Changes in dermal histomorphology following surgical weight loss versus diet-induced weight loss in the morbidly obese patient.

Introduction: Patients with postgastric bypass and diet-induced weight loss present to the plastic surgeon for various body contouring procedures. Gross differences in skin dermal elasticity may exist between these populations; however, studies evaluating histologic differences are lacking. This prospective study aims to evaluate histomorphologic differences in morbidly obese patients following surgical versus diet-induced (nonsurgical) weight loss. Further, we aim to elicit if postoperative complications are correlated with the mechanism of weight loss and potential histomorphologic differences.
Methods: Defined infraumbilical skin specimens were collected during abdominal contouring procedures following weight loss achieved through surgical or nonsurgical means. Specimens were stained for elastic fiber content and morphology, collagen deposition, and inflammation. All sections underwent evaluation for quality and quantity of elastic fibers, collagen architecture, and presence of inflammation in the context of age-matched controls. Histomorphological results were compared between the 2 groups and subanalyzed according to clinical variables and postbody contouring wound complications.
Results: Between July 2008 and December 2010, 30 consecutive patients with significant weight loss (17 surgical, 13 nonsurgical) underwent a panniculectomy (n = 15), abdominoplasty (n = 13), and lower body lift (n = 2), with an average age of 48.3 ± 11.10 years and a body mass index of 39.23 ± 13.65 kg/m. Demographic and clinical variables were not statistically significant between the 2 groups. Blinded histologic evaluation revealed a trend toward normal elastic fiber appearance (P = 0.255), increased wound complications (P = 0.546), and mild inflammation (P = 0.462) in the surgical group. Analysis of dermal histomorphology correlating with wound complications was not statistically significant at follow-up (4.76 ± 5.55 months). Interestingly, there was a persistent inflammatory component in both groups when compared with age-matched controls.
Conclusions: Although the differences in histomorphology between the surgical and nonsurgical weight loss groups did not reach statistical significance, the results demonstrated an existence of weight loss-induced histomorphological skin changes that may impact future studies. The study did not demonstrate a relationship between dermal histomorphology and postoperative wound complications, suggesting that aberrant healing in body contouring procedures involves a multifactorial process.