As pointed out by Way, Admirand, and Dunphy, the true incidence of CBD stones in patients undergoing surgery for gallstones is probably between 12% and 15% in the United States. By using indications essentially identical to those stated below and by performing routine preexploratory cystic duct cholangiography, Way performed CBD explorations in only 21% of 952 cholecystectomies. These explorations were positive for calculi in 65% of the patients explored. Of the 952 cholecystectomy cases, 14% had CBD stones. In 6 additional reports collected by Way in which routine cystic duct cholangiography was employed, the results were similar. On the other hand, the same author cited 3 other reports from the Lahey Clinic of cases in which preexploratory cholangiography was not performed. Here, of 33% of patients undergoing CBD exploration only 30% of the ducts contained stones. Whereas the use of routine cystic duct cholangiograms resulted in the recovery of CBD stones in over 14% of the cholecystectomies reported by Way and colleagues, the authors who omitted preexploratory cholangiography were able to discover CBD stones in only 10% of their cholecystectomy cases. In other words, routine preexploratory cholangiography markedly reduces the number of CBD explorations performed yet achieves a higher recovery rate of CBD stones (see Table 50-1).