Low-temperature ablation device

Abstract

The cryoablation device of the present invention utilizes a first distal balloon and a second proximal balloon attached to a shaft. The proximal balloon is used to position the distal balloon, which is also referred to as the cryoballoon, and is supplied with a cooling medium for performing cryoablation. The shaft is used to deliver the balloons to a target location within the patient's body and provides multiple lumens, for example, for supplying medium to the proximal and distal balloons, respectively.

Description

Technical Field

[0001] The present invention relates to a cryoablation device including a cryoballoon that uses a coolant supplied to the cryoballoon, particularly for performing cryoablation of the stomach.

Background Art

[0002] Obesity is the cause of many serious diseases such as diabetes, joint disorders, and heart failure. In addition to non-invasive treatments such as diet and sports activities, there are also effective invasive surgical treatments and interventional treatments such as sleeve gastrectomy, gastric band surgery, intragastric balloon, gastric bypass surgery, gastric pacemaker, Botox injection, and resection of the vagus nerve gastric branches.

[0003] When ablating (burning) the pulmonary veins of atrial fibrillation, the principle of circumferential cryoablation is applied.

Summary of the Invention

[0008] This section describes the general features of the present invention with reference, for example, to possible embodiments of the invention.

[0009] The present invention relates to a cryoablation device comprising a shaft having a proximal end and a distal end, a first balloon located at the distal end of the shaft, and a second balloon located on the shaft adjacent to the first balloon. The first balloon is a cryoablation balloon, also called a distal balloon or cryoablation balloon. The second balloon is a positioning balloon, also called a proximal balloon or a positioning and protective balloon. The shaft can be, for example, a multi-lumen catheter.

[0010] In this context, the phrase "at the distal end of the shaft" means that the shaft either does not protrude distally beyond the first balloon at all, or protrudes distally beyond the first balloon by its maximum length, which may be an absolute length such as 5 cm, 2 cm, 1 cm, 0.5 cm, 0.2 cm, or 0.1 cm, or a fraction of the shaft length such as 5%, 2%, 1%, 0.5%, 0.2%, or 0.1%.

[0011] The distal end of the shaft can be positioned within the first balloon. In this case, the first balloon can rotate around the distal end of the shaft. In another embodiment, the first balloon is positioned entirely on the shaft, meaning that both the proximal and distal ends of the first balloon are connected to the shaft.

[0012] During use, the distal end of the shaft is introduced into the patient, and the first and second balloons, both in a deflated state, are brought to the target site for ablation. For example, the distal end of the shaft is inserted orally and guided through the esophagus to the stomach. The shaft is preferably flexible.

[0013] The shaft includes at least one first outlet within the first balloon and at least one first supply lumen ending with at least one first outlet. A cryogenic medium, such as N2O or CO2, is supplied into the first balloon through the first supply lumen and the first outlet. The cryogenic medium inflates the first balloon, causing it to adhere to or remain stationary in contact with the tissue to be treated. The cryogenic medium then reduces thermal energy from the tissue in contact with the first balloon.

[0014] The first outlet can function as a throttle to expand the cryogenic medium as it moves from the first supply lumen into the first balloon.

[0015] The first outlet can be called a cryogenic outlet, and the first supply lumen can be called a cryogenic supply lumen.

[0016] The other end of the first supply lumen, i.e., the end not ending at at least one first outlet, is connected to a cryogenic medium source, such as a cryogenic medium tank or cartridge. This connection may be direct or indirect, with indirect meaning via an additional conduction located at the proximal end of the shaft.

[0017] The shaft further includes at least one second outlet in the second balloon and at least one second supply lumen ending with at least one second outlet. A packing medium is supplied into the second balloon through the second outlet and the second supply lumen. The packing medium may be a liquid such as water or saltwater, or a gas such as air. The packing medium inflates the second balloon.

[0018] The other end of the second supply lumen, i.e., the end not ending at at least one second outlet, is connected to a filling medium source, such as a syringe or pump connected to a filling medium tank. This connection can be made directly or indirectly via an additional conduction located at the proximal end of the shaft. The filling medium can be supplied to or removed from the second balloon, for example, through the same second lumen.

[0019] The second balloon has several functions. Its first function is to position the cryoablation device, and therefore the first balloon, at the target position. In the case of gastrectomy, the second balloon prevents the shaft, and therefore the first balloon, from being pulled into the esophagus. Its second function is to straighten the stomach wall when a pulling force is applied to the shaft. This pulling force straightens the stomach in the cranial-caudal direction, or longitudinally, so that the first balloon contacts the stomach wall along a closed curve. This makes complete circumferential resection possible.

[0020] Each of the first and second balloons may have a skin that is tightly bonded to the shaft along its entire outer circumference. Tight bonding means that the cryogenic medium cannot escape from between the shaft and the first balloon, and the packing medium cannot escape from between the shaft and the second balloon. Thus, the combination of the shaft and the first or second balloon forms a volume containing either the cryogenic medium or the packing medium, respectively.

[0021] In one embodiment, the second balloon and the first balloon are made of a single outer shell that is securely connected to the shaft at at least two locations: the proximal side of the second balloon and the boundary between the second and first balloons. Optionally, the first balloon may also be securely connected to the shaft at its distal end. However, the second balloon and the first balloon can also be made of completely separate outer shells.

[0022] In one aspect, the outer shapes of the first balloon and the second balloon are rotationally symmetric with respect to the shaft. This means that the cross-section in a plane perpendicular to the shaft of each balloon is circular. In this aspect, the cryoablation device is basically rotationally invariant, at least at the target position. Therefore, when using this device, shaft rotation alignment, and thus balloon rotation alignment, is not necessary. However, it is possible to adjust the shape of the first balloon and / or the second balloon according to the shape of the tissue to be treated.

[0023] The shape can be, for example, disc-shaped or donut-shaped with parallel or inclined shoulders.

[0024] Note that the shaft typically has flexibility such that its distal end can be moved to the target position. The shaft has a shaft axis defined as the center of the shaft along the proximal-distal direction of the shaft. A plane perpendicular to the shaft means that the plane is perpendicular to the tangent of the shaft axis at the position where the plane intersects the shaft.

[0025] In one aspect,the diameter of the second balloon is 2.5 - 5 cm, and the diameter of the first balloon is 1.25 - 2 times the diameter of the second balloon. In this document, unless otherwise specified, all balloon sizes and / or ratios are shown in the inflated state at the nominal pressure. The nominal pressure is greater than the pressure at the target point, for example, up to 1 atmosphere, particularly 0.5 atmosphere.

[0026] In a cryoablation device for gastrectomy, the diameter of the first balloon is, for example, greater than 5 cm, for example, 6 - 10 cm. The diameter of the second balloon is, for example, 3 - 4 cm.

[0027] In one aspect, the first balloon and the second balloon are short. Here, "short" means that the maximum diameter of the balloon is larger than the length of the balloon, for example, 2 times, 3 times, or 4 times. The length of the balloon means the distance along the shaft where both ends (proximal end and distal end) of the balloon are firmly connected to the shaft. It can also be measured as the maximum spread of the balloon in the shaft direction. The length of the second balloon and / or the first balloon is, for example, 25 mm or less.

[0028] Due to the short characteristic of the balloon, especially the first balloon, the contact area between the balloon and the treatment target tissue becomes small. Therefore, in one aspect, the first balloon is short and the second balloon is not necessarily short.

[0029] The second balloon and / or the first balloon is made of, for example, a semi-compliant material. A balloon made of a semi-compliant material, that is, a semi-compliant balloon, only slightly increases in size as the internal pressure increases when the balloon reaches its nominal size.

[0030] In one aspect, the distance between the first balloon and the second balloon along the shaft is 5 cm or less, for example, 2 cm, 1 cm, 0.5 cm, or less. Here, the distance means the distance between the distal end of the second balloon and the proximal end of the first balloon. The end of the balloon is the point firmly connected to the shaft.

[0031] The distance between the first balloon and the second balloon is typically selected according to the desired use of the cryoablation device. In the case of gastric wall resection, the height in the cephalocaudal direction where the tissue is resected is defined by the distance between the second balloon and the first balloon when a tensile force is applied to the shaft so that the second balloon contacts the esophagus. At this time, the first balloon has a defined distance to the cardia.

[0032] In one embodiment, the shaft further comprises a first exhaust lumen connected to the interior of the first balloon. Through the first exhaust lumen, the cryogenic medium can be removed from the first balloon, for example, to deflate the first balloon or to allow a constant flow of the cryogenic medium, thereby removing the cryogenic medium heated during ablation and supplying fresh cryogenic medium. The first exhaust lumen can be coupled to a pump or other device for removing the cryogenic medium from the first balloon. This coupling can be done directly at the proximal end of the shaft or indirectly via an additional conduction located at the proximal end of the shaft.

[0033] In one embodiment, the shaft comprises a plurality of first outlets distributed around the outer circumference of the shaft or at the distal end of the shaft. The plurality of cryogenic outlets are, for example, evenly distributed around the outer circumference of the shaft. The plurality of outlets are located at the distal end of the shaft, for example, when the shaft terminates inside a first balloon.

[0034] Multiple first outlets allow the temperature of the outer surface of the first balloon that comes into contact with the tissue to be made as uniform as possible. The shaft is composed of, for example, 4, 6, 8, 10, 12, or 16 first outlets.

[0035] In one embodiment, the number of first supply lumens is equal to the number of first outlets. In this embodiment, each of the first supply lumens is associated with exactly one first outlet and terminates at the first outlet. By adjusting the supply of cryogenic medium to multiple first supply lumens, the temperature distribution around the circumference of the first balloon in contact with the tissue can be controlled. The greater the amount of cryogenic medium supplied to a particular first outlet, the lower the temperature of the outer circumference of the first balloon at the location facing that particular first outlet.

[0036] However, it is also possible to provide a first supply lumen with fewer first outlets than the first outlet. In this case, one first supply lumen can end in two or more first outlets.

[0037] In one embodiment, the first supply lumen is uniformly distributed around the inner circumference of the shaft. However, it is also possible to group two or more first supply lumen together, in which case the group of first supply lumen is uniformly distributed around the inner circumference of the shaft.

[0038] In one embodiment, the shaft further comprises a venting lumen having an outlet to the outside of the shaft at its distal end. The venting lumen communicates, for example, the distal end of the shaft with the outside of the patient's body. In this embodiment, the distal end of the shaft can mean any position on the shaft, or the distal end face of the shaft distal to the distal end of the first balloon. In the case of gastric wall ablation, the venting lumen connects the stomach to the outside of the patient in order to release digestive gases from the stomach and introduce outside air into the stomach. If the first balloon ruptures, the cryogenic medium is discharged from the stomach through the venting lumen, thus avoiding gastric over-inflation and discomfort. The same applies to the filling medium if the second balloon ruptures.

[0039] In one embodiment, the ventilation lumen and the second supply lumen are located radially opposite each other within the shaft. This results in the shaft's cross-section being essentially mirror-symmetric.

[0040] In one embodiment, the ventilation lumen and the second supply lumen are located within the wall of the shaft. This means that the wall of the shaft forms both the ventilation lumen and the second supply lumen.

[0041] In one embodiment, at least one first supply lumen, at least one second supply lumen, and at least one ventilation lumen, preferably each, has a circular cross-section in a plane perpendicular to the shaft.

[0042] In one embodiment, the interior of the shaft not occupied by at least one first supply lumen, at least one second supply lumen, and the ventilation lumen forms a first exhaust volume, to the extent applicable.

[0043] The shaft has, for example, a circular cross-section. In one embodiment, the shaft has an outer diameter of less than 8 millimeters, for example, 5 to 7 millimeters, and especially 6 millimeters.

[0044] In one embodiment, the second balloon and / or the first balloon has two shoulders tightly coupled to the shaft at their radially inner ends, and a connecting portion connecting the radially outer ends of the two shoulders. The shoulders and the connecting portion may be formed integrally or by joining two or more parts. In one example, the balloon is continuous at the transition from the shoulder to the connecting portion. This means that at the intersection of the balloon and a plane on the shaft axis, the tangents to the shoulders and the connecting portion are the same at the transition point.

[0045] In one embodiment, for example, the shoulder of the first balloon has a truncated cone shape with an opening angle between 70 and 85 degrees, for example between 72 and 78 degrees, and particularly between 75 degrees.

[0046] This means that at the intersection of the side wall and the plane parallel to the shaft axis, the angle between the shoulders is 140 to 170 degrees, for example, 144 to 156 degrees, and especially 150 degrees.

[0047] The conical shoulder portion is positioned around the axis of the shaft, for example, at the point where the shoulder portion connects to the shaft.

[0048] In one embodiment, the connection is a curved connection between the radially outer ends of the shoulder portions. The curved connection has a constant radius, for example, 4 to 7 millimeters, and particularly 5 millimeters.

[0049] The shaft may have a fitting at or near its proximal end. For example, near the proximal end means starting at a distance of less than 15 cm, less than 10 cm, or less than 5 cm from the proximal end. The only limitation is that when the first balloon is at its target position, the fitting is located outside the patient. The fitting has at least one connector, which connects to one of the first supply lumen, the second supply lumen, the first exhaust lumen, or the ventilation lumen. The connector may be a standardized type, such as a Luer connector.

[0050] In one embodiment, the cryogenic ablation apparatus includes a cryogenic medium supply conveyor, such as a tank or cartridge connected to a first supply lumen, for supplying the cryogenic medium into a first balloon through a first supply lumen. The cryogenic medium supply conveyor is connected, for example, to a corresponding connector of a shaft joint.

[0051] In one embodiment, the cryogenic ablation apparatus includes a cryogenic medium exhaust conveyor, such as a pump connected to a first exhaust lumen, for removing the cryogenic medium from a first balloon through a first exhaust lumen. The cryogenic medium exhaust conveyor is connected, for example, to a corresponding connector of a shaft joint. Instead of using a cryogenic medium exhaust conveyor, the cryogenic medium may be exhausted from the first balloon solely by the pressure inside the first balloon. The cryogenic medium exhaust conveyor can facilitate the deflation of the first balloon for removal from a target position.

[0052] In one embodiment, the cryoablation apparatus includes a packing medium conveyor, such as a syringe, connected to a second supply lumen for supplying a packing medium to a second balloon via a second supply lumen and / or for removing the packing medium therefrom. The packing medium discharge conveyor is connected, for example, to a corresponding connector of a shaft joint.

[0053] In one embodiment, the cryoablation apparatus includes at least one marker. This marker can be used to locate the distal end of the shaft and / or at least one of the second balloon and the first balloon in the patient's medical image. This marker may be a radiopaque marker visible in X-ray images or a marker visible in ultrasound images.

[0054] In one embodiment, the marker may be positioned at the distal end of the shaft, that is, distal to the first balloon. In another embodiment, the marker may be attached to the balloon. The marker may, for example, have the shape of a circular ring centered on the shaft and may be positioned on or on part of the balloon's outer shell.

[0055] In yet another embodiment, the marker is placed on the portion of the shaft that remains outside the patient when the first balloon is in the target position. Such a marker allows monitoring of the insertion depth of the shaft, for example, before inflating the first balloon.

[0056] For example, the present invention does not, particularly does not, or includes any invasive steps that would require specialized medical expertise to perform and would involve substantial physical interference with the body, even if performed with the necessary professional care and expertise, thus posing a substantial health risk.

[0057] For example, the present invention does not include the step of inserting the distal end of the shaft and the balloon into the patient. For this reason alone, the implementation of the present invention does not require or imply any surgical or therapeutic action, in particular a surgical or therapeutic step.

[0058] The present invention will be described below with reference to accompanying drawings illustrating specific embodiments of the invention, and then to the background. However, the scope of the present invention is not limited to the specific features disclosed in the context of the drawings. [Brief explanation of the drawing]

[0059] [Figure 1] Figure 1 shows a typical structure of a cryoablation apparatus. [Figure 2] Figure 2 is a cross-sectional view of the apparatus shown in Figure 1. [Figure 3] Figure 3 shows the supply of the packing medium to the second balloon and the removal of the packing medium from the second balloon. [Figure 4] Figure 4 shows the supply and removal of the cryogenic medium to the first balloon. [Figure 5] Figure 5 is a cross-sectional view of the first balloon. [Figure 6] Figure 6 shows the shape of the first balloon. [Modes for carrying out the invention]

[0060] Figure 1 shows an exemplary structure of a cryogenic ablation apparatus 1 according to the present invention. The apparatus 1 comprises a flexible shaft 2 having a distal end 2a, a second balloon 3, and a first balloon 4. The first balloon 4 is also called a cryogenic balloon. The second balloon 3 and the first balloon 4 are firmly attached to the shaft 2. That is, the shaft 2 and the second balloon 3 form a second volume for the packing medium, and the shaft 2 and the first balloon 4 form a first volume for the cryogenic medium.

[0061] The cryoablation apparatus according to this embodiment is designed for cryoablation of the stomach wall. The shaft 2, the second balloon 3, and the first balloon 4 are sized appropriately for this application.

[0062] In this exemplary embodiment, the external shapes of the second balloon 3 and the first balloon 4 are rotationally symmetric with respect to the shaft 2. The first balloon 4 is closer to the distal end 2a of the shaft 2 than the second balloon 3.

[0063] The upper part of Figure 2 shows a cross-sectional view of the low-temperature ablation apparatus 1, and the lower part of Figure 2 shows an enlarged cross-section of the shaft 2 in a plane perpendicular to the plane of the cross-section in the upper part of Figure 2.

[0064] As can be seen from Figure 2, the length of the second proximal balloon 3 is l p The length of the first low-temperature balloon 4 is l c It is smaller than. In this embodiment, the length l of the second balloon 3 p The length of the first balloon 4 is in the range of 4 to 25 millimeters, for example, about 16 millimeters. c This range is 5 to 35 millimeters, for example, about 24 millimeters. In this embodiment, the term "length" refers to the range of volume enclosed by the balloons corresponding to the direction of shaft 2. This range ends where each balloon is firmly connected to shaft 2.

[0065] In this embodiment, the distance f between the distal end 2a of the shaft 2 and the first balloon 4 is equal to the length l of the first balloon 4. c It is smaller than, for example, about 1 to 10 millimeters. The distance d between the second balloon 3 and the first balloon 4 along the shaft 2 is equal to the length l of the second balloon 3. p It is less than one-quarter of the length, for example, 1 to 4 millimeters. Distance d means the distance between the distal end of the volume enclosed by the second balloon 3 and the proximal end of the volume enclosed by the first balloon 4. Here, the end of the volume is the position where the corresponding balloon is firmly connected to the shaft 2.

[0066] The low-temperature ablation apparatus 1 further has a joint 5 at the proximal end of the shaft 2.

[0067] As shown in the lower part of Figure 2, the shaft 2 has a circular outer shape and is composed of several different lumens. The first supply lumen 9 supplies cryogenic medium to the first balloon 4. The second supply lumen 11 supplies filling medium to the second balloon 3. The vent lumen 12 connects the distal end 2a of the shaft 2 to the gastric vent 8 of the joint 5. Through the vent lumen 12 and the gastric vent 8, air or other gases can flow from the stomach to the outside of the patient, or vice versa.

[0068] The remaining volume within shaft 2 forms a first exhaust lumen 10 for removing the cryogenic medium from the first balloon 4.

[0069] As shown in the lower part of Figure 2, the second supply lumen 11 and the ventilation lumen 12 are formed within the wall of the shaft 2.

[0070] Within the joint 5, the second supply lumen 11 is connected to the filling medium port 7, and through this filling medium port 7, the filling medium can be supplied to the second balloon 3 from a filling medium reservoir (not shown), such as a syringe, via the second supply lumen 11. On the other hand, the filling medium can be returned from the second balloon 3 to, for example, a filling medium reservoir, via the second supply lumen 11 and the filling medium port 7.

[0071] At the proximal end of shaft 2, connector 13 is connected to a first supply lumen 9, allowing the flow of cryogenic medium from a cryogenic medium reservoir (not shown) through the first supply lumen 9 into the first balloon 4. A first exhaust lumen 10 is connected to and terminates at an exhaust port 6. The cryogenic medium is removed from the first balloon 4 through the first exhaust lumen 10 and the exhaust port 6. This is achieved by the pressure inside the first balloon 4 or by an additional pump (not shown) connected to the exhaust port 6.

[0072] Initially, for example, the second balloon 3 and the first balloon 4 are deflated to introduce the distal end 2a of shaft 2 into the stomach through the esophagus along with the two balloons.

[0073] Figure 3 is a cross-sectional view of a portion of the cryoablation apparatus 1, with the cross-sectional plane passing through the second supply lumen 11 and the ventilation lumen 12. As shown in this figure, the cryoablation apparatus 1 includes a second supply port 14 within the second balloon 3. The second supply lumen 11 terminates at the second supply port 14. The packing medium can be supplied to the second balloon 3 through the second supply lumen 11 and the second supply outlet 14 to inflate the second balloon 3. To deflate the second balloon 3, the packing medium is removed through the second supply outlet 14 and the second supply lumen 11. The movement of the packing medium is indicated by arrows in the second supply lumen 11, the second supply port 14, and the second balloon 3.

[0074] For cryoablation of the gastric wall, the distal end 2a, the first balloon 4, and the second balloon 3 are inserted into the stomach, and the second balloon 3 is inflated first. Then, by pulling the shaft 2 in the cranial direction, the second balloon 3 comes into contact with the gastric wall, slightly stretching the stomach. Stretching the stomach has the effect of the inflated first balloon 4 coming into contact with the gastric wall all around. The force with which the shaft 2 is pulled can be, for example, in the range of 0.5 kilograms to 2.5 kilograms, for example, 1 kilogram or 10 Newtons. The first balloon 4 can be inflated before pulling the shaft 2, after pulling it, or after inflating the second balloon 3.

[0075] Similar to Figure 3, Figure 4 is a cross-sectional view of a portion of the cryoablation apparatus 1, but the cross-sectional plane is slightly rotated around the axis of the shaft 2 and intersects a portion of the first supply lumen 9. As shown in Figure 4, the shaft 2 includes a plurality of first outlets 15 in the first balloon 4. Each first outlet 15 is connected to one of the first supply lumen 9, and the cryogenic medium, such as N2O or CO2, supplied through the first supply lumen 9 flows toward the first balloon 4, is constricted through the first outlets 15 inside the first balloon 4, and as a result its inner surface is cooled (Joule-Thomson effect). As indicated by the arrows, the expanded cryogenic medium flows through the first balloon 4 and sprays against the inner surface of the first balloon 4, freezing the tissue in contact with the first balloon 4 by heat conduction.

[0076] The shaft 2 is further equipped with a first outlet 16 within the first balloon 4 and is connected to a first exhaust lumen 10. The cryogenic medium cools the outer shell of the first balloon 4 and then exits the first balloon 4 through the first outlet 16 and the first exhaust lumen 10. This means there is a continuous flow of cryogenic medium for continuous cooling of the inner surface of the first balloon 4.

[0077] Figure 5 is a cross-sectional view of the shaft 2 and the first balloon 4, with the cross-sectional plane perpendicular to the axis of the shaft 2. In the embodiment of the cryoablation apparatus 1 shown in this figure, the shaft 2 includes four first outlets 14 and four first supply lumens 9. For simplicity, only one first outlet 14 and one first supply lumen 9 are numbered.

[0078] At each first outlet 14, the cryogenic medium is constricted against the inner surface of the first balloon 4 at a specific opening angle, as shown by the dashed lines. The opening angle is preferably selected so that the cryogenic medium is constricted around the entire circumference of the first balloon 4 facing the first outlet 14.

[0079] The first outlets 14 are preferably evenly distributed around the outer circumference of the shaft 2. They may have the shape of slits running circumferentially around the shaft 2. In this context, the shape of the slits means that the length of the first outlets 14 in the circumferential direction of the shaft 2 is greater than the width of the first outlets 14 in the axial direction of the shaft 2.

[0080] Figure 6 shows exemplary dimensions of the first balloon 4. The first balloon 4 is rotationally symmetric with respect to the shaft 2 and has a maximum diameter of 60 millimeters. Its length is 24 millimeters. The first balloon 4 is formed of two shoulders 17 and a curved connector 18 connecting the radially outer ends of the shoulders 17. Each shoulder 17 resembles a truncated cone and is firmly connected to the shaft 2 at its smaller diameter end. The opening angle of the conical shoulders 17 is 75 degrees, which is the angle between the shoulder and the axis of the shaft 2. As a result, the angle between the opposing line segments forming the shoulders 17 is 150 degrees.

[0081] The curved connector 18 has a constant radius of 5 millimeters, but can have any shape as long as it closes the gap between the shoulders 17. Preferably, the curved connector transitions to the shoulder in a stable manner. In this embodiment shown in Figure 6, this is achieved by the curved connector 18 being an arc extending at least 150 degrees. Generally, the transition is stable if the arc extends at least twice the opening angle of the conical shoulders 17.

[0082] The second balloon 3 has the same structure, consisting of a curved connecting portion between the shoulder and the radially outer end, but may have a smaller diameter.

Claims

1. A shaft (2) having a proximal end and a distal end (2a), A first balloon (4) is positioned at the distal end (2a) of the shaft (2), A second balloon (3) is positioned on the shaft (2) in close proximity to the first balloon (4) and Equipped with, The shaft (2) is The first balloon (4) has at least one first outlet (15), At least one first supply lumen (9) ending at at least one first outlet (15), The second balloon (3) has at least one second outlet (14), At least one second supply lumen (11) ending at at least one second outlet (14) and It has, The shaft (2) has a plurality of first outlets (15) distributed around the outer circumference of the shaft (2) or at the distal end (2a) of the shaft (2), The number of the first supply lumens (9) is equal to the number of the first outlets (15), or less than the number of the first outlets (15). A low-temperature ablation apparatus (1) characterized by the following:

2. The cryogenic ablation apparatus (1) according to claim 1, characterized in that the outer shapes of the first balloon (4) and the second balloon (3) are rotationally symmetric with respect to the shaft (2).

3. The cryogenic ablation apparatus (1) according to claim 2, characterized in that the diameter of the second balloon (3) is 2.5 to 5 centimeters, and the diameter of the first balloon (4) is 1.25 to 2 times the diameter of the second balloon (3).

4. The cryoablation apparatus (1) according to any one of claims 1 to 3, characterized in that the first balloon (4) and the second balloon (3) are short.

5. The cryoablation apparatus (1) according to any one of claims 1 to 3, characterized in that the distance between the first balloon (4) and the second balloon (3) along the shaft (2) is 5 cm or less, for example, 2 cm or less.

6. The cryogenic ablation apparatus (1) according to any one of claims 1 to 3, characterized in that the shaft (2) further has a first exhaust cavity (10) connected inside the first balloon (4).

7. The cryoablation apparatus (1) according to claim 1, characterized in that the first supply lumen (9) is uniformly distributed along the inner circumference of the shaft (2).

8. The cryoablation apparatus (1) according to any one of claims 1 to 3, characterized in that the shaft (2) further has a ventilation lumen (12) having an outlet to the outside of the shaft (2) at the distal end (2a) of the shaft (2).

9. The cryogenic ablation apparatus (1) according to claim 8, characterized in that the ventilation lumen (12) and the second supply lumen (11) are arranged on radially opposite sides within the shaft (2).

10. The cryogenic ablation apparatus (1) according to claim 8, characterized in that the ventilation lumen (12) and the second supply lumen (11) are arranged within the wall of the shaft (2).

11. The cryoablation apparatus (1) according to any one of claims 1 to 3, characterized in that the shoulder portion (17) of the first balloon (4) has a truncated cone shape with an opening angle between 70 and 85 degrees.

12. The cryoablation apparatus (1) according to claim 11, characterized in that the first balloon (4) further has a curved connecting portion (18) between the radially outer ends of the shoulder portion (17).

13. The low-temperature ablation apparatus (1) according to claim 12, characterized in that the curved connecting portion (18) has a constant radius of 4 to 7 millimeters.

Images