Intraoperative liver biopsy during metabolic and bariatric surgery: diagnostic yield, safety, and national trends.

BACKGROUND: The reliability of noninvasive methods to detect metabolic dysfunction-associated steatotic liver disease and metabolic-associated steatohepatitis (MASH) or advanced liver disease remains uncertain. OBJECTIVES: To test the hypothesis that routine liver biopsy (LB) during metabolic and bariatric surgery (MBS) at an academic center would identify a high prevalence of MASH with minimal operative risk. SETTING: Single-center metabolic and bariatric surgery accreditation and quality improvement center in Louisiana and national metabolic and bariatric surgery accreditation and quality improvement data, 2020-2023. METHODS: Institutional and national MBS cases were analyzed. Patients aged <18 years, open procedures, conversions/revisions, and missing biopsy results (institutional data) were excluded. LB characteristics and case outcomes were examined using logistic regression to determine the association of postoperative complications. RESULTS: A total of 980 institutional cases and 695,343 national cases were identified. Local routine LB prevalence was 48%, while national prevalence for LB was 3.5%. Routine LB locally revealed steatosis in 71.8%, nonalcoholic steatohepatitis in 31.6%, and fibrosis in 20.6%. Black race was associated with lower odds of steatosis (odds ratio [OR]: .34), MASH (OR: .28), and fibrosis (OR: .45). In contrast, hypertension (OR: 1.93) and insulin-dependent diabetes (OR: 2.66) were associated with increased nonalcoholic steatohepatitis risk. Postoperative complications were not different between routine LB and non-LB patients locally (P > .05). Cases with LB nationally had slightly lower estimates of complications, although small but significant differences were observed with the larger sample. CONCLUSIONS: Metabolic dysfunction-associated steatotic liver disease/MASH is highly prevalent in MBS. Not only is LB safe and not risk prohibitive but it also identifies advanced liver disease that is generally poorly detected preoperatively and can affect postoperative treatment and outcomes.