Clinical Impact of Bacterial Colonization of the Airways during a Stent Trial in Patients with Excessive Central Airway Collapse

INTRODUCTION: Short-term airway stenting is performed in patients with severe excessive central airway collapse to assess whether airway stabilization leads to symptomatic improvement, thereby supporting surgical management. Interpretation of stent trials, however, may be confounded by complications such as bacterial colonization and granulation tissue formation. METHODS: This is a retrospective review of patients who underwent airway stenting at our institution between 2016 and 2022. We assessed the incidence of airway bacterial colonization, defined as conversion from a negative pre-stent to a positive post-stent bronchial wash (BW) culture, and the development of granulation tissue 7-14 days after stent placement, as well as their correlation with clinical outcomes. RESULTS: Pre- and post-stent bronchial washings were available from 101 stent trials. Airway bacterial colonization was observed in 40% of cases, with S. aureus accounting for 79%. Granulation tissue developed in 63% of cases, and it was significantly more frequent in silicone stents compared to uncovered self-expanding metallic airway stents (odds ratio [OR] = 16; 95% CI: 1.6-166.7, p = 0.02). It was also more frequent in patients with positive post-stent BW (adjusted OR = 2.6; 95% CI: 0.9-6.6, p = 0.05) and in cases of early colonization (adjusted OR = 2.98; 95% CI: 0.9-9.5, p = 0.065). Although colonization and granulation tissue occurred more frequently in patients with no clinical improvement, neither was independently associated with increased odds of a negative stent trial. CONCLUSION: Bacterial colonization, particularly with S. aureus, occurs early after stent deployment and is associated with granulation tissue formation. However, these complications did not significantly affect clinical stent trial outcomes.