Intraoperative measurement of common duct resistance

Biliary tract resistance was measured in 142 patients at the time of cholecystectomy, using a simple technique in which contrast media is infused through the cystic duct at a fixed flow rate. A sharp demarcation exists between the resistance of patients with normal and abnormal common bile ducts. A resistance of less than 2.5 units was found in only one patient with a common duct abnormality, and the test was improperly performed in that case. Two patients with normal common ducts had resistance values of greater than 2.5 units, for a false-positive rate of 1.63%. Overall, the technique gave accurate results in 97.9% of the cases studied.