Factors associated with acute pancreatitis in patients with impacted duodenal papillary stones: a retrospective cohort study

Impaction of a stone at the duodenal papilla can obstruct biliopancreatic outflow and thereby lead to acute pancreatitis. But not all patients with an impacted papillary stone (IPS) had the clinical features of pancreatitis. This study aimed to identify factors associated with acute pancreatitis in patients with IPS.We retrospectively analyzed patients with IPS who underwent endoscopic retrograde cholangiopancreatography (ERCP) at Tianjin Nankai Hospital. Clinical factors were compared between patients with/without acute pancreatitis before ERCP. Factors associated with acute pancreatitis were identified by univariable and multivariable binary logistic regression.The final analysis included 174 patients with acute pancreatitis (pancreatitis group, PG) and 130 patients without acute pancreatitis (non-pancreatitis group, NPG). Preoperative incidences of jaundice (85.6 vs. 72.3%), acute cholangitis (54.6 vs. 33.8%), and hyperlipidemia (39.1 vs. 22.3%) were higher in the PG than in the NPG (p < .05). High tension in the duodenal papilla (83.3 vs. 71.5%), circular papillary orifice (82.8 vs. 70.0%), and distal stone impaction (90.8 vs. 82.3%) were more common in the PG than in the NPG (p < .05), whereas stone diameter and common bile duct diameter did not differ significantly between groups. Multivariable logistic regression revealed that jaundice, acute cholangitis, hyperlipidemia, and dot/circular papillary orifice were independently associated with acute pancreatitis (p < .05).Jaundice, acute cholangitis, and hyperlipidemia are independent risk factors for acute pancreatitis in patients with IPS. Prompt ERCP in patients with these features might reduce acute pancreatitis risk. Dot/circular papillary orifice may be an anatomical factor of acute pancreatitis, which needs more evidence.