Changes in oscillatory and nonlinear dynamic processes of microcirculation in patients with obliterating atherosclerosis of lower limb arteries after revascularization

Aim: To study the nature of changes in oscillatory and nonlinear dynamic processes in the skin microcirculatory system by laser Doppler fl owmetry in patients with obliterating atherosclerosis of the lower limbs arteries (OALLA) after limb revascularization. Material and Methods. 27 male patients with OALLA before and after endovascular revascularization of the aff ected limb (median age 63.0 [60.0; 69.0] years) were studied. Microcirculation (MC) of the foot skin with assessment of nonlinear dynamic processes and spectral wavelet analysis of blood fl ow fl uctuations was studied by laser Doppler fl owmetry. The normalized amplitude indices of blood fl ow fl uctuations were determined in frequency ranges refl ecting: endothelial, neurogenic, myogenic, respiratory, pulse factors of hemocirculation. Bypass parameters and nutritive blood fl ow were assessed. An occlusion test was performed to determine capillary blood fl ow reserve. The study of nonlinear dynamic processes included assessment of fractal dimension, entropy determination and phase portrait analysis. Results. Limb revascularization in patients with OALLA resulted in improvement of the clinical picture accompanied by statistically signifi cant increase in nutritive blood fl ow (+9.7%) and reserved dilatation potential of microvessels (+43.2%), decrease in arteriolo-venular blood shunting (–5.0%) and venous plethora (–14.3%). The analysis of nonlinear dynamic processes of the MC showed that after angioplasty, along with the remaining defi cit of oscillatory processes energy, there was a decrease in the fractal dimension index (–14.3%), indicating the limitation of lability of the functional system of the microvascular bed. At the same time, an increase in the chaotization of the regulatory mechanisms of the peripheral blood fl ow was established. Conclusions. The results showed positive functional changes of the MC system associated with the improved clinical picture in patients with OALLA after limb revascularization. At the same time, changes in the nonlinear dynamics parameters indicate a compensatory increase in the chaotization of the system together with the remaining limitation of its functional lability and the energy defi cit of oscillatory processes.