Sphincter of Oddi manometry: is timing everything?

Abstract

To determine if cholangiography has an effect on sphincter of Oddi (SO) activity, a prospective study was conducted. Twenty-five patients with suspected SO dysfunction underwent biliary SO manometry (SOM). According to the modified Geenen-Hogan criteria, 12 were classified as biliary type III, seven were biliary type II, and six had idiopathic pancreatitis. Patients were sedated with i.v. medications acknowledged as not affecting biliary basal sphincter pressures, including diazepam, droperidol, and meperidine. Conventional station pull-through manometry of the biliary part of the sphincter was performed before and after contrast injections of the biliary system. In this study group, the mean basal sphincter pressure was not significantly altered by contrast injection (52.9 ± 42.1 mm Hg before vs 55.1 ± 38.1 mm Hg after, p = 0.52). In addition, there was concordance (normal vs abnormal) between basal sphincter pressure before and basal sphincter pressure after contrast injection in 24 of 25 patients (96%). Furthermore, when patients were stratified into subgroups (elevated or normal SO basal pressure, use of a guidewire, meperidine administration, prior biliary sphincterotomy, gallbladder removed or in situ, and length of the interval between the end of contrast injection and the second pull-through), cholangiography did not significantly alter postinjection basal pressures. Finally, in 10 patients the quality and length of the SOM tracing were good enough to allow assessment of phasic SO activity. The phasic pressure wave frequency, amplitude, and duration were in the normal range before and after contrast injection. The authors concluded that cholangiography immediately before SOM infrequently alters SO basal pressure. With respect to clinical practice, the authors advocated the strategy of performing cholangiography before SOM, recognizing that if structural lesions are identified ( e.g., stones, tumors), SOM can be avoided.