A thermal and cold composite ablation needle

Abstract

The present invention relates to the technical field of soft tissue ablation, and in particular to a thermal and cold composite ablation needle, which includes a needle shaft and a needle tip located at the lower end of the needle shaft. A cooling working medium tube is provided in the center inside the needle shaft. An inner conductor is provided on the outer side of the middle and upper part of the cooling working medium tube. An insulating tube is provided on the outer side of the inner conductor. An insulating tube boss is provided at the needle tip end of the insulating tube. An outer conductor is provided on the outer side of the insulating tube above the insulating tube boss. The insulating tube below the insulating tube boss forms an insulating tube embedding section, and the insulating tube embedding section is inserted into the upper end inside the needle tip. The thermal and cold composite ablation needle of the present invention has dual functions of microwave thermal ablation and cryoablation, expands the applicable scope of microwave ablation and cryoablation, and for tumor tissues with dangerous organs around the target tissue, cryoablation and microwave rewarming are adopted for the adjacent area, and microwave ablation is adopted for the far area.

Description

Technical Field

[0001] The present invention relates to the technical field of soft tissue ablation, and particularly to a thermal and cold composite ablation needle. Background Art

[0002] Minimally invasive ablation treatment of solid tumor tissues and nodules by heat is an important clinical means, mainly divided into two categories: heat ablation and cryoablation. Common heat ablation includes laser, radiofrequency, and microwave ablation, and common cryoablation includes gas refrigeration and liquid refrigeration.

[0003] Microwave ablation uses a microwave ablation needle to release microwave energy to tumor tissues. Polar molecules (mostly water) in the tumor tissues rotate at high speed under the action of the microwave field and quickly generate heat to reach a relatively high temperature, causing tissue dehydration, coagulation, and protein denaturation, so that the tumor tissues are inactivated and lose the ability to proliferate, achieving the purpose of treatment. Rapid freezing can cause tissue cell necrosis to form an irreversible coagulative necrosis freezing area, and tumor cells are particularly sensitive to freezing compared to normal tissues.

[0004] Microwave energy belongs to radiative emission, with the characteristics of a large action area, fast heating speed, and high surgical efficiency. However, it is difficult to control the influence on adjacent blood vessels, and carbonization is also likely to occur in the needle tip area. During the operation, in order to prevent the needle shaft from being too hot and scalding normal tissues, additional cooling measures need to be taken to cool the needle shaft. Cryoablation forms an ice ball, with the characteristics of good control of the ablation boundary and obvious ultrasonic imaging effect. However, cryoablation belongs to contact conduction cooling, with a slow freezing speed and a long operation time. During the operation, in order to prevent the needle shaft from being too cold and freezing normal tissues, a vacuum insulation layer also needs to be made outside the cooling medium return pipe, and the manufacturing process and maintaining vacuum are difficult.

[0005] Chinese Patent Application CN201910872384.9 proposed a thermal and cold ablation needle, which uses the evaporation and heat absorption of liquid refrigerant at the ablation needle treatment site to lower the temperature of the target tissue, and then passes high-temperature alcohol vapor to quickly rewarm the tissue. The American EndoCare argon-helium knife uses argon to achieve freezing and helium to rewarm.

[0006] However, these methods all have problems such as complex equipment, long operation time, expensive and difficult-to-obtain helium, etc., and are very inconvenient to use. Summary of the Invention

[0007] The purpose of the present invention is to provide a thermal and cold composite ablation needle, which has dual functions of microwave thermal ablation and cryoablation, expands the applicable scope of microwave ablation and cryoablation, and for tumor tissues with dangerous organs around the target tissue, cryoablation and microwave rewarming are used for the adjacent area, and microwave ablation is used for the far area.

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

[0009] A thermal and cold composite ablation needle, comprising a needle rod and a needle tip located at the lower end of the needle rod. A cooling medium tube is provided in the center of the interior of the needle rod. An inner conductor is provided on the outer side of the upper middle part of the cooling medium tube. An insulating tube is provided on the outer side of the inner conductor. An insulating tube boss is provided at the needle tip end of the insulating tube. An outer conductor is provided on the outer side of the insulating tube above the insulating tube boss. The insulating tube below the insulating tube boss forms an insulating tube insertion section, and the insulating tube insertion section is inserted into the upper end interior of the needle tip.

[0010] Wherein, the lower end of the inner conductor extends into the needle tip, and a needle tip connection sleeve is inlaid between the outer wall of the inner conductor and the inner wall of the needle tip. The needle tip connection sleeve is located below the insulating tube insertion section.

[0011] Wherein, an evaporation chamber is provided inside the needle tip. The evaporation chamber is located below the needle tip connection sleeve, and the cooling medium tube extends into the evaporation chamber.

[0012] Wherein, the needle tip connection sleeve is made of pure copper to connect the inner conductor with the inner wall of the needle tip, forming a microwave radiation antenna.

[0013] Wherein, the inner conductor, the insulating tube and the outer conductor together constitute a rigid coaxial microwave transmission cable;

[0014] The inner conductor is made of copper, silver or a composite material with a copper or silver surface;

[0015] The insulating tube is made of PTFE material and is closely fitted with the outer wall of the inner conductor and the inner wall of the outer conductor;

[0016] The outer conductor is made by plating copper or silver on the inner wall of a medical 304 or 316 stainless steel tube, or a thin-walled stainless steel tube is used as the needle rod, and a thin-walled copper or silver capillary tube is nested inside.

[0017] Wherein, the outer diameter of the insulating tube insertion section is adapted to the inner hole diameter of the upper end of the needle tip, and the length of the insulating tube insertion section is 0.5 - 2 mm.

[0018] Wherein, the outer diameter of the insulating tube boss is the same as the outer diameter of the outer conductor, and the length of the insulating tube boss is 1 - 3 mm.

[0019] Wherein, the needle tip is made of hard copper or a hard metal material with a copper or silver surface. Its tip is a three-sided needle shape or a conical shape, and an opening is made towards the needle tip direction at the end, and the wall thickness is 0.10 - 0.20 mm.

[0020] Wherein, the inner conductor and the outer conductor are connected to a connector of a microwave input channel at the reverse end of the needle tip to form a microwave transmission path.

[0021] Among them, the cooling working fluid tube is made of a stainless steel capillary tube. Leakage holes for the cooling medium are formed by circumferentially opening holes on the wall surface of the needle tip end of the cooling working fluid tube. The leakage holes and the through holes of the cooling working fluid tube at the needle tip end together form a cooling medium overflow channel;

[0022] A gap of 0.2 - 0.3 mm is provided between the outer wall of the cooling working fluid tube and the inner wall of the inner conductor to form a return channel for the cooling working fluid;

[0023] The tail end of the cooling working fluid tube is connected to the cooling working fluid supply tube; The cryogenic working fluid uses liquid nitrogen or high - pressure argon.

[0024] For tumor tissues without dangerous organs around the target tissue, through the thermal - cold composite ablation needle of the present invention, microwave ablation is used to improve the surgical efficiency; Freezing ablation and microwave ablation can also be alternately used to further destroy the lesion tissue.

[0025] The thermal - cold composite ablation needle of the present invention cancels the cooling water system of the conventional microwave ablation, and at the same time cancels the vacuum heat insulation structure, the recovery device for the cooling working fluid and the heating working fluid of the conventional freezing ablation, simplifies the system, and improves the convenience of clinical application.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] (1) The microwave ablation needle in the prior art does not have the ability to perform cryoablation on lesion tissues, and its use for lesion tissues near dangerous organs is restricted; At the same time, the rewarming technique used in the cryoablation needle in the prior art is the heat conduction method, and the melting speed of the ice ball is very slow, and the surgical efficiency is relatively low.

[0028] However, the thermal - cold composite ablation needle of the present invention is internally provided with a cryogenic working fluid channel and a heat exchange structure is provided inside the needle tip of the microwave ablation needle. It can not only achieve traditional microwave ablation, but also achieve traditional cryoablation, combines the advantages of the two, broadens the scope of ablation treatment for lesion tissues, and at the same time utilizes the physical properties of these two energies that are completely opposite. Through appropriate dose control, some safety requirements that need to be additionally controlled during the ablation process of these two energies are solved.

[0029] (2) By using the thermal - cold composite ablation needle of the present invention, cryoablation can be used to precisely control the ablation size of lesion tissues near dangerous organs, and microwave ablation can be used to achieve rapid ablation and improve the surgical efficiency.

[0030] (3) Using microwave radiation to generate heat speeds up the rewarming speed of the ice ball, and rapid freezing and rapid rewarming are more likely to destroy the lesion tissue.

[0031] (4) The vacuum insulation structure of the outer tube of the traditional cryoablation needle is cancelled, improving the reliability of the product.

[0032] (5) The cooling water channel of the traditional microwave ablation needle is cancelled.

[0033] (6) Quick needle retraction: When using cryoablation, the ice ball needle track can be quickly dissolved by microwave to achieve quick needle retraction; when using microwave ablation, the cooling working medium is used to ensure that the needle tip is at a relatively low temperature so as not to cause tissue adhesion to achieve quick needle retraction. Description of the Drawings

[0034] Figure 1 is a schematic diagram of the needle body structure of the thermal and cold composite ablation needle of the present invention;

[0035] Figure 2 is the cooling working medium path of the thermal and cold composite ablation needle of the present invention;

[0036] Figures 3-4 is a schematic diagram of the thermal and cold ablation method.

[0037] Among them, 1 - cooling working medium tube, 2 - inner conductor, 3 - insulating tube, 4 - outer conductor, 31 - insulating tube boss, 32 - insulating tube insertion section, 5 - needle tip connection sleeve, 6 - evaporation cavity, 7 - leakage hole, 8 - needle tip, 9 - cryogenic working medium, 10 - reflux working medium, 11 - thermal and cold composite ablation needle, 12 - lesion tissue, 13 - freezing area, 14 - large blood vessel or organ, 15 - thermal field area. Detailed Embodiment

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Combined with Figure 1 As shown, a thermal and cold composite ablation needle includes a needle rod and a needle tip 8 located at the lower end of the needle rod. A cooling working medium tube 1 is provided in the center inside the needle rod. An inner conductor 2 is provided on the outer side of the upper middle part of the cooling working medium tube 1. An insulating tube 3 is provided on the outer side of the inner conductor 2. An insulating tube boss 31 is provided at the needle tip end of the insulating tube 3. An outer conductor 4 is provided on the outer side of the insulating tube 3 above the insulating tube boss 31. The insulating tube 3 below the insulating tube boss 31 forms an insulating tube insertion section 32, and the insulating tube insertion section 32 is inserted into the upper end inside of the needle tip 8.

[0040] The lower end of the inner conductor 2 extends into the needle 8, and a needle connection sleeve 5 is embedded between the outer wall of the inner conductor 2 and the inner wall of the needle 8. The needle connection sleeve 5 is located below the insulating tube embedding section 32.

[0041] An evaporation chamber 6 is provided inside the needle 8. The evaporation chamber 6 is located below the needle connection sleeve 5, and the cooling working medium tube 1 extends into the evaporation chamber 6.

[0042] The needle connection sleeve 5 is made of pure copper to connect the inner conductor 2 with the inner wall of the needle 8, forming a microwave radiation antenna.

[0043] The inner conductor 2, the insulating tube 3, and the outer conductor 4 together constitute a rigid coaxial microwave transmission cable. The inner conductor 2 is made of copper, silver, or a composite material with a copper or silver surface. The insulating tube 3 is made of PTFE material and is closely fitted with the outer wall of the inner conductor 2 and the inner wall of the outer conductor 4. The outer conductor 4 is made by plating copper or silver on the inner wall of a medical 304 or 316 stainless steel tube, or by using a thin-walled stainless steel tube as the needle rod and nesting a thin-walled copper or silver capillary tube inside. The rigid structure composed of the inner conductor 2, the insulating tube 3, and the outer conductor 4 serves as the needle rod of the ablation needle.

[0044] The outer diameter of the insulating tube embedding section 32 is adapted to the inner hole diameter of the upper end of the needle 8. The length of the insulating tube embedding section 32 is 0.5 - 2 mm, and it is closely fitted with the needle 8 to play a supporting role.

[0045] The outer diameter of the insulating tube boss 31 is the same as the outer diameter of the outer conductor 4. The length of the insulating tube boss 31 is 1 - 3 mm, which is used for insulation between the inner conductor 2 and the outer conductor 4.

[0046] The needle 8 is made of hard copper or a hard metal material with a copper or silver surface. Its tip is a three-sided needle shape or a conical shape, with an opening at the end towards the tip of the needle, and the wall thickness is 0.10 - 0.20 mm.

[0047] The inner conductor 2 and the outer conductor 4 are connected to the connector of the microwave input channel at the reverse end of the needle to form a microwave transmission path.

[0048] The cooling working medium tube 1 is made of a stainless steel capillary tube. Circumferential holes are formed on the wall surface at the needle end of the cooling working medium tube 1 to form leakage holes 7 (i.e., throttling holes) for the cooling medium. The leakage holes 7 and the through hole at the needle end of the cooling working medium tube 1 together form a cooling medium overflow channel to increase the overflow speed of the cooling working medium.

[0049] There is a gap of 0.2 - 0.3 mm between the outer wall of the cooling working medium tube 1 and the inner wall of the inner conductor 2, forming a return channel for the cooling working medium;

[0050] The tail end of the cooling working medium tube 1 is connected to the cooling working medium supply tube; the refrigerating working medium 9 is liquid nitrogen or high-pressure argon.

[0051] Combined Figure 2 As shown, the phase change process and refrigeration process of the cooling working fluid are specifically as follows:

[0052] After the refrigeration working fluid 9 enters the cooling working fluid pipe 1 and flows out from the leakage hole 7 (throttling hole) into the evaporation chamber 6, it absorbs heat through the needle 8 and expands and evaporates. The return working fluid channel is at atmospheric pressure, and the return working fluid 10 is naturally discharged from the ablation needle return working fluid channel under the extrusion of the refrigeration working fluid 9, continuously taking away the heat of the needle 8. Since the temperature of the refrigeration working fluid 9 is theoretically between -180°C and -196°C, there is a large temperature difference between it and the diseased tissue. The needle 8 is a good conductor of heat, so the temperature of the diseased tissue contacted by the needle 8 is rapidly reduced to form an ice ball state, achieving the purpose of destroying the cell structure of the diseased tissue. This is also the principle commonly used for cryoablation of tissues at present.

[0053] The temperature of the return working fluid 10 that has completed the heat and cold exchange through the needle 8 is still relatively low. Since the heat conductivity of the insulating tube 3 is poor, the temperature of the outer surface of the needle rod is limitedly affected and will not reach the degree of frostbite to normal tissues.

[0054] The return working fluid 10 is argon or liquid nitrogen close to room temperature, non-toxic, odorless, and harmless, and can be directly discharged into the air without recycling treatment.

[0055] Combined Figures 3-4 As shown, the thermal and cold ablation techniques and control methods are specifically as follows:

[0056] Figures 3-4 It shows the ablation position relationship of the diseased tissue near the dangerous organ. In this case, cryoablation, microwave rewarming, and retracting the needle for microwave ablation are used.

[0057] Such as Figure 3 As shown, the tip of the needle 8 is inserted into the distal end of the diseased tissue 12, and the cryoablation mode is started to inject a large flow rate of the cooling working fluid until a frozen area 13 is formed. Keep it for an appropriate time and then turn off the refrigeration working fluid 9; start small-power microwave for rewarming, and the microwave power for rewarming should be such that the heat is not sufficient to act on the large blood vessels or organs 14. Repeat this several times to achieve thermal and cold ablation of the dangerous area. In this stage, microwave radiation heating is used, which is much faster than the traditional heat conduction rewarming speed.

[0058] Such as Figure 4As shown (where 15 is the thermal field area), then the ablation needle is retracted a certain distance, and the microwave ablation mode is started at the conventional power. At the same time, a small flow rate of the cryogenic refrigerant 9 is turned on to cool the inner conductor and the needle tip 8 of the thermal-cold composite ablation needle 11, preventing the surface temperature of the needle shaft from being too high during high-power microwave ablation and scalding normal tissues; since the surface temperature of the needle tip 8 is reduced, the carbonization adhesion phenomenon of the contacting tissue is reduced. At this time, the rapid thermal ablation is completely achieved by utilizing the high-efficiency characteristics of microwave ablation, improving the surgical efficiency. The two energy ablation methods form a complete coverage of the lesion tissue 12.

[0059] Since the thermal-cold composite ablation needle can realize the capabilities of microwave radiation and heat-cold exchange, in clinical practical applications, according to the size and location of the lesion tissue 12, only the cryoablation or microwave ablation mode or a combination of the two can also be adopted.

[0060] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A thermal and cold composite ablation needle, characterized in that: it includes a needle rod and a needle tip (8) located at the lower end of the needle rod. A cooling working medium tube (1) is provided in the center of the needle rod. An inner conductor (2) is provided on the outer side of the upper middle part of the cooling working medium tube (1). An insulating tube (3) is provided on the outer side of the inner conductor (2). An insulating tube boss (31) is provided at the needle tip end of the insulating tube (3). An outer conductor (4) is provided on the outer side of the insulating tube (3) above the insulating tube boss (31). The insulating tube (3) below the insulating tube boss (31) forms an insulating tube embedding section (32), and the insulating tube embedding section (32) is inserted into the upper end inside of the needle tip (8); the lower end of the inner conductor (2) extends into the needle tip (8). A needle tip connecting sleeve (5) is inlaid between the outer wall of the inner conductor (2) and the inner wall of the needle tip (8), and the needle tip connecting sleeve (5) is located below the insulating tube embedding section (32); An evaporation cavity (6) is provided inside the needle tip (8), and the evaporation cavity (6) is located below the needle tip connecting sleeve (5). The cooling working medium tube (1) extends into the evaporation cavity (6); The needle tip connecting sleeve (5) is made of pure copper to connect the inner conductor (2) with the inner wall of the needle tip (8) to form a microwave radiation antenna.

2. The thermal and cold composite ablation needle according to claim 1, characterized in that: the inner conductor (2), the insulating tube (3) and the outer conductor (4) together form a rigid coaxial microwave transmission cable; the inner conductor (2) is made of copper, silver or a composite material with a copper or silver surface; the insulating tube (3) is made of PTFE material and is closely fitted with the outer wall of the inner conductor (2) and the inner wall of the outer conductor (4); the outer conductor (4) is made by plating copper or silver on the inner wall of a medical 304 or 316 stainless steel tube, or a thin-walled stainless steel tube is used as the needle rod and a thin-walled copper or silver capillary tube is nested inside.

3. The thermal and cold composite ablation needle according to claim 1, characterized in that: the outer diameter of the insulating tube embedding section (32) is adapted to the inner hole diameter of the upper end of the needle tip (8), and the length of the insulating tube embedding section (32) is 0.5 - 2 mm.

4. The thermal and cold composite ablation needle according to claim 1, characterized in that: the outer diameter of the insulating tube boss (31) is the same as the outer diameter of the outer conductor (4), and the length of the insulating tube boss (31) is 1 - 3 mm.

5. The thermal and cold composite ablation needle according to claim 1, characterized in that: the needle tip (8) is made of hard copper or a hard metal material with a copper or silver surface. Its tip is in the shape of a three-sided needle or a cone, with holes opened towards the needle tip direction at the end, and the wall thickness is 0.10 - 0.20 mm.

6. The thermal and cold composite ablation needle according to claim 1, characterized in that: the inner conductor (2) and the outer conductor (4) are connected to a connector of a microwave input channel at the reverse end of the needle tip to form a microwave transmission path.

7. The thermal and cold composite ablation needle according to claim 1, characterized in that: The cooling working fluid pipe (1) is made of a stainless steel capillary tube. The wall surface of the needle tip end of the cooling working fluid pipe (1) is circumferentially perforated to form leakage holes (7) for the cooling medium. The leakage holes (7) and the through holes of the cooling working fluid pipe (1) at the needle tip end together form a cooling medium overflow channel; There is a gap of 0.2 - 0.3 mm between the outer wall of the cooling working fluid pipe (1) and the inner wall of the inner conductor (2), forming a return channel for the cooling working fluid; The tail end of the cooling working fluid pipe (1) is connected to the cooling working fluid supply pipe; the refrigerating working fluid (9) is liquid nitrogen or high-pressure argon.

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