Morphology of the native ascending aorta after the Norwood procedure for aortic atresia: impact on survival and right ventricular dysfunction.

ABSTRACT

OBJECTIVES: Our goal was to evaluate the impact of variable morphology of the native ascending aorta after the Norwood I procedure in patients with hypoplastic left heart syndrome/aortic atresia on long-term survival and systemic right ventricular dysfunction. METHODS: Of 151 survivors of the Norwood procedure for hypoplastic left heart syndrome/aortic atresia at our institution between January 2001 and December 2020, we included patients with available and measurable aortograms prior to stage II palliation. The diameter of the native ascending aorta, the length of the native ascending aorta and the angle between the native ascending aorta and the proximal pulmonary artery were measured. We investigated the impact of these morphologic parameters on mortality and on right ventricular dysfunction (defined as at least moderate). RESULTS: Angiograms were available for 78 patients. The median diameter of the native ascending aorta was 3.2 mm (2.6-3.7), the median length of the native ascending aorta was 15.4 mm (13.3-17.9) and the median angle between the native ascending aorta and the proximal pulmonary artery was 44° (35°-51°). During the median follow-up of 6.5 years, 8 (10%) patients died and systemic right ventricular dysfunction occurred in 19 patients (24%). No significant association between aortic morphology and mortality could be detected. Right ventricular function was negatively affected by a larger angle between the native ascending aorta and the proximal pulmonary artery [odds ratio 1.07 (1.01-1.14), P = 0.02]. CONCLUSIONS: In survivors of the Norwood procedure for hypoplastic left heart syndrome/aortic atresia with available angiograms, no significant association between native aortic morphology and mortality could be demonstrated after stage II palliation, within the scope of this limited study. A larger anastomosis angle between the native ascending aorta and the proximal pulmonary artery emerged as a risk factor for right ventricular dysfunction.