Maladaptive aortic properties after the Norwood procedure: An angiographic analysis of the Pediatric Heart Network Single Ventricle Reconstruction Trial

Abstract

Objectives: Aortic arch reconstruction in children with single ventricle lesions may predispose to circulatory inefficiency and maladaptive physiology leading to increased myocardial workload. We sought to describe neoaortic anatomy and physiology, risk factors for abnormalities, and impact on right ventricular function in patients with single right ventricle lesions after arch reconstruction.

Methods: Prestage II aortic angiograms from the Pediatric Heart Network Single Ventricle Reconstruction trial were analyzed to define arch geometry (Romanesque [normal], crenel [elongated], or gothic [angular]), indexed neoaortic dimensions, and distensibility. Comparisons were made with 50 single-ventricle controls without prior arch reconstruction. Factors associated with ascending neoaortic dilation, reduced distensibility, and decreased ventricular function on the 14-month echocardiogram were evaluated using univariate and multivariable logistic regression.

Results: Interpretable angiograms were available for 326 of 389 subjects (84%). Compared with controls, study subjects more often demonstrated abnormal arch geometry (67% vs 22%, P < .01) and had increased ascending neoaortic dilation (Z score 3.8 ± 2.2 vs 2.6 ± 2.0, P < .01) and reduced distensibility index (2.2 ± 1.9 vs 8.0 ± 3.8, P < .01). Adjusted odds of neoaortic dilation were increased in subjects with gothic arch geometry (odds ratio [OR], 3.2 vs crenel geometry, P < .01) and a right ventricle-pulmonary artery shunt (OR, 3.4 vs Blalock-Taussig shunt, P < .01) but were decreased in subjects with aortic atresia (OR, 0.7 vs stenosis, P < .01) and those with recoarctation (OR, 0.3 vs no recoarctation, P = .04). No demographic, anatomic, or surgical factors predicted reduced distensibility. Neither dilation nor distensibility predicted reduced right ventricular function.

Conclusions: After Norwood surgery, the reconstructed neoaorta demonstrates abnormal anatomy and physiology. Further study is needed to evaluate the longer-term impact of these features.

Trial registration: ClinicalTrials.gov NCT00115934.

Keywords: Norwood; aorta; coarctation.

Conflict of interest statement

Conflict of Interest Statement: C.P.H., J.S.L., and K.D.H. receive support from the National Center for Advancing Translational Sciences of the National Institutes of Health (UL1TR001117). All other authors have nothing to disclose with regard to commercial support.

Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

A, Arch geometry in the SVR trial cohort (neoaorta) and single ventricle controls. The P value shown (<.001) is for individual comparisons. The Romanesque arch has a smooth semicircular form with an approximate 1:1 height to width ratio, the crenel arch has a rectangular form with width greater than height, and the gothic arch has an angular appearance with height greater than length. B, Representative examples of neoaortic morphology and geometry. i, Romanesque (normal) arch geometry; ii, crenel arch geometry; iii, ascending neoaortic dilation; iv, recoarctation.

Figure 2

A, Variability was seen in neoaortic arch geometric classification between PHN centers. B, Reconstructed neoaortas had a greater aortic index when compared with the single-ventricle control population. Significant center variability was seen again. PHN, Pediatric Heart Network; LV, left ventricle; Asc, ascending; Ao, aorta; Desc, descending.