Balloon dilatation of simple aortic coarctation in neonates and infants.

Twenty-one infants with isolated native coarctation of aorta (mean age 4.73 +/- 2.85 months, range 15 days-12 months) underwent balloon dilatation in the last seven years at our institute. Seven of them were less than three months and 14 were older than three months. The procedure was successful in relieving the coarctation (gradient < 20 mm Hg) in five of seven (71%) infants up to three months and 12 of 14 (86%) above three months. Peak systolic gradients decreased from 70.8 +/- 20.1 to 14.5 +/- 11 mm Hg in the younger infants and from 47.7 +/- 11.7 to 11.4 +/- 9.9 mm Hg in infants above three months. Post-dilatation angiogram showed the coarctation segment to be equal to the isthmus in both the groups, 0.96 +/- 0.14 and 0.96 +/- 0.12 respectively. One three months old infant died immediately after a successful dilatation possibly due to coronary embolism, and another neonate died a few days later of unrelated pre-existing septicemia. Left ventricular function improved in all the infants with depressed preprocedure ejection fraction. Restenosis defined as peak instantaneous echo-Doppler gradient above 20 mm Hg with a significant narrowing on two-dimensional echocardiography occurred in all the five infants up to three months over a period of 1 to 12 months. Follow-up information over a period of 4 to 24 months was available in 11 of 14 older infants of which three had restenosis. Gradients progressively increased in all the four infants (2 of either group) with an initial partially successful result. A small isthmus relative to the descending thoracic aorta at diaphragm is an important predictor of restenosis/inadequate result. This discrepancy was seen much more in smaller infants, post-dilatation coarctation index being 0.68 +/- 0.11 vs 0.81 +/- 0.16 (p = 0.07). Four of the infants underwent a repeat successful dilatation. Balloon dilatation is safe and effective in infants above three months of age. In infants up to three months the procedure is feasible and leads to improvement in left ventricular function, but restenosis occurs rapidly in all of them.