Covered versus uncovered self-expandable metallic stents for palliation of malignant pyloric obstruction in gastric cancer patients: a randomized, prospective study

Background: Self-expandable metallic stents (SEMSs) provide effective palliation of malignant pyloric obstruction in patients with inoperable gastric cancer. Objective: To compare the effectiveness and side effects of covered and uncovered SEMSs for the palliation of malignant pyloric obstruction. Design: Prospective, randomized, single-center study. Setting: Tertiary-care cancer center hospital. Patients: This study involved 80 patients with pyloric obstruction related to inoperable gastric cancer. Intervention: Covered or uncovered SEMS placement. Main Outcome Measurements: Technical and clinical success rates as well as the patency rate at 8 weeks after placement. Results: Both groups had a technical success rate of 100% with no immediate complications. Both groups also had comparable clinical success rates (covered SEMS, 95% [38 of 40] and uncovered SEMS, 90% [36 of 40], P = .68) and 8-week patency rates (covered SEMS, 61.3% [19 of 31] and uncovered SEMS, 61.1% [22 of 36], P > .99). Stent migration within 8 weeks was more common in the covered SEMS group (25.8% [8 of 31]) than in the uncovered SEMS group (2.8% [1 of 36], P = .009), whereas re-stenosis because of tumor ingrowth was more common in the uncovered SEMS group (25.0% [9 of 36] vs 0% [0 of 31] in the covered SEMS group, P = .003). Overall patient survival and stent patency did not differ between groups (P = .27 and 0.61 by log-rank test, respectively). Limitations: The study population was limited to gastric cancer patients, and stent designs were changed in the midst of the study period. Conclusion: Both the covered and uncovered SEMSs are effective and have comparable 8-week patency in patients with malignant pyloric obstruction, despite different patterns of late stent failure.