The Fate of the Left Ventricular Outflow Tract Following Interrupted Aortic Arch Repair.

Objectives: To examine the probability of left ventricular outflow tract (LVOT) reintervention following interrupted aortic arch (IAA) repair in neonates with LVOT obstruction (LVOTO) risk. Methods: This retrospective multicenter study included 150 neonates who underwent IAA repair (2003-2017); 100 of 150 (67%) had isolated IAA repair (with ventricular septal defect closure) and 50 of 150 (33%) had concomitant LVOT intervention: conal muscle resection (n = 16), Ross-Konno (n = 7), and Yasui operation (n = 27: single-stage n = 8, staged n = 19). Demographic and morphologic characteristics were reviewed. Factors associated with LVOT reoperation were explored using multivariable analysis. Results: Concomitant LVOT intervention was more likely in neonates with type B IAA, bicuspid aortic valve, aberrant right subclavian artery, smaller aortic valve annulus, and ascending aorta dimensions. On follow-up, five-year freedom from LVOT reoperation was highest following Ross-Konno (100%), 77% following Yasui (mainly for neo-aortic regurgitation), 77% following isolated IAA repair (mainly for LVOTO), and 47% following IAA repair with concomitant conal resection, P  = .033. While all patients had low peak LVOT gradient at time of discharge, those who had conal resection developed higher gradients on follow-up ( P  = .007). Ross-Konno and Yasui procedures were associated with higher right ventricular outflow tract (RVOT) reoperation. In the cohort following isolated IAA repair, aortic sinus Z score was associated with LVOT reoperation. Conclusions: Both Yasui and Ross-Konno operations effectively mitigate late LVOTO risk. The highest risk of reintervention for LVOTO was associated with conal muscle resection while the lowest risk is associated with Ross-Konno. The RVOT reoperation risk in patients who had Ross-Konno or Yasui does not seem to affect survival.