R. Agah et al., RATE-PROCESS MODEL FOR ARTERIAL TISSUE THERMAL-DAMAGE - IMPLICATIONS ON VESSEL PHOTOCOAGULATION, Lasers in surgery and medicine, 15(2), 1994, pp. 176-184
A numerical model for thermal damage to human arterial tissue is prese
nted, based on protein denaturation kinetics. The model involves deter
mination of coefficients of rate processes A and Delta E, which are ti
ssue type-dependent (arterial tissue in this study), and definition of
threshold damage. A feedback-controlled constant surface temperature
device was used to induce 80 coagulative lesions of arterial human tis
sue ranging in temperature from 66 degrees C to 76 degrees C and in du
ration from 15 to 1,500 seconds. The measured coefficients were determ
ined to be A = 5.6 x 10(63) s(-1) and Delta E = 430 KJ mole(-1). These
numerical values closely approximate the coefficients of the rate pro
cess for denaturation of collagen molecules. These and other histologi
cal observations strongly suggest collagen to be the primary coagulati
ng component of arterial tissue at the onset of thermal coagulative da
mage. The ability of this model to predict onset of tissue coagulation
during laser coagulation was studied using 10 postmortem human arteri
al samples exposed to argon laser irradiation. (C) 1994 Wiley-Liss, In
c.