Covered Versus Uncovered Metal Stents for Malignant Gastric Outlet Obstruction: a Systematic Review and Meta-analysis

Background And Aims: Self-expandable metal stents (SEMSs) are used for palliation of malignant gastric outlet obstruction (GOO). Studies comparing covered SEMSs (C-SEMSs) and uncovered SEMSs (U-SEMSs) have led to inconclusive results. We compared efficacy and safety of C-SEMSs versus U-SEMSs in patients with GOO.

Methods: We searched MEDLINE, EMBASE, and Cochrane Library from 2000 to 2019 to identify available studies comparing C-SEMSs versus U-SEMSs in patients with GOO. Primary outcomes were stent survival and patient survival, whereas secondary outcomes were clinical and technical success, Gastric Outlet Obstruction Score System (GOOSS) score after the procedure, overall adverse events, reintervention rate, dysfunction rate, stent occlusion, and stent migration.

Results: Overall, 7 randomized controlled trials and 9 observational studies were identified that included 1741 patients. C-SEMSs were associated with higher stent survival (hazard ratio, .68; 95% confidence interval [CI], .48-.96), whereas patient survival did not statistically significantly differ between C-SEMS and U-SEMS groups (hazard ratio, .96; 95% CI, .75-1.23). Clinical and technical success were not statistically different between groups (odds ratios, 1.1 [95% CI, .76-1.61] and .69 [95% CI, .21-2.3], respectively). There were no differences in terms of overall adverse events, reintervention rate, dysfunction rate, and GOOSS rate ≥2 after SEMS placement. U-SEMSs were associated with a higher rate of occlusion (odds ratio, .34; 95% CI, .21-.53) and C-SEMSs with a higher rate of migration (odds ratio, 4.28; 95% CI, 2.79-6.57).

Conclusions: C-SEMSs were associated with higher stent survival (time between stent deployment and stent dysfunction) compared with U-SEMSs, whereas no differences in terms of patient survival (time between stent deployment and patient's death) emerged. However, U-SEMSs were associated with higher risk of occlusion and C-SEMSs with higher risk of migration. Further studies using new C-SEMSs with an antimigration system are needed.