Hypoxemia and pulmonary hyperperfusion due to systemic collateral arteries after total repair of transposition of the great arteries.

Two cases of hypoxemia and pulmonary hyperperfusion due to large bronchial collateral arteries after total repair of simple transposition of the great arteries (TGA) are presented. Pulmonary hyperperfusion was not present before total repair. Hypoxemia and congestive heart failure quickly abated after surgical ligation of these enlarged bronchial collateral arteries. The patients were totally corrected quite late (at 21 and 22 months respectively) by current standards. It is suggested that: (1) large bronchial collaterals may develop in patients with simple TGA especially if total correction is delayed; (2) preoperative angiographic evaluation of patients with simple TGA who come in for total correction late, should include special aortic root injection to exclude the presence of bronchial collaterals; (3) hypoxemia and pulmonary congestion after total correction of TGA by atrial switch procedure (Mustard or Senning) may in fact be due to bronchial collaterals and not obstruction of the pulmonary veins.