Abstract
Tracheal bronchus is a congenital anatomical variant of patients with accessory bronchus in the right upper lobe deriving directly from the supracarinal trachea. Pre-operative consultation with the anesthesiologist is important for patient safety and can avoid adverse effects induced by endotracheal intubation. In this report, we described a case of tracheal bronchus in which general anesthesia was performed for video-assisted thoracoscopic surgery. We discussed some of the issues surrounding to complications in tracheal bronchus.
Keywords
Tracheal bronchus; Endobronchial tube; One-lung ventilation;
1. Introduction
Tracheal bronchus is a congenital anatomical variant of patients with accessory bronchus deriving directly from the supracarinal trachea. In general, these abnormalities are asymptomatic, but the abnormal bronchus lumen could be blocked by the endotracheal tube after general anesthesia. In this report, we describe a case of lung cancer receiving general anesthesia under video assisted thoracoscopic surgery (VATS). Endobronchial tube was routinely in placed, but one-lung ventilation was not satisfactorily achieved due to blockage of outlet of tracheal bronchus. We described the peri-operative scenarios when facing tracheal bronchus and proposed the solutions for these patients.
2. Case presentation
A57 year-old man patient, weight 87 kg and 183 cm in height, diagnosed as right lung adenocarcinoma was scheduled for wedge resection with VATS. He had hypertension under medication control with the American Society of Anesthesiologists (ASA) physical classification status II. Endobronchial tube (37Fr, left, Mallinckrodt, Covidien Inc., MA, USA) with one-lung ventilation was performed smoothly under fiberoptic bronchoscopy. After starting the surgery, right upper lobe failed to collapse. When checking with the fiberoptic bronchoscopy, superior lateral opening of right bronchus was not seen. Subsequent bronchoscopy showed a supernumerary tracheal bronchus, 2 cm above the carina, connecting apical segment of the right upper lobe which was compatible with the pre-operative computed tomography image (Fig. 1). We lowered the tracheal cuff pressure below 20 mmHg allowing the collapse of right upper lobe and switched the ventilator to pressure-control mode. The surgical procedure resumed with satisfactory one-lung ventilation and the surgery proceeded uneventfully.
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3. Discussion
Tracheal bronchus was first described by Sandifort in 1785and being an aberrant, accessory or ectopic bronchial branch arising directly from the lateral wall of the trachea above the carina with prevalence at least 1 in 5000 (range 0.1–2%).1–3 The most common types were supernumerary and displaced type with marked right sided predilection.2 Most patients are asymptomatic and identified incidentally from computed tomography of the chest. Tracheal bronchus is associated with recurrent infection and in children, respiratory distress. Occasionally, a tracheal bronchus may be intubated inadvertently during the administration of anesthesia or the treatment of respiratory failure. The incidental obstruction can cause atelectasis, post obstructive pneumonia or respiratory failure.3 Seriously, it may cause pneumothorax or inadequate ventilation if the endotracheal tube was intubated into the anomalous lobe accidentally. Bronchoscopy examination played a definite role in the tracheal bronchus detection.4 In this case, installation with low pressure or deflation of tracheal cuff ensured adequate deflation of surgical side (right) with tracheal bronchus. In cases of surgical side opposite to the tracheal bronchus, selective bronchial blocker to the lesioned lung would be an appropriate alternative.5
4. Conclusion
It is important to be aware of complications among patient with tracheal bronchus receiving general anesthesia. Pre-operative chest computed tomography and bronchoscope examination is important and specific management during one-lung ventilation might be needed to avoid adverse outcomes.
Conflicts of interest
None.