Numerical simulations to analyze the impact of vascular network complexity over cryosurgical treatment process of two-dimensional liver tumor tissue

Cryosurgery is a minimally invasive surgery widely used for liver cancer. The vascular network present in the tissue affects the temperature distribution across the tissue. The present study focuses upon the numerical simulations of cryosurgery for liver tumor with vascular network. The phase change which occurs in bioheat equation has been tackled using Effective heat capacity method and the vessels are constructed following Murray's Law. Blood flow in the vascular network is assumed to be Newtonian and laminar. The continuity equation, Navier's Stoke Equation coupled with heat energy equation is solved for the vascular network. Finite Element Method (FEM) has been implemented for the numerical simulations using COMSOL Multiphysics software. The ice balls generated in 600s around the cryoprobe are analyzed. Necrosis of the tissue with the presence of vascular network have been determined for tissue kept under freezing for 600s. The numerical results have been compared with experimental results of Ge et al.[1] and found to be in good agreement with the experimental study. Further, impact of vascular network for optimal planning of the surgery have been numerically simulated in the present study.