A NEW DESIGN OF THE ESOPHAGEAL WALLSTENT ENDOPROSTHESIS RESISTANT TO DISTAL MIGRATION

OBJECTIVE. Because plastic-covered metallic stents used in the palliat ion of patients with unresectable esophageal cancer are associated wit h significant rates of migration, particularly when the lower end of t he stent projects into the gastric fundus, the purpose of this study w as to establish whether two new prototype designs of the Wallstent eso phageal endoprosthesis are prone to migration. SUBJECTS AND METHODS. A cylindrical stent and a conical stent were studied. Both designs incl uded plastic covering inside the metallic mesh. In addition, the conic al device incorporated a variation in the braiding angle between the u pper and lower parts of the endoprosthesis. Ten conical stents and eig ht cylindrical stents were inserted in 18 patients with tumors involvi ng the gastroesophageal junction who were followed up with esophagogra phy and endoscopy. RESULTS. All insertions of stents were successful. Two cylindrical stents (25%) migrated distally. Two conical stents (20 %) migrated proximally. One perforation occurred that was associated w ith distal migration of a cylindrical stent. CONCLUSION. The frequency of distal migration of cylindrical stents is unacceptably high, Conic al stents are resistant to distal migration, although improvements in design are required to deal with the problem of proximal migration.