Use of studded PolyflexTM stents in patients with neoplastic obstructions of the central airways

Abstract

Respiration 2002;71:81–7. Bolliger CT, Breitenbuecher A, Brutsche M, Heitz M, Stanzel F. Study Summary: In this prospective multicenter study, the authors report their preliminary experience of using a new version of PolyflexTM stent for relief of central airway obstruction. Twenty-six patients with symptomatic central airway obstruction resulting from malignant tumor were included in the study. A total of 27 stents were placed using rigid bronchoscopy under general anesthesia. The stents were deployed using either a dedicated Ruesch applicator or a Dumon applicator. The median follow up was 4.3 months. Spirometry, performance status, and dyspnea improved at 1 and 3 months’ follow up. However, 17 of 26 patient died within 3 months of stent placement as a result of progression of their disease. The main complications were stent migration in 1 patient (3.7%) and stent obstruction resulting from secretions in 4 patients (15%). Follow-up bronchoscopy did not show other complications such as ingrowth of tumor or granuloma formation at the stent ends. In 3 long-term survivors, the stent could be removed after the control of the underlying tumor. Comments: Airway stent placement is an important palliative treatment in patients with extrinsic compression of the central airways. There are several stent designs with their unique properties, advantages, and disadvantages (Clin Chest Med 2000;38:395–408). There is an intense interest in improving the stent design. PolyflexTM stents consist of a polyester wire mesh embedded in a silicone coating. An earlier version of this stent was tested in an animal model and was found to have a high incidence of stent migration (Chest 1999;115:469–501). The stent used in this study is an improved version with small studs on the outer surface to prevent its migration after the placement. It is also thinner and more flexible than the Dumon stent. The initial results from this study are favorable. The stents were well tolerated. Most patients experienced improvement in dyspnea and performance status. The migration rate was 3.7%, which is apparently lower than 9.5% reported with Dumon stent (Journal of Bronchology 1996;6:31). Another advantage was the very low incidence of granuloma formation, which is seen in nearly 15% of patients after a metallic stent placement (Chest 2003;124:1993–9). However, as reported for silicone stents, obstruction resulting from tenacious secretion remained a significant problem (Ann Thorac Surg 2003:76:167–74). Several limitations of the study should be pointed out. The study size was quite small. More importantly, the median duration of follow up was only 4.3 months. Low incidence of stent migration in this study could have resulted from short follow up. In this regard, it could be more valid to compare complication per patient per month when comparing 1 study with another. It is also important to point out that no patient in this study had benign airway stenosis. Thus, its role in patients with benign airway stenosis remains unclear. The delivery system used for stent placement needs further improvement. Finally, the stent placement requires rigid bronchoscopy and general anesthesia. This is a clear disadvantage over metallic stents that are routinely placed using flexible bronchoscopy under conscious sedation. The most ideal way to compare 2 devices used for similar purpose is a randomized prospective study. A direct comparison between Dumon and PolyflexTM stents is needed. Future studies should also directly compare PolyflexTM stents with metal stents for patients with malignant central airway compression. Until such data are available, the choice of airway stent will largely remain a matter of personal experience and preference.