HEATING EFFECT OF THERMALLY SIGNIFICANT BLOOD VESSELS IN PERFUSED TUMOR TISSUE DURING CRYOSURGERY

Abstract

The purpose of this work is to evaluate the heating effect of thermally significant blood vessels (TSBVs) during cryosurgery process. A theoretical model is developed to describe the heat transfer of perfused tissue containing a 6 mm-radius tumor and a countercurrent artery–vein pair in the vicinity of the tumor. The novelty of the model is that both the Pennes bio-heat transfer equation and the energy transport equation are used to govern the heat transfer of perfused tumor tissue and the heat convection and diffusion of the blood flow. The explicit finite different method is used to solve the transient equations with the second boundary condition set for the boundary of both the blood vessels and the tissue. The results indicate that the heating effect of the blood on the tissue surrounding the countercurrent artery–vein pair may cause parts of the tumor to be insufficiently frozen for a pre-designed cryosurgery protocols, and which may lead to regeneration of the tumor cells. A quite important issue has been raised by this study, i.e., the cryosurgery protocols should be carefully designed with full attention being paid to the heating effect of TSBVs in case of a countercurrent artery–vein pair in the vicinity of the tumor.