Study of a non-water-cooled microwave ablation needle based on a vacuum needle rod to achieve carbonization-free operation: design, simulation, and experimental research.

Background: At present, the microwave ablation needle used in clinic needs to add water circulation in the needle rod to reduce the rod temperature. However, the water circulation will take away a lot of heat during the ablation process, which requires increasing the ablation dose to achieve the expected thermal coagulation target volume. This undoubtedly increases the risk of carbonization.

Methods: A design scheme of non-water-cooled microwave ablation needle based on double-layer vacuum structure was proposed. Two types of non-water-cooled microwave ablation needles with long and short needles were designed, and the ablation simulation was carried out by establishing the finite element simulation model.

Results: Simulation and experimental results indicate that, at 20 W power, the long-needle vacuum tube ablation needle can create a carbonization-free solidification zone with a length of 34 mm after 180 s of ablation, whereas the short-needle vacuum tube ablation needle requires 300 s to form a similar zone with a length of 30 mm. Additionally, the axial ratio of the solidification zone created by the long-needle vacuum tube ablation needle exceeds that of the short-needle one. Consequently, the long-needle vacuum tube ablation needle is more apt for creating a larger solidification zone with minimal carbonization, while also achieving a more spherical shape.By comparing the ablation effects of long needle vacuum tube ablation needle and ky-2450b1 under low power,It is verified that the vacuum tube non-water-cooled ablation needle can ensure the effective ablation volume and non carbonization ablation under low-power and short-time ablation, which provides an important technical scheme for clinical optimization of the therapeutic effect of microwave ablation.

Conclusions: The LPH-W-F-MWA is more adept at creating a larger coagulation zone with minimal carbonization, achieving a more spherical shape to a greater extent. This ensures both an effective ablation volume and char-free ablation, offering a crucial technical solution for optimizing the therapeutic effect of MWA in clinical settings.