Covered Gianturco stent for tracheal stricture: application of polychlorovinylidene and polyurethane as covering materials

The aim of this study was to assess the efficacy and safety of thin membran es of polychlorovinylidene (PCV) or polyurethane (YU) as covering materials for Gianturco stents in the treatment of severe tracheal stricture caused by intraluminal tumor. Manufactured Gianturco stents covered with PCV or PU membrane were used to treat six malignant and one benign tracheal strictur e. The initial results, complications, clinical follow-up, bronchoscopic fi ndings, and three autopsy microscopic examinations were reviewed. Informed consent was obtained after the nature of the treatment had been fully expla ined before every procedure. The stents successfully dilated the tracheal s trictures, providing immediate relief of respiratory symptoms in all patien ts with no major complications. During the follow-up period, the covering m aterials prevented tumor ingrowth until death or intraluminal granuloma for mation. Autopsies proved that no histological change occurs in the tracheal mucosa in response to the presence of PCV or PU; however, ulcer formation occurred in one patient and penetration of the stent struts into the trache al wall in two. Bloody sputum with ulcer formation, minimal granuloma forma tion at the distal end of the stent, and abnormal bacterial load in the spu tum were long-term complications. The Gianturco stent covered with PCV or P U membrane is a useful option as a palliative treatment for malignant and a n emergent salvage for benign tracheal stricture, because both materials ar e thinner and less voluminous than the others. However, the indications for its use are limited to patients with poor prognoses, because hemoptysis, g ranuloma formation, and bacterial propagation remain problematic.