Background and Aim: This study aims to identify the factors influencing decision to proceed with fiberoptic bronchoscophy (FB) or rigid bronchoscophy (RB) when initial FB doesn't provide diagnosis, and it assesses outcomes of these procedures.

Methods: We performed a retrospective analysis of 158 patients who underwent diagnostic RB and 50 patients who underwent recurrent diagnostic FB among patients diagnosed with malignant airway tumours.

Results: There were no significant differences in age, comorbidities, or anticoagulant use between the groups. When initial FB procedures were analysed, rate of procedure failure was higher in RB arm due to central airway obstruction and intraprocedural complications, whereas rate of patients with inconclusive diagnosis was significantly higher in the recurrent FB arm (p<0.001). Likewise, patients in RB arm who underwent only airway assessment or bronchial lavage in first FB was higher (p<0.001). Recurrent FB arm experienced more complications during second procedure (p=0.005). Neuroendocrine tumours or tracheal lesions was higher in RB arm (p=0.005). RB arm patients also had higher hospitalization rates (59.5%) and longer stays (6.38 days) (p=0.001). Patients in the RB arm received significantly faster diagnosis (p<0.001).

Conclusion: Our findings suggest that, for patients with central airway lesions, particularly situated in trachea, due to risk of life-threatening complications such as hemorrhage during FB, considering that recurrent FBs can prolong the time to diagnosis and elevate the risk of complications, RB should be prioritized as diagnostic approach.