Endoscopic Retrograde Cholangiopancreatography (ERCP) in patients with altered anatomy due to Billroth II (BII) gastrectomy remains challenging. Difficulties arise from the need to traverse the afferent loop, reach the major duodenal papilla, and achieve selective cannulation due to reversed anatomy. These challenges often demand the use of specialized techniques and both side-viewing and forward-viewing endoscopes. This study aims to evaluate the efficacy and safety of ERCP in this patient population.

We conducted a 20-year retrospective study in our hospital between February 2005 and October 2025. Non-naive ERCP patients with BII anatomy were excluded. Data on demographics, indications, endoscope type used (duodenoscope, gastroscope) and procedural outcomes were systematically collected. Initial endoscopic evaluation with gastroscope  was performed in all patients to determine the optimal approach. The study outcomes included successful afferent loop intubation, papilla cannulation, completion of procedure, and rate of procedure-related complications.  Standard ERCP devices and pharmacological sedation were used in all patients. 

A total of 54 patients (42 males, 12 females) were studied. The median age of the group was 78.5 years. The most common indication was choledocholithiasis (n=42, 77.8%). Other indications included cholangitis (n=3, 5.6%), obstructive jaundice (n=3, 5.6%), biliary colic (n=2, 3.7%), cholangiocarcinoma (n=2, 3.7%), and pancreatic cancer (n=2, 3.7%).

The majority of procedures, 44 (81.5%), were performed using a duodenoscope, while 10 procedures (18.5%) utilized a gastroscope. The overall technical success rate for the entire cohort was 85.2% (46/54). A detailed analysis revealed a success rate of 84.1% (37/44) in the duodenoscope group compared to 90.0% (9/10) in the gastroscope group (p=0.46). The rates of successful afferent loop intubation  (95.5% vs 90%) and selective cannulation (86.4% vs 90%) did not differ significantly between the two endoscope type groups.

Among the cohort, 6 patients (11.1%) had a concurrent Braun anastomosis, a configuration usually excluded from prior studies. Success was significantly lower in patients of this subgroup compared to standard BII anatomy (50.0% vs 89.6%,p = 0.036, <0.05).

 Regarding safety, major complications occured in 5 patients (9.3%). This included three perforations(5.5%) requiring surgery, one post-ERCP bleeding managed endoscopically, and one case of pancreatitis. All complications except one perforation occurred in the duodenoscope group. No case of cholangitis were recorded in either group.

In this study, ERCP in patients with Billroth II anatomy demonstrated efficacy and safety comparable to existing literature. No statistically significant differences were found between endoscope types. However, patients with a concurrent Braun anastomosis had a  statistically significant lower sucess rate (p = 0,036), highlighting the technical challenge of this complex anatomy.