Computational analysis of skin folding after bariatric surgery

Obesity is a growing global health issue. Bariatric surgery enables rapid weight loss but often results in excess skin as a side effect. Body-contouring surgery can remove this excess skin, but its costs limit access to patients. The severity of skinfolds varies among post-Massive Weight Loss (p-MWL) patients, though the underlying reasons remain poorly understood. To investigate this, we developed a finite element model incorporating a kinematic growth model, to simulate adipose tissue shrinkage and analyze skin folding patterns following massive fat loss. We specifically investigated how skin thickness and its stiffness relative to the fat tissue affect the wavelength and depth of skin folds. Our results showed that inter-patient differences in skin stiffness may explain variations in folding risk, with higher stiffness increasing the likelihood of skin folding in p-MWL patients. Additionally, increased skin thickness contributes to deeper and larger folds. Finally, higher skin stiffness was found to reduce the fat loss needed to initiate folding. This study improves our understanding of the key parameters determining the skin folding risk after massive weight loss in p-MWL patients. These insights contribute to a more mechanistic understanding and an improved risk assessment of the skin folding risk in p-MWL patients, which can ultimately enhance clinical decision making and thus the quality of life of these patients.