Objectives: To assess the incidence of elevated sphincter of Oddi baseline pressure and the response to endoscopic sphincterotomy in patients with suspected sphincter of Oddi dysfunction.
Design: A 5-year prospective clinical trial.
Methods: One-hundred and eight patients with recurrent biliary-type pain after cholecystectomy were enrolled. After thorough investigation, 35 patients with suspected type II sphincter of Oddi dysfunction (SOD) and another 29 type III patients remained for further investigation. Both groups were similar with respect to demographic data and severity of pain. Biliary manometry was performed in all except three patients in either group. Endoscopic sphincterotomy was performed in all patients with abnormal sphincter of Oddi baseline pressure (> 40 mmHg). All patients were clinically re-evaluated after 4-6 weeks, and thereafter the sphincterotomized patients were followed for a median period of 2.5 years.
Results: An abnormal sphincter of Oddi baseline pressure was found in 62.5% of the type II patients and in 50% of the patients with suspected type III SOD (P = 0.66). At the 4-6 week follow-up none of those patients without abnormal manometry, but 70% of the patients with type II SOD, and 39% of the type III SOD patients, respectively, reported subjective benefit after sphincterotomy (P = 0.13 type II vs. type III). However, after a median follow-up of 2.5 years, sustained symptomatic improvement after sphincterotomy was found in 60% of the type II patients, but only in 8% of the patients with type III SOD (P < 0.01).
Conclusion: Disregarding a lack of difference in the incidence of abnormal sphincter of Oddi baseline pressure between type II and type III SOD, the Geenen-Hogan classification helps to predict the clinical outcome after endoscopic sphincterotomy.