The clinical need for sphincter of Oddi manometry in gastrointestinal endoscopy units

The clinical need for sphincter of Oddi manometry (SOM) was investigated by retrospective analysis of 736 consecutive endoscopic retrograde cholangiopancreatography (ERCP) referrals (1985-89). During this period SOM was not performed in any unit in Greece including our own. Assuming a conservative or a more liberal policy in the utilization of SOM, a biliary and a pancreatic group of patients were established respectively, depending on the clinical presentation. ERCP was diagnostic in 168/194 (86.6%) of patients referred for post-cholecystectomy symptoms, but SOM was considered to be necessary to establish a diagnosis in the remaining 26 (13.4%) patients (biliary group). ERCP revealed pancreatic and/or biliary pathology in 46/69 (66.7%) patients, referred for symptoms attributed to pancreatitis, but 11/69 (15.9%) patients with pancreas divisum and 12/69 (17.4%) with acute recurrent idiopathic pancreatitis may have benefitted from SOM for planning endoscopic therapy (pancreatic group). Thus, only 5 patients from each group per 147 ERCP annual referrals were candidates for SOM. When taking into account that to run a SOM service the minimum annual number of investigations should be 50 and that the provision of ERCP in the UK is 50 per 100,000 of population per year, it is extrapolated that such a Gastrointestinal Endoscopy Unit should serve a population of 1.5 to 3 million.