Left heart hypoplasia and neonatal aortic arch obstruction: Is the Rhodes left ventricular adequacy score applicable?

Objective: Although the influence of small left heart structures on outcome of a biventricular repair in neonatal critical aortic stenosis is well doc umented, little is known about its effect in neonates with aortic arch obst ruction and coarctation, The purpose of this study was to evaluate the infl uence of small left heart structures on early and late results of repair an d the ability to achieve a biventricular repair in neonates with coarctatio n and aortic arch obstruction. Patients: Neonates included in this study ha d a left ventricular adequacy score (as proposed by Rhodes and associates f or critical aortic stenosis) that would have predicted a need for a univent ricular (Norwood) repair. All were ductus dependent but had antegrade ascen ding aortic flow and a small but nonstenotic aortic valve (<30 mm Hg gradie nt). Twenty neonates aged 10 +/- 9 days were identified for the study with weights averaging 3.1 +/- 0.6 kg, Selected left heart measurements obtained by preoperative echocardiography included the following: aortic anulus 5.3 +/- 0.3 mm, mitral anulus 8.4 +/- 1.0 mm, transverse aortic arch 3.4 +/- 0 .6 mm, and left ventricular volume 25 +/- 4 mL/m(2). All patients underwent coarctation repair by resection and extended end-to-end anastomosis to enl arge the transverse arch as needed. Three patients underwent simultaneous p ulmonary artery banding because of a hemodynamically significant ventricula r septal defect, These 3 patients have subsequently had their defects succe ssfully closed without mortality. Results: There were no early or late deat hs at a follow-up of 38 +/- 16 months after the operation. Three patients ( 3/20, 15%) have had to undergo reintervention with balloon aortoplasty beca use of recurrent coarctation (gradient > 20 mm Hg) in 2 and resection of su baortic stenosis in 1. Late follow-up in the remaining patients reveals 1 w ith moderate subaortic stenosis (gradient = 43 mm Hg), 2 with mild aortic s tenosis (gradient <30 mm Hg), and 2 with mild to moderate mitral stenosis, At late follow-up, 16 patients (16/20, 80%) are completely free of symptoms and 4 (4/20, 20%) have mild residual symptoms. Conclusions: Biventricular physiology can be successfully achieved in neonates with small left heart s tructures and aortic arch obstruction with minimal mortality and excellent late functional results. Standard echocardiographic measurements used to pr edict the need for a univentricular repair in critical aortic stenosis are not valid for the neonate with aortic arch obstruction.