Increased liver elasticity in patients with biliary obstruction

Background: Transient elastography (with the FibroScan^® apparatus) is a recently developed method for evaluating the severity of liver fibrosis by measuring liver elasticity. Liver elasticity may differ from the normal level in patients with obstructive jaundice because the retained bile may expand the liver. Because little is known about liver elasticity in patients with obstructive jaundice, we evaluated this feature in these patients. Methods: Between April 2007 and April 2008, 178 patients with biliary or pancreatic disease underwent transient elastography at the University of Tokyo Hospital. We excluded 77 patients because of concomitant cirrhotic liver disease, liver tumors, or a history of abdominal surgery. The remaining 101 patients were included in the study and were divided into obstructive jaundice (OJ; n = 43) and nonobstructive jaundice (NJ; n = 58) groups. Results: The basic patient characteristics did not differ significantly between the two groups, except for the causative diseases. The mean liver elasticity was significantly higher in the OJ group than in the NJ group (12.0 vs. 6.2 kPa, p < 0.01). In 24 patients from the OJ group, transient elastography was performed before and after biliary drainage; there was a marked reduction in the elasticity after the procedure in these patients (p < 0.01). Conclusions: Liver elasticity increases in patients with biliary obstruction. This increase is reduced after biliary drainage, implying that the increased FibroScan^® values before drainage are not due to liver fibrosis, but to temporarily increased elasticity.