Although operative cholangiography is without question a helpful and a generally reliable means of evaluating the biliary duct system, certain potential exists for technical or interpretive error. The source of such error includes (1) air bubbles; (2) improper position of patient in relation to x-ray source; (3) "coning" of the distal common duct; (4) confusion of functional for organic obstruction; and (5) inclination on the part of the surgeon to disregard evidence before him. Substantial improvement results from (1) prefilling the injection system to avoid air bubbles; (2) rotation of the operating table 15 degrees to the right to place biliary tract in relief of vertebral column; (3) proper interpretation of "coning" effect; (4) acceptance of spasm as an obstructive factor following choledochotomy; and (5) persistence in a given study until complete delineation is obtained.
Custer MD, Clore JN. Source of Error in Operative Cholangiography. Arch Surg. 1970;100(6):664-667. doi:10.1001/archsurg.1970.01340240032006