Irradiation stents vs. conventional metal stents for unresectable malignant biliary obstruction: A multicenter trial

Background & Aims Placement of an irradiation stent has been demonstrated to offer longer patency and survival than an uncovered self-expandable metallic stent (SEMS) in patients with unresectable malignant biliary obstruction (MBO). We aim to further assess the efficacy of an irradiation stent compared to an uncovered SEMS in those patients. Methods We performed a randomized, open-label trial of participants with unresectable MBO at 20 centers in China. A total of 328 participants were allocated in parallel to the irradiation stent group (ISG) or the uncovered SEMS group (USG). Endpoints included stent patency (primary), technical success, relief of jaundice, overall survival, and complications. Results The first quartile stent patency time (when 25% of the patients experienced stent restenosis) was 212 days for the ISG and 104 days for the USG. Irradiation stents were significantly associated with a decrease in the rate of stent restenosis (9% vs. 15% at 90 days; 16% vs. 27% at 180 days; 21% vs. 33% at 360 days; p  = 0.010). Patients in the ISG obtained longer survival time (median 202 days vs. 140 days; p  = 0.020). No significant results were observed in technical success rate (93% vs. 95%; p  = 0.499), relief of jaundice (85% vs. 80%; p  = 0.308), and the incidence of grade 3 and 4 complications (8.5% vs. 7.9%; p  = 0.841). Conclusions Insertion of irradiation stents instead of uncovered SEMS could improve patency and overall survival in patients with unresectable MBO. Lay summary For patients with unresectable malignant biliary obstruction (MBO), placement of a self-expandable metallic stent (SEMS) is a recommended palliative modality to relieve pruritus, cholangitis, pain, and jaundice. However, restenosis is a main pitfall after stent placement. Data from this first multicenter randomized controlled trial showed that insertion of an irradiation stent provided longer patency and better survival than a conventional metal stent. ClinicalTrials.gov ID: NCT02001779.