The implications of a tracheal bronchus on one-lung ventilation and fibreoptic bronchoscopy in a patient undergoing thoracic surgery: a case report

Due to its anatomical complexity, a tracheal bronchus has important clinical implications for one-lung ventilation (OLV). We present a case of successful OLV in a patient with a high a type I (i.e., high take-off) tracheal bronchus. This anomaly presented unusual fibreoptic bronchoscopic (FOB) views that were difficult to discern from the normal carinal bifurcation. A 35-yr-old male presented for posterior basal segmentectomy of the left lower lobe under video-assisted thoracoscopy. The preoperative chest radiography was reported as normal, but a computed tomography scan of the chest revealed a right upper lobe tracheal bronchus. The inlet of the tracheal bronchus was located high above the carina, and the distal trachea had significant narrowing. Because the main trachea was divided into a tracheal bronchus and a distal trachea with similar diameters and with an acute angle of divergence, FOB views of the tracheal bronchus take-off appeared similar to the normal carinal bifurcation. Moreover, the actual carina had an atypical appearance with the main bronchi shifted laterally and a blunted carinal ridge. As a result of this atypical tracheobronchial anatomy, we used an Arndt endobronchial blocker system instead of a double-lumen tube (DLT) for right-sided OLV. One-lung ventilation was satisfactory throughout the uncomplicated operation. Careful preoperative assessment of tracheobronchial anatomy is imperative in order to choose an appropriate method of OLV and prevent potential complications. In a type I tracheal bronchus with a narrowed distal trachea, a bronchial blocker may have advantages over the conventional DLT in achieving OLV.