Absence of accessory pancreatic duct emptying through the minor ampulla is a major risk factor for gallstone pancreatitis

An accessory pancreatic duct (PD) emptying through an accessory ampulla is reported in 60% of people. A patent accessory PD draining through an accessory ampulla may be protective against temporary pancreatic ductal obstructive process such as gallstone pancreatitis (GSP) and maybe post-ERCP pancreatitis by decompressing the pancreatic ductal system through this "valve of escape". Aim: To determine the prevalence of a patent accessory PD draining through the minor ampulla in patients with GSP and post-ERCP pancreatitis and to compare it to an age-matched control group. Setting: Endoscopy Unit VA Medical Center. Statistical Analysis: Chi-square and Student-t test. Methods: All pancreatograms of patients with GSP (Group I), those who developed post-ERCP pancreatitis (Group II) and those with choledocholithiasis but without evidence of acute pancreatitis (Control Group = Group III) were retrospectively reviewed by independent radiologists seeking for the presence/absence of a patent accessory PD draining through the minor ampulla. GSP was defined as acute abdominal pain with elevated serum amylase/lipase, evidence of cholestasis (elevated alkaline phosphatase and/or bilirubin) or ALT elevation of at least three times the upper limit. Post-ERCP pancreatitis was denned as abdominal pain along with a rise in amylase/lipase levels after ERCP. Results: There were 45 patients in Group I, 19 in Group II and 39 in Group HE. All were men and matched for age. The mean age in Group I was 63.6±1.9 years and not different from Group II (60.3±2.9 years) or Group III (58.9±2.2 years). The prevalence of a patent accessory pancreatic duct draining through the accessory ampulla for each group is depicted below. Accessory Duct Group I Group II Group III Patent 4 (8.9%) 3 (15.8%) 17 (43.6%) Absent 41 (91.2%) 16 (84.2%) 22 (56.4%) I vs. III: p= 0.0006; II vs. III p= 0.07 Conclusions: 1) The prevalence of a patent accessory PD draining through the minor ampulla in patients with GSP was significantly lower than those with choledocholithiasis without acute pancreatitis. 2) There was a trend towards a lower prevalence in post-ERCP pancreatitis compared to controls. 3) These findings provide an insight about the pathogenesis of gallstone pancreatitis and may be important in other processes such as post-ERCP pancreatitis.