Early palliation of univentricular hearts with subaortic stenosis and ventriculoarterial discordance. The arterial switch option.

The optimal Fontan-type operation greatly depends on appropriate initial palliation. Several surgical techniques have been used in infancy to palliate patients with univentricular hearts, ventriculoarterial discordance, and subaortic stenosis. The two most common are pulmonary artery banding and Damus-Norwood procedures. Palliative arterial switch operation is another surgical option that was used in this early series of seven infants. The principle of this operation is to "switch" the subaortic obstruction into a subpulmonary obstruction; the coronary artery relocation on the large pulmonary trunk creates a harmonious aortic root and the connection of the rudimentary ventricular chamber to the pulmonary artery trunk creates a natural protection of the pulmonary vascular bed through the restrictive bulboventricular foramen. Seven infants with univentricular hearts, ventriculoarterial discordance, and subaortic stenosis underwent a palliative arterial switch operation. All infants had an associated aortic arch obstruction of various degrees, including one with interrupted aortic arch, five with coarctation with severe arch hypoplasia, and one with isolated arch hypoplasia. There were three with double-inlet left ventricle, three with tricuspid atresia, and one with transposition of the great arteries with ventricular septal defect and severe right ventricular hypoplasia. The subaortic obstruction was patent at birth in five patients who underwent a palliative switch operation in the first 2 months of life, and rapidly occurred following a previous neonatal pulmonary artery banding associated with arch repair in two patients who underwent a switch operation at 5 and 8 months of age, respectively. The operation includes aortic arch repair without prosthetic material, an atrial septectomy, and the arterial switch. An associated pulmonary shunt was required in five patients and a pulmonary artery banding in one. There was one early death in a patient with [S,L,L] anatomy and congenital atrioventricular block, leading to an early mortality of 14% (95% confidence limits: 1% to 28%). There was one late death. Four survivors are waiting for a Fontan-type procedure, and one survivor had satisfactory right ventricular growth. Early palliative arterial switch operation offers several advantages: reconstruction of a harmonious aortic root, natural protection of the pulmonary bed through the restrictive bulboventricular foramen, prevention of deleterious myocardial hypertrophy, and arch reconstruction without the introduction of a foreign material. This aggressive technique may provide a satisfactory palliation in infants with univentricular hearts and ventriculoarterial discordance, when the bulboventricular foramen/aortic anulus ratio is less than 0.8 or when the subaortic stenosis is severe enough to be associated with an arch obstruction.(ABSTRACT TRUNCATED AT 400 WORDS)