Endoscopic retrograde cholangiopancreatography (ERCP) is essential for managing biliary and pancreatic diseases, but its success can be hindered by gastrointestinal substenoses proximal to the papilla of Vater that a Standard Duodenoscope (STD) cannot traverse. This prospective study evaluates the efficacy and safety of the Slim Duodenoscope (SLD), a thinner device designed to overcome such anatomical limitations.

Consecutive patients in whom papillary access with a STD had failed and who subsequently underwent ERCP with the SLD were prospectively enrolled at two Italian referral centers (October 2023–November 2025).

Forty-one ERCPs with the SLD were performed. Indications included obstructive jaundice (n=38; 68.3%), specifically 13 cases of choledocholithiasis and 15 biliary strictures (10 malignant, 3 indeterminate, and 2 benign); cholangitis (n=9; 22.0%), bile leak (n=2; 4.9%), and scheduled biliary stent removal (n=2; 4.9%).  Among the 41 patients, strictures  were located as follows: one at the hypopharynx in post-radiation therapy sequelae; seven in the esophagus (including 2 esophageal diverticula, 2 compressions from cervical osteophytes, 1 peptic stricture, 1 caustic stricture, and 1 post-parathyroidectomy stricture); one at the cardia due to achalasia; two in the stomach following sleeve gastrectomy with a sharply angulated gastric lumen; one at the pylorus caused by gastric adenocarcinoma; 2 in the duodenal bulb (1 peptic and 1 due to malignant infiltration); twenty-three at the superior duodenal flexure (comprising 16 malignant infiltrations, 5 peptic strictures, and 2 extrinsic compressions); and finally, four in the second portion of the duodenum, all resulting from malignant infiltration. The SLD successfully passed the stricture in 33 patients (80.5%), enabling therapeutic success in 29 (87.9%). Failure occurred in 8 cases (19.5%), due to 7 malignant and 1 benign stricture. Among benign strictures, passage success reached 95%. Two ERCP-related complications (4.9%), not directly attributable to the use of the SLD, were reported: cholangitis and septic shock.

The SLD is a game-changer for patients with luminal narrowing, providing access where STD fail. Its high success rate—especially in benign strictures—highlights the value of referring these patients to centers equipped with this device. By enabling ERCP in situations otherwise destined for percutaneous drainage, EUS-guided interventions, or surgery, the SLD expands therapeutic options and helps avoid more invasive alternatives.