A fundamentals-based vaporization model for radiofrequency ablation of biological tissues: Comparison with the enthalpy method

Abstract

Intratissue vaporization is a crucial phenomenon to be considered in the theoretical modeling of the radiofrequency ablation (RFA) of biological tissues. The enthalpy method (EM) is one of the most common methods to model it. However, this method does not consider either the vapor pressure or the water content in gas phase and consequently does not realistically consider vaporization. Our objective was to develop a new fully coupled model (FCM) for liver RFA including a multiphase porous media model as well as the vapor pressure and the fraction of water in form of liquid and gas. The results show that the FCM can efficiently calculate the vapor pressure and the water content in all the points and times during the RFA, what differences this model from other existing models. As compared to EM, the FCM presents a more uniform solution without unrealistic fluctuations in the temperature and electrical impedance progresses.