Benign tracheobronchial stenoses: Changes in short-term and long-term pulmonary function testing after expandable metallic stent placement

Purpose: To determine the short- and long-term improvement in airflow dynamics in patients undergoing tracheobronchial stent placement for benign airway stenoses. Methods: Twenty-two patients underwent 34 tracheal and/or bronchial stent placement procedures for benign airway stenoses and had the results of pulmonary function tests available. Stent placement indications included bronchomalacia after lung transplantation (n = 11), postintubation stenoses (n = 6), relapsing polychondritis (n = 2), and 1 each of tracheomalacia, tracheal compression, and histoplasmosis. Six patients underwent more than one stent placement procedure (range: 2-7 procedures). The mean forced expiratory volume in one second (FEV₁), forced expiratory flow rate in the midportion of the forced vital capacity curve (FEF_25-75), forced vital capacity, and peak flow (PF) rate obtained before stent placement were compared with those immediately after stent placement and with those measurements most remote from stent placement using the paired two-tailed t test. Results: All patients reported improved respiratory function immediately after stent placement. The mean FEV₁, FEF_25-75, and PF rate improved significantly (p < 0.001, p = 0.002, and p = 0.009, respectively) after stent placement. On long-term follow-up averaging 15 months after stent placement, these parameters declined despite patients' subjective sense of improvement. Segregating the population into transplant and nontransplant airway stenosis etiologies, however, FEF_25-75 and PF rate remained significantly improved (p = 0.045, p = 0.027, respectively), over the long term for the latter. FEV₁ increased after subsequent stent placements for patients receiving multiple stents. Conclusion: Stent placement for benign tracheobronchial stenoses provides significant immediate improvement in airflow dynamics. Long-term improvement in airflow obstruction may be expected, and additional stent placements may further improve pulmonary function.