Elastic Fibers Density: a New Parameter of Improvement of NAFLD in Bariatric Surgery Patients.

Purpose: Obesity is a major risk factor for nonalcoholic fatty liver disease (NAFLD), affecting 25% of the worldwide population. Weight loss through bariatric surgery can improve much of the liver steatosis, inflammation, and fibrosis. However, it is not known whether there is reversal of the elastic fiber deposition process, triggered by hepatic damage and related to worse prognosis.

Materials And Methods: Individuals submitted to bariatric surgery at our institution, from March 2016 to June 2017, with intraoperative liver biopsy confirming NAFLD were approached. Those who consented were submitted to a second liver biopsy 1 year later and were included. Specimens were sliced and stained with hematoxylin-eosin and Sirius red for histological assessment according to Brunt's criteria and with orcein for digital analysis morphometrics using ImageJ®. Quantification of elastic fibers was accomplished by corrected integrated density.

Results: Thirty-seven patients were included. Body mass index, metabolic markers, NAFLD activity score, and fibrosis improved 1 year after the procedure. The elastic fiber density showed a significant decrease: 239.3 × 10 absorbance micrometer (141.08-645.32) to 74.62 × 10 absorbance micrometer (57.42-145.17), p = 0.007.

Conclusion: Liver elastic fiber density decreases with the reversal of NAFLD through weight loss.