Histology-controlled study of efficacy and safety of isolated and combined use of popular hardware methods for cosmetic correction

Objective. To identify ultrasound and morphological changes in epidermis and dermis after exposure to radiofrequency microneedling, microsfocused ultrasound, and photodynamic therapy. Material and methods. In 4 patients, paraumbilical region was divided into 5 sectors. Each one was subjected to hardware procedure: segment I — radiofrequency mecroneedling; segment II — microsfocused ultrasound; segment III — photodynamic therapy; segment IV — combination of radiofrequency microneedling, microsfocused ultrasound and photodynamic therapy in one procedure; segment V — control. Control methods included histological and ultrasound examination before exposure and 30 days later. Results. Ultrasound examination of segment I showed higher hyperechogenicity and thickening of dermal layer. In segment II, we visualized higher thickening and echogenicity of dermis, as well as more homogeneous subcutaneous fat. In segment III, deep layers of skin were not changed, but epidermis looked more uniform and clearer. In segment IV, we found the most pronounced changes in all tissue layers. Histological examination of segment I showed moderate thickening of epidermis with slightly higher density of collagen fibers in superficial dermis. Segment II was characterized by thickening of epidermis due to basal layer, enhanced synthesis of collagen and higher density of dermal fibers. In segment III, epidermis looked thicker due to thickening of stratum corneum, and there were some signs of dermal remodeling. The most pronounced morphological changes were logically found in segment IV: significant thickening of epidermis and pronounced signs of dermal remodeling. Conclusion. Results of this study confirm the effectiveness of all these techniques and correlate with previous data. At the same time, signs of tissue remodeling are clearer after combined exposure.