Experience With Biventricular Intervention for Neonates With Mitral Valve Abnormalities in the Setting of Critical Left-Side Heart Obstruction

Background. Mitral valve (MV) abnormalities may adversely impact outcomes after biventricular repair of critical left-side heart obstruction. Methods. Neonates with left-side heart obstruction and MV abnormality (anatomically abnormal or hypoplastic but otherwise normal [Z-score -1.5 to -4]) who underwent biventricular repair from December 2005 to December 2012 were included. Institutional selection criteria determined suitability for biventricular repair. Primary outcomes (death, univentricular conversion, pulmonary hypertension) and secondary outcomes (reinterventions) were compared between hypoplastic and anatomically abnormal MV groups. Freedom from reintervention was determined by Kaplan-Meier analysis. Results. There were 55 patients with hypoplastic MV (n = 35) or anatomically abnormal MV (n = 20). Initial interventions included arch repair (n = 45, with ventricular septal defect closure in 7), balloon aortic valvuloplasty (n [8), and Ross-Konno operation (n = 2). None had initial MV intervention. Follow-up was available on 46 patients (84%) at a median of 25 months. Primary outcome occurred in 6 patients (13%): 2 deaths, 1 univentricular conversion, and 3 pulmonary hypertension. Twenty-six patients (57%) underwent 36 follow-up interventions, often for arch obstruction (n = 26). All follow-up MV interventions (n = 4) occurred in patients with anatomically abnormal MV. Median reintervention-free time was 7.3 months. Freedom from reintervention at 6, 9, and 12 months was 65%, 38%, and 27%, respectively. Neither MV size nor anatomy was associated with primary outcome. Conclusions. Using our selection criteria, most neonates with left-side heart obstruction and MV abnormalities who underwent biventricular repair had reasonable survival with complex reintervention needs in early follow-up. The MV reintervention occurred in patients with abnormal anatomy, not hypoplasia. (C) 2015 by The Society of Thoracic Surgeons