[Severe respiratory failure secondary to vascular ring. Report of 2 cases].

Vascular compression of the airways is an infrequent situation that can be masked by inespecific respiratory symptoms. We present two cases with severe respiratory distress, that needed assisted mechanical ventilation in patients with overdistended lungs which improved when the endotracheal cannula was shifted near the carina. The chest radiograph showed hyperinflation of the lungs; an identation was demonstrated in the esophagogram and the endoscopy demostrated extrinsic esophagical compression. The angiogram documented double aortic arch in the first case and aberrant subclavia artery in the second. Vascular section and liberation of trachea and esophagus were performed with good outcome. The decrease of thoracic overdistention when the cannula was placed in the lower part of the trachea gave the clue to the diagnosis of vascular ring. A high index of suspicion is necessary for an early diagnosis.