Balloon Dilatation of the Sphincter of Oddi Facilitates Passage of Glass Beads from the Canine Biliary Tract

ABSTRACT

Laparoscopic management of common duct stones is increasing. The most widely used technique involves transcystic duct scope placement and stone extraction. Occasionally, stones cannot be retrieved and are allowed to pass spontaneously after manipulation of the sphincter of Oddi. This study examines a model of sphincter of Oddi dilatation in the dog to facilitate passage of glass beads simulating gallstones. In 24 dogs, glass beads of varying sizes (3–8 mm) were implanted in the gallbladder and allowed to pass spontaneously over 1 month. In three separate groups, these animals underwent (1) sham instrumentation of the sphincter of Oddi (control), (2) sphincter dilatation with balloon catheters, or (3) transduodenal sphincterotomy. At the end of 1 month, all the animals were autopsied, and the glass beads were retrieved. Histologic sections of the pancreas were examined for possible pancreatitis. The results of this study show that no animal experienced pancreatitis from sphincter manipulation or the passage of glass beads. The control animals who underwent sham manipulation of the sphincter passed 10% of their glass beads. In contrast, after sphincter dilatation, 52.5% of the 3-mm glass beads passed or 22% of all size beads. Animals with sphincterotomy passed a similar amount of glass beads as those with balloon dilatation. These studies suggest that balloon dilatation is as efficacious as sphincterotomy in facilitating the passage of glass beads from the canine biliary tract.