Defining the Subscarpal Lipo-Aponeurotic System (SLAS): Anatomical, Histopathological, and Biomechanical Analysis

Based on previous reports on the subscarpal lipo-aponeurotic system (SLAS), the authors describe their experience with biplanar lipo-abdominoplasty. The SLAS was found to serve as an excellent flap for tightening the abdominal wall and improving the abdominal contour. The purpose of this study was to explore the anatomy of the SLAS, its biomechanical properties, and its microscopic composition using tissue analysis and morphometric quantification. Cadaver dissections were performed on preserved cadavers in the anatomic laboratories of the faculty of medicine. Tissue samples were also obtained from abdominoplasty procedures conducted on living patients. These tissues then underwent mechanical analyses and pathological characterization. Average nominal stress-strain curves demonstrated that for each given strain measurement, SLAS samples exhibited significantly higher stress than the subcutaneous samples, at a statistically significant level (P < .001). Average collagen area percent per 100 microscopic fields was found to be 12 ± 1.4 in the subcutaneous fields and 19.7 ± 2.4 in the corresponding SLAS fields (P = .013). Individual variation in information entropy in the tissue samples demonstrated a statistically significant increase in the SLAS sample when compared with the corresponding subcutaneous tissue, with an average of 1.59 ± 0.27 and 1.46 ± 0.25, respectively (P < .0001). SLAS exhibited unique biomechanical, histopathological, and anatomical properties in this study. The unique anatomical qualities of SLAS are important to consider in abdominal wall surgeries. Level of Evidence: 5 (Therapeutic).