Intermediate results following complex biventricular repair of left ventricular outflow tract obstruction in neonates and infants

Abstract

Objectives: Although the majority of infants with severe left ventricular outflow tract obstruction (LVOTO) can be managed with balloon or surgical aortic valvotomy, a more complex biventricular repair may be required in a subset of infants with multi-level obstruction, failure of or complication to prior intervention. In the presence of normal left ventricle size and inflow, the Ross procedure is applied in patients with/without ventricular septal defect (VSD), while the Yasui procedure is applied only in those with VSD. We report mid-term outcomes in a single institution.

Methods: Thirty-five consecutive infants with severe LVOTO underwent complex biventricular repair using the Ross (n=21) or Yasui (n=14) procedure. Outcomes were studied using univariate and multivariable parametric models.

Results: The Ross procedure was done at a median age of 88 days (8-353 days), in 8/21 (38%) neonates. As many as 12/21 (57%) had prior catheter and/or surgical intervention. Concomitant procedures included arch reconstruction (n=4/21, 19%) and mitral valve repair (n=6/21, 29%). In addition, 14/21 (67%) had annular enlargement (modified Ross-Konno). Haemodynamic manifestation was isolated obstruction (n=10/21, 48%) or mixed obstruction/regurgitation (n=11/21, 52%). Survival was 81% at 1 month, 70% at 1 year and 63% at 5 years. In multivariable regression models, factors associated with increased risk of mortality included neonatal surgery (p=0.007), mitral valve repair (p=0.02), longer cross-clamp time (p=0.003), and postoperative extracorporeal membrane oxygenator (ECMO) (p=0.004). Freedom from any cardiac re-operation was 86% at 5 years. The Yasui procedure was done at a median age of 36 days (7-207 days), 6/14 (43%) in neonates. As many as 13/14 procedures (93%) were primary and one procedure followed a prior single-stage Norwood palliation. A total of 10/14 (71%) had critical aortic stenosis and 4/14 (29%) had atresia. All patients had VSD, and 11/14 (79%) required concomitant arch reconstruction. Survival was 79% at 1 month and 5 years while 5-year freedom from re-operation was 57%.

Conclusions: Complex biventricular repair can be performed in neonates and infants with severe LVOTO with mid-term survival that is equivalent to that published following balloon or surgical aortic valvotomy. Associated lesions are significant factors that influence outcome and proper patient selection may further improve survival. In neonates with concomitant arch obstruction and VSD, the Yasui operation may be associated with lower early mortality risk. Neonates with concomitant mitral valve pathology may be better served with single ventricle palliation strategy.