Abstract 2601: Staged Left Ventricular Recruitment in Patients with Hypoplastic Left Heart Disease and Borderline Left Ventricle

Abstract

Although hypoplastic left heart (LH) disease occurs as a spectrum, the initial management in neonates with hypoplastic LH syndrome and a borderline left ventricle (LV) is dichotomous: single ventricle palliation (SVP) or biventricular (BiV) repair. Once SVP is pursued, rarely are attempts made to salvage the LH or achieve subsequent BiV conversion. Staged LV recruitment may be achieved in selected patients following SVP by a surgical strategy consisting of relief of inflow and outflow tract obstructions, resection of endocardial fibroelastosis (EFE), and promotion of flow through the LV. All patients with hypoplastic LH and borderline LV (LV end diastolic volume [LVEDV] z scores between −5 and −0.5) who underwent stage 1 procedure between 1995 and 2007 were retrospectively analyzed. Patients with ventricular septal defects and valvular atresia were excluded. Those who underwent LV recruitment (Group 1, n=27) were compared to those who did not (Group 2, n=30). LV recruitment consisted of one or more procedures for EFE resection (27/27), mitral (MV) valvuloplasty (16/27), aortic (AoV) valvulo-plasty (21/27), atrial septal defect restriction (13/27), and augmentation of pulmonary blood flow (12/27). Predictors of increase in LVEDV were determined by multivariable analysis. Mean initial z scores for LVEDV, AoV, and MV for the entire cohort were −2.8 ± 1.2, −2.9 ± 1.0, and −2.0 ± 1.3 respectively, with no significant differences between groups. Stage 1 mortality was 2/27 in Group 1 and 2/30 in Group 2. LVEDV, AoV, and MV z scores increased significantly over time in Group 1, whereas they declined in Group 2 (slope of LVEDV z score regression = 0.76/yr vs. −0.06/yr, P <0.001), with restriction of the atrial septum at any stage being the strongest independent predictor of increase in LVEDV ( P <0.001). To date, BiV conversion has been achieved in 5/27 Group 1 patients and none in Group 2 ( P =0.015). In patients with borderline LH disease who undergo a stage I procedure during the neonatal period, it is possible to increase LH dimensions using a strategy of AoV and MV valvuloplasty, EFE resection, and modulation of LV filling. In a subset of patients, this strategy has allowed establishment of biventricular circulation.