Biliary tract motor dysfunction

Gallbladder and sphincter of Oddi motility regulates the flow of bile from the liver to the duodenum. During the interdigestive period most secreted bile is diverted into the gallbladder where it is concentrated, but a significant minority of the biliary secretion passes directly into the duodenum. Regulation of this flow is mainly via the phasic contractions of the sphincter of Oddi and the sphincter basal tone. The phasic contractions expel small volumes of fluid into the duodenum, but most of the flow occurs between the contractions and is therefore not dependent on peristaltic pumping, but rather on a small pressure gradient. During fasting, just prior to duodenal phase III activity, the gallbladder expels up to 40% of its volume and the sphincter phasic contractions increase. Following a meal, the gallbladder empties its contents, and the sphincter of Oddi resistance is reduced via a fall in basal pressure and inhibition of the amplitude of phasic contractions. Control of this activity is via an interplay of both neuronal and hormonal factors which together have an effect on both gallbladder and sphincter of Oddi motility. Abnormalities in motility are recognized for both the gallbladder and the sphincter of Oddi. Gallbladder dyskinesia is objectively diagnosed using the radionuclide GBEF. In patients with a GBEF less than 40% cholecystectomy results in relief of symptoms. In post cholecystectomy patients sphincter of Oddi dysfunction presents as either biliary-like pain or idiopathic recurrent pancreatitis. Endoscopic sphincter of Oddi manometry provides the most objective diagnostic information. In patients with a sphincter of Oddi stenosis, characterized manometrically as an elevated basal pressure, division of the sphincter results in relief of symptoms. For patients with biliary-like pain, division is performed as an endoscopic sphincterotomy, whereas for patients with idiopathic recurrent pancreatitis, a sphincteroplasty and pancreatic duct septectomy are required.