CLINICAL AND LABORATORY EVALUATION OF A NEW THIN-WALLED SELF-EXPANDING TRACHEOBRONCHIAL SILICONE STENT - PROGRESS AND PITFALLS

Background: Although widely established in the management of malignant airway lesions, currently available tracheobronchial prostheses made of silicone have their drawbacks resulting from rigidity and wall thic kness, Therefore we present clinical follow-up data obtained with a no vel thin-walled expandable prototype silicone airway stent (Polyflex s tent, Willy Rusch AG, Kernen, Germany) in 19 patients, Methods: Sevent een of 19 patients had tracheobronchial complications of infiltrating cancer: five had respiratory-digestive fistulas, 14 had mixed-type obs tructions (mucosal infiltration plus extrinsic compression), and two h ad diffuse tracheal hemorrhages from the tumor surface (three patients had more than one complication). Two of 19 patients had benign postin tubation stricture and malacia, Overall, 33 stents were implanted eith er simultaneously or in a consecutive manner, Scanning electron micros copy was performed both on prototype stents and on other available sil icone stents for comparison, Results: The treatment improved the patie nts' clinical condition substantially. The mechanical properties of th e new prosthesis were excellent, Important stent-associated side effec ts were early mucus retention (n = 7), infolding of the inner silicone layer (n = 2), and stent dislodgment (n = 2), As of February 1997, 10 patients have died of causes unrelated to stent placement, Seven pati ents with malignant airway disease are still alive from 2 weeks up to 7 months after initial treatment, Scanning electron microscopy of expl anted and unused prototypes suggested that an extremely ragged luminal microstructure may contribute to the firm adhesion of secretory mater ial and that technical smoothing of the surface avoids such complicati ons, Conclusions: The novel self-expandable silicone airway stent may be a promising addition to commonly used stent types, Short-term and m edium-term management of fistulas, tumor surface bleeding, and strictu res (malignant and benign) is satisfactory, Scanning electron microsco py of stents provides information on peculiar features of microstructu re and material that may be of use in clinical research and technical innovation.