[Unexpected intraoperative respiratory distress; an infant who developed tracheomalacia and fatal aortoesophageal fistula due to unrecognized vascular ring].

Vascular rings cause respiratory distress and dysphasia by tracheoesophageal compression. We present a case of tracheomalasia and fatal aortoesophageal fistula due to unrecognized vascular ring. A 3-month-old (7.3 kg) boy underwent V-P shunt operation under sevoflurane anesthesia. The trachea was intubated easily using vecuronium with a relatively large-size tube with a diameter of 4.5 mm, because of leakage. Gastric intubation was difficult. During scrubbing of the head, an asthma-like respiratory distress suddenly occurred. The condition responded poorly to ventilatory support and pharmacological interventions. Although intraoperative fiberscopy through the tracheal tube and chest X-ray showed no tracheobroncheal abnormality, postoperative fiberscopy revealed a tracheomalacia. Adequate ventilation was possible only when the tip of the tracheal tube was located between the stenotic part and the tracheal carina. On the 9th postoperative day, during respiratory management with a tracheal tube, fatal esophageal hemorrhage broke out. Postmortern examination revealed a double aortic arch with tracheal stenosis and aortoesophageal fistula. The nasogastric tube may have led to fistula formation by compression of the esophageal wall against an anomalous vessel. When anesthetists encounter an infantile respiratory distress, even in perioperative period, vascular rings should be taken into consideration.