Cost-effectiveness of operative cholangiography.

(1) Three hundred seventy-seven of 1,616 patients undergoing cholecystectomy between January 1, 1971 and December 31, 1975 had intraoperative cholangiograms and form the basis for this study. (2) The cholangiograms of thirty-seven patients were interpreted as positive for ductal disease, but only twenty-three had confirmed disease on common bile duct exploration. The average false-positive rate was 38 per cent per year. (3) One hundred nine patients had cholangiograms because of small stones in the gallbladder, and only one study was true-positive. (4) One hundred nineteen patients had cholangiograms without any clinical indication for the study. Only one was true-positive for intraductal disease. (5) Operative cholangiograms done routinely or for multiple small stones rarely reveal intraductal disease (2 of 228, or 0.9 per cent). (6) Of 149 cholangiograms in patients with clinical indications other than multiple small stones, twenty-one of twenty-six positive cholangiograms were true-positive, for an 81 per cent accuracy. (7) Operative time was prolonged an average of 31 minutes when cholangiography was performed. (8) The 377 cholangiograms cost $21,866. Of the 228 studies done routinely or for only multiple small stones, two were positive, for a cost of $6,612 per positive examination. (9) Therefore, to be cost-effective, the use of intraoperative cholangiography is indicated only when standard criteria for ductal exploration, with the exception of the presence of small calculi, are present.