Histopathological features of tissue alterations induced by low frequency ultrasound with cavitational effects on...

Low frequency, high energy level ultrasound (US) induces physical effects on tissues called ultrasonic cavitation (UC). Endermic US therapy has recently been proposed as a method to reduce non-invasively the amount of adipose tissue. Very few published studies have dealt with the biological effects of such therapies on human adipose tissue. The aim of this study is to evaluate, through histopathological examination, the effects of various levels of ultrasonic radiation on supravital human adipose tissue. Four ex vivo human tissue samples were treated as follows: sample 1: no US radiation; sample 2: US radiation 2,5 W/cm2 for 15 minutes; sample 3: US radiation 5 W/cm2 for 15 minutes; sample 4: infiltration of 30 ml physiological saline and US radiation, 5 W/cm2 for 15 minutes. For lower levels of ultrasonic energy, interruption of the adipocytic membranes was evident both in the surface and in the deeper cutaneous and subcutaneous layers, with focal dissolution and homogenization of the surface dermal fascia. For higher levels of ultrasonic energy, alterations of the adipocytes and of the collagen fibers were greater, resulting in the dissolution of the cells and of the interlobular fibrous septa. Both effects were amplified by tumescent saline infiltration. The histological lesions demonstrated in adipocytes confirm the theoretical premises of a possible usefulness in the treatment of localized adiposis. The alterations observed in the connective stroma could have positive effects on the structural re-organization and consequently on the in vivo external appearance of the treated areas.