Feasibility and safety of duodenal covered self-expandable metallic stent fixation: an experimental study.

BACKGROUND AND AIMS: Migration of duodenal covered self-expandable metallic stents (C-SEMS) is the main cause of stent dysfunction in patients with malignant gastric outlet obstruction. However, the ideal method to prevent migration has not been clarified. We aimed to evaluate the feasibility and safety of duodenal C-SEMS fixation in this experimental study. METHODS: We used the over-the-scope clip (OTSC), suture, and clip methods to fix duodenal C-SEMS and evaluated the gripping force of each device and invasion depth based on pathological findings. RESULTS: The OTSC and suturing systems had a significantly higher mean gripping force compared with the clipping system (OTSC vs. clip: 13.2 vs. 1.0 Newtons [N], P < 0.001; suture vs. clip: 8.5 vs. 1.0 N, P < 0.001). OTSC compression was stronger compared with suturing (OTSC vs. suture: 13.2 vs. 8.5 N, P = 0.006). The submucosal layer, but not the muscle layer, was compressed more widely and deeply by OTSC compared with clips based on pathological findings by hematoxylin and eosin staining. CONCLUSION: Both OTSC and suturing methods used for duodenal C-SEMS fixation were feasible compared with the clipping method. The pathological evaluation of invasion depth indicated that OTSC may be safe even for preventive use. This study suggested that these methods can be applied clinically for duodenal C-SEMS fixation.