A Simplified Approach to Predicting Reintervention in the Arterial Switch Operation.

We investigated patients with transposition anatomy suitable for the arterial switch operation (ASO) to evaluate a simplified approach to prediction of reintervention. A retrospective review was performed of 180 consecutive patients who underwent ASO from 2009 to 2018. Patients were classified as Category I (n = 122) d-transposition of great arteries (dTGA) + intact ventricular septum, Category II (n = 28) dTGA + ventricular septal defect (VSD) and Category III (n = 30) dTGA + Aortic arch obstruction (AAO) +/- VSD or Taussig-Bing Anomaly (TBA) +/- AAO. Outcomes included reintervention-free survival (using Kaplan-Meier estimates) and predictors of reintervention. Median follow up was 3.3 (interquartile range 1.7-5.8) years with no difference between categories(P = 0.082). There were 3 mortalities- 2 early (one each in Category I and II) and one late (in Category I). Reintervention-free survival for the whole group at 1, 3, 5 and 8 years was 94%, 91%, 90% and 86% respectively. Conventional criteria predicting reintervention included the presence of TBA(P = 0.0054) and AAO(P = 0.027). Low birth weight did not predict reintervention(P = 0.2). When analyzed by category, multivariable analysis showed that patients in Category III carried a high risk of reintervention [Hazard risk (HR) = 7.43, 95% confidence interval (CI)=(2.39, 23.11), P < 0.001], but so did those in Category II [HR=6.90, 95% CI = (2.19, 21.75, P < 0.001] when compared to Category I. Conventional risk factors for technical difficulty may not be the best predictors of reintervention. A simplified approach highlights Category II patients (dTGA + VSD) as being at substantial risk of re-intervention, and not part of a low risk cohort.