Safety and Utility of Liver Biopsy During Bariatric Surgery in the New Zealand Setting

Background Asymptomatic liver disease is common in bariatric patients and can be diagnosed with intraoperative biopsy. This study aimed to establish the risk-benefit profile of routine liver biopsy, prevalence of clinically significant liver disease, relationship between liver pathology and body mass index, and compare outcomes between ethnic groups. Methods This retrospective cohort study included all patients who had index bariatric surgery at Auckland City Hospital between 2009 and 2016. Diagnosis of liver disease was based on intraoperative biopsy histology. Outcomes included safety (biopsy-related complication) and utility (liver pathology meeting criteria for referral). Liver pathology and referral rates were compared between ethnic groups. Results Of 335 bariatric surgery patients, 234 (70%) underwent intraoperative liver biopsy. There were no biopsy-related complications. Histological findings were as follows: normal 25/234 (11%), non-alcoholic fatty liver disease (NAFLD) 207/234 (88%), and other pathological findings in 35/234 (15%). Histological finding meeting referral criteria was present in 22/234 (9%). Of these, 12/22 (55%) were referred. Number needed to biopsy to identify histology meeting referral criteria: n = 11. Maori had a similar NAFLD rate to non-Maori [51/56 versus 156/178, p = 0.48]. Pasifika patients had a higher rate than non-Pasifika [39/40 versus 168/194, p = 0.049]. Maori and Pasifika patients had similar referral rates to non-Maori and non-Pasifika [2/3 versus 5/9, p = 0.73; 2/2 versus 5/10, p = 0.19]. Conclusions Intraoperative liver biopsy during bariatric surgery is safe and identified liver disease in 89%, with 9% meeting referral criteria. Pasifika patients have a higher rate of NAFLD than non-Pasifika.