Efficacy and safety of transpancreatic sphincterotomy in endoscopic retrograde cholangiopancreatography: a retrospective cohort study.

Background: Difficult cannulation represents a common obstacle during endoscopic retrograde cholangiopancreatography (ERCP). We assessed the efficacy and adverse events of transpancreatic sphincterotomy (TPS), and investigated potential associated confounders. Methods: All patients referred to our department for ERCP during 2015-2020 were eligible if they had intact papilla and visceral anatomy. In addition to standard measures, TPS was combined with pancreatic stent placement. Apart from demographics, we retrieved data related to the indication, periampullary anatomy, necessity for TPS or fistulotomy, their outcomes and complications. Chi-square test was employed to investigate associations between TPS and independent variables. When significance was observed, the respective variables were inserted into a regression model. Results: A total of 1082 individual patients were eligible, with an equal female: male ratio and a mean age of 72.7±15.82 years. Seventy-three patients (6.7%) underwent TPS, with a 95.9% successful cannulation rate. Papilla morphology or regional diverticulum did not affect the decision to perform TPS, though it was significantly associated with malignant common bile duct (CBD) obstruction as the ERCP indication (P=0.001). Considering adverse events, TPS did not increase the incidence of post-ERCP pancreatitis (PEP), though it affected bleeding (P=0.005). Regression analysis revealed a protective role of TPS against PEP (risk ratio [RR] 0.015, 95% confidence interval [CI] 0.23-5.05; P<0.001), while the aforementioned risk of hemorrhage was attributed to previous precut attempts (RR 3.02, 95%CI 1.42-6.43; P=0.004). Conclusion: TPS combined with pancreatic stenting is an effective and safe modality in difficult cannulation cases and could be the first-choice alternative in malignant CBD obstruction.