Feasibility of Double-Deployment Small-Diameter Covered Metallic Stent for Malignant Distal Biliary Obstruction (with Video)

Background/Objectives: Covered self-expandable metallic stents (CSEMS) are commonly used to treat malignant distal biliary obstructions. A 10-mm CSEMS carries the risk of obstructing the pancreatic and cystic duct orifices by adhering to the bile duct; therefore, postoperative pancreatitis and cholecystitis are reported to occur at a certain frequency. We have adopted a new drainage technique for malignant distal biliary obstruction called ''double-slim SEMS stenting" (DSS), where two small-diameter CSEMS are placed side-by-side. We aimed to compare the efficacy and safety of biliary drainage using DSS with those of conventional CSEMS. Methods: In total, 50 patients who underwent endoscopic biliary drainage for malignant distal biliary obstructions between April 2019 and March 2022 at Hyogo Medical University Hospital were enrolled. Patients were divided into DSS and Conventional groups, and the technical success rate, clinical success rate, adverse events, success rate for reintervention, recurrent biliary obstruction (RBO) rate, and time to RBO (TRBO) were evaluated. Results: There were no significant differences in patient characteristics between the DSS (n = 20) and Conventional groups (n = 30). The technical and clinical success rates were 100% in the DSS group. The incidence of adverse events was not significantly different between the two groups (DSS/Conventional: 10.0% [2/20]/20.0% [6/30]) (p = 0.34). No acute cholecystitis was observed in the DSS group. The incidence rates of RBO were 30% (6/20) and 43% (13/30) in the DSS and Conventional groups, respectively (p = 0.92). The median TRBO in the DSS group was 378 days, while the TRBO in the Conventional group was 195 days (p = 0.03), resulting in significantly longer TRBO in the DSS group. Conclusions: DSS emerges as a viable and safe approach for biliary drainage in malignant distal biliary obstruction, demonstrating a lower incidence of adverse events and longer TRBO compared to conventional CSEMS.