Abstract 2195: Factors Affecting Risk of Reintervention on the Aortic Arch After Balloon Dilation of Distal Aortic Arch Obstruction Following the Norwood Procedure
Balloon angioplasty (BA) is a safe and effective acute therapy for distal aortic arch obstruction (COA) after the Norwood procedure (NP). However, recurrent obstruction requiring repeat intervention is not uncommon. Our objective was to determine whether there are identifiable factors associated with increased risk of re-intervention in this patient population. All patients with hypoplastic left heart syndrome or related single ventricle anomalies that underwent BA as the initial intervention for COA following NP at our institution were retrospectively analyzed. From 3/85 to 10/08, 110 pts underwent BA and 106 had adequate follow-up data. The median age at initial BA was 4.4 mo. Patients who underwent BA during an unplanned catheterization (43; 41%) for symptomatic COA had an earlier age at presentation (median age of 2.9 vs. 5.1 months; p<0.0001) and were more likely to have significant ventricular dysfunction. The median follow-up was 4.6 yrs (0.5–21 yrs). The procedure was considered acutely successful in 88% of pts, with an average gradient reduction overall from 26 mmHg to 4 mmHg (p<0.0001) and COA diameter increase of 53% (p<0.0001). By Kaplan-Meier analysis, freedom from COA reoperation was 86% at 1 yr, and 84% at 5 yrs. Freedom from any reintervention was 70% at 1 yr, and 59% at 5 yrs. Independent variables associated with shorter freedom from reintervention by univariate analysis were: age ≤3 mo, moderate or worse ventricular dysfunction on pre-catheterization echocardiogram, higher post-BA peak gradient, smaller COA diameter after BA, lower COA index (ratio of COA diameter to descending aorta diameter) after BA, and unplanned catheterization. By multivariable Cox regression analysis, independent predictors of shorter freedom from reintervention were age ≤3 mo (p<0.001), higher post-BA peak gradient (p=0.017), and lower COA index after BA (p<0.001). We conclude that despite a high acute success rate, a significant proportion of patients treated with BA for COA after NP undergo reintervention during follow-up. The risk of arch reintervention is highest in patients who are younger at BA and have a less successful acute result.