Operative cholangiography: is there a statistical alternative?

Data from 424 patients who underwent cholecystectomy were analysed on a computer by both univariate and multivariate methods to determine the factors that identify patients with stones in the common bile duct. The presence of common bile duct stones was associated with increased age (p = 0.003), increased numbers of gallbladder stones (p less than 0.0001), a diagnosis of acute cholecystitis (p = 0.06), and a history of jaundice (chi-square = 22.2; p less than 0.001). A dilated common bile duct was the most significant indicator of the presence of stones (chi-square = 155.5; p less than 0.0001), and a dilated cystic duct was second (chi-square = 47; p less than 0.001). Using multivariate analysis, 89.5 percent of patients were correctly classified as having bile duct stones without the use of cholangiographic data (chi-square = 246.5; p less than 0.0001). Common bile duct diameter and the number of gallbladder stones emerged as the most important variables; additional historical factors, including the presence of jaundice and pancreatitis did not add to their predictive value. If multivariate analysis was used without cholangiographic data, bile duct stones would be missed in 3 percent of patients and unnecessary explorations would be carried out in 7.5 percent.