Congenital Anomalies of the Tracheobronchial Tree: A Meta-Analysis and Clinical Considerations

Background The aim of this study was to determine the prevalence and anatomical features of major tracheobronchial anomalies (mTBAs). Methods Major electronic databases were systematically searched to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcome was the prevalence of mTBAs, specifically tracheal bronchus (TB) and accessory cardiac bronchus (ACB). Secondary outcomes included the origin and types of TB and ACB. Results A total of 27 studies (n=119,695 patients) were included. A TB was present in 0.99% (95% CI 0.67-1.37) of patients, while an ACB was present in 0.14% (95% CI 0.09- 0.20). The overall prevalence of TB was higher in imaging than in operative studies (1.81% vs 0.82%). It was also higher in pediatric (2.55%) than in adult studies (0.50%). Patients with other congenital anomalies were 15 times more likely to have a TB (OR=14.89; 95% CI 7.09-31.22). The most common origin of TBs was from the trachea (81.42%), primarily from the right side (96.43%). The most common origin of ACBs was from the intermediate bronchus (74.32%). ACBs terminated as blind-ending diverticulum in two-thirds of cases. Conclusions mTBAs are present in approximately 1% of the population, although the prevalence is higher in pediatric patients and those with accompanying congenital anomalies. Although rare, mTBAs can be associated with significant respiratory morbidities, and present challenges during airway management in surgical and critical care patients. Establishing a pre-operative diagnosis of these variations is essential for planning and implementing an appropriate airway management strategy to minimize attendant complications.
Congenital Anomalies, Tracheobronchial Tree, Meta-Analysis, Clinical