Balloon arterioplasty of recurrent coarctation after the modified Norwood procedure in infants

Coarctation of Be reconstructed aorta after the modified Norwood procedure for hypoplastic left heart syndrome is a relatively common occurrence that can have significant adverse effects. From 1992-98, 65 infants with hypopla stic left heart syndrome or variants thereof underwent a modified Norwood p rocedure. Of the 50 survivors of Stage I palliation, 10 (20%) were subseque ntly diagnosed with clinically significant obstruction of the aortic arch a t a median age of 5.1 months. Eight of these patients underwent coarctation balloon arterioplasty. All 8 patients underwent successful dilation of the coarctation, with a decrease in the pressure gradient from 43 +/- 20 to 4 +/- 5 mmHg and an increase in aortic diameter at the site of obstruction fr om 3.5 +/- 0.5 to 7.0 +/- 1.0 mm (both P < 0.001). There was also a signifi cant increase in lower extremity systolic blood pressure. Although there wa s no immediate increase in cardiac output after dilation in most patients, ventricular function was improved in 3 patients within 24-48 hr of the proc edure and in all but 2 at the most recent follow-up (median 2 years). Two p atients developed bradycardia during wire placement that required cardiopul monary resuscitation. Two others died suddenly during the follow-up period. All surviving patients have undergone subsequent palliative procedures; no ne have required repeat intervention for arch obstruction. We found a 20% i ncidence of coarctation in survivors of the modified Norwood procedure. Bal loon arterioplasty is effective in relieving this obstruction, and should b e carried out promptly upon diagnosis to minimize its deleterious effects o n ventricular function. Balloon dilation, however, should be considered a h igh-risk procedure in these fragile infants, and special attention must be given to cardiovascular support. (C) 2000 Wiley-Liss, Inc.