Rate process model for arterial tissue thermal damage: Implications on vessel photocoagulation

Abstract

A numerical model for thermal damage to human arterial tissue is presented, based on protein denaturation kinetics. The model involves determination of coefficients of rate processes A & δE, which are tissue 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 tissue ranging in temperature from 66°C to 76°C and in duration from 15 to 1,500 seconds. The measured coefficients were determined to be A = 5.6 × 1063 s−1 and δE = 430 KJ mole−1. These numerical values closely approximate the coefficients of the rate process for denaturation of collagen molecules. These and other histological observations strongly suggest collagen to be the primary coagulating component of arterial tissue at the onset of thermal coagulative damage. The ability of this model to predict onset of tissue coagulation during laser coagulation was studied using 10 postmortem human arterial samples exposed to argon laser irradiation. © 1994 Wiley‐Liss, Inc.

Investigation of radiofrequency ablation process in liver tissue by finite element modeling and experiment

“…Damage integral value W=1 corresponds to 63% probability of cell death at a specific point, and value W=4.6 corresponds to 99% probability of cell death at a point in the model. The significance of W=1 has been reported as the point at which tissue coagulation first occurs (12).…”

Prototype laser-activated shape memory polymer foam device for embolic treatment of aneurysms

“…At a temperature of ϳ67°C ͑ϳ30°C above body temperature͒, thermal damage of arterial tissue occurs within a few minutes, 15 a time scale similar to that of device deployment. Given the minutes time scale for thermal damage at 67°C, our design goal is a maximum deployment time of 60 s and desired deployment time under 30 s. To avoid causing thermal damage to the already compromised aneurysm wall under zero or low flow conditions, the optimal combination of foam T g , laser power, dye concentration, and flow will need to be determined.…”

Remote Temperature Estimation in Intravascular Photoacoustic Imaging

“…The damage analysis was performed for the arterial tissue with the initial temperature distribution taken from the temperature map (Fig. 6) at time t =0.1 ms, and the rate process coefficients for arterial tissue (A = 5.6·10 63 , E a = 430 KJ/mol) obtained from the literature (Agah et al 1994). The accumulated damage coefficient for the temperature distribution observed after approximately 5 thermal relaxation times (25 ms) is 6.4·10 -11 which suggest that the temperature increase and the exposure time are small and do not cause any significant thermal change in the artery tissue following IVPA imaging.…”