Practical classification of the branching types of the biliary tree: an analysis of 1,094 consecutive direct cholangiograms.

BACKGROUND: The structure of the biliary tree has been classified according to the relationship between the hepatic segmental ducts and the cystic duct. Because laparoscopic cholecystectomy demands precise knowledge of biliary anatomy, we propose a simplified classification of the bile ducts.

STUDY DESIGN: A consecutive series of 1,094 direct cholangiograms were analyzed and the letters A, P, R, L, and C were designated for the right anterior, right posterior, right, left, and cystic ducts, respectively. The arborizing patterns of the hepatic bile ducts were classified into either the bifurcation of the right and left ducts (RL); triple confluence of the right anterior, right posterior, and left ducts (APL); separate branching of A and P in the duodenohepatic direction; or discrete branching of P and A (P-AL) where branches A and P were in reverse of A-PL. Cystic duct anomaly was added in parentheses.

RESULTS: The classified ducts had the following distribution: RL, 67.7 percent; APL, 17.7 percent; A-PL, 8.0 percent; and P-AL, 6.0 percent. Cystic duct anomalies occurred in 1.6 percent of all the cases and were in frequent association with the P-AL pattern. The most common type was P-AL (P-C) seen in 0.5 percent of cases, where the cystic duct merged into the lower branching P.

CONCLUSIONS: Our practical classification of the biliary tree anatomy may contribute to the practice of biliary surgery.