CN114305673B - Microwave ablation catheter and device for portal vein cancer embolism - Google Patents

Abstract

The invention provides a portal vein tumor thrombus microwave ablation catheter, which consists of a flexible tube body and an axially parallel coaxial cable and a guide wire guide tube arranged inside the flexible tube body. The coaxial cable moves from the inside to the outside from the coaxial The cable is composed of an inner conductor, a coaxial cable insulation layer and a coaxial cable outer conductor; a microwave radiating head is connected to the far end of the coaxial cable. The catheter has a small diameter and can adapt to the needs of traveling inside the vein. It can accurately reach the portal vein tumor thrombus through the guide wire for ablation, and can effectively open the portal vein.

Description

A microwave ablation catheter and device for portal vein tumor thrombus

Technical field

The present invention relates to the technical field of medical devices, and in particular to a microwave ablation catheter and device for portal vein tumor thrombus.

Background technique

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. About 35-50% of liver cancer patients also have portal vein tumor thrombosis (PVTT), which leads to a serious negative prognosis due to the increased risk of tumor spread into the blood. factors and a high risk of recurrence. Current research considers PVTT as a complex anatomical and clinical condition with different prognoses and novel treatment possibilities depending on the degree of involvement of the portal venous system, biological aggressiveness of the tumor, complications due to portal hypertension, and clinical characteristics of the patient. A wide range of patients and tolerance to antineoplastic treatments.

According to reports, without treatment, the median survival time of patients with liver cancer combined with portal vein tumor thrombus is only between 2.7 and 4 months, but the survival period also ranges from 5 months to 5 years, and the situation is extremely variable. . In recent years, progress has been made in the diagnosis and treatment of liver cancer combined with portal vein tumor thrombus, but there are still many challenges in how to further improve the prognosis of patients with liver cancer combined with portal vein tumor thrombus, especially in patients with intermediate and advanced liver cancer.

Minimally invasive therapy is a major trend in the treatment of liver cancer combined with portal vein tumor thrombus. Minimally invasive ablation therapy for liver cancer combined with portal vein tumor thrombus has the advantages of less trauma, accurate efficacy, accurate positioning, and good selectivity. The commonly used minimally invasive treatments in clinical practice are radiofrequency ablation (RFA) and microwave coagulation therapy (MCT). However, microwave coagulation therapy (MCT) uses rigid straight rod microwaves to ablate the portal tumor thrombus area from outside the portal vein, which cannot open the portal vein. The radiofrequency ablation (RFA) method requires the return electrode to be placed on the patient's back, and the doctor cannot control the high-frequency current to flow along the portal vein tumor thrombus area that needs to be ablated to perform effective ablation operations. Although the HAB I B radiofrequency ablation catheter currently available for clinical use can conform to the ablation, its indication is for intraluminal use in the biliary tract and digestive tract, and radiofrequency ablation is greatly affected by the thermal sedimentation effect and is not suitable for intravascular use.

Contents of the invention

In order to solve the above problems, the present invention provides a microwave ablation catheter and device suitable for portal vein tumor thrombus. The catheter has a small diameter and can adapt to the needs of traveling inside the vein. It can accurately reach the portal vein tumor thrombus site through the guide wire for ablation, and can effectively Open the portal vein.

In order to achieve the above-mentioned object of the invention, the present invention provides a portal vein tumor thrombus microwave ablation catheter, which is composed of a flexible tube body and an axially parallel coaxial cable and a guidewire guide tube arranged inside the flexible tube body. The coaxial cable is composed of From the inside to the outside, it is composed of the coaxial cable inner conductor, the coaxial cable insulation layer and the coaxial cable outer conductor; the far end of the coaxial cable is connected to a microwave radiation head.

Preferably, the flexible tube body and/or guide wire guide tube are made of PEEK material.

Preferably, the distal end of the coaxial cable is connected to the microwave radiating head through an inner conductor of the coaxial cable.

Preferably, the coaxial cable is a semi-rigid coaxial cable.

Preferably, a handle is provided at one end of the flexible pipe body away from microwave radiation. The handle partially wraps the flexible pipe body. A first outlet and a second outlet are provided at one end of the handle away from the flexible pipe body. The coaxial cable extends to the outside of the first outlet, and the guide wire The guide tube extends to the second outlet.

Preferably, the first outlet is parallel to the axis of the coaxial cable.

Preferably, the handle further includes a protective sheath wrapped around the flexible tube.

Preferably, the distal extension length of the microwave radiating head is greater than the distal extension length of the guide wire guide tube.

Preferably, the guidewire guide tube can accommodate guidewires of 0.035 inches or less.

The present invention also provides a portal vein tumor thrombus microwave ablation device, which includes the microwave ablation catheter described in the above technical solution and a microwave generator.

Compared with the existing technology, the beneficial effects of the present invention are:

Due to the limitation of the diameter of the coaxial cable itself, some existing technologies use multi-lumen catheters to combine guide wires and coaxial cables. However, the overall catheter diameter generally exceeds 2 mm. The diameter is large, making it difficult to insert the portal vein, especially the stenotic portal vein. Passing through the pulmonary veins cannot meet the needs of microwave ablation treatment of portal vein tumor thrombi. Generally, coaxial cables are composed of four layers of materials. From the inside to the outside, they are the inner conductor of the coaxial cable, the insulation layer surrounding the inner conductor, the mesh conductor, and the outermost insulating sheath. This invention creatively arranges the guide wire guide tube inside the insulating outer sheath of the coaxial cable, which greatly reduces the overall diameter of the microwave ablation catheter, making it suitable for traveling in narrow veins to reach the portal vein tumor thrombus area, which provides precise ablation and opening of the portal vein. Provides implementation possibilities.

The microwave ablation catheter provided by the present invention has at least the following advantages:

(1) The microwave ablation catheter can pass through narrow veins (such as pulmonary veins, etc.) to reach the portal vein tumor thrombus that needs to be ablated, achieving the purpose of ablation from the inside of the portal vein outward;

(2) The microwave ablation catheter can accommodate a guide wire, and the guide wire is used for precise positioning. The flexible catheter can accurately reach the area requiring ablation treatment under the guidance of the guide wire;

(3) The microwave radiating head at the distal end of the microwave ablation catheter can effectively ablate cancer tissue inside and outside the portal vein, and gradually open up the portal vein tumor thrombus with the guidance of the guide wire;

(4) Compared with traditional external ablation of portal vein tumor thrombus and radiofrequency ablation, there is no need to place additional loop electrodes, the ablation site is more precise and controllable, and damage to normal tissue can be minimized.

Description of drawings

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without any creative work fall within the scope of protection of the present invention.

Figure 1 is a schematic structural diagram of the microwave ablation catheter according to the present invention;

Figure 2 is a schematic structural diagram of the handle of the microwave ablation catheter according to the present invention;

Figure 3 is a schematic structural diagram of the microwave ablation device according to the present invention;

Among them: 1 is the microwave radiating head, 2 is the microwave ablation catheter, 3 is the handle, 4 is the microwave generator, 5 is the guide wire, 6 is the connecting wire, A is the distal end of the microwave ablation catheter, 21 is the flexible tube body, and 22 is Guide wire guide tube, 23 is the coaxial cable, 231 is the inner conductor of the coaxial cable, 232 is the insulating layer of the coaxial cable, 233 is the outer conductor of the coaxial cable, 234 is the first guide wire outlet, 31 is the first outlet, 235 /32 is the second outlet/second guide wire outlet, 33 is the handle housing, and 34 is the protective cover.

Detailed ways

The technical solution of the present invention will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the implementations of the present application, rather than all implementations; and the structures shown in the drawings are only schematic and do not represent actual objects. It should be noted that based on these embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of this application.

In this article, the terms "first" and "second" are only used to explain the relative relationship between angles or positions, and do not limit the absolute position or order. Those skilled in the art should understand it. The term "distal end" refers to the end far away from the microwave generator or closer to the patient when used; "proximal end" refers to the end close to the microwave generator or relatively far away from the patient when used.

As shown in Figures 1-3, the present invention provides a portal vein tumor thrombus microwave ablation catheter, which consists of a flexible tube body 21 and an axially parallel coaxial cable 23 and a guide wire guide tube 22 arranged inside the flexible tube body 21. The coaxial cable 23 is composed of a coaxial cable inner conductor 231, a coaxial cable insulation layer 232 and a coaxial cable outer conductor 233 from the inside to the outside; a microwave radiating head 1 is connected to the far end of the coaxial cable 23. The guide wire guide tube 22 in the present invention is used to accommodate the guide wire. The coaxial cable 23 is used to receive the microwave power from the microwave generator and transmit it to the microwave radiating head 1. The microwave radiating head 1 performs microwave radiation to achieve microwave ablation. The flexible tube The body 21 wraps the coaxial cable 23, the guide wire guide tube 22 and the microwave radiation head 1 to form a small diameter, flexible microwave ablation catheter, which can easily travel inside the vein and reach the inside of the portal vein, so as to complete the internal ablation of the portal vein tumor thrombus. Several development marks can be provided on the microwave ablation catheter of the present invention for tracking, and other marking methods can also be used for marking.

In the present invention, the flexible tube body 21 is easy to bend, which can meet the needs of traveling in non-linear veins, so that the microwave ablation catheter of the present invention can smoothly reach the portal vein tumor thrombus site through the guidance of the guide wire, avoiding the risk to the patient. The veins are damaged without unnecessary puncture damage to the patient's normal cells. In the present invention, the flexible pipe body 21 is usually made of insulating material; in some specific embodiments of the present invention, the flexible pipe body 21 is made of PEEK (polyetheretherketone) material.

In the present invention, the guide wire guide tube 22 mainly provides space for the guide wire, and axially penetrates the interior of the flexible tube body 21. A first guide wire outlet 234 is provided at the distal end, and a second guide wire outlet 235 is provided at the proximal end. , the guide wire 5 enters and exits the guide wire guide tube 22 through the first guide wire outlet 234 and the second guide wire outlet 235 . Preferably, the extension length of the distal end of the first guide wire outlet 234 is shorter than the microwave radiation head, so that the microwave radiation head can deeply ablate the portal vein tumor thrombus until the portal vein is gradually opened. In order to control the diameter of the microwave ablation catheter of the present invention, the present invention preferably makes the guide wire guide tube 22 into an inner diameter size that can accommodate a guide wire of less than or equal to 0.035 inches. In the present invention, the guide wire guide tube 22 is preferably made of insulating material; in some specific embodiments of the present invention, the guide wire guide tube 22 is made of PEEK material.

In the present invention, the coaxial cable 23 is preferably a semi-rigid coaxial cable. The coaxial cable 23 of the present invention is connected to a microwave radiating head 1 at the distal end, and the microwave radiating head 1 is also axially parallel to the guide wire guide tube; in some specific embodiments of the present invention, the distal end of the coaxial cable The coaxial cable inner conductor 231 is connected to the proximal end of the microwave radiating head 1; preferably, the connection between the coaxial cable inner conductor 231 and the microwave radiating head 1 is partially exposed.

In the present invention, microwaves are radiated to surrounding tissues through the microwave radiating head 1, and the microwave magnetic field causes water molecules in the surrounding tissues to move at high speed, heating the tissues through molecular friction and causing coagulation, dehydration and necrosis. The tumor tissue ablated by microwave can be absorbed by the matrix to achieve the purpose of treating portal vein tumor thrombus. In the present invention, the microwave radiation head 1 is preferably cylindrical in order to quickly penetrate the portal vein.

Preferably, the microwave ablation catheter further includes a handle 3. The handle 3 can be arranged at the end of the microwave ablation catheter, such as at the proximal end of the flexible tube body, to facilitate hand-held operation; the handle 3 can also be arranged at the non-end of the microwave ablation catheter, such as a segmented microwave ablation catheter. It is connected or fixedly connected to a certain section of the microwave ablation catheter, or is set on the microwave ablation catheter with an adjustable position. In some specific embodiments of the present invention, the handle 3 is provided at the distal end of the flexible pipe body 21, and the handle 3 partially wraps the flexible pipe body 21. The end of the handle 3 away from the flexible pipe body 21 is provided with a first outlet 31 and a second outlet 32. , the coaxial cable 23 and the guide wire guide tube 22 are separated inside the handle, the coaxial cable 23 extends outside the first outlet 31 , and the guide wire guide tube 22 extends to the second outlet 32 . Preferably, the first outlet 31 is axially parallel to the coaxial cable 23 . Preferably, the handle 3 further includes a protective sheath 34 wrapped around the flexible tube body 21 .

The present invention also provides a portal vein tumor thrombus microwave ablation device, which includes the microwave ablation catheter described in the above technical solution, and a microwave generator 4. Microwave generator functions known in the art can be used in the present invention. In the present invention, the microwave ablation catheter and the microwave generator can be connected directly, or they can be connected through a section of connecting wire 6, or through other transfer and connection structures. The structure of the connecting wire 6 can be the same as that of the microwave ablation catheter of the present invention, or it can be a different structure (such as using a conventional coaxial cable as the connecting wire). In some specific embodiments of the present invention, the connecting wire 6 is connected to a coaxial cable extending from the first outlet 31 on the handle.

Microwave generators are the source of ablative microwave energy. Microwave generators generally use solid-state microwave oscillators and power amplifiers to generate 2.45GHz microwaves. In some specific embodiments of the present invention, the microwave generator may also include a power controller for controlling different levels of microwave output, such as 30W, 50W, 70W and 90W. The power level used depends on the size of the object to be ablated. In some embodiments of the present invention, the microwave generator may also include a timer for displaying the ablation time. In some specific embodiments of the present invention, the microwave generator may also include a front panel, which is provided with multiple windows for monitoring the operation process of the system, such as timers, temperature sensors, power monitoring sounds, and power display windows.

In some embodiments of the present invention, the microwave generator may further include a temperature sensor for monitoring the temperature of the ablation catheter body during the ablation operation. Further preferably, a digital display window can be set to display the real-time ablation catheter temperature, and a temperature knob can be set to set the upper limit of the temperature. Once the temperature of the ablation catheter reaches the limit temperature, the alarm will sound and the microwave emission will be terminated; the limit temperature can preferably be set, for example, to 40 degrees Celsius. In some specific embodiments of the present invention, the microwave generator may also include a temperature control device, and the temperature control device is used to change the limit temperature.

Before use, the microwave ablation catheter of the present invention is connected to the microwave generator. After confirming the site that requires microwave ablation, guide the guide wire 5 into the tumor thrombus inside the portal vein through puncture, let the guide wire pass through the guide wire guide tube, and make the microwave ablation catheter of the present invention enter the patient's vein along the guide wire 5 until it reaches The portal vein requires ablation site. Turn on the power of the microwave generator, and the microwave radiates to the surrounding tissue through the microwave radiating head 1, ablating a high-temperature ablation zone at the target location, and moving the microwave ablation catheter back and forth to form a longer-distance ablation zone to achieve the therapeutic effect of opening the portal vein. . If a larger ablation area is required, the guidewire can also be moved and repositioned before performing the above steps.

In one embodiment of the present invention, the microwave ablation catheter usage process includes: (i) using real-time ultrasound guidance to access the correct PV through an 18G puncture needle; contrast agent injection to display a portal map "above" the tumor thrombus, Display the "upper" border of the PV tumor thrombus; (ii) Use a 5Fr guiding catheter to introduce a 0.035-inch diameter wire through the thrombus into the superior mesenteric vein (SMV), and perform portal venography "below" the thrombus to record the "lower" border of the PV tumor thrombus . The microwave ablation catheter is introduced through a 0.035-inch diameter wire at the location between the upper and lower borders and is activated by power to achieve ablation. The microwave ablation catheter can be repositioned within the upper and lower borders to create a more cylindrical ablation zone.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be made. regarded as the protection scope of the present invention.

Claims (8)

1. The microwave ablation catheter for the portal vein cancer embolus is characterized by comprising a flexible tube body, and an axially parallel coaxial cable and a guide wire guide tube which are arranged in the flexible tube body, wherein the coaxial cable comprises a coaxial cable inner conductor, a coaxial cable insulating layer and a coaxial cable outer conductor from inside to outside; the far end of the coaxial cable is connected with a microwave radiation head;

the guide wire guide tube is made of an insulating material;

the soft pipe body is made of insulating materials;

the end, far away from the microwave radiation, of the flexible pipe body is provided with a handle, the handle wraps the flexible pipe body, the coaxial cable and the guide wire guide pipe are separated in the handle, the end, far away from the flexible pipe body, of the handle is provided with a first outlet and a second outlet, the coaxial cable extends out of the first outlet, and the guide wire guide pipe extends to the second outlet; the first outlet is axially parallel to the coaxial cable.

2. The portal vein cancer embolus microwave ablation catheter of claim 1, wherein the flexible tube and/or guide wire guide tube is made of PEEK material.

3. The portal vein cancer embolus microwave ablation catheter of claim 1, wherein the distal end of the coaxial cable is connected to a microwave applicator by a coaxial cable inner conductor.

4. The portal vein cancer embolus microwave ablation catheter of claim 3, wherein the coaxial cable is a semi-rigid coaxial cable.

5. The portal vein cancer embolus microwave ablation catheter of claim 1, wherein the handle further comprises a protective sheath wrapped around the flexible tube body.

6. The portal vein cancer embolus microwave ablation catheter of claim 1, wherein the microwave radiation head extends distally longer than the guidewire guide catheter.

7. The portal vein cancer embolus microwave ablation catheter according to claim 1 or 6, wherein said guidewire guide tube is capable of receiving a guidewire of 0.035 inches or less.

8. A portal vein cancer embolus microwave ablation device comprising the microwave ablation catheter of any of claims 1-7, and a microwave generator.