A new coated self-expanding metal stent for malignant esophageal strictures

The development of self-expanding metallic stents (SEMS) is an important medical advance. Not only is the concept new and exciting but this technology has the potential to be utilized by a wide range of subspecialties. For any physician-cloggologist who deals with obstructed biologic cylinders, this new technology has potential.¹ Already these devices have been placed in obstructed ureters, urethras, coronary arteries, and other blood vessels. Their main application to date for digestive diseases has been in the obstructed biliary tree.² A logical extension would be to use this device for obstructions in the esophagus. Song et al., ³ in Korea, and Schaer et al.,⁴ in Oregon, reported palliative therapy for esophagogastric neoplasms using a modified Gianturco^® stent. Domschke et al.⁵ reported the use of an uncoated metallic Wallstent^® in a single patient with esophageal cancer. Although, SEMS are very appealing because they are delivered in a small diameter device, but expand to a much larger size after they are deployed, they do have some limitations. For the most part, the SEMS used to date are not coated and after placement there is space between the metallic lattices. This provides a space through which tumor ingrowth can and has occurred. Also, once implanted endoscopic removal is virtually impossible. Therefore, it seemed relevant to develop a coated stent which would prevent tumor ingrowth, allow removal, and possibly be impregnated with an active pharmacologic agent.