Sphincter of Oddi manometry does not predispose to post-ERCP acute pancreatitis

Background: Sphincter of Oddi manometry is helpful in selecting patients with sphincter of Oddi dysfunction who will respond to sphincterotomy. However, studies have shown that sphincter of Oddi manometry is associated with a high risk of post-procedure pancreatitis. The primary objective of this study was to evaluate the safety of sphincter of Oddi manometry in patients with sphincter of 20ddi dysfunction. The secondary objective was to determine the risk factors for post-ERCP pancreatitis in patients with sphincter of Oddi dysfunction. Methods: Data were collected retrospectively for 268 patients who had elective ERCP performed at 3 tertiary care medical centers between 1996 and 2000. Consecutive patients with suspected sphincter of Oddi dysfunction formed the case group; the control group consisted of patients with bile duct stone. The case group was further subclassified into group A, patients who underwent sphincter of Oddi manometry followed by immediate ERCP, and group B, patients who had ERCP without manometry. The rate of post-ERCP acute pancreatitis was compared between case and control groups. Results: Twenty-seven percent of patients in the case group with suspected sphincter of Oddi dysfunction developed acute pancreatitis compared with 3.2% of patients in the control group with bile duct stone (p<0.001). There was no significant difference in the rate of acute pancreatitis in patients with sphincter of Oddi dysfunction who underwent sphincter of Oddi manometry and ERCP compared with patients with sphincter of Oddi dysfunction who had ERCP without sphincter of Oddi manometry (odds ratio 0.72: 95% CI[0.08, 9.2]). Multivariable logistic regression analysis showed that biliary sphincterotomy (p = 0.006) and pancreatography (p = 0.03) were independent predictors of acute pancreatitis. Conclusions: Patients with suspected sphincter of Oddi dysfunction are at higher risk of post-ERCP acute pancreatitis. Sphincter of Oddi manometry by itself does not appear to predispose to this complication.