Investigation of the Heat Sink Effect during Microwave Ablation in Hepatic Tissue: Experimental and Numerical Analysis

The presence of a large blood vessel in the proximity of tumor masses during microwave ablation (MWA) can compromise the procedure success. Blood vessels cause convective heat dissipation (i.e., heat sink effect, HSE) in the tissue surrounding the vessel. In this scenario, cytotoxic temperatures may not be achieved within the target area, resulting in ineffective cancer removal. In this paper, we investigated HSE in hepatic tissue from both an experimental and numerical perspective. MWA was performed mimicking two clinical scenarios (i.e., with and without a blood vessel near the heat source). Fiber Bragg grating sensors measured tissue temperature during the procedure, whereas numerical simulations were carried out to evaluate temperature distribution theoretically. Temperature profiles obtained by simulations and experiments confirmed the influence of HSE with a significant cooling effect nearby the vessel. The proposed approach allowed to quantify the HSE impact on MWA outcomes, laying the foundations for optimizing the treatment parameters in terms of ablated volume and malignant cells destruction.