Distal malignant biliary obstruction (DMBO) commonly requires endoscopic retrograde cholangiopancreatography (ERCP) with transpapillary stent placement. Although ERCP is the standard of care, the real incidence and clinical impact of post-ERCP pancreatitis (PEP) in DMBO remain unclear, as most data derive from mixed populations including benign or proximal lesions. 

This study aimed to assess the incidence, severity, and predictors of PEP and other ERCP-related adverse events (AEs) in a tertiary referral center, providing preliminary data from a high-volume specialized unit.

We conducted a single-center retrospective study including 246 consecutive patients with radiologically and histologically confirmed DMBO who underwent ERCP with transpapillary biliary stenting between January 2022 and June 2024 at the University Hospital “G.B. Rossi” in Verona, Italy. Clinical, imaging, and procedural variables were collected and analyzed, including age, sex, bilirubin levels, tumor size, duodenal infiltration, cannulation technique, sphincterotomy, and pancreatic stent placement. PEP was defined according to the Revised Atlanta Classification (2012) and graded as mild, moderate, or severe. Adverse events within 31 days were recorded. Univariate and multivariate logistic regression analyses were performed to identify potential predictors of PEP. Variables with p < 0.10 in univariate analysis were entered into the multivariate model.

Among 246 patients (mean age 67.2 ± 10.6 years; 54% males), pancreatic adenocarcinoma was the most frequent cause of DMBO (85%). The overall rate of post-ERCP adverse events was 26.4%, with PEP being the most common (10.2%). Most pancreatitis cases were mild (84%), three were moderate (12%), and one severe (4%), resulting in a 1.6% rate of clinically significant (moderate-to-severe) PEP. Other AEs included cholangitis (6.9%), intraprocedural bleeding (3.3%), and cholecystitis (2.4%); no patient required ICU admission or died within 31 days. Univariate analysis showed a protective trend for tumor size >30 mm (p=0.09) and an increased risk of PEP with pancreatic stent placement (p=0.05) and pancreatic-assisted cannulation (p=0.09). In multivariate logistic regression, none of the variables reached formal significance; however, pancreatic stent placement remained the strongest predictor (OR 4.2, 95% CI 0.88–20.1, p=0.07). These findings suggest that PEP risk is mainly associated with procedural complexity rather than intrinsic patient characteristics.

In this preliminary tertiary-center experience, ERCP with transpapillary stenting for DMBO showed a low incidence of clinically relevant PEP. 

Although PEP occurred in about 10% of cases, moderate or severe forms were rare (1.6%) and did not result in mortality or prolonged hospitalization. The observed trends suggest that pancreatic stent placement and complex cannulation may increase PEP risk, while larger tumors appear protective, possibly due to mechanical ductal obstruction.

These results highlight the crucial role of operator expertise and procedural standardization in minimizing adverse events.

ERCP remains the safest and most effective first-line approach for biliary drainage in DMBO when performed in expert hands.

Future multicenter prospective studies are warranted to validate these findings and develop risk stratification models tailored to malignant biliary obstruction.