Malignant biliary obstruction (MBO) in the setting of duodenal narrowing is a frequent and challenging scenario in advanced gastrointestinal cancers. Although EUS-guided biliary drainage has emerged as a promising alternative, its use is still limited to specialized centers with dedicated expertise. In daily practice, endoscopists often face two situations: patients with pre-existing enteral stents placed for gastric outlet obstruction (GOO), which complicate biliary access, and patients with duodenal substenoses that appear clinically insignificant but prove non-transitable during ERCP. In both cases, positioning or navigating through duodenal stents can represent a pragmatic solution to enable ERCP.

We conducted a single-center observational study including consecutive patients with MBO in the setting of duodenal narrowing. Patients were stratified into two groups according to stent indication: those who underwent ERCP-directed stent placement to enable biliary access, and those with pre-existing enteral stents previously positioned for palliation of GOO. The primary aim was the technical success, defined as successful cannulation of the biliary tract followed by correct placement of a stent. Secondary endpoints included the clinical success,  the safety of the procedure, and the need for reintervention. Reinterventions were categorized according to indication: biliary reintervention, performed for stent dysfunction or recurrent biliary obstruction, and GOO-related reintervention, performed for recurrence or progression of duodenal obstruction.

Thirty-five patients were included, with a mean age of 68 years and a slight male predominance. The majority had pancreatic cancer and advanced disease stages. Most underwent ERCP-directed stent placement (29, 80.5%) , while a smaller subgroup carried pre-existing enteral stents for GOO (7, 19.5%). Clinical indications were mainly jaundice, with a minority presenting with cholangitis. Papilla status was balanced between naïve and previously treated, and sphincterotomy was rarely performed. Metal stents were the preferred choice, either fully covered (82.7%) or uncovered (13.8%), with only one case requiring plastic stents due to hilar cholangiocarcinoma. ERCP was feasible in 30 out of 35 patients (82.9%), confirming a high rate of technical success. Clinical success was achieved in 26 out of 35 patients (74.3%). Procedural adverse events occurred in 2 patients (5.7%), both classified as grade IIIb, consisting of periprocedural collections requiring drainage. Reintervention was necessary in four cases (11.4%): three for cholangitis due to stent dysfunction, and one for stent occlusion, with subsequent ERCP and EUS-guided gastroenterostomy. 

ERCP in malignant biliary obstruction with duodenal stenosis is feasible (83.3% technical success), with a good clinical efficacy. Severe procedural adverse events were rare (5.6%) , while stent dysfunction required reintervention in 11.1% of cases. Overall survival remained limited, reflecting advanced disease stage.