WallFlex® and Evolution® Duodenal Stents Have Similar Efficacy but Different Safety for Malignant Gastric Outlet Obstruction

BackgroundThe WallFlex(& REG;) and Evolution(& REG;) stents are the most widely used duodenal stents, but no study has compared them.AimsWe aimed to compare the efficacy and safety of WallFlex(& REG;) and Evolution(& REG;) stents for malignant gastric outlet obstruction.MethodsWe included all consecutive patients who were treated for malignant gastric outlet obstruction with WallFlex(& REG;) or Evolution(& REG;) self-expandable metal uncovered duodenal stents between 2013 and 2020. Multivariable Cox models were performed to assess duodenal stent failure, as defined by gastric outlet obstruction necessitating another duodenal stent.ResultsWe included 129 patients: 74 received a WallFlex(& REG;) stent and 55 received an Evolution(& REG;) stent. The non-failure rate was of 68% (95%CI 55-84) and 65% (95%CI 50-84) at 6 months and of 48% (95%CI 32-73) and 45% (95%CI 27-74) at 1 year, with the WallFlex(& REG;) and Evolution(& REG;) stents, respectively. The median time to duodenal stent failure was 10.5 months in the WallFlex(& REG;) group and 9.3 months in the Evolution(& REG;) group. The type of duodenal stent was not associated with duodenal stent failure (p logrank = 0.43, adjusted hazard ratio 1.55; 95%CI 0.77-3.14). The overall survival was similar between the two groups (p logrank = 0.92). Three patients had complications due to Evolution(& REG;) stents; it consisted in dismantled stents that led to hemorrhage in one patient.ConclusionsWallFlex(& REG;) and Evolution(& REG;) duodenal stents had similar efficacy for malignant gastric outlet obstruction. There were more adverse events with Evolution(& REG;) stents.