Cardiovascular magnetic resonance of pulmonary artery growth and ventricular function after Norwood procedure with Sano modification.

D Scott Lim,Benjamin B Peeler,G Paul Matherne,Christopher M Kramer

doi:10.1186/1532-429x-10-34

D Scott Lim, Benjamin B Peeler + Show 2 more

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https://doi.org/10.1186/1532-429x-10-34

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Abstract

For hypoplastic left heart syndrome (HLHS), there have been concerns regarding pulmonary artery growth and ventricular dysfunction after first stage surgery consisting of the Norwood procedure modified with a right ventricle-to-pulmonary artery conduit. We report our experience using cardiovascular magnetic resonance (CMR) to determine and follow pulmonary arterial growth and ventricular function in this cohort.Following first stage palliation, serial CMR was performed at 1 and 10 weeks post-operatively, followed by cardiac catheterization at 4 – 6 months. Thirty-four of 47 consecutive patients with HLHS (or its variations) underwent first stage palliation. Serial CMR was performed in 20 patients. Between studies, ejection fraction decreased (58 ± 9% vs. 50 ± 5%, p < 0.05). Pulmonary artery growth occurred on the left (6 ± 1 mm vs. 4 ± 1 mm at baseline, p < 0.05) but not significantly in the right. This trend continued to cardiac catheterization 4–6 months post surgery, with the left pulmonary artery of greater size than the right (8.8 ± 2.2 mm vs. 6.7 +/- 1.9 mm, p < 0.05). By CMR, 5 had pulmonary artery stenoses initially, and at 2 months, 9 had stenoses. Three of the 9 underwent percutaneous intervention prior to the second stage procedure.In this cohort, reasonable growth of pulmonary arteries occurred following first stage palliation with this modification, although that growth was preferential to the left. Serial studies demonstrate worsening of ventricular function for the cohort. CMR was instrumental for detecting pulmonary artery stenosis and right ventricular dysfunction.

Highlights

Hypoplastic left heart syndrome is a congenital cardiac malformation involving hypoplasia of the ascending aorta, aortic valve atresia or stenosis, a hypoplastic left ventricle, and mitral atresia or hypoplasia[1]
Concern remains regarding the growth of the pulmonary arteries and right ventricular function with this surgical modification, which involves a ventriculotomy in the systemic right ventricle[9]
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Summary

Introduction

Hypoplastic left heart syndrome is a congenital cardiac malformation involving hypoplasia of the ascending aorta, aortic valve atresia or stenosis, a hypoplastic left ventricle, and mitral atresia or hypoplasia[1]. The first stage surgical palliation involves aortic arch augmentation, atrial septectomy, and an aorto-pulmonary shunt for pulmonary blood flow. A large number of institutions (including the University of Virginia) have switched to the "Sano" modification of the Norwood procedure, with improved short-term results in some, but not all centers[7,8]. This "Sano" modification of the Norwood procedure uses a valveless right ventricle-to-pulmonary artery conduit in place of the aorto-pulmonary shunt for pulmonary blood flow. Concern remains regarding the growth of the pulmonary arteries and right ventricular function with this surgical modification, which involves a ventriculotomy in the systemic right ventricle[9]. While echocardiography has become the primary imaging modality in pediatric cardiology, it is limited in its ability to image the branch pulmonary arteries after this surgical intervention

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