Implantation of Ultraflex nitinol stents in malignant tracheobronchial stenoses

Study objective: To assess the uncovered Ultraflex nitinol stent (Boston Sc ientific; Natick, MA) for its efficacy and safety. Design, setting, and patients: Between October 1997 and October 1998, we ca rried out a prospective multicenter study at six hospitals in Japan. Fifty- four Ultraflex stents were inserted in 34 patients with inoperable malignan t airway stenosis using a flexible and/or a rigid bronchoscope under fluoro scopic and endoscopic visualization. Measurements and results: Clinical, endoscopic examination, and pulmonary f unction on days 1, 30, and 60 after stent implantation showed improvement. In 19 patients (56%), stent implantation was performed as an emergency proc edure because of life-threatening tracheobronchial obstruction. Immediate r elief of dyspnea was achieved in 82% of the patients. The dyspnea index imp roved significantly after implantation (before vs days 1, 30, and 60; p < 0 .001). Significant improvements were observed in obstruction of airway diam eter (81 +/- 15% before vs 14 +/- 17% on day 1, 12 +/- 12% on day 30, and 2 2 +/- 28% on day 60; p < 0.001). Vital capacity (VC), FEV1, and peak expira tory flow (PEF) increased significantly after stent implantation: before vs immediately after VC (p < 0.01), FEV1 (p < 0.001), and PEF (p < 0.05). The main complications were tumor ingrowth (24%) and tumor overgrowth (21%). A fter coagulation with an Nd-YAG laser or argon plasma coagulation, mechanic al coring out using the bevel of a rigid bronchoscope was necessary in pati ents showing tumor ingrowth or overgrowth. Removal and reposition were poss ible in case of misplacement. There were no problems with migration and ret ained secretions. The median survival time of patients was 3 months. The 1- year survival rate was 25.4%. Conclusions: In this study of the Ultraflex nitinol stent, we have demonstr ated that patients were relieved from dyspnea, which contributed to improve d quality of life, with minimal complications. This stent can be used safel y, even in the subglottic region. Owing to its excellent flexibility and bi ocompatibility, the stent is also indicated in certain complicated situatio ns, eg, narrow stenosis, hourglass stenosis, curvilinear stenosis, bilatera l mainstem bronchial stenoses, and long stenosis of varying diameters.