Resolution of nonalcoholic steatohepatits after gastric bypass surgery

Background: Nonalcoholic fatty liver disease (NAFLD) has been increasingly recognized as a common chronic liver condition. Previous studies have been variable regarding the histological outcomes after rapid weight loss. The aim of this study was to characterize the histopathologic changes in NASH following laparoscopic Roux-en-Y Gastric Bypass surgery (LRYGBP). Methods: We retrospectively analyzed paired needle liver biopsies taken during and following LRYGBP in 39 patients, according to the recent NIH-based NAFLD criteria. Results: The cohort included 33 females and 6 males (range 24-57 years). 23 patients (58.9%) had steatolhepatitis, 12 with fatty liver (30.7%), and 4 were normal (10.2%). Follow-up needle liver biopsies were performed at a mean interval of 18 months (range 6-41 months). No significant differences in length or number of portal tracts between the paired biopsies were noted. The mean decrease in weight and BMI was 50.2 kg and 18.2 kg/m(2), respectively. The initial prevalence of hepatic pathology: steatosis (89.7%), hepatocellular ballooning (58.9%), and centrilobular/perisinusoidal fibrosis (50%) improved significantly after LRYGBP: steatosis (2.9%), ballooning (0%), and centrilobular fibrosis (25%). Mitigation in the lobular inflammation score (2.23 +/- 0.63 vs 1.95 +/- 0.56, P=0.01) and stage of fibrosis (1.14 +/- 1.05 to 0.72 +/- 0.97, P=0.002) were also noted. However, no improvements were detected in portal tract inflammation and fibrosis. Conclusions: Over a mean period of 18 months, histological improvements and resolution of NASH occurs after LRYGBP. Long-term studies are warranted to assess for potential changes in the portal regions or relapse of NASH that could result with weight regain or malnutrition.