Effect of B-mode ultrasound- guided extracorporeal low- level focused sonotherapy on early stage atherosclerosis regression using color doppler ultrasonography and histopathology

Abstract

Background and Aims : Excessive lipid accumulation by macrophages plays a crucial role in atherosclerosis. Foam cells are generated by uncontrolled uptake of modified LDL, especially oxidized LDL. We developed an experimental sonotherapy system and investigated its effectiveness on macrophage- derived foam cells density reduction and arterial hemodynamic parameters improvement, wherein diagnostic B- mode ultrasound is combined with the therapy system, with a goal of increased safety.Methods: Briefly, New Zealand white rabbits underwent primary balloon dilatation injury at the right common carotid artery followed by a 1.5% cholesterol-rich diet injury for three weeks. Histopathology and B- mode ultrasonography results showed the early stage atherosclerosis formation in all of the rabbits' arteries. Then, treatment group underwent extracorporeal low- level focused sonotherapy (F= 1 MHz, I= 2 w/cm2, PD= 100 ms). Foam cells density and arterial hemodynamic parameters were evaluated in the treatment group compared with the control group using histopathology and color Doppler ultrasonography, respectively.Results: from histopathology and color Doppler ultrasonography showed a significant reduction in the mean value for immune and foam cells density, Resistive Index (RI), Pulsatility Index (PI), Peak Systolic Velocity (PSV), End Diastolic Velocity (EDV), Mean Velocity (MV) and significant increase in the mean value for volume Flow (VF) in the treatment group compared with the control group (p < 0.05).Conclusions: Anti- inflammatory, lipid effluxion, reverse cholesterol transport and machrophages egress effect of sonotherapy reduces the immune and foam cells density and increase the endothelial Nitric Oxide synthase (eNOS), resulting in arterial hemodynamic parameters improvement and early stage atherosclerosis regression. Background and Aims : Excessive lipid accumulation by macrophages plays a crucial role in atherosclerosis. Foam cells are generated by uncontrolled uptake of modified LDL, especially oxidized LDL. We developed an experimental sonotherapy system and investigated its effectiveness on macrophage- derived foam cells density reduction and arterial hemodynamic parameters improvement, wherein diagnostic B- mode ultrasound is combined with the therapy system, with a goal of increased safety. Methods: Briefly, New Zealand white rabbits underwent primary balloon dilatation injury at the right common carotid artery followed by a 1.5% cholesterol-rich diet injury for three weeks. Histopathology and B- mode ultrasonography results showed the early stage atherosclerosis formation in all of the rabbits' arteries. Then, treatment group underwent extracorporeal low- level focused sonotherapy (F= 1 MHz, I= 2 w/cm2, PD= 100 ms). Foam cells density and arterial hemodynamic parameters were evaluated in the treatment group compared with the control group using histopathology and color Doppler ultrasonography, respectively. Results: from histopathology and color Doppler ultrasonography showed a significant reduction in the mean value for immune and foam cells density, Resistive Index (RI), Pulsatility Index (PI), Peak Systolic Velocity (PSV), End Diastolic Velocity (EDV), Mean Velocity (MV) and significant increase in the mean value for volume Flow (VF) in the treatment group compared with the control group (p < 0.05). Conclusions: Anti- inflammatory, lipid effluxion, reverse cholesterol transport and machrophages egress effect of sonotherapy reduces the immune and foam cells density and increase the endothelial Nitric Oxide synthase (eNOS), resulting in arterial hemodynamic parameters improvement and early stage atherosclerosis regression.