Hepatic complications of bariatric surgery : the reverse side of the coin

BACKGROUND: Even if the jejunoileal bypass has been definitely abandoned due to the high rate of hepatic complications, cases of liver injury after the new bariatric procedures are still reported. We aimed to review the available literature concerning liver damage associated with the older and newer types of bariatric surgeries.METHODS: An extensive literature search of MEDLINE was performed using different combinations of the following terms: "bariatric surgery OR biliopancreatic diversion OR jejunoileal bypass OR roux-en-y gastric bypass OR vertical banded gastroplasty OR laparoscopic adjustable gastric banding" AND "hepatic/liver damage OR hepatic/liver impairment OR hepatic/liver failure".RESULTS: Although weight loss after bariatric surgery frequently induces an improvement of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, and even the regression of hepatic fibrosis, bariatric procedures have been also associated with cases of acute liver failure or of chronic liver disease evolving until cirrhosis. After the jejunoileal bypass has been definitely abandoned, most of the recently described cases concern biliopancreatic diversion with/without duodenal switch, but liver damage has been reported after almost all types of bariatric surgeries. Protein-calorie malnutrition, bacterial overgrowth, lipotoxicity and genetic background are likely to play a central role in the physiopathology of hepatic injury.CONCLUSIONS: Understanding the inner mechanisms underlying acute or chronic liver injury after bariatric surgery can help in the prevention, early recognition and treatment of these rare but concrete cases