A patent accessory pancreatic duct prevents pancreatitis following endoscopic retrograde cholangiopancreatography.

BACKGROUND/AIM Pancreatitis is the most common and feared complication of endoscopic retrograde cholangiopancreatography (ERCP). We previously examined patency of the accessory pancreatic duct (APD) by dye injection endoscopic retrograde pancreatography (ERP). APD patency was found in 43% of 291 control cases who had no particular changes in the head of the pancreas compared to only 6% in patients with acute pancreatitis. APD patency was closely related with the shape of the terminal portion of the APD. This study aimed to clarify whether patency of the APD prevents post-ERCP pancreatitis. METHODS We examined retrospectively the terminal shape of the APD by ERP in 34 patients with post-ERCP pancreatitis. Based on these data, patency of the APD was estimated from its terminal shape in patients with post-ERCP pancreatitis. RESULTS The stick-type APD (p < 0.01), which indicated high patency, was less frequent, and the branch-type APD (p < 0.01) and halfway-type APD, or no APD (p < 0.01), which showed quite low patency, were more frequent in patients with post-ERCP pancreatitis compared with controls. Accordingly, the estimated patency of the APD in post-ERCP pancreatitis patients was only 16%, which was significantly lower than the 43% in controls. There was no significant relationship between the estimated APD patency and the severity of post-ERCP pancreatitis. CONCLUSIONS The estimated APD patency was significantly lower in patients with post-ERCP pancreatitis. A patent APD may function as a second drainage system to reduce the pressure in the main pancreatic duct and prevent post-ERCP pancreatitis.