Radiographic Improvement of Hepatic Steatosis After Laparoscopic Roux-en-Y Gastric Bypass

Abstract

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease and the leading cause of cirrhosis in developed nations. Studies confirm improvement of liver histopathology after significant weight loss, but biochemistry and sonography do not always show this. Computed tomographic (CT) findings of NAFLD include low attenuation of liver parenchyma and hepatomegaly. We hypothesized that patients experiencing significant weight loss after laparoscopic Roux-en-Y gastric bypass (LRYGB) would show CT improvement of NAFLD.

Methods: A retrospective review was performed on primary LRYGB patients at this institution from 2006 to 2014. We identified patients with either a preoperative abdominal CT or an early postoperative scan (prior to significant weight loss) as well as those with scans performed at >60 days postoperation. Radiologic interpretations were reviewed; descriptions of steatosis, hypodensity, fatty infiltration, fatty liver, fatty changes, or liver parenchyma measuring ≤40 Hounsfield units averaged at three locations on non-contrast CT were documented. Later, scans were reviewed for improvement by these criteria.

Results: Nineteen patients had perioperative radiographic evidence of NAFLD, with 89.5 % female, average age 41.5, and median body mass index (BMI) 46.9 kg/m². Sixteen (84.2 %) showed radiographic improvement of NAFLD. The median time between scans was 826 days, with median BMI at that point of 30.5 kg/m². The three without radiographic improvement still experienced significant weight loss (average BMI points lost = 19.3 kg/m², ±5.6).

Conclusions: While weight loss and comorbidity improvement are common, they are not universal after LRYGB. Radiographic improvement of NAFLD in 84 % of patients was salutary.

Keywords: Bariatric; Fatty liver; Gastric bypass; Hepatic steatosis; NAFLD; Weight loss surgery.