Sphincter of Oddi dysfunction.

Biliary-like pain alone, or associated with a transient increase in liver or pancreatic enzyme, may be the clinical manifestations of sphincter of Oddi dysfunction. Since it is not always possible to dissociate functional conditions from subtle structural changes, the term sphincter of Oddi dysfunction is used to define motility abnormalities caused by 'sphincter of Oddi stenosis' and 'sphincter of Oddi dyskinesia'. Both sphincter of Oddi stenosis and sphincter of Oddi dyskinesia may account for obstruction to flow through the sphincter of Oddi and may thus induce retention of bile in the biliary tree and pancreatic juice in the pancreatic duct. Most of the clinical information concerning sphincter of Oddi dysfunction refers to post-cholecystectomy patients who have been arbitrarily classified according to clinical presentation, laboratory results and endoscopic retrograde cholangiopancreatography findings in: (a) biliary type I, (b) biliary type II, and (c) biliary type III. Prevalence of biliary-type of pain has been reported to vary from 1 to 1.5% in unselected postcholecystectomy people, to 14% in a selected group of patients complaining of postcholecystectomy symptoms. The frequency of sphincter of Oddi dysfunction, as shown by manometry, differs in the different clinical subgroups: 65-95% in biliary group I, mainly due to sphincter of Oddi stenosis; 50-63% in biliary type II, and 12-28% in biliary type III. In patients with idiopathic recurrent pancreatitis, sphincter of Oddi dysfunction varies from 39 to 90%. Diagnostic work-up of postcholecystectomy patients for suspected sphincter of Oddi dysfunction includes liver biochemistry and pancreatic enzymes, plus negative findings of structural abnormalities. Usually, this would include transabdominal ultrasound and endoscopic retrograde cholangiopancreatography. Depending on the available resources, endoscopic ultrasound and magnetic resonance cholangiography may precede endoscopic retrograde cholangiopancreatography in specific clinical conditions. Quantitative evaluation of bile transit from the hepatic hilum to the duodenum at choledochoscintigraphy appears valuable in the decision to undertake sphincter of Oddi manometry or to treat. Sphincterotomy is the standard treatment for sphincter of Oddi dysfunction. In biliary type I patients, the indication for endoscopic sphincterotomy is straightforward without the need of any additional investigation. Slow bile transit in biliary type II is an indication to undergo endoscopic sphincterotomy without sphincter of Oddi manometry. Slow bile transit in biliary type III patients is an indication to perform sphincter of Oddi manometry. Diagnostic work-up of patients with gallbladder in situ is part of the same diagnostic algorithm that has initially excluded the presence of a gallbladder dysfunction.