Effect of duodenal papilla morphology on biliary cannulation and complications in patients with common bile duct stones

Background: The endoscopic appearance of the major duodenal papilla influences biliary cannulation and complications. This study aimed to investigate the role of major duodenal papillae in the endoscopic treatment of common bile duct (CBD) stones.

Methods: This retrospective study was conducted at Bishan Hospital of Chongqing Medical University between January 2018 and August 2022. Patients with native papillae who underwent endoscopic treatment for CBD stones were recruited and divided into four groups according to Haraldsson's classification of papillae (types I-IV). Univariate and multivariate logistic regression analyses were used to identify risk factors for difficult cannulation and post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP).

Results: A total of 596 patients with CBD stones were enrolled. The proportion of patients with type I papilla was the highest (n = 231, 38.8 %), followed by type III papilla (n = 175, 29.4 %), type IV papilla (n = 101, 16.9 %) and type II papilla (n = 89, 14.9 %). Difficult cannulation occurred in 188 of 596 patients (31.5 %), with most cases occurring in those with type III papilla (71/175, 40.6 %, P = 0.020). Multivariate analysis revealed that age [odds ratio (OR) = 1.034, 95 % confidence interval (CI): 1.021-1.047, P < 0.001], type III papilla (OR = 2.255, 95 % CI: 1.439-3.535, P < 0.001), gallbladder in situ (OR = 2.486, 95 % CI: 1.346-4.590, P = 0.004), and CBD diameter < 10 mm (OR = 1.600, 95 % CI: 1.049-2.441, P = 0.029) were risk factors for difficult cannulation. The total incidence of PEP was 10.9 %. Compared with the other types of papillae, the rate of PEP was the highest in those with type I papilla (15.2 %, P = 0.030). Multivariate analysis demonstrated that PEP was associated with difficult cannulation (OR = 1.811, 95 % CI: 1.044-3.143, P = 0.035) and white blood cells (WBCs) < 10 × 10⁹/L (OR = 2.199, 95 % CI: 1.051-4.600, P = 0.036).

Conclusions: The endoscopic appearance of the major papilla is an important factor that influences both biliary cannulation and outcomes. Type III papilla is more frequently difficult to cannulate in the endoscopic treatment of CBD stones.