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

Background: The WallFlex and Evolution stents are the most widely used duodenal stents, but no study has compared them.

Aims: We aimed to compare the efficacy and safety of WallFlex and Evolution stents for malignant gastric outlet obstruction.

Methods: We included all consecutive patients who were treated for malignant gastric outlet obstruction with WallFlex or Evolution 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.

Results: We included 129 patients: 74 received a WallFlex stent and 55 received an Evolution 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 and Evolution stents, respectively. The median time to duodenal stent failure was 10.5 months in the WallFlex group and 9.3 months in the Evolution 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 stents; it consisted in dismantled stents that led to hemorrhage in one patient.

Conclusions: WallFlex and Evolution duodenal stents had similar efficacy for malignant gastric outlet obstruction. There were more adverse events with Evolution stents.