Utility and safety of routine liver biopsy during bariatric surgery

Abstract

Utility and safety of routine liver biopsy during bariatric surgery Hannah Collins1, Grant Beban2, John Windsor2, Rishi Ram2, Nicholas Evennett2, Benjamin Loveday2 1North Shore Hospital, Auckland, New Zealand. 2Auckland City Hospital, Auckland, New Zealand Routine liver biopsy at the time of bariatric surgery may be performed due to the high prevalence of asymptomatic liver disease in this population. Its safety and utility in the New Zealand setting is undetermined. This retrospective cohort study aimed to establish the safety of liver biopsy during bariatric surgery, and determine how frequently it changed management. The study included all patients who underwent index bariatric surgery at Auckland City Hospital (2008-2016). Liver disease diagnosis was based on pathology reports. Safety outcomes were defined as bleeding or bile leak requiring transfusion or re-intervention. Utility outcomes were defined as further investigations, referral to a hepatologist or treatment initiated based on biopsy findings. Subgroup analyses were performed to identify differences for ethnic minorities. 71% (238/335) of bariatric surgery patients underwent intraoperative liver biopsy. There were no biopsy-related complications. Histological findings were normal in 11% (25/238), non-alcoholic fatty liver disease (NAFLD) in 87% (207/238), and fibrosis ≥stage F3, cirrhosis or other finding that met criteria for referral in 8% (18/238). Among patients who met referral criteria, 72% (13/18) were referred. Maori patients had a similar rate of NAFLD to non-Maori (84% (49/58) vs 88% (158/180),p=0.52) while Pacific Island patients had a statistically significant higher rate than non-Pacific Island (98% (39/40) vs 85% (168/198),p=0.03). When referral criteria were met, Maori and Pacific Island patients had non-significant higher referral rates (86% (6/7) vs 64% (7/11),p=0.31; 100% (2/2) vs 69% (11/16),p=0.35). On logistic regression, BMI was not predictive of normal histology (OR 0.92,p=0.12) or disease meeting referral criteria (OR 0.91,p=0.15). Routine intraoperative liver biopsy is safe and detects previously undiagnosed, clinically significant liver pathology in 8% of bariatric patients. Additionally, 87% have more mild NAFLD. Rates of subsequent referral of patients with advanced NAFLD are low and could be improved.