A cryoablation catheter, comprising a balloon (1) and a delivery catheter (2) passing through the balloon (1). The delivery catheter (2) is provided with a fluid inflow cavity (21) and a fluid outflow cavity (22) therein. The fluid inflow cavity (21) extends into the balloon (1), and a side wall of the fluid inflow cavity (21) is provided with a spray head (211) that injects a liquid into the balloon (1). The spray head (211) has a number of spray holes (2111, 2112) circumferentially arranged on the exterior of the fluid inflow cavity (21). An end of the fluid outflow cavity (22) has a cross section (24) that seals the fluid outflow cavity (22), and a side wall of the fluid outflow cavity (22) is provided with a reflow hole (221) in communication with the balloon (1). A fluid flows from the fluid inflow cavity (21) through the nozzle holes (2111, 2112) into the balloon (1). The nozzle holes (2111, 2112) are evenly distributed outside the fluid inflow cavity (21), so that the interior of the balloon (1) is uniformly filled with the refrigeration fluid, ensuring the uniformity of heat exchange at each part of the balloon (1) in an axial direction. The fluid then flows out from the reflow hole (221). The structural design can effectively improve the heat exchange efficiency of the fluid, and the production and processing processes are relatively simple.

TECHNICAL FIELD

The present application relates to the technical field of cryoablation medical devices, in particular to a cryoablation catheter.

BACKGROUND

Hypertension is a major risk factor for stroke, coronary heart disease, heart failure, vascular disease, and chronic renal failure. A plurality of clinical studies have shown that intractable hypertension accounts for 20% to 30% of a total number of hypertension. Intractable hypertension refers to the failure to reach a target blood pressure value in a process of drug treatment with a highest tolerated dose (including a combined treatment of three antihypertensive drugs with diuretics). These patients are at high risk of major cardiovascular events. In recent years, prospective cohort studies and randomized controlled studies abroad have shown that transcatheter radiofrequency ablation of renal sympathetic denervation (RDN) has a significant and durable antihypertensive effect on some patients with resistant hypertension, which has broad clinical application prospects.

Kidneys play a key role in blood pressure regulation through sodium water reabsorption, regulation of renin release, and sympathetic interactions. The basic principle of RDN in the treatment of hypertension is to release energy locally through the radiofrequency catheter or other devices inserted into the renal artery, and selectively destroy the renal sympathetic nerve fibers in the outer membrane through the inner and middle membranes of the renal artery, so as to reduce the activity of renal sympathetic nerve and block the role of sympathetic overexcitation in maintaining hypertension, especially intractable hypertension.

The Chinese patent application with publication No. CN208625843U discloses a cryoablation catheter with a liquid return cavity. The cryoablation catheter includes a handle unit, a delivery unit and a refrigeration unit which are sequentially connected. The refrigeration unit includes a balloon and a cold source releasing structure arranged in the balloon, the delivery unit includes a sheath tube, and a liquid injection cavity and a liquid return cavity which are arranged in the sheath tube, a proximal end of the sheath tube is in sealing connection with a distal end of the handle unit, a distal end of the sheath tube is in sealing connection with a proximal end part of the balloon, a proximal end of the liquid injection cavity is in fluid communication with a liquid injection joint arranged on the handle unit, a distal end of the liquid injection cavity is arranged at the proximal end of the balloon and in fluid communication with the balloon, and a liquid return port of the liquid return cavity is arranged in the distal end part of the balloon. The gas in the balloon is effectively discharged, a refrigeration performance of the cryoablation catheter is improved, and a refrigeration efficiency is improved.

However, in the above patent application, the liquid is returned through the circulating liquid return cavity, the liquid in the balloon diffuses outward with a cold source release structure as a center, and its refrigeration effect is poor.

SUMMARY

One objective of the present application is to provide a cryoablation catheter, so as to solve the technical problem of a poor refrigeration effect of a cryoablation catheter in the prior art.

In order to realize the above objective, the technical solution adopted in the present application is to provide a cryoablation catheter, including a balloon and a delivery catheter passing through the balloon. Relative to the balloon, one end, close to the balloon, is a proximal end, one end, away from the balloon, is a distal end, and the delivery catheter is internally provided with a fluid inflow cavity and a fluid outflow cavity; the fluid inflow cavity extends into the balloon, an outer side of the fluid inflow cavity is provided with a spray head that injects a liquid into the balloon, and the spray head has a plurality of nozzle holes circumferentially arranged on an exterior of the fluid inflow cavity; and a tail end of the fluid outflow cavity has a cross section that seals the fluid outflow cavity, and a side wall of the fluid outflow cavity is provided with a reflow hole in communication with the balloon.

Further, the delivery catheter further includes a guide wire cavity, and the guide wire cavity passes through the balloon.

Further, before the cross section, the fluid inflow cavity and the guide wire cavity are both arranged in the fluid outflow cavity; and after the cross section, the guide wire cavity is arranged in the fluid inflow cavity.

Further, before the cross section, the fluid inflow cavity and the guide wire cavity are arranged in the fluid outflow cavity in parallel.

Further, the spray head includes a catheter body wrapped on an outer side of the fluid inflow cavity, the nozzle holes are evenly and circumferentially arranged on the catheter body, and the catheter body is in communication with the fluid inflow cavity.

Further, before the cross section, the fluid inflow cavity is located in the fluid outflow cavity, and the guide wire cavity is located in the fluid inflow cavity.

Further, before the cross section, the fluid outflow cavity, the fluid inflow cavity and the guide wire cavity are concentric round tube.

Further, the spray head is integrated with the fluid inflow cavity, and the nozzle holes are circumferentially arranged on a side wall of the fluid inflow cavity.

Further, the balloon adopts a single-layer balloon, two ends of the balloon are directly fixed to the delivery catheter, the spray head injects the liquid into the balloon, and the reflow hole is located on an inner side of a side wall of the proximal end of the balloon.

Further, the balloon adopts a double-layer balloon, and the nozzle holes are divided into a first nozzle hole that injects the liquid into a gap between the double-layer balloon and a second nozzle hole that injects the liquid into the double-layer balloon.

Further, the reflow hole is located in the gap between the double-layer balloon, the first nozzle hole is located at the distal end of the double-layer balloon, and the reflow hole is located at the proximal end of the double-layer balloon.

Further, the cryoablation catheter further includes a handle arranged at one end, away from the balloon, of the delivery catheter and an input unit, wherein the input unit includes: a guide wire cavity inlet end in communication with the guide wire cavity; a fluid inflow end in communication with the fluid inflow cavity; a fluid outflow end in communication with the fluid outflow cavity; and a catheter electronic component adapter configured to be in communication with an external instrument.

The beneficial effects of the cryoablation catheter provided by the present application lie in that: compared with the prior art, according to the cryoablation catheter of the present application, a fluid flows from the fluid inflow cavity through the nozzle holes on the spray head into the balloon. The nozzle holes are evenly distributed outside the fluid inflow cavity, so that an interior of the balloon is uniformly filled with a refrigeration fluid, ensuring the uniformity of heat exchange at each part of the balloon in an axial direction. The fluid then flows out from the reflow hole. The structural design of the present application can effectively improve the heat exchange efficiency of the fluid, and the production and processing processes are relatively simple.

DESCRIPTION OF REFERENCE NUMBERS

DETAILED DESCRIPTION

The technical solutions of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the embodiments described below are a part, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments acquired by those of ordinary skill in the art without creative work shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the orientation or position relationship indicated by the terms “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, “inner”, “outer” and the like is based on the orientation or position relationship shown in the accompanying drawings, only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the indicated device or component must have a specific orientation and be configured and operated in the specific orientation, and therefore, it should not be construed as limitations on the present application. In addition, the terms “first”, “second” and “third” are only used to describe the purposes, and should not be construed to indicate or imply relative importance.

In the description of the present application, it should be noted that, unless otherwise expressly specified and limited, the terms “install”, “connection” and “connect” should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integrated connection; may be a mechanical connection or an electrical connection; and may be a direct connection, an indirect connection through an intermediate medium, or an internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application may be understood in specific situations.

In addition, the technical features involved in the different implementations of the present application described below may be combined with each other as long as there is no conflict with each other.

Please refer toFIG.1toFIG.6together, the cryoablation catheter provided by the present application is now described. The cryoablation catheter includes a balloon1, a delivery catheter2passing through the balloon1, and an input unit4arranged at one end, away from the balloon1, of the delivery catheter2. Relative to the balloon1, one end, close to the balloon1, is a proximal end, one end, away from the balloon1, is a distal end, and the delivery catheter2is internally provided with a fluid inflow cavity21, a fluid outflow cavity22and a guide wire cavity23. The fluid inflow cavity21and the guide wire cavity23may extend into the balloon1, a spray head211is arranged on an outer side of the delivery catheter2located in the balloon1in a sleeving mode, the spray head211has a plurality of nozzle holes (not separately marked, namely a first nozzle hole2111and a second nozzle hole2112) which may inject a liquid into the balloon1. A tail end of the fluid outflow cavity22has a cross section24that seals the fluid outflow cavity22, and the fluid outflow cavity22ends at the cross section24. A side wall of the fluid outflow cavity22is provided with a reflow hole221in communication with an outer balloon12.

According to the cryoablation catheter provided by the present application, compared with the prior art, a fluid flows from the fluid inflow cavity21through the nozzle holes arranged on the spray head211into the balloon1, the nozzle holes on the spray head211are circumferentially arranged on an outer side of the fluid inflow cavity21, so that an interior of the balloon1is uniformly filled with a refrigeration fluid, ensuring the uniformity of heat exchange at each part of the balloon1in an axial direction. The fluid then flows out from the reflow hole221, the fluid inflow cavity21and the fluid outflow cavity22are both arranged in the delivery catheter2and in communication with each other to form reflowing, the heat exchange efficiency of the fluid can be effectively improved, the overall structure is simple, and the production and processing processes are simple.

The input unit4includes a fluid inflow end42in communication with the fluid inflow cavity21, a fluid outflow end43in communication with the fluid outflow cavity22, a guide wire cavity inlet end41in communication with the guide wire cavity23, and a catheter electronic component adapter44configured to be in communication with an external instrument. The cryoablation catheter further includes a handle3arranged at the end, away from the balloon1, of the delivery catheter2, and the handle3is arranged on an exterior of the delivery catheter2in a sleeving mode, which may facilitate holding.

Specifically, the delivery catheter2is a catheter body integration of the whole delivery catheter, the input unit4is arranged at the end, away from the balloon1, of the delivery catheter2, and the fluid flows into from the fluid inflow end42. The spray head211is arranged on an outer side of the fluid inflow cavity21in a sleeving mode, the nozzle holes of the spray head211are circumferentially arranged on the fluid inflow cavity21and are connected with each other, and the reflow hole221is arranged on the fluid outflow cavity22. The fluid inflow cavity21is configured to deliver the fluid into the balloon1, and the nozzle holes of the spray head211and the reflow hole221are configured to make the fluid uniformly flow into the balloon1. The fluid outflow cavity22is configured to output the fluid in the balloon1, so that the fluid can form a circulation, a distal end of the fluid inflow end42is connected to the fluid inflow cavity21, a proximal end is connected to a Luer taper, and the connection with the external instrument can be realized through the Luer taper. A distal end of the fluid outflow end43is connected to the fluid outflow cavity22, a proximal end is connected to the Luer taper, and the connection with the external instrument can be realized through the Luer taper. The catheter electronic component adapter44may be connected to an external control instrument, so that control and other information of the whole cryoablation catheter us transmitted to the control instrument, and the connection with an external control device is realized.

Further, please refer toFIG.1toFIG.6together, as a specific implementation of the cryoablation catheter provided by the present application, the delivery catheter2further includes a guide wire cavity23, and the guide wire cavity23passes through the balloon1. Specifically, a guide wire and other auxiliary related devices may be inserted into the delivery catheter2through the guide wire cavity inlet end41, the guide wire cavity23penetrates through the whole delivery catheter2, the proximal end is connected to the guide wire cavity inlet end41, which may be in direct or indirect contact with a human body through the guide wire cavity23. Of course, according to the actual situation and specific needs, in other embodiments of the present application, a separate guide wire cavity23may further be not arranged, and there is no unique limitation here.

The delivery catheter2has an end connector5at the other end of the balloon1, the end connector5is configured to fix the balloon1, the guide wire cavity23passes through the delivery catheter2and extends out of the balloon1to be in communication with the end connector5, the guide wire cavity23passes through the end connector5to be in direct or indirect contact with the human body, a middle part of the end connector5is provided with an opening, and the guide wire cavity23is the opening, so as to be in direct or indirect contact with the external human body.

Further, please refer toFIG.4toFIG.6, as a specific implementation of the cryoablation catheter provided by the present application, before the cross section24, the fluid inflow cavity21and the guide wire cavity23are both arranged in the fluid outflow cavity22. After the cross section24, the guide wire cavity23is arranged in the fluid inflow cavity21. Specifically, the cross section24is configured to partition and seal the fluid outflow cavity22, the reflow hole221is located at a proximal end of the cross section24, the cross section24and the reflow hole221are both arranged in the balloon1, the reflow hole221is arranged in the outer balloon12, and may be in communication with the fluid in the outer balloon12, which ensures that the fluid in the balloon reflows to the fluid outflow cavity22through the reflow hole221. The cross section24and the reflow hole221are both sequentially arranged at the proximal end of the balloon1, so that the liquid may flow out of the reflow hole221after filling the balloon1, and the problems that the liquid flows out of the reflow hole221without filling the balloon1, resulting in a low utilization of the fluid are avoided.

Further, please refer toFIG.6, as a specific implementation of the cryoablation catheter provided by the present application, the balloon1adopts a double-layer balloon1, and the nozzle holes221include a first nozzle hole2111that injects the liquid into a gap between the double-layer balloon1and a second nozzle hole2112that injects the liquid into the double-layer balloon. Specifically, the double-layer balloon1means that the balloon1has an inner balloon11and an outer balloon12, the inner balloon11is wrapped in the outer balloon12, there is a gap between the inner balloon11and the outer balloon12, so that the fluid may flow between the inner balloon11and the outer balloon12, the proximal ends of the inner balloon11and the outer balloon12are directly fixed to an outer edge of the fluid outflow cavity22, and the distal ends are fixed to the end connector5. The first nozzle hole2111is arranged in the inner balloon11to inject the liquid into the inner balloon11, and may include a plurality of nozzle holes uniformly arranged in the inner balloon11, and the nozzle holes may be surrounded into an annulus and uniformly arranged at intervals. The second nozzle hole2112is arranged in the inner balloon11, and also is an annulus to inject the liquid into the inner balloon11. The stability of the whole balloon1can be improved through the double-layer balloon1, moreover, the liquid between the inner balloon11and the outer balloon12is cooled by the liquid in the inner balloon11, the heat transmission ensures that a cooling degree of the liquid between the inner balloon11and the outer balloon12is high, and a cooling region is relatively uniform, which effectively avoids the problem of nonuniform heat and cold prone caused by a single-layer balloon.

Preferably, the spray head211is arranged in the balloon1, the first nozzle hole2111is circumferentially arranged at a distal end of the spray head211in a single row, and the second nozzle hole2112is circumferentially arranged in the middle of the spray head211in a multi-row.

Since in front of the cross section24, the fluid outflow cavity22needs to be in direct communication with the interior of the balloon1, the fluid inflow cavity21and the guide wire cavity23are both directly arranged in the fluid outflow cavity22in front of the cross section24, the reflow hole221is directly arranged on the fluid outflow cavity22, namely on an outer side wall of the whole delivery catheter2, so that a reflow effect is better, and the structure and processing are relatively simple. Behind the cross section24, the fluid outflow cavity22has been sealed by the cross section24, that is, there is no fluid outflow cavity22. The fluid inflow cavity21is sequentially connected to the spray head211and the end connector5. The spray head211is in communication with the interiors of the inner balloon11and the outer balloon12and delivers the fluid into the interiors, the reflow hole221is not arranged in the inner balloon11, according to a fluid flow law, when filling the inner balloon11, the fluid may flow from the second nozzle hole2112; and when the inner balloon11is fully filled, the fluid may flow out of the second nozzle hole2112, and such design has a better effect and relatively simple structure and processing.

Further, please refer toFIG.5, as a specific implementation, before the cross section24, the fluid inflow cavity21and the guide wire cavity23are arranged in the fluid outflow cavity22in parallel. Specifically, in front of the cross section24, an outer side wall of the delivery catheter2is an outer side wall of the fluid outflow cavity22, and two parallel tube wires of the fluid inflow cavity21and the guide wire cavity23are arranged in the delivery catheter2. A separate blocking component (not marked in figure) is arranged at the cross section24, an outer edge of the blocking component directly abuts against an inner side wall of the delivery catheter2, the blocking component is provided with a through hole for the tube wires of the fluid inflow cavity21and the guide wire cavity23to pass through, the through hole is in sealing connection with the fluid inflow cavity21or the guide wire cavity23, that is, at this time, the fluid outflow cavity22is partitioned by the blocking component, and the fluid inflow cavity21and the guide wire cavity23can still deliver. Behind the cross section24, the fluid inflow cavity21is no longer provided with a separate tube wire, that is, the fluid inflow cavity21is directly connected to the spray head211, and the guide wire cavity23is still provided with a separate tube wire. The catheter prepared by this mode is provided with a separate tube wire in front of the cross section24, and then is adjusted behind the cross section24, that is, processing can be facilitated, the structure is relatively simple, and processing is convenient.

Of course, according to the actual situations and specific needs, in other embodiments of the present application, it may further be: in front of the cross section24, the fluid outflow cavity22, the fluid inflow cavity21and the guide wire cavity23are all separate tube wires, a connecting catheter is arranged at the cross section24, and is provided with a sealing wall at the cross section24, the tube wire of the fluid outflow cavity22may be directly and fixedly arranged on the connecting catheter in a sleeving mode and in communication with the connection catheter, and is sealed by the blocking cross section24. The fluid inflow cavity21and the guide wire cavity23may both directly pass through the sealing wall, the fluid inflow cavity21is no longer provided with a separate tube wire after passing through the sealing wall, so that the fluid directly flows into the connecting catheter, the guide wire cavity23is still provided with a separate catheter body, so that the normal operation of a guide wire is ensured, and there is not unique limitation here.

Since in the embodiment, when the guide wire cavity23is close to the cross section24, the guide wire cavity23approaches to the middle of the fluid inflow cavity21from the side wall of the fluid outflow cavity22, the fluid flow velocity on both sides of the fluid inflow cavity21close to the cross section24is inconsistent, that is, the fluid flow velocity on both sides of the guide wire cavity23in a region where bending occurs is different. Therefore, in order to ensure the uniformity of heat exchange in the balloon1, the first nozzle hole2111is arranged on one side away from the cross section24.

A spray head211of a catheter body is arranged on the outer side of the fluid inflow cavity21in a sleeving mode, the spray head211of the catheter body is in communication with the fluid inflow cavity21, and the first nozzle hole2111and the second nozzle hole2112are both formed in the spray head211of the catheter body. Through the transfer of the spray head211of the catheter body, the first nozzle hole2111and the second nozzle hole2112can uniformly spray out the fluid, so that the uniformity of heat exchange in the balloon1is ensured.

Further, please refer toFIG.6, as a specific implementation of the cryoablation catheter provided by the present application, the reflow hole221is located in the gap between the double-layer balloon1, the first nozzle hole2111is located at the distal end of the double-layer balloon1, and the reflow hole221is located at the proximal end of the double-layer balloon1. Since a volume in the inner balloon11is limited, and a reflow hole221is not arranged in the inner balloon11, the liquid sprayed by the second nozzle hole2112needs to reflow into the spray head211through the second nozzle hole2112, and then is sprayed between the inner balloon11and the outer balloon12by the first nozzle hole2111, so that the liquid can be recycled, and the liquid flowing into the inner balloon11may further cool the liquid between the inner balloon11and the outer balloon12repeatedly, so as to ensure the uniformity of internal cooling of the whole balloon1. The reflow hole221is arranged at the proximal end of a flow channel between the inner balloon11and the outer balloon12, which can ensure that the liquid can realize complete circulation in the double-layer balloon1, and avoid that the liquid directly flows out of the reflow hole221without circulation. Of course, according to the actual situations and the specific needs, in other embodiments of the present application, the reflow hole221may also be arranged on one side, close to the proximal end, of the interior of the inner balloon11, and there is no unique limitation here.

Preferably, the reflow hole221is arranged in the outer balloon12, at this time, it can be ensured that the fluid flows into the outer balloon12through the interior of the inner balloon11to flow out, so that the fluid in the balloon1may fully flow.

Please refer toFIG.7toFIG.12, as another specific implementation of the cryoablation catheter provided by the present application, the difference between this embodiment and embodiment 1 is that the balloon1adopts a single-layer balloon, the proximal end of the balloon1is directly fixed to an outer edge of the fluid outflow cavity22, and the distal end is fixed to the end connector5. The spray head211injects the liquid into the balloon1, and the reflow hole221is located on an inner side of a side wall of the proximal end of the balloon1. The spray head211may only include second nozzle holes2112which directly inject the liquid into the balloon1.

The plurality of second nozzle holes2112directly and uniformly surround the outer side of the spray head211at intervals, and the second nozzle holes2112may further extend in a transmission direction of the delivery catheter2. The reflow hole221is arranged at the proximal end of the balloon1, and the reflow hole221is arranged in the balloon1, which can ensure that the liquid can realize complete circulation in the balloon1, and avoid that the liquid directly flows out of the reflow hole221without circulation.

Please refer toFIG.13toFIG.16, as another specific implementation of the cryoablation catheter provided by the present application, the difference between this embodiment and embodiment1is that the delivery catheter2adopts a multi-cavity duct, before the cross section24, the fluid inflow cavity21and the guide wire cavity23are both arranged in the fluid outflow cavity22. After the cross section24, the guide wire cavity23is arranged in the fluid inflow cavity21, and before the cross section24, the fluid inflow cavity21is located in the fluid outflow cavity22, and the guide wire cavity23is located in the fluid inflow cavity21. Specifically, the delivery catheter2adopts a mode of nesting multiple ducts layer by layer, since in front of the cross section24, the fluid outflow cavity22needs to be in direct communication with the interior of the balloon1, the fluid outflow cavity22is located at the outermost layer in front of the cross section24, a catheter body of the fluid inflow cavity21is directly arranged in the fluid outflow cavity22, and the outer side of the duct of the fluid inflow cavity21is the fluid outflow cavity22; then the catheter body of the guide wire cavity23is directly arranged in the fluid outflow cavity22, and the outer side of the duct of the guide wire cavity23is the fluid inflow cavity21; and at this time, the reflow hole221may be directly arranged on an outer side wall of the whole delivery catheter2, so that the reflow effect is better, and the structure and processing are relatively simple.

Behind the cross section24, a gap between the outer edge of the fluid inflow cavity21and the delivery catheter2is sealed by the cross section24, that is, there is no fluid outflow cavity22, a blocking method of the cross section24at this time may be that the inner side wall of the fluid outflow cavity22is adhered to the outer side wall of the delivery catheter2, or the tail end of the fluid outflow cavity22is sealed by arranging a blocking piece, and at this time, a blocking effect of the cross section24can be realized. The spray head211of the fluid inflow cavity21needs to be connected to the interior of the balloon1, and deliver the fluid into the balloon1, therefore, the fluid inflow cavity21is directly arranged on the outermost part of the delivery catheter2, and at this time, the outer wall of the fluid inflow cavity21may be directly attached and fixed to the outer wall of the delivery catheter2. The spray head211is directly arranged on the outer side of the fluid inflow cavity21in a sleeving mode, so that the liquid flows into the balloon1through the spray head211; or the spray head211and the fluid inflow cavity21are directly one component, and the nozzle holes are directly formed in the side wall of the fluid inflow cavity21, so that a spraying effect of the nozzle holes is better, and the structure and processing are relatively simple.

Preferably, in the embodiment, since the guide wire cavity23is always located in a middle region of the whole delivery catheter2, the flow velocity and flow rate of the fluid on both sides of the guide wire cavity23are the same, so the spray head211may be a through hole directly formed in the side wall of the fluid inflow cavity21, and the effect of uniform head exchange can be realized.

Further, referring toFIG.6, as a specific implementation of the cryoablation catheter provided by the present application, before the cross section24, the fluid outflow cavity22, the fluid inflow cavity21and the guide wire cavity23are concentric round tube. Specifically, the nesting mode of the fluid outflow cavity22, the fluid inflow cavity21and the guide wire cavity23is nesting of layer by layer, the mode adopting the concentric round tube is that the three cavities are concentric, at this time, the production and processing may be more facilitated, it can be ensured that the flow of the liquid on both sides is consistent, and the problem of excessive flow on single side is avoided.

Please refer toFIG.17, as another specific implementation of the cryoablation catheter provided by the present application, the difference between this embodiment and embodiment 1 is that the balloon1still adopts a double-layer balloon1, but the delivery catheter2adopts a multi-cavity duct, the structure and layout of the double-layer balloon1are consistent with those in embodiment 1, and the delivery catheter2is consistent with the delivery catheter2in embodiment 3 in structure.

Apparently, the above embodiments are only examples for clear explanation, and are not limited to the implementations. For ordinary technical personnel in the art, other different forms of variations or changes may further be made on the basis of the above description. It is unnecessary and impossible to enumerate all the implementations here. The apparent variations and changes introduced thereby are still within the scope of protection created by the present application.