Comparison study of metastasis hepatic coagulation

In our contribution we are interested in tissue coagulation by Nd-YAG and Ar lasers in order to know which laser is necessary to use for the destruction of hepatic metastasis. For that we have developed a mathematical model, in which the liver tissue is considered homogeneous, and isotropic, the absorbed energies is optimized by the beam broadening model and the transfer of heat is modeled by the bioheat equation. The solution of this equation by the finite volumes method gives the space-time variation of the temperature, which makes it possible to determine the necrosis depth by using the Arrhenius integral. The results obtained show that the temperature of coagulation is reached for strong intensity in the case of the Nd-YAG laser compared with the Ar laser, and that the volume of the coagulated zone is considerable in the case of the Nd-YAG laser, from this fact it is selected in gastro-enterology. (author)