Extrahepatic bile duct angulation by T-tube: The elbow sign

The normal shape of the extrahepatic bile ducts approximates a straight line. The cholangiograms of 50 patients with indwelling T-tube catheters were retrospectively reviewed between 4 and 14 weeks postcholecystectomy. We observed a lateral distortion in the shape of the bile ducts in 35 patients (70%) such that an angle measured between the proximal and distal parts of the duct, centered at the site of T-tube insertion, decreased to between 60° and 158°. We have called this observation the elbow sign, which to our knowledge has not been previously described and appears to be of no clinical consequence.