Evaluation of post-ERCP pancreatitis: potential causes noted during controlled study of differing contrast media. Midwest Pancreaticobiliary Study Group.

Background: Possible sources of post-ERCP pancreatitis were evaluated during a prospective, randomized, controlled study comparing different contrast media.

Methods: A total of 1979 patients were randomized and subdivided into groups during the study. Patients were grouped for comparison depending on the type of procedure performed during ERCP. Diagnostic patients studied with pancreatograms (Group I) were compared with other groups, specifically, those not studied with pancreatograms (Group IV). All patients had subjective and objective estimates of the difficulty in cannulation of both ducts. The incidence of postprocedural pancreatitis was compared between and within each group.

Results: In Group I there was a progressively higher incidence of pancreatitis with increased numbers of pancreatic duct injections. Patients with the highest (19.5%) frequency of pancreatitis received 10 or more injections into the pancreatic duct. Group I cases with difficult common bile duct cannulations had a higher frequency of post-ERCP pancreatitis (9.5%), as compared with the entire group (5.6%).

Conclusions: There was a higher incidence of pancreatitis associated with increased manipulation around the papillary orifice, especially with multiple pancreatic duct injections. There was also a slightly higher incidence of post-ERCP pancreatitis in cases with difficult common bile duct cannulation. Endoscopists are encouraged to evaluate and develop safer cannulation techniques that minimize the number of injections into the pancreatic duct and enhance selective cannulation.