Ran B Luo, MD1, Toshiaki Suzuki, MD1, Domingo Montalvo, MD1, Jonathan C Hooker, BS1, Shanglei Liu, MD1, Jonathan C DeLong, MD1, Jessica L Reynolds, MD1, Bryan J Sandler, MD1, Scott Reeder, MD2, Claude B Sirlin, MD1, Santiago Horgan, MD1, Garth R Jacobsen, MD1. 1University of California, San Diego, 2University of Wisconsin
Introduction : Nonalcoholic fatty liver disease (NAFLD) is an emerging epidemic in the obese population with non-alcoholic steatohepatitis (NASH) quickly becoming a leading cause of liver cirrhosis in the western world. Bariatric surgery is known to reverse metabolic complications of obesity, but the timing of liver improvements post-operatively have not been well described.
Methods: This was an IRB-approved, NIH funded, multi-institutional prospective study. Patients meeting NIH criteria for bariatric surgery underwent MRIs at five separate time points: baseline, after pre-operative liquid diet (PLD), and post-operative 1, 3, and 6 months. The patients underwent liver biopsies at the time of bariatric surgery and received the three post-operative MRI scans only if they were biopsy positive for NAFLD. Liver volumes and proton-density fat fraction (PDFF) were then calculated from the MRI images using OsiriX (Pixmeo SARL, Bernex, Switzerland) imaging software. Primary outcomes were changes in patient weight, body mass index (BMI), percent excess weight loss (EWL%), liver volume, and PDFF. Patients NAFLD status was re-evaluated based previously a published PDFF cut off of 6.4% for diagnosing grade 1 or higher hepatic steatosis.
Results: From October 2010 to June 2015, 124 patients were recruited for the study. 49 patients (39.5%) completed all MRI scans. The mean age was 50.9±10.8 years with a mean liquid diet duration of 15.5±5.5 days. At 6 months follow up, patients achieved a mean EWL% of 45.0±13.9%. Mean BMI decreased from 45.3±5.9kg/m2 to 34.4±5.1kg/m2 and mean liver volume decreased from 2464.6±619.4cm3 to 1874.3±387.8 cm3 with a mean volumetric change of 22.2±12.1 % (Table 1).
PDFF decreased from 16.6±7.8 % to 4.4±3.4 %, with a mean change of 71.0±20.0 %. At 6 month follow up, 83.7% patients fell below the 6.4% PDFF cutoff for MRI diagnosed NAFLD (Graph 1). Liver volume plateaued at post-operative one month, but PDFF and BMI continued to decrease.
Conclusion: Patients with NAFLD undergoing bariatric surgery can expect significant decreases in both their liver volume and fat density at 6 months. Liver volume changes plateau 1-month post-bariatric surgery, but liver fat percentage continues to decrease at 6 months post-operatively. Patients with NAFLD experienced significant improvement of their liver fat composition with 83.7% of patients under previously established steatosis cutoffs by MRI-PDFF imaging criteria within 6 months.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 79707
Program Number: S144
Presentation Session: Plenary 2
Presentation Type: Podium