Ultrasonic ablation catheter and ultrasonic ablation system

Abstract

The invention discloses an ultrasonic ablation catheter and an ultrasonic ablation system, and belongs to the technical field of medical instruments, the ultrasonic ablation catheter comprises a catheter, a tip tube, a balloon and an ultrasonic transducer, the catheter comprises an inner tube and an outer tube, the far end of the inner tube extends out of the outer tube, a guide wire cavity is formed in the inner tube, and a water channel is formed between the inner tube and the outer tube; the tip tube is provided with an internal channel which is communicated with the guide wire cavity; the balloon is arranged on the outer diameter side of the portion, extending out of the outer tube, of the inner tube, an ablation cavity is formed between the balloon and the inner tube, the far end of the balloon is connected with the tube wall of the tip tube, the near end of the balloon is connected with the tube wall of the outer tube, and the water channel is communicated with the ablation cavity. The ultrasonic transducer is located in the ablation cavity and arranged on the outer diameter side of the inner tube in a sleeving mode. The ultrasonic transducer is isolated from the inner wall of the blood vessel through water, the inner wall of the blood vessel in contact with the balloon can be protected, the balloon has the advantages of being simple in structure and convenient to operate, the efficient and uniform ablation effect can be achieved, and a new technical means is provided for treatment of refractory hypertension.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an ultrasonic ablation catheter and an ultrasonic ablation system. Background Art

[0002] Hypertension, as a common and frequently occurring disease of the cardiovascular system, poses a serious threat to the health and life of people around the world. It is defined as an adult systolic blood pressure (SBP) ≥ 140 mmHg and / or diastolic blood pressure (DBP) ≥ 90 mmHg at rest without the use of antihypertensive drugs. It is one of the main factors leading to all-cause mortality worldwide. Although there are currently a variety of antihypertensive drugs available, hypertension is still not effectively controlled in a large number of patients due to poor lifestyle control and drug compliance. What is more serious is that even in the case of strict compliance with antihypertensive drug treatment, about 15% to 18% of hypertensive patients still have poor blood pressure control and eventually develop refractory hypertension (RH). Patients with refractory hypertension often have a poor prognosis and are accompanied by damage to target organs such as the heart, brain, and kidneys. Therefore, effectively controlling the blood pressure of patients with refractory hypertension has become an urgent problem to be solved.

[0003] In recent years, it has been confirmed that overactivation of the sympathetic nervous system plays a vital role in the development of hypertension. Overactivation of the sympathetic nerves not only leads to increased renin secretion, but also causes increased sodium reabsorption in the renal tubules, which in turn causes sodium retention, a key factor in the development and maintenance of hypertension. In order to explore new treatment methods, scholars have tried to control hypertension by surgically removing the sympathetic nerves in the early days, but this method has not been widely promoted due to its high mortality rate and serious complications.

[0004] With the continuous advancement of electrophysiological technology, catheter-based renal sympathetic nerve ablation (RDN) has emerged. This technology destroys the sympathetic nerves around the renal artery through radiofrequency or ultrasonic energy, reduces the activity of systemic sympathetic nerves, and thus effectively treats refractory hypertension. Among them, percutaneous renal artery radiofrequency ablation, as an innovative treatment method, selectively cuts off the renal sympathetic nerves through radiofrequency ablation, achieving a good antihypertensive effect.

[0005] However, the existing renal artery ablation technology still has some shortcomings. For example, when the Paradise system performs renal artery ablation, the transducer and the wire part need to pass a large current, which generates strong heat and often causes system failure. In addition, although the Paradise system uses a one-time 360° surround treatment, its catheter structure is complex, and the wire has a separate lumen and is not in direct contact with the cooling water, which may lead to poor cooling effect. The TIVUS system has the problem of not being able to meet 360° surround emission at one time, and multiple ablations through a rotating catheter are required to achieve comprehensive ablation, which not only increases the difficulty of the operation, but may also cause uneven ablation due to the influence of the vascular path and the catheter body.

[0006] In view of the shortcomings of existing technologies, how to further improve the ablation effect and reduce vascular damage is a technical problem that needs to be solved. Summary of the invention

[0007] The purpose of the present invention is to provide an ultrasonic ablation catheter and an ultrasonic ablation system to solve the problems existing in the above-mentioned prior art. By setting an ultrasonic transducer in the ablation cavity of a balloon and utilizing ultrasonic energy to achieve renal artery ablation, the ultrasonic transducer and the inner wall of the blood vessel are isolated by water, thereby protecting the inner wall of the blood vessel in contact with the balloon. It not only has the characteristics of simple structure and convenient operation, but also can achieve efficient and uniform ablation effect, providing a new technical means for the treatment of refractory hypertension.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] The present invention provides an ultrasonic ablation catheter, comprising a catheter, a tip tube, a balloon and an ultrasonic transducer, wherein the catheter comprises an inner tube and an outer tube, the distal end of the inner tube extends out of the outer tube, the interior of the inner tube is a guidewire cavity, and a water channel is between the inner tube and the outer tube; the tip tube has an internal channel, and the guidewire cavity is connected to the internal channel; the balloon is arranged on the outer diameter side of the portion of the inner tube extending out of the outer tube, an ablation cavity is formed between the balloon and the inner tube, the distal end of the balloon is connected to the tube wall of the tip tube, the proximal end of the balloon is connected to the tube wall of the outer tube, and the water channel is connected to the ablation cavity; the ultrasonic transducer is located in the ablation cavity, and the ultrasonic transducer is sleeved on the outer diameter side of the inner tube.

[0010] In one embodiment, the balloon is a compliant balloon, a semi-compliant balloon, or a non-compliant balloon.

[0011] In one embodiment, a restraining wire is provided on the outer sleeve of the balloon, and pillow portions and groove portions are formed in a spaced relationship along the length of the balloon by the restraint of the restraining wire.

[0012] In one embodiment, the water channel is divided into a water inlet channel and a water outlet channel by a partition, and a wire for connecting the ultrasonic transducer is arranged in the water inlet channel.

[0013] In one embodiment, it also includes a catheter seat, which is connected to the proximal end of the catheter. The catheter seat includes a water inlet interface, a water outlet interface and a plug. The water inlet interface is connected to the water inlet channel, the water outlet interface is connected to the water outlet channel, and the plug is connected to the wire; a stress protection sleeve is provided at the position where the catheter is connected to the catheter seat.

[0014] In one embodiment, the water inlet interface is a male connector, and the water outlet interface is a female connector.

[0015] In one embodiment, the ultrasonic transducer adopts PZT-8 series piezoelectric ceramics, the piezoelectric ceramics have a diameter of 1mm to 2mm, a length of 5mm to 10mm, and a cylindrical structure, and can be mounted on the outer diameter side of the inner tube. The frequency of the ultrasonic transducer is designed to be 7MHz to 10MHz, which is used for 360° surround emission and uniform ablation of the renal artery sympathetic nerves.

[0016] The present invention also provides an ultrasonic ablation system, comprising the ultrasonic ablation catheter and a device host as described above, wherein the device host comprises an ultrasonic controller and a circulating water pump, wherein the ultrasonic controller is used to connect the ultrasonic transducer, and the circulating water pump is used to connect the water channel.

[0017] In one embodiment, a cooling circulation device is further included, wherein the cooling circulation device includes a shell and a pressure sensor disposed in the shell, wherein the pressure sensor is connected to the water channel and is used to monitor the internal pressure of the balloon.

[0018] In one embodiment, the cooling circulation device also includes a double row of pipes, an infusion tube and a water bag, the water channel includes a water inlet channel and a water outlet channel, the first tube of the double row of pipes connects the water inlet channel and the water outlet of the circulating water pump, the second tube of the double row of pipes connects the water outlet channel and the water inlet of the circulating water pump, and the water bag is connected to the water inlet of the circulating water pump.

[0019] Compared with the prior art, the present invention has achieved the following technical effects:

[0020] The present invention arranges an ultrasonic transducer in the ablation cavity of the balloon and utilizes ultrasonic energy to achieve renal artery ablation. The ablation cavity is connected to a water channel so that the ultrasonic transducer and the inner wall of the blood vessel are isolated by water, thereby protecting the inner wall of the blood vessel in contact with the balloon. The present invention not only has the characteristics of simple structure and convenient operation, but also can achieve efficient and uniform ablation effect, providing a new technical means for the treatment of refractory hypertension. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of an ultrasonic ablation catheter in an embodiment of the present invention;

[0023] Figure 2 for Figure 1 Cross-sectional view of the median duct;

[0024] Figure 3 A schematic diagram of a chocolate balloon in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of a double-row tube in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of an infusion tube in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of a device host in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of a handle in an embodiment of the present invention;

[0029] Figure 8 A schematic diagram of a cooling circulation device in an embodiment of the present invention;

[0030] Fig. 9 Schematic diagram of an ultrasonic ablation system in an embodiment of the present invention;

[0031] Fig.10 A schematic diagram of an ultrasonic ablation process in an embodiment of the present invention;

[0032] Fig.11 Schematic diagram of ultrasonic main lobe and side lobe;

[0033] Fig.12 Schematic diagram of the sidelobe suppression principle in an embodiment of the present invention;

[0034] Among them, 1. Equipment host; 2. Ultrasonic ablation catheter; 3. Handle; 4. Double-row tube; 5. Infusion tube; 6. Cooling circulation device; 7. Water bag; 8. Main lobe; 9. Side lobe;

[0035] 11. Housing; 12. Display screen;

[0036] 21. Tip tube; 22. Balloon; 23. Ultrasonic transducer; 24. Catheter; 25. Stress protection sleeve; 26. Catheter seat; 27. Plug; 28. Water inlet interface; 29. ​​Water outlet interface;

[0037] 221, pillow portion; 222, groove portion;

[0038] 231, wire;

[0039] 241. Inner tube; 242. Outer tube; 243. Guide wire cavity; 244. Water inlet channel; 245. Water outlet channel; 246. Partition. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide an ultrasonic ablation catheter and an ultrasonic ablation system to solve the problems existing in the prior art. An ultrasonic transducer is arranged in the ablation cavity of a balloon, and ultrasonic energy is used to achieve renal artery ablation. The ultrasonic transducer and the inner wall of the blood vessel are isolated by water, thereby protecting the inner wall of the blood vessel in contact with the balloon. The system not only has the characteristics of simple structure and convenient operation, but also can achieve efficient and uniform ablation effects, providing a new technical means for the treatment of refractory hypertension.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figures 1 to 12As shown, the present invention provides an ultrasonic ablation catheter, including a catheter 24, a tip tube 21, a balloon 22 and an ultrasonic transducer 23. The catheter 24 includes an inner tube 241 and an outer tube 242. The inner tube 241 is sleeved between the outer tube 242, and a support structure is provided to allow the two to be spaced apart. The distal end of the inner tube 241 extends out of the outer tube 242. The interior of the inner tube 241 is a guidewire cavity 243, which is used to pass the guidewire. The guidewire cavity 243 is in the middle position. Compared with the four-cavity structure, the guidewire cavity 243 is not in the center, and the guidewire "climbing" process is required. The guidewire passability of the present invention is better. It should be noted that the distal end refers to the end away from the operator, and the proximal end refers to the end close to the operator. There is a water channel between the inner tube 241 and the outer tube 242, and the water channel is used to flow cooling water to achieve isolation and cooling effects. The tip tube 21 has an internal channel, and the guidewire cavity 243 is connected to the internal channel so that the guidewire can be passed through the tip tube 21, which is convenient for the movement of the catheter 24 along the guidewire. The balloon 22 is arranged on the outer diameter side of the portion of the inner tube 241 extending out of the outer tube 242, and an ablation cavity is formed between the balloon 22 and the inner tube 241. The distal end of the balloon 22 is connected to the wall of the tip tube 21 to achieve the blocking of the distal end of the ablation cavity; the proximal end of the balloon 22 is connected to the wall of the outer tube 242, and the water channel is connected to the ablation cavity, that is, the cooling water flowing in the water channel can enter the ablation cavity inside the balloon 22. The ultrasonic transducer 23 is located in the ablation cavity, and the ultrasonic transducer 23 is sleeved on the outer diameter side of the inner tube 241 and protected by cooling water. The mechanical loss of the ultrasonic transducer 23 and the wire 231 will generate heat. On the one hand, the inner tube 241 is used to support the ultrasonic transducer 23 so that it is not in direct contact with the outer tube 242. At this time, the ultrasonic transducer 23 is in a ring shape and radiates circumferential ablation. It can transmit ultrasonic energy over a long distance without direct contact with the renal artery intima, thereby achieving direct ablation of the sympathetic nerves of the renal artery adventitia, playing a role in protecting the vascular intima, and the corresponding risk of postoperative renal artery stenosis may be smaller; on the other hand, the cooling water in the ablation cavity can completely submerge the ultrasonic transducer 23, which is convenient for isolating and cooling the ultrasonic transducer 23. By adopting a cooling water protection mechanism, the temperature of the tissue in contact with the surface of the balloon 22 (renal artery intima side) is kept low, which can protect the renal artery intima and avoid damage.

[0044] The present invention arranges the ultrasonic transducer 23 in the ablation cavity of the balloon 22 and utilizes ultrasonic energy to achieve renal artery ablation. The ablation cavity is connected to a water channel so that the ultrasonic transducer 23 and the inner wall of the blood vessel are isolated by water, thereby protecting the inner wall of the blood vessel in contact with the balloon 22. The present invention not only has the characteristics of simple structure and convenient operation, but also can achieve efficient and uniform ablation effect, providing a new technical means for the treatment of refractory hypertension.

[0045] In one embodiment, the ultrasonic transducer 23 can be made of piezoelectric ceramics. For example, PZT-8 series ceramics (composite materials) have good concentricity and uniform wall thickness; the electrode thickness is uniform, and the high-temperature polarization process endows it with stable depolarization performance; and it has low dielectric loss, high piezoelectric performance, high mechanical conversion efficiency and high coercive electric field; the diameter of the piezoelectric ceramic is 1 mm to 2 mm, and the length is 5 mm to 10 mm, showing a cylindrical structure and capable of being sleeved on the outer diameter side of the inner tube 241. The frequency of the ultrasonic transducer 23 can be designed to be 7 MHz to 10 MHz, and the ultrasonic transducer 23 can emit in a 360° surround, capable of uniformly ablating the renal artery sympathetic nerve.

[0046] In one embodiment, the balloon 22 is a compliant balloon, a semi-compliant balloon or a non-compliant balloon. When it is a non-compliant balloon, according to the renal artery size distribution, the diameter specification of the balloon 22 can be 3 mm to 8 mm, and the effective length can be 8 mm to 20 mm, having multiple different specifications; when it is a compliant balloon, it can be of one specification, and the diameter of the balloon 22 is adjusted by adjusting the pressure to meet different renal artery structures; when it is a semi-compliant balloon, it is between the compliant balloon and the non-compliant balloon, that is, the diameter of the balloon 22 can be adjusted, but the adjustment range is smaller than that of the compliant balloon.

[0047] In one embodiment, a restraining wire is sleeved outside the balloon 22. The restraining wire can be made of nickel-titanium metal wire or polymer wire. Through the restraint of the restraining wire, the pillow parts 221 and the groove parts 222 are distributed at intervals in the length direction of the balloon 22, and at this time it can be called a chocolate balloon. During the ultrasonic ablation process, when the coating distribution on the outer surface of the ultrasonic transducer 23 is uneven, when the ultrasonic wave is emitted, since the surface is not smooth, when the ultrasonic wave propagates outward, the main lobe 8 and the side lobe 9 are derived (as Fig.11 shown). The sound beams formed by the maxima outside the main lobe 8 are all side lobes 9. The side lobe 9 is also called the secondary lobe, which will reduce the ablation intensity. Therefore, the main lobe 8 should be enhanced as much as possible and the side lobe 9 should be suppressed to improve the performance. The interval distribution of the pillow parts 221 and the groove parts 222 on the chocolate balloon not only can effectively suppress the side lobe 9 during the sound field diffusion, but also can minimize the damage to the vascular intima to the greatest extent. As Fig.12 shown, when the side lobes 9 emitted from different parts are emitted outward on the protruding surface (pillow part 221) of the chocolate balloon, those with opposite directions will cancel each other out, so as to achieve the suppression of the side lobe 9 and retain the main lobe 8, and the energy in the direction of the main lobe 8 remains the largest. The chocolate balloon can only have circumferential restraint, as Figure 3 shown, forming a ring-shaped splicing, or it can be restrained in the axial direction to form a "field" shape, which is not shown here.

[0048] In one embodiment, since the chocolate balloon is bounded by a restraining wire on the outside, the chocolate balloon is a non-compliant balloon with an outer diameter of different specifications ranging from 2.0 mm to 9.0 mm.

[0049] In one embodiment, the water channel is divided into a water inlet channel 244 and a water outlet channel 245 by a partition 246, and the catheter 24 forms a three-chamber structure, that is, it has three cavities: a water inlet channel 244, a water outlet channel 245 and a guidewire cavity 243. The cross section is as follows: Figure 2 As shown, compared with the four-chamber structure, under the same catheter cross-section, the cooling water lumen area is larger, and a higher cooling water flow regulation can be achieved, so it can meet higher excitation energy treatment, thereby shortening the operation time and improving the treatment effect. A wire 231 is arranged in the water inlet channel 244, one end of the wire 231 is welded to the ultrasonic transducer 23, and the other end is welded to the plug 27. The plug 27 is connected to the device host 1 and is used to provide energy and control to the ultrasonic transducer 23. The cooling water temperature in the water inlet channel 244 is relatively lower than the cooling water temperature in the water outlet channel 245. The wire 231 is arranged in the water inlet channel 244, which can directly take away the heat generated by the wire 231 when it is working, effectively reduce the heat generated by the wire 231, achieve efficient cooling, and be safer, so as to avoid the failure of treatment caused by the wire 231 melting due to high temperature.

[0050] In one embodiment, it also includes a catheter seat 26, which is connected to the proximal end of the catheter 24. The catheter seat 26 includes a water inlet interface 28, a water outlet interface 29 and a plug 27. The water inlet interface 28 is connected to the water inlet channel 244, which is used to allow cooling water to enter the water inlet channel 244; the water outlet interface 29 is connected to the water outlet channel 245, which is used to discharge the cooling water from the water outlet channel 245; the plug 27 is connected to the wire 231, which is used to connect the ultrasonic transducer 23 to the ultrasonic controller.

[0051] In one embodiment, the water inlet interface 28 adopts a male connector, which is used to connect to the water inlet pipe, and the water outlet interface 29 adopts a female connector, which is used to connect to the water outlet pipe. The male connector and the female connector may have a foolproof design, for example, the male connector is set as an inner cone Luer connector, and the female connector is set as an outer cone Luer connector, which can directly distinguish the water inlet interface 28 and the water outlet interface 29, and can prevent the operator from making mistakes due to omission or forgetfulness when connecting the water inlet pipe and the water outlet pipe.

[0052] In one embodiment, a stress protection sleeve 25 is provided at the location where the catheter 24 and the catheter seat 26 are connected. The stress protection sleeve 25 protects the connection between the catheter 24 and the catheter seat 26 from bending and damage.

[0053] like Figures 1 to 12As shown, the present invention also provides an ultrasonic ablation system, including the ultrasonic ablation catheter 2 and the device host 1 as described above, the device host 1 includes an ultrasonic controller and a circulating water pump, and is provided with corresponding control circuits, etc. The ultrasonic controller is used to connect the ultrasonic transducer 23, control the amplitude and frequency of the ultrasonic wave and other parameters, and excite the ultrasonic transducer 23 in the form of frequency tracking so that it emits ultrasonic waves to ablate the renal artery. The circulating water pump is used to connect the water channel so as to provide cooling water with set pressure and flow rate as needed. The ultrasonic ablation system can also include a handle 3, a cooling circulation device 6, and a connecting cable, etc. The handle 3 is convenient for handheld operation, control opening, closing or adjusting parameters, etc. The cooling circulation device 6 includes a shell for holding consumables used in surgery, and the connecting cable is used to connect the various devices. The device host 1 also includes a shell 11, a display screen 12, a main control board, an amplifier board, a switching power supply, a cooling fan, a stepper motor, a filter, internal connecting wires, etc. The display screen 12 is used to display corresponding parameters and other information. The cooling fan is used to dissipate heat from the device host 1 and cooling water. The remaining devices are conventional settings for realizing corresponding functions and will not be repeated here.

[0054] In one embodiment, the cooling circulation device 6 also includes a pressure sensor, which is disposed in the equipment host 1 (which can be disposed in the shell of the cooling circulation device 6). The pressure sensor is connected to the water channel. The pressure sensor is used to monitor the internal pressure of the balloon 22, implement an algorithm to dynamically adjust the cooling water flow rate, and provide real-time feedback on the integrity of the balloon 22 during surgery.

[0055] In one embodiment, the cooling circulation device 6 also includes a double-row pipe 4, an infusion tube 5 and a water bag 7. The water channel includes an inlet channel 244 and an outlet channel 245. The double-row pipe 4 has a first tube and a second tube arranged in parallel. The two ends of the first tube are respectively connected to the inlet channel 244 and the outlet of the circulating water pump, and the two ends of the second tube are respectively connected to the outlet channel 245 and the inlet of the circulating water pump. Under the action of the circulating water pump, the cooling water circulates in the cooling circulation system formed by the circulating water pump, the inlet channel 244, the balloon 22 and the outlet channel 245. It should be noted that the circulating water pump can be a centrifugal pump, a piston pump or other forms of water pumps. No matter which form of water pump is used, the circulating water should be guaranteed to flow in one direction (a one-way valve can be set or it can be achieved by the driving direction of the water pump itself). The water bag 7 is connected to the water inlet of the circulating water pump to provide or supplement cooling water. The cooling water is preferably sterile water to avoid bringing bacteria into the human body.

[0056] In one embodiment, the overall length of the ultrasonic ablation catheter 2 is 70 cm to 120 cm, the length of the infusion tube 5 is 100 mm to 200 mm, and the length of the double-row tube 4 is 2 m to 3 m.

[0057] In one embodiment, in order to ensure the internal pressure of the balloon 22 in the working state, the cross-section of the double-row tube 4 is 0.4 mm 2 , 0.5mm 2 , 0.6mm 2 The pressure corresponding to different water flow rates is shown in Table 1 below:

[0058] Table 1: Circulating cooling water flow and pressure test data for different double-row pipe cross-sectional areas

[0059]

[0060] It can be seen from Table 1 that as the cooling water flow rate increases, the internal pressure of the balloon 22 shows an increasing trend. As the pressure increases, the balloon 22 has a risk of rupture. By controlling the internal pressure of the balloon 22 to maintain within a suitable range, the risk of rupture of the balloon 22 can be reduced.

[0061] Under the protection of cooling water, the temperature of the tissue in contact with the surface of the balloon 22 (renal artery intima side) is relatively low. Through in vitro pig liver testing, it can be observed that the ablation range is 2mm to 8mm, of which about 1mm to 2mm of the inner wall is protected. Therefore, it is not easy to form thrombus or eschar during the ablation process, which can protect the renal artery intima and reduce damage.

[0062] In one embodiment, the present invention provides the ultrasonic ablation principle and working process as follows:

[0063] Ultrasound refers to mechanical waves with a frequency of >20,000 Hz. When it is transmitted in tissues, the mechanical energy will be absorbed by human tissues and converted into heat energy. It mainly utilizes the thermal effect of ultrasound to deliver ultrasound energy directly to the adventitia and surrounding tissues of the renal artery, and to generate heat energy around the adventitia through the thermal effect of ultrasound to ablate the renal sympathetic nerves.

[0064] When in use, the femoral artery is punctured by the Seldinger (percutaneous puncture technique), and an angiography catheter is placed in the arterial sheath. Under the guidance of the super-smooth guide wire, the angiography catheter is sent in for renal artery angiography. Subsequently, the ultrasonic ablation catheter 2 is positioned at the opening of the renal artery. According to the size data of the distal, middle and proximal ends of the artery revealed by the renal artery angiography, an ultrasonic ablation catheter 2 of appropriate specifications is selected. Under the guidance of the guide wire, the ultrasonic ablation catheter 2 is sent to the renal aorta near the distal branch, and the device host 1 is connected to start filling the balloon 22 until the internal pressure of the balloon 22 is maintained at 1atm~3atm, and the ultrasonic transducer 23 is placed in the center of the balloon 22, that is, the center of the blood vessel. At this time, ultrasonic ablation treatment is started through the device host 1, and the ultrasonic energy will be transmitted to the surroundings at 360°, with a target depth of 1mm~8mm, and 80% of the sympathetic nerves are concentrated in this range to achieve the purpose of efficient nerve damage. At the same time, cooling water (sterile water can be used) is also running, which can protect the inner wall of the blood vessel in contact with the balloon 22, and take away the heat generated by the ultrasonic transducer 23 and the wire 231. Each treatment time is 5s-20s. After the treatment, the pressure can be relieved and gradually move toward the opening of the renal artery. The next ablation position is determined based on the length of the main trunk of the renal artery. Repeat the above treatment process until the ablation of both renal arteries is completed. In general, each renal artery can undergo 2 to 3 ablation treatments to achieve the interruption of the renal artery sympathetic nerves.

[0065] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An ultrasonic ablation catheter, characterized in that: include: A catheter, the catheter comprising an inner tube and an outer tube, the distal end of the inner tube extending out of the outer tube, the interior of the inner tube being a guidewire cavity, and a water channel being between the inner tube and the outer tube; a tip tube, the tip tube having an internal passage, the guidewire cavity communicating with the internal passage; A balloon, the balloon is arranged on the outer diameter side of the portion of the inner tube extending out of the outer tube, an ablation cavity is formed between the balloon and the inner tube, the distal end of the balloon is connected to the tube wall of the tip tube, the proximal end of the balloon is connected to the tube wall of the outer tube, and the water channel is connected to the ablation cavity; and an ultrasonic transducer, wherein the ultrasonic transducer is located in the ablation cavity and is sleeved on the outer diameter side of the inner tube.

2. The ultrasonic ablation catheter according to claim 1, characterized in that: The balloon is a compliant balloon, a semi-compliant balloon or a non-compliant balloon.

3. The ultrasonic ablation catheter according to claim 1, characterized in that: The outer sleeve of the balloon is provided with a restraining wire, and through the restraint of the restraining wire, pillow parts and groove parts distributed at intervals are formed in the length direction of the balloon.

4. The ultrasonic ablation catheter according to any one of claims 1 to 3, characterized in that: The water channel is divided into a water inlet channel and a water outlet channel by a partition, and a wire for connecting the ultrasonic transducer is arranged in the water inlet channel.

5. The ultrasonic ablation catheter according to claim 4, characterized in that: It also includes a catheter seat, which is connected to the proximal end of the catheter. The catheter seat includes a water inlet interface, a water outlet interface and a plug. The water inlet interface is connected to the water inlet channel, the water outlet interface is connected to the water outlet channel, and the plug is connected to the wire; a stress protection sleeve is provided at the position where the catheter is connected to the catheter seat.

6. The ultrasonic ablation catheter according to claim 5, characterized in that: The water inlet interface adopts a male connector, and the water outlet interface adopts a female connector.

7. The ultrasonic ablation catheter according to claim 1, characterized in that: The ultrasonic transducer adopts PZT-8 series piezoelectric ceramics, which have a diameter of 1mm to 2mm, a length of 5mm to 10mm, and a cylindrical structure. It can be mounted on the outer diameter side of the inner tube. The frequency of the ultrasonic transducer is designed to be 7MHz to 10MHz, which is used for 360° surround emission and uniform ablation of the renal artery sympathetic nerves.

8. An ultrasonic ablation system, characterized in that: include: The ultrasonic ablation catheter according to any one of claims 1 to 7; And a device host, the device host includes an ultrasonic controller and a circulating water pump, the ultrasonic controller is used to connect the ultrasonic transducer, and the circulating water pump is used to connect the water channel.

9. The ultrasonic ablation system according to claim 8, characterized in that: It also includes a cooling circulation device, which includes a shell and a pressure sensor arranged in the shell. The pressure sensor is connected to the water channel and is used to monitor the internal pressure of the balloon.

10. The ultrasonic ablation system according to claim 9, characterized in that: The cooling circulation device also includes a double row of pipes, an infusion tube and a water bag. The water channel includes a water inlet channel and a water outlet channel. The first tube of the double row of pipes connects the water inlet channel and the water outlet of the circulating water pump, the second tube of the double row of pipes connects the water outlet channel and the water inlet of the circulating water pump, and the water bag is connected to the water inlet of the circulating water pump.

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