Clinical and radiographic predictors of successful therapeutic bronchoscopy for the relief of malignant central airway obstruction

Background: Malignant central airway obstruction (CAO) occurs in approximately 20-30% of patients with lung cancer and is associated with debilitating symptoms and poor prognosis. Multimodality therapeutic bronchoscopy can relieve malignant CAO, though carries risk. Evidence to guide clinicians regarding which patients may benefit from such interventions is sparse. We aimed to assess the clinical and radiographic predictors associated with therapeutic bronchoscopy success in relieving malignant CAO.

Methods: We reviewed all cases of therapeutic bronchoscopy performed for malignant CAO at our institution from January 2010-February 2017. Therapeutic bronchoscopy success was defined as establishing airway patency of > 50%. Patient demographics and baseline characteristics, oncology history, degree of airway obstruction, procedural interventions, and complications were compared between successful and unsuccessful groups. Univariate and multivariate logistic regression identified the significant clinical and radiographic predictors for therapeutic success. The corresponding simple and conditional odds ratio were calculated. A time-to-event analysis with Kaplan-Meier plots was performed to estimate overall survival.

Results: During the study period, 301 therapeutic bronchoscopies were performed; 44 (14.6%) were considered unsuccessful. Factors associated with success included never vs current smoking status (OR 5.36, 95% CI:1.45-19.74, p = 0.010), patent distal airway on CT imaging (OR 15.11, 95% CI:2.98-45.83, p < 0.0001) and patent distal airway visualized during bronchoscopy (OR 10.77, 95% CI:3.63-31.95, p < 0.001) in univariate analysis. Along with patent distal airway on CT imaging, increased time from radiographic finding to therapeutic bronchoscopy was associated with lower odds of success in multivariate analysis (OR 0.96, 95% CI:0.92-1.00, p = 0.048). Median survival was longer in the successful group (10.2 months, 95% CI:4.8-20.2) compared to the unsuccessful group (6.1 months, 95% CI:2.1-10.8, log rank p = 0.015).

Conclusions: Predictors associated with successful therapeutic bronchoscopy for malignant CAO include distal patent airway visualized on CT scan and during bronchoscopy. Odds of success are higher in non-smokers, and with decreased time from radiographic finding of CAO to intervention.