Safety and efficacy of intracavitary microwave ablation in hepatic gland tumours: Numerical and in vitro studies

Abstract

The microwave ablation (MWA) of large hepatic gland tumour using multiple trocars operated at 2.45/6 GHz frequencies has been analysed. The ablation region (in vitro) obtained using parallel and non-parallel insertion of multiple trocars into the tissue has been analysed and compared with the numerical studies. The present study has considered a typical triangular-shaped hepatic gland model for experimental and numerical analysis. COMSOL Multiphysics software with inbuilt bioheat transfer, electromagnetic waves, heat transfer in solids and fluids and laminar flow physics has been used to obtain the numerical results. Experimental analysis has been conducted on egg white using a market-available microwave ablation device. It has been found from the present study that MWA operated at 2.45/6 GHz with the non-parallel position of multiple trocars into the tissue leads to a considerable increase in the ablation region as compared to the parallel insertion of trocars. Hence, non-parallel insertion of trocars is suitable to treat irregular-shaped large cancerous tumours (>3 cm). The non-parallel simultaneous insertion of trocars can overcome the healthy tissue ablation issue as well as the problem associated with indentation. Further, reasonable accuracy (with the difference being nearly ±0.1 cm in ablation diameter) has been achieved in comparing the ablation region and temperature variation between experimental and numerical studies. The present study may create a new path in the ablation of large size tumours (>3 cm) with multiple trocars of all shapes by sparing the healthy tissue.