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 degrees and 158 degrees. 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.