the refrigerant can enable the balloon to bear larger load in the spraying process, and the balloon is easy to crack in the expansion deformation process, so that the conventional cryoablation catheter has higher requirements on the material of the balloon, the deformation of the balloon is limited, and when the balloon is abutted to the focus position, the balloon can cause blood flow to be blocked due to overlarge pressure generated on the focus position, and corresponding complications are caused. For the above reasons, the cryoablation catheter 100 provided by the utility model can form the annular structure 131 through the plurality of pre-shaped ablation segments 132, and the inner tube 130 does not need to be deformed and expanded radially in the flowing process of the refrigerant, so that the inner tube 130 bears small load, and the adverse phenomenon of cracking caused by overlarge expansion deformation of the inner tube 130 can be prevented, meanwhile, the plurality of ablation segments 132 forming the annular structure 131 have no fixed connection relationship, namely no connection relationship between two adjacent ablation segments 132, the ablation segments 132 have larger deformation/displacement space when being subjected to external force, the cryoablation catheter can be suitable for the adhesion of blood vessel walls in various shapes, and the hollowed-out part in the middle of the annular structure 131 can be used for blood circulation, so that the flow of blood flow in the blood vessel cannot be influenced in the ablation process, the adverse phenomenon of blocking the blood flow caused by the inner tube 130 in the cryoablation process is prevented, and the risk of blood flow blocking caused by using the balloon structure in the prior art is avoided.

In an embodiment, as shown in fig. 1 and 2, when the plurality of ablation segments 132 are in the second state and the central tube 120 moves from the proximal end to the distal end relative to the outer tube 110, the plurality of inner tubes 130 can be switched from the second state to the first state, and at this time, the cryoablation catheter 100 is in a strip shape as a whole, so as to facilitate evacuation of the cryoablation catheter 100 at the focus position of the patient after the cryoablation operation is completed.

Further, as shown in fig. 1 and fig. 2, in the first state, the combination of the plurality of inner tubes 130 is projected inside the outer tube 110 along any section of the central tube 120 in the radial direction, that is, the inner tube 130 and the central tube 120 are located inside the outer tube 110 during the process of inserting and withdrawing the cryoablation catheter 100 into and from the lesion position of the patient, and the whole cryoablation catheter 100 is in a strip shape, so as to improve the smoothness of inserting and withdrawing the cryoablation catheter 100 into and from the lesion position of the patient, and facilitate the operation of inserting and withdrawing the cryoablation catheter 100 into and from the lesion position of the patient.

In one embodiment, as shown in fig. 2, in the first state, the inner tube 130 is wholly or at least partially attached to the outer wall of the central tube 120, that is, the inner tube 130 is partially or wholly attached to the outer wall of the central tube 120, so that a combination of a plurality of inner tubes 130 is projected inside the outer tube 110 along any section of the central tube 120 in the radial direction, and the cryoablation catheter 100 is wholly elongated, so that the cryoablation catheter 100 can be conveniently extended into the lesion position of the patient, in preparation for performing a subsequent cryoablation operation on the lesion position, or in order to facilitate an evacuation operation of the cryoablation catheter 100 at the lesion position after the ablation operation is completed.

Further, as shown in fig. 2, in the first state, the inner tube 130 is integrally attached to the outer wall of the central tube 120, that is, the inner tube 130 is attached to the outer wall of the central tube 120 without gaps along the axial direction of the inner tube, so that the overall outer diameter of the cryoablation catheter 100 in the first state is ensured to be minimum, and when the cryoablation treatment is required to be performed on the lesion position of the patient, the cryoablation catheter 100 is convenient to extend into the lesion position of the patient, or the cryoablation catheter 100 is convenient to withdraw from the lesion position of the patient after the cryoablation operation is completed.

In order to improve the stability of the ablation segment 132 during the ablation process, in an embodiment, as shown in fig. 1 and 2, the inner tube 130 further has a first support segment 133 and a second support segment 134. The first support section 133 and the second support section 134 are respectively connected to two ends of the ablation section 132, that is, the inner tube 130 includes the first support section 133, the ablation section 132 and the second support section 134 connected in sequence. The first support segment 133 is inserted into the outer tube 110, and a distal portion of the first support segment 133 exposes a distal portion of the outer tube 110, and an end of the second support segment 134 distal from the ablation segment 132 is connected to a distal portion of the center tube 120.

In the second state, the center tube 120 pulls the inner tube 130 to bend in accordance with a predetermined shape, the plurality of first support sections 133 in the pre-shaped inner tube 130 are spaced apart in the circumferential direction of the center tube 120, and the first support sections 133 are bent between the ablation sections 132 to form first corners 135. 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 being pre-shaped, and the plurality of first support sections 133 may form a tapered structure to support the annular structure 131 formed by the plurality of ablation sections 132. Likewise, the second support sections 134 in the pre-shaped inner tube 130 are distributed at intervals inside the annular structure 131 formed by the ablation sections 132, and a second corner 136 is formed by bending between the second support sections 134 and the ablation sections 132, and the second support sections 134 and the annular structure 131 together form a hub structure for supporting the annular structure 131 formed by the ablation sections 132. The cryoablation catheter 100 has the advantages that 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, so that the stability of the ablation sections 132 in the ablation process is improved, and the bonding reliability of the ablation sections 132 and focus positions is further improved.

It should be noted that, when the central tube 120 moves from the proximal end toward the distal end relative to the outer tube 110, the first support segment 133, the ablation segment 132, and the second support segment 134 may all abut against the outer wall of the central tube 120, so as to facilitate the evacuation operation of the cryoablation catheter 100 from the lesion site of the patient.

Further, as shown in fig. 1, the first corner 135 and/or the second corner 136 are obtuse, i.e. in one embodiment only the first corner 135 is obtuse, in another embodiment only the second corner 136 is obtuse, in yet another embodiment both the first corner 135 and the second corner 136 are obtuse. The cryoablation catheter 100 has the advantages that the first corner 135 formed by bending the first support section 133 and the ablation section 132 and/or the second corner 136 formed by bending the second support section 134 and the ablation section 132 are obtuse angles, so that the overall smoothness of the bent inner tube 130 can be ensured to be higher, the flow speed uniformity of the refrigerant in the inner tube 130 can be improved, and the refrigerant can flow into the backflow cavity of the central tube 120 conveniently.

In an embodiment, as shown in fig. 1, a plurality of ablation segments 132 are sequentially joined end to form an annular structure 131, that is, when the inner tube 130 performs cryoablation operation on a lesion position, two ends of the ablation segments 132 are respectively adjacent to ends of two adjacent ablation segments 132, so that the annular structure 131 formed by the plurality of ablation segments 132 can completely abut against and ablate the lesion position. In another embodiment, in the extending direction of the ablation segments 132, the plurality of ablation segments 132 partially overlap, and the remaining portions of the plurality of ablation segments 132 are joined to form an annular structure 131 for ablating a lesion location. As in the present embodiment, two ends of two adjacent ablation segments 132 close to each other overlap, and other portions of the plurality of ablation segments 132 are joined to form the annular structure 131.

In order to improve the ablation effect of the ablation segment 132 on the lesion position, in an embodiment, as shown in fig. 1 and 2, the connection portion of the inner tube 130 and the central tube 120 inserted in the outer tube 110 is a sealing structure, on one hand, the sealing structure can improve the reliability of the fixed connection between the proximal portion of the inner tube 130 and the outer tube 110, and on the other hand, the sealing structure can prevent the blood flowing in the blood vessel from flowing backward to the outer tube 110. If a sealing ring can be disposed at the connection portion of the inner tube 130 and the central tube 120 inserted into the outer tube 110, the inner tube 130 is matched with the outer tube 110 without a gap, so as to improve the stability of the inner tube 130 after bending and pre-shaping, and further, the annular structure 131 formed by the plurality of ablation segments 132 can be better attached to the focus position, and the ablation effect of the ablation segments 132 on the focus position is improved. It should be noted that, after the sealing structure is disposed at the connection portion where the inner tube 130 and the central tube 120 are inserted into the outer tube 110, since the inner tube 130 is located at the outer side of the central tube 120, that is, the outer wall of the inner tube 130 is close to the inner wall of the outer tube 110, and the central tube 120 is not in contact with the outer tube 110, the proximal portion of the inner tube 130 is fixed to the outer tube 110 and is not movable, but the disposed sealing structure does not affect the movement of the central tube 120 relative to the outer tube 110, so that the switching between the first state and the second state of the cryoablation catheter 100 can be achieved during the movement of the central tube 120.

To enable the plurality of ablation segments 132 to be pre-formed into the annular structure 131, in one embodiment, as shown in fig. 1 and 2, the distal portion of the inner tube 130 is made of a shape memory material, and the inner tube 130 exhibits superelasticity in a physiological environment. Such shape memory materials may include shape memory alloys and/or shape memory polymers, such as inner tube 130 being made of nickel-titanium alloys, copper-based alloys, and/or other controllably deformable materials that allow multiple inner tubes 130 to be deformed into different geometric configurations, shapes, and/or sizes, etc. Because the inner tube 130 has a shape memory property, the ablation segment 132 can always keep being bent and expanded in a preset shape in the process of pulling the inner tube 130 to bend, i.e. the ablation segment 132 can be ensured to return to a preset annular structure 131 to perform the ablation operation, and the inner tube 130 presents super-elasticity at physiological temperature, so that the ablation segment 132 can be well attached to the focus position after the annular structure 131 is formed, and the ablation effect of the ablation segment 132 on the focus position is improved.

In one embodiment, as shown in fig. 1 and 2, the distal end portion of the inner tube 130 is connected to the distal end portion of the central tube 120, and since the ablation segment 132 is located at the middle position of the inner tube 130 in this embodiment, the distal end portion of the inner tube 130 is connected to the distal end portion of the central tube 120, the ablation segment 132 has a larger deformation/displacement space during the traction process of the central tube 120, so as to improve the adaptation of the ablation segment 132 to the blood vessel walls of different shapes.

In order to ablate the lesion location, in one embodiment, as shown in fig. 2 and 3, the central tube 120 has a backflow cavity 121, and the inner tube 130 is in communication with the backflow cavity 121, that is, the inner tube 130 and the central tube 130 may form a circulation loop for the refrigerant to flow, so that the refrigerant ablates the lesion location in a process of flowing in the ablation section 132 of the inner tube 130.

With continued reference to fig. 4, the cryoablation catheter 100 further includes a handle 140, the handle 140 being attached to the proximal end of the outer tube 110, and an operator may perform pushing or withdrawing of the cryoablation catheter 100 into and out of the lesion site by grasping the handle 140. The handle 140 is provided with an air inlet pipe 141 and an air outlet pipe 142 by screwing, inserting and the like, the air inlet pipe 141 is communicated with the proximal ends of the inner pipes 130, for example, the inner pipes 130 can be directly inserted into the air inlet pipe 141, the air outlet pipe 142 is communicated with the reflux cavity 121, namely, the air outlet pipe 142 is communicated with the proximal end of the central pipe 120, for example, the central pipe 120 can be directly inserted into the air outlet pipe 142. The refrigerant can be conveyed to the inner tube 130 through the air inlet tube 141, the refrigerant is subjected to the close ablation treatment on the focus position in the flowing process of the inner tube 130, and continuously flows to the air outlet tube 142 through the backflow cavity 121, namely, the air inlet tube 141, the inner tube 130, the backflow cavity 121 and the air outlet tube 142 can form a circulation loop for the refrigerant to flow, the air outlet tube 142 can recover the refrigerant after the ablation treatment, the loss of the refrigerant is avoided, the utilization rate of the refrigerant is improved, the refrigerant is continuously supplemented towards the inner tube 130 through the air inlet tube 141, the refrigerant in the ablation section 132 is ensured to be always maintained at a lower temperature, and the ablation effect of the cryoablation catheter 100 on the focus position is improved.

Further, as shown in fig. 2-5, the handle 140 is provided with a connector 146, and in this embodiment, the connector 146 is disposed on a side of the handle 140 near 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 141, for example, the air inlet 141 is connected to the air inlet 1461 by screwing, plugging, etc., 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, plugging, etc. The air inlet 1461 is connected to a cold source (not shown) through the air inlet pipe 141, and the refrigerant in the cold source is sequentially delivered to the inner pipe 130 through the air inlet pipe 141, the air inlet 1461 and the air outlet 1462 to perform cryoablation treatment on the lesion position.

In this embodiment, the connector 146 may be a multi-way connector, for example, the connector 146 is a three-way connector, that is, the connector 146 has an air inlet 1461 and three air outlets 1462, one air inlet 1461 may be directly connected to the air inlet pipe 141, the three air outlets 1462 may be respectively connected to the three inner pipes 130, and the air inlets 1461 and the air outlets 1462 may allow the refrigerant to be respectively delivered to the three inner pipes 130 for performing the cryoablation treatment on the lesion position. When the connector 146 is a multi-way connector, the connection arrangement can be performed according to the above-provided embodiments, and the description is omitted here.

To prevent the backflow of the refrigerant, in one embodiment, as shown in fig. 2-5, a check valve (not shown) is provided on the connection head 146, for example, the check valve may be a one-way valve, and the check valve is provided 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 towards the direction of delivering to the inner pipe 130, and by arranging the check valve on the connector 146, the adverse phenomenon of backflow of the refrigerant in the flowing process can be prevented, so as to ensure that the flow direction and the flow velocity of the refrigerant in the inner pipe 130 are fixed, and further ensure the ablation effect of the refrigerant in the inner pipe 130 on the focus position.

In one embodiment, as shown in fig. 1, 2 and 4, the handle 140 has a receiving cavity 143, and the receiving cavity 143 can receive the inner tubes 130 and the outer tubes 110, so that the inner tubes 130 and the outer tubes 110 can be inserted and connected to the outer tubes 110. The handle 140 is provided with a dial 144, the dial 144 is slidable on the handle 140, the dial 144 is connected to the proximal end portion of the central tube 120, as in this embodiment, the handle 140 is provided with a sliding slot 145, and the dial 144 is slidably disposed in the sliding slot 145 along the axial direction of the central tube 120. Since the proximal portion of the central tube 120 is inserted into the outer tube 110, the cryoablation catheter 100 does not reserve an operation space for the central tube 120 by an operator, at this time, the operator can act on the shifting block 144 by pushing, pulling, shifting, or the like, so that the shifting block 144 slides in the sliding groove 145 along the axial direction of the central tube 120 and drives the central tube 120 to move on the outer tube 110 along the axial direction thereof, that is, the cryoablation catheter 100 is switched 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, thereby facilitating the operation of inserting and withdrawing the cryoablation catheter 100, or driving the plurality of ablation segments 132 to form the annular structure 131 to ablate the focus position.

To facilitate pushing of the cryoablation catheter 100, in one embodiment, as shown in fig. 2 and 3, the central tube 120 further has a guidewire lumen 122, the guidewire lumen 122 being configured for passage of a guidewire (not shown), a guidewire inlet 147 being provided on the handle 140, the guidewire lumen 122 being in communication with the guidewire inlet 147. When the cryoablation catheter 100 is required to be pushed to the focus position, a guide wire is inserted into the guide wire cavity 122 through the guide wire inlet 147, so that the cryoablation catheter 100 can reach the focus position along the guide wire, the pushing of the cryoablation catheter 100 is guided and positioned, and the pushing operation of an operator on the cryoablation catheter 100 to reach the focus position is facilitated.

In one embodiment, as shown in fig. 1, cryoablation catheter 100 further includes a temperature sensor (not shown). A temperature sensor is disposed in the ablation segment 132, the temperature sensor being configured to sense a temperature of the refrigerant flowing within the ablation segment 132. Since the ablation treatment of the lesion position is mainly performed by the refrigerant flowing in the ablation section 132, the temperature sensor is arranged in the ablation section 132, so that the real-time temperature of the ablation treatment of the lesion position can be provided more accurately, and the refrigerant source can control the flow rate of the refrigerant delivered to the inner tube 130 based on the temperature of the refrigerant in the area of the ablation section 132. It should be noted that, the number of the temperature sensors may be multiple, and the multiple temperature sensors are disposed at intervals in the ablation segment 132, so as to obtain the temperature parameters of the refrigerant in each area of the ablation segment 132, improve the control accuracy of the refrigerant flow, and further improve the ablation effect of the ablation segment 132 on the focus position.

In one embodiment, as shown in fig. 1, cryoablation catheter 100 further includes a pressure sensor (not shown). A pressure sensor is provided at the end of the distal end portion of the center tube 120 for sensing the pressure of the refrigerant flowing in the inner tube 130. The pressure sensor monitors the pressure of the refrigerant flowing in the inner tube 130 in real time, so that the excessive pressure of the refrigerant flowing is prevented, the inner tube 130 is damaged, and the ablation effect is influenced. Specifically, when the pressure sensor senses that the pressure of the annular structure 131 formed by the ablation segment 132 acting on the focal position is too high, the conveying amount of the refrigerant towards the inner tube 130 can be reduced or stopped, so that the pressure of the ablation segment 132 acting on the focal position is reduced, and the ablation treatment effect of the cryoablation catheter 100 on the focal position is improved.

In addition, as shown in fig. 1 and 2, the present utility model provides a cryoablation device (not shown). The cryoablation device comprises a cold source and a cryoablation catheter 100 as in any of the above embodiments, the cryoablation catheter 100 being connected to the cold source, such as the cold source being connected to the proximal end of the inner tube 130.

In the cryoablation device, when the lesion position is to be cryoablated, the cryoablation catheter 100 is extended into and positioned at the lesion position in the first state, the central tube 120 moves 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 a predetermined shape, the plurality of ablation segments 132 form a ring-shaped structure 131 and are abutted against the vessel wall in the second state, the cold source conveys the refrigerant toward the inner tube 130, and the refrigerant flowing in the ablation segments 132 ablates the lesion position and forms continuous lesions. After the cryoablation treatment of the lesion site is completed, the cold source stops the delivery of the refrigerant, a rewarming fluid is input into the inner tube 130, then the central tube 120 moves distally from the proximal end relative to the outer tube 110, the central tube 120 pulls the inner tube 130 distally and against the outer wall of the central tube 120, and the cryoablation catheter 100 is switched from the second state to the first state again, facilitating evacuation of the cryoablation catheter 100 from the lesion site of the patient.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims

1. A cryoablation catheter, said cryoablation catheter comprising:

2. The cryoablation catheter as recited in claim 1 wherein a plurality of inner tubes are switchable from the second state to the first state in response to proximal-to-distal movement of the central tube relative to the outer tube with a plurality of the ablation segments in the second state.

3. The cryoablation catheter as recited in claim 1 or 2 wherein in said first condition a combination of a plurality of said inner tubes project inside said outer tube along any cross-section of said central tube radial direction.

4. A cryoablation catheter as recited in claim 3 wherein in said first condition said inner tube abuts wholly or at least partially against said outer wall of said center tube.

5. The cryoablation catheter as recited in claim 1 wherein the inner tube further has a first support section and a second support section, the first and second support sections respectively joined to two ends of the ablation section, the first support section being inserted into the outer tube, the end of the second support section distal from the ablation section being connected to a distal portion of the central tube;

6. The cryoablation catheter as recited in claim 5 wherein the first and/or second corners are obtuse angles.

7. The cryoablation catheter as recited in claim 1 wherein a plurality of said ablation segments are joined end-to-end in sequence to form said annular structure; or alternatively, the first and second heat exchangers may be,

8. The cryoablation catheter as recited in claim 1 wherein the junction of the inner tube and the center tube interposed between the outer tube is a sealed structure.

9. The cryoablation catheter as recited in claim 1 wherein the distal portion of the inner tube is made of a shape memory material and exhibits superelasticity in a physiological environment.

10. The cryoablation catheter as recited in claim 1 wherein the distal portion of the inner tube is connected to an end of the central tube on a distal side thereof.

11. The cryoablation catheter as recited in claim 10 wherein the central tube has a flashback chamber, the inner tube communicating with the flashback chamber.

12. The cryoablation catheter as recited in claim 11 further comprising a handle attached to the proximal end of the outer tube, the handle being provided with an air inlet tube in communication with the proximal ends of the plurality of inner tubes and an air outlet tube in communication with the flashback chamber.

13. The cryoablation catheter as recited in claim 12 wherein the handle has a receiving cavity for receiving the inner tube and the outer tube, the handle having a dial slidably disposed thereon, the dial being coupled to a proximal portion of the center tube.

14. The cryoablation catheter as recited in claim 12 wherein the handle is provided with a connector having at least one air inlet port and at least one air outlet port disposed thereon, the air inlet port being connected to the air inlet tube and the air outlet port being connected to the proximal end of the inner tube.

15. The cryoablation catheter as recited in claim 14 wherein a check valve is disposed on the connector, the check valve being disposed at the air inlet and/or the air outlet.

16. The cryoablation catheter as recited in claim 1 wherein the central tube further has a guidewire lumen for passage of a guidewire.

17. The cryoablation catheter as recited in claim 1 further comprising a temperature sensor disposed in the ablation segment for sensing a temperature of a refrigerant flowing within the ablation segment.

18. The cryoablation catheter as recited in claim 1 further comprising a pressure sensor disposed at an end of the central tube distal portion for sensing the pressure of refrigerant flowing within the inner tube.

19. A cryoablation apparatus, said cryoablation apparatus comprising:

a cold source;

the cryoablation catheter as recited in any one of claims 1-18 wherein the cryoablation catheter is coupled to the cold source.