ORIGINAL CONTRIBUTIONS Intraoperative Liver Biopsy During Adolescent Bariatric Surgery: Is It Really Necessary? R. Ellen Jones 1 & Ann Ming Yeh 2 & Neerajah Kambham 3 & Marwa Abu El Haija 2 & Janey Pratt 1 & Matias Bruzoni 1 # Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Background Nonalcoholic fatty liver disease (NAFLD) is prevalent in children with obesity and is definitively diagnosed with liver biopsy. However, the utility of routine biopsy during adolescent bariatric surgery remains unknown. We describe the usefulness of routine versus selective intraoperative liver biopsy in adolescents undergoing bariatric surgery. Methods A retrospective review of adolescents who received bariatric surgery at our institution between 2007 and 2018 was performed. Prior to 2014, all patients routinely received intraoperative liver biopsy. After 2014, biopsy was performed selectively on an individual basis for transaminitis or clinical concern. Demographic, biochemical, and histopathologic data were compared between patients who underwent routine, selective, or no biopsy. Results There were 77 patients who received bariatric surgery during the study period: 32 underwent routine biopsy, 13 selective biopsy, and 32 no biopsy. Selective liver biopsy was more likely to show pathologic evidence of fibrosis (84.6% versus 31.2%, p = 0.000) and steatosis (100.0% versus 59.4%, p = 0.003), and higher mean NAFLD activity score compared with routine biopsies (4.4 versus 2.1, p = 0.001). Patients with steatosis had significantly higher preoperative fasting insulin (41.4 versus 21.1 mIU/L, p = 0.000), and patients with fibrosis had significantly higher glycated hemoglobin (6.1% versus 5.5%, p = 0.033) and alanine aminotransferase (81.5 versus 52.7 mg/dL, p = 0.043). There were no biopsy complications or changes in manage- ment due to biopsy results. Conclusions Routine intraoperative liver biopsy during adolescent bariatric surgery possesses questionable benefit, as it does not appear to impact short-term postoperative management. Prospective, longitudinal studies are needed to better understand the meaningfulness of liver histopathology in this population. Keywords Liver biopsy . Adolescent . Bariatric surgery . Nonalcoholic fatty liver disease . Nonalcoholic steatohepatitis . Utility Introduction Adolescent patients with obesity often suffer from nonalco- holic fatty liver disease (NAFLD) [1–6]. Histopathology from liver biopsy is the gold standard for diagnosis of NAFLD, as biochemical and imaging workup are not sophisticated enough to prove NAFLD [7, 8]. While biopsy may secure definitive diagnosis, the procedure itself is not without risk. Additionally, the natural history of pediatric liver histopathol- ogy in the setting of NAFLD remains understudied, and the timing of when to offer pediatric liver biopsy is somewhat controversial [9, 10]. Overall, this decision must be individu- alized to the patient with full explanation of potential risks, benefits, and meaningfulness of biopsy results [11]. For ado- lescents undergoing bariatric surgery, intraoperative biopsy represents an attractive opportunity to obtain tissue for diag- nosis of obesity-related liver disease, but there is little data regarding the utility of intraoperative liver biopsy in this pop- ulation [1, 12, 13]. While no formal guidelines exist regarding intraoperative liver biopsy in pediatric patients undergoing bariatric surgery, many of these children do suffer from liver disease. When routine biopsy is implemented, approximately 60–85% of * Matias Bruzoni mbruzoni@stanford.edu 1 Department of Surgery, Division of Pediatric Surgery, Stanford University Medical Center, 300 Pasteur Dr Rm M116, Alway Bldg MC 5733, Stanford, CA 94305, USA 2 Department of Pediatrics, Division of Gastroenterology, Stanford University Medical Center, Stanford, CA, USA 3 Department of Clinical Pathology, Stanford University Medical Center, Stanford, CA, USA Obesity Surgery https://doi.org/10.1007/s11695-019-04136-4