Uncommon biliary tree anatomy

This 54 year old lady had been referred for management of choledocholithiasis prior to undergoing a cholecystectomy. The ultrasound report suggested a single stone in the mid CBD. Initial contrast injection outlined the stone (A: white arrow). Things were about to get interesting, however as further contrast made the picture clearer. We could now see the stone (B: white arrow), the cystic duct (B: blue arrow) and what appeared to be a dividing line right in the middle of the CBD (B: red arrow). And even more contrast finally showed us what we were dealing with: double common bile duct with a common opening with the stone in the left stem (C: white arrow), right and left hepatic ducts draining separately into right and left bile ducts (C: yellow arrows), the cystic duct draining into the right bile duct (C: blue arrow). The arrowheads show black areas which are actually bile ducts viewed head on (C: red arrowhead shows the entrance of the cystic duct into the right bile duct). The stone was removed with an extraction balloon after sphincterotomy (D). The last diagram (E) shows the the modified classification of extrahepatic bile duct duplication as proposed by Choi et al.. Ours seems to be a Va type. The important thing here is the clear communication of this abnormal ductal anatomy to the surgeon who will be doing her cholecystectomy so as to prevent any inadvertent ductal injury and compromised drainage of any of the hepatic lobes.