Histological Changes in Skin and Subcutaneous Cellular Tissue in Patients with Massive Weight Loss After Bariatric Surgery.

Introduction: Morbid obesity is a public health problem with high social and economic impact. Due to failure in its treatment with traditional weight loss strategies, surgical interventions are usually required, which give rise to massive weight loss. Until now, the studies made are inconclusive regarding the histological changes in the skin caused by massive weight loss, which may later generate post-surgical complications. Therefore, the objective of this study is to evaluate the cutaneous histological changes before and after bariatric surgery.

Material And Methods: Two skin biopsies were taken from nine different patients who underwent bariatric surgery. The first biopsy was taken before the surgical intervention, and the second biopsy was taken a year after the surgery and massive weight loss. Histological analysis was performed using haematoxylin & eosin staining, Weigert's Resorcin-Fuchsin, and Masson's trichrome stain to analyse the percentage of collagen fibres, percentage of fibrosis, percentage of vascularity, vascular layer involvement and adipocyte population. The differences between the biopsies were evaluated with the Student's T test and Mann-Whitney U test, with a p-value of <0.05.

Results: Biopsies from post-bariatric patients with MWL showed an increase in fibrosis percentage, and a decrease in collagen fibres, elastic fibres of the dermis, adipocyte population, as well as reduced vascular proliferation.

Conclusion: MWL after bariatric surgery gives rise to changes in the skin and subcutaneous cellular tissue. Skin shows an increased fibrosis percentage after massive weight loss. Elastic and collagen fibres become disorganized after massive weight loss. Vascular proliferation is decreased after massive weight loss.

Level Of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .