Multicenter Feasibility Study of the Newly Developed Tapered Covered Metal Stent for Malignant Biliary Obstruction in Patients with Pancreatic Cancer

Background and Aim: In SEMS deployment for distal malignant biliary obstruction (DMBO), occlusion by biliary sludge and food residue remains challenging. We developed a novel tapered covered metal stent (TMS) with 10mm body diameter, 4mm distal tip, and 10mm tapered length based on fluid dynamics simulation and evaluated its safety and efficacy.
Methods: We conducted a multicenter retrospective observational study of 33 pancreatic cancer patients with unresectable DMBO who received TMS between January 2021-December 2022. Technical success rate, early and late adverse events, and recurrent biliary obstruction (RBO) were evaluated.
Results: Median age was 77 years (IQR 70-86.5), with 11 males and 22 females. TMS lengths: 6cm/7cm/8cm: 8/3/22 cases. Technical success: 97.0%. EST status: 15 prior/17 simultaneous/1 none. Early adverse events: moderate cholecystitis (3 cases), mild pancreatitis (2 cases). Late adverse event: cholecystitis (1 case). Among 32 successful cases, RBO occurred in 6 cases (18.8%): ingrowth (1), distal migration (2), proximal migration (2), and occlusion (1). Kaplan-Meier analysis showed long-term patency with overall rate not reaching 50%.
Conclusions: The novel TMS demonstrated high technical success (97.0%) and low RBO rate (18.8%), suggesting safety and efficacy for DMBO in pancreatic cancer. Further prospective studies are needed.