16 - Sphincter of Oddi Manometry

Abstract

Sphincter of Oddi (SO) dysfunction refers to an abnormality of SO contractility, and may cause pancreatobiliary-type pain, cholestasis and/or recurrent pancreatitis. Sphincter of Oddi manometry (SOM) is the only available method to measure the SO motor activity directly. Although SOM can be performed intraoperatively and percutaneously, it is most commonly performed at the time of endoscopic retrograde cholangiopancreatography (ERCP). The use of manometry to detect motility disorders of the SO is similar to its use in other parts of the gastrointestinal tract. However, performance of SOM is more technically demanding and hazardous, with adverse event rates (in particular, pancreatitis) approaching 20% in several series. Maximal efficiency is achieved by combining ERCP and SOM in a single session. It is preferable to perform cholangiography and/or pancreatography before carrying out SOM because certain findings (e.g., stone, stricture) may obviate the need for SOM. Mastery of the fundamentals of ERCP and appropriate training are necessary for the physician who evaluates patients with SOM. At a minimum, the endoscopist must be skilled in diagnostic ERCP because performance of SOM cannot be accomplished without selective cannulation of the desired bile duct and/or pancreatic duct. In this chapter, we review the technique and performance of SOM, with an emphasis on the technical and cognitive skills sets required.