BALLOON DILATATION OF THE SPHINCTER OF ODDI FACILITATES PASSAGE OF GLASS-BEADS FROM THE CANINE BILIARY-TRACT

Laparoscopic management of common duct stones is increasing. The most widely used technique involves transcystic duct scope placement and st one extraction. Occasionally, stones cannot be retrieved and are allow ed 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 dog s, glass beads of varying sizes (3-8 mm) were implanted in the gallbla dder and allowed to pass spontaneously over 1 month. In three separate groups, these animals underwent (1) sham instrumentation of the sphin cter of Oddi (control), (2) sphincter dilatation with balloon catheter s, or (3) transduodenal sphincterotomy. At the end of 1 month, all the animals were autopsied, and the glass beads were retrieved. Histologi c sections of the pancreas were examined for possible pancreatitis. Th e results of this study show that no animal experienced pancreatitis f rom 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 sph incterotomy passed a similar amount of glass beads as those with ballo on dilatation. These studies suggest that balloon dilatation is as eff icacious as sphincterotomy in facilitating the passage of glass beads from the canine biliary tract.