Mathematical modeling of varicose veins ultrasound heating

During the last decade less invasive endovenous methods of treatment of lower limb varicose veins (LLVV) have obtained widespread appreciation. Nevertheless, the problem of improving their long-term results is still actual. The aim of this study is investigation of the biothermomechanical response of the venous wall to the low-frequency ultrasound exposure, which is an advanced method in the treatment of LLVV. The model designed to analyze frequency range of the ultrasound instrument and the different values of its pullback velocity. According to the simulation results, the frequency range, in which necrotic changes of the venous wall can be caused was determined. The dependencies of the venous wall collagen denaturation time on the temperature and pullback velocity of the ultrasound instrument were obtained. After the developed model is supplemented with temperature dependencies of the physical properties of the venous wall, these results can be used to form requirements for ultrasound treatment modes for lower limb varicose veins.