Anatomic and non-anatomic substrates in infants with two ventricles undergoing aortic arch repair

Objectives: We sought to examine the relative importance of surgical lesion complexity versus the presence of genetic/syndromic/extracardiac anomalies (GSAs) in determining survival, morbidity or need for reinterventions following repair for aortic arch hypoplasia.

Methods: A single-centre, retrospective cohort study of infants undergoing biventricular aortic arch repair via sternotomy from 2010 to 2021 was conducted. Survival analysis was performed using Kaplan-Meier methods, with additional Bayesian survival modelling for subgroups. Composite morbidity comprised respiratory, renal, neurologic, or sepsis-related complications.

Results: Of 83 included infants, n = 13/83 (15.7%) had complex repairs; 27/83 (32.5%) were GSA+. Operative mortality was significantly higher in GSA+ versus GSA- patients (18.5% vs. 1.8%; p = 0.01), though not for complex versus non-complex repairs. Overall 10-year Kaplan-Meier survival was 86.7%. Bayesian modelling suggested equivalent post-discharge attrition in non-complex/GSA+ and complex/GSA- patients, with the poorest outcomes in complex/GSA+ patients; non-complex/GSA- patients had 100% survival. GSA+ patients exhibited higher composite morbidity (44.4% vs. 7.1% in GSA- p < 0.001), with their mode of death seemingly related to a high incidence of respiratory and neurological morbidity, notably in Dandy-Walker syndrome. The 10-year freedom from arch reinterventions was 87.7%; neither complexity, GSA status, nor post-repair peak arch velocity predicted the need for arch reinterventions.

Conclusions: Whilst anatomic complexity may have been somewhat neutralised as a risk factor for operative mortality, in contrast to GSA+ status, there is further post-discharge attrition attributable to complexity or GSA+ status, with additive risk effects. Morbidity directly related to certain syndromes underlies some of this risk. Non-anatomic substrates represent a persistent limitation to outcomes of surgical aortic arch repair in infants.