An Angiographic Predictor of Pulmonary Artery Stenosis After the Norwood-Sano Operation for Hypoplastic Left Heart Syndrome

The objective of this study was to determine angiographic predictors of future pulmonary artery stenosis (PS) in patients with hypoplastic left heart syndrome (HLHS) at the time of pre-stage 2 cardiac catheterization (PS2C). The Sano modification of the Norwood operation (NSO) for HLHS includes placement of a right ventricle-to-pulmonary artery (RV-PA) conduit. Branch PS is a recognized complication. Data from patients with HLHS who underwent NSO from 2005 to 2009 and who underwent PS2C were reviewed retrospectively. Nakata and McGoon indices were calculated in the traditional fashion, and modified Nakata and McGoon indices were calculated using the narrowest branch PA diameters. Thirty-three patients underwent NSO and 28 patients underwent PS2C. Mean follow-up was 35.8 ± 7.5 months. Ten (36 %) patients had significant left branch PS, with two requiring balloon angioplasty and eight requiring stent placement, a median of 15.2 months after PS2C (interquartile range 1.2, 32.8). The modified Nakata index was predictive of future intervention for left PS (receiver operating characteristic curve area under the curve 0.811), with a cut-off of 135 mm 2 /m 2 and a sensitivity of 100 % and specificity of 72.2 %. A modified Nakata index <135 mm 2 /m 2 at PS2C predicts future need for intervention on left-branch PS in patients with HLHS after the NSO. Surgical pulmonary arterioplasty at the time of stage 2 surgical palliation may obviate the need for future interventions.