PURPOSE: 1] To compare the incidence of granulation tissue formation for different airway stents. 2] To measurethe clinical consequences of granulation tissue.
METHODS: Patients who underwent airway stent placement for malignant central airway obstruction in the last 5 years were reviewed. Standard definitions were used. Time to stent obstruction due to granulation tissue for different stents was compared using a Cox model.
RESULTS: 212 stent insertion bronchoscopies were performed in 183 patients. Median age was 59 years (interquartile range 51-68) in 99 males and 84 females. A total of 235 stents were placed. Of these, 58 (25%) were in the trachea, 55 (24%) were in the right main stem extending into the bronchus intermedius, 27 (11%) were in the bronchus intermedius, 62 (26%) were in the left main bronchus and 33 (14%) were at the carina (Y stents). ). Of the 226 stents analyzed, 137 (58%) were Ultraflex, 36 (15%) were Alveolus and 53 (23%) were silicone stents. A total of 43 cases developed granulation tissue (incidence rate 0.0022 events/patient stent day). The risk of granulation tissue formation was higher with silicone stents as compared to Ultraflex stents (HR 3.30, 95% CI 1.6-6.9, p=0.002). Similarly, the risk was higher with alveolus stents (HR 2.67, 95% CI 1.03-6.95, p=0.04). Stent lumen obstruction > 50% occurred in 18 of 43 cases (43%). Post-obstructive pneumonia as a consequence of granulation tissue occurred in 14 of 43 cases (33%). 5 (12%) of 43 cases required either non-invasive ventilation or mechanical ventilation. 16 (37%) stents were removed due to the effects of granulation tissue formation.
CONCLUSIONS: Silicone and Alveolus stents are more prone to granulation tissue development as compared to Ultraflex stent in patients with malignant central airway obstruction. The consequences of granulation tissue are significant including pneumonia and respiratory failure.
CLINICAL IMPLICATIONS: Prospective studies are required to understand the relationship between granulation tissue formation and stent type in patients with airway stents.
DISCLOSURE: The following authors have nothing to disclose: Archan Shah, Pushan Jani, Carlos Jimenez, George Eapen, Mona Sarkiss, Rodolfo Morice, David Ost
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