Surgical clips as a nidus for biliary stone formation: diagnosis and therapy.

Two cases in which a cystic duct stump clip migrated into the common bile duct and formed the nidus for a stone are reported. In one case, the diagnosis was made before ERCP, on the basis of CT findings. In the second case, a retrospective review of plain abdominal films showed evidence of clip migration. Both patients were treated successfully with endoscopic sphincterotomy, as have most such patients reported in the literature. Although clip migration can occur after both open and laparoscopic cholecystectomy, there is some evidence that this complication may be more common after the laparoscopic procedure. Clip migration can be diagnosed before cholangiography by carefully reviewing plain abdominal films and CT scans. ERCP confirms the diagnosis, and sphincterotomy with clip and stone removal is the therapeutic procedure of choice. Additional surgical procedures only rarely are required.