Normal sphincter of oddi motor function

With the introduction of endoscopic retrograde cholangiopancreatography (ERCP) manometry, the characteristics of sphincter of Oddi (SO) motor activity have been described. SO manometry is the only available method to measure SO motor activity directly and is usually performed at the time of ERCP. SO manometry is considered to be the gold standard for evaluating patients for sphincter dysfunction. This review reports the technique of SO manometry and normal values for SO manometry. SO motility is characterized by prominent phasic contractions superimposed on a tonic pressure. Elevated basal SO pressure is the most consistent and reliable criteria to diagnose SO dysfunction. Basal pressures obtained from the biliary sphincter are similar to the basal pressure obtained from the pancreatic sphincter. Abnormal SO manometric values are shown. Factors that influence SO pressures, and interpretation of SO manometric tracing are discussed. The most common and serious complication of SO manometry is post-manometry pancreatitis. In healthy volunteers with normal sphincter function, pancreatitis is almost never seen. However, in patients with SO dysfunction, the incidence of pancreatitis is high. The use of new nonperfused microtransducers may reduce this complication.