A contemporary comparison of the effect of shunt type in hypoplastic left heart syndrome on the hemodynamics and outcome at stage 2 reconstruction

Objective: We compare the hemodynamics and perioperative course of shunt type in hypoplastic left heart syndrome at the time of stage 2 reconstruction and longer-term survival. Methods: We retrospectively reviewed the echocardiograms, catheterizations, and hospital records of all patients who had a stage 1 reconstruction between January 2002 and May 2005 and performed a cross-sectional analysis of hospital survivors. Results: One hundred seventy-six patients with hypoplastic left heart syndrome and variants underwent a stage 1 reconstruction with either a right ventricle-pulmonary artery conduit (n = 62) or a modified Blalock-Taussig shunt (n = 114). The median duration of follow-up is 29.1 months (range, 0-57 months). By means of Kaplan-Meier analysis, there is no difference in survival at 3 years (right ventricle-pulmonary artery conduit: 73% [95% confidence limit, 59%-83%] vs modified Blalock-Taussig shunt: 69% [95% confidence limit, 59%-77%]; P = .6). One hundred twenty-four patients have undergone stage 2 reconstruction (78 modified Blalock-Taussig shunts and 46 right ventricle-pulmonary artery conduits). At the time of the stage 2 reconstruction, patients with right ventricle-pulmonary artery conduits were younger (153 days [range, 108-340 days]; modified Blalock-Taussig shunt, 176 days [range, 80-318 days]; P = .03), had lower systemic oxygen saturation (73% [range, 58%-85%] vs 77% [range, 57%-89%], P < .01), and had higher preoperative hemoglobin levels (15.8 g/dL [range, 13-21 g/dL] vs 14.8 g/dL [range, 12-19 g/dL], P < .01) compared with those of the modified Blalock-Taussig shunt group. By means of echocardiographic evaluation, there was a higher incidence of qualitative ventricular dysfunction in patients with right ventricle-pulmonary artery conduits (14/46 [31%] vs 9/73 [12%], P = .02). However, no difference was observed in common atrial pressure or the arteriovenous oxygen difference. Conclusion: Interim analyses suggest no advantage of one shunt type over another. This report raises concern of late ventricular dysfunction and outcome in patients with a right ventricle-pulmonary artery conduit.