Winged Partially Covered Self-Expandable Metal Stent to Prevent Distal Migration in Malignant Gastric Outlet Obstruction.

Abstract

Through-the-scope implantation of self-expandable metal stents can be used for the palliation of malignant gastric outlet obstruction. Although covered stents were developed to prevent tumor ingrowth, often seen with uncovered stents, migration is still a major problem. Especially, surgical treatment is required for some patients if distal migration occurs. To evaluate the usefulness of the newly designed winged stent that was developed to prevent distal stent migration. This was a single-center, single-arm, retrospective study. A total of 63 inoperable cancer patients with symptomatic gastric outlet obstruction were reviewed to evaluate the safety and efficacy of a newly designed partially covered self-expandable metal stent with star-shaped wing flaps at the proximal end to reduce distal stent migration. Technical and clinical successes were achieved in 100% and 87.3% of patients, respectively. The gastric outlet obstruction scoring system score significantly improved after stent placement (from median 1 to 2, P < 0.001). The median duration of stent patency was 147days (interquartile range 76-201), and median duration of overall survival was 176days (interquartile range 79-325). Stent migration was observed in seven patients (11.1%), and restenosis was developed in 12 patients (19.0%). All cases of migration were proximal, and no distal migration was observed. Endoscopic removal of migrated stents was performed successfully in all cases. The newly designed winged stent showed feasible efficacy and safety for malignant gastric outlet obstruction. Furthermore, it effectively prevented distal stent migration.