Higher Pre-Operative Non-Invasive Fibrosis Scores are not Associated with Surgical Outcomes in Patients with MASLD Undergoing Metabolic and Bariatric Surgery.

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of cirrhosis in Canada. Metabolic and bariatric surgery (MBS) leads to histologic improvement in patients with MASLD and obesity; however, patients with advanced fibrosis may be at risk for decompensation in liver function following MBS. There are currently no Canadian data evaluating the association between pre-operative advanced fibrosis and post-operative complications among patients with obesity undergoing MBS. Methods: We conducted a single-centre retrospective cohort study of individuals undergoing primary MBS (Roux-en-Y gastric bypass and sleeve gastrectomy) between September 2016 and August 2021. The primary exposure was pre-operative NAFLD (non-alcoholic fatty liver disease) fibrosis score (NFS). Outcomes of interest included post-operative complications and health care utilization at 30 and 90 days, and weight loss at 30 days post-operatively. Results: After exclusions, 204 patients who received MBS and had the data required to calculate NFS were included. The median age was 46 years (interquartile range 38-55 years) and 181 (89%) were female. A total of 55 (27%) patients had NFS, suggesting advanced fibrosis. There was no significant difference in 30- or 90-day complications and health care utilization rates in patients with higher NFS. Conclusions: Patients undergoing MBS have a high prevalence of steatosis and advanced fibrosis based on the NFS. Our data suggest that higher NFS is not associated with higher short-term post-operative complications in patients undergoing MBS. Further work needs to be done to determine the optimal method of screening for advanced liver disease in patients living with severe obesity.