Efficacy of a New Non-Invasive System Delivering Microwave Energy for the Treatment of Abdominal Adipose Tissue: Results of an Immunohistochemical Study

Unwanted abdominal fat is a common aesthetic concern treated through various interventions, including surgical and energy-based devices, often leading to inconsistent results. This study aimed to evaluate the feasibility of a localized, non-invasive microwave (MW) device for preferential heating of subcutaneous adipose tissue using a controlled electromagnetic field. Five female volunteers scheduled for abdominoplasty were enrolled, each undergoing a single MW treatment session five days prior to surgery. Histological analyses of adipose tissue and skin samples were conducted using Hematoxylin and Eosin staining and immunohistochemistry for Perilipin-1 and CD68. Epidermal and dermal layers remained unaffected, as evidenced by unaltered morphology in treated samples. In contrast, the absence of Perilipin-1 expression in disrupted fat cell membranes indicated adipocyte non-viability and irreversible injury. Inflammatory responses, including CD68-positive macrophages surrounding damaged adipocytes, were observed, suggesting the activation of the monocyte/macrophage system for the clearance of adipocyte residues. Microscopic and immunohistochemical findings demonstrate the effectiveness of the MW device in reducing subcutaneous fat. This study also discussed the underlying mechanisms involved in macrophage recruitment and the removal of adipocyte residues.