Duodenal switch has no detrimental effects on hepatic function and improves hepatic steatohepatitis after 6 months.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a common histological finding on liver biopsy in morbidly obese patients. The condition, although benign, can progress to cirrhosis and liver failure. We investigated the effect of the duodenal switch (DS) operation on hepatic function and architecture, specifically hepatic steatosis and NASH.

METHODS: Between November 1999 and June 2004, 697 DS operations were performed for the treatment of morbid obesity. A Tru-Cut needle liver biopsy was routinely performed during the DS operation. Liver function tests were drawn preoperatively for AST and ALT, and again postoperatively at 6, 12 and 18 months and yearly thereafter. Repeat Tru-Cut liver biopsy was performed on all patients (n = 78) who underwent a second intra-abdominal operation for any indication > or = 6 months postoperatively. The pathologist evaluated the 2 sets of liver biopsies in a blinded fashion. The hepatic adipose tissue content and the degree of hepatitis were compared in these patients.

RESULTS: A transient worsening of the AST (13% of the baseline value, P<.02) and ALT ( 130-160% of the baseline value, P<.0001) levels was found at 6 months after the DS operation. Normal levels were achieved by 12 months postoperatively. A progressive improvement of about 3 grades in severity of NASH and a 60% improvement in hepatic steatosis, were seen by 3 years after the DS operation.

CONCLUSION: DS improves both hepatic steatosis and its resulting inflammation. No detrimental effects on hepatic function were noted after 6 months.