The effect of the Valsalva maneuver on the diameter of the common hepatic duct in extrahepatic biliary obstruction

The internal diameter of the common hepatic duct as measured by ultrasonography is an imperfect predictor of extrahepatic biliary obstruction. This study examined the effect of the Valsalva maneuver on the diameter of the duct in 25 consecutive patients (12 with obstruction; 13 without obstruction) who underwent endoscopic retrograde cholangiopancreatography (ERCP). A normal response was defined as a decrease in the diameter of greater than 1 mm at the level of the portal vein. The response to the Valsalva maneuver improved the predictive outcome (sensitivity, 100%; specificity, 92.3%) suggesting that this maneuver should be part of the routine assessment of the common hepatic duct.