Clinical Outcomes, Program Evolution, and Pulmonary Artery Growth in Single Ventricle Palliation Using Hybrid and Norwood Palliative Strategies

Background Hybrid strategies for single ventricle palliation may differ from Norwood strategies in terms of anatomic and physiologic growth stimuli to the pulmonary arteries (PA), hemodynamics, resource utilization, and survival. Few studies have directly compared these strategies. Methods In all, 58 patients underwent Norwood (Blalock-Taussig shunt; n = 39) or hybrid (n = 19) single ventricle palliation (2004 to 2007). Hemodynamics, PA morphology, hemodynamics, resource utilization, and survival were reviewed. Results At pre–stage 2 evaluation, there were nonsignificant trends toward lower ventricular end-diastolic pressure, higher mixed venous saturation, and larger Nakata and lower lobe indices in the hybrids. Mean PA pressures were not different between groups. Four Norwood patients (10%) underwent transplantation before stage 2 palliation. Forty-two patients underwent stage 2 palliation (bidirectional cavopulmonary shunt or stage 2 hybrid (aortic arch reconstruction and bidirectional cavopulmonary shunt). Requirement for PA plasty, postoperative CVP, stage 2 survival, and 1-year survival were similar between groups. Combined (stage 1 plus stage 2) intubation time, intensive care unit time, and hospital length of stay was shorter for hybrids in comparison with Norwood survivors ( p < 0.05). Comparison of resource utilization at the time of arch reconstruction (Norwood procedure or stage 2 hybrid), demonstrated a time-related trend toward improvement (weak negative correlation: intubation, rho = −0.386, p = 0.172; intensive care unit stay, rho = −0.487, p = 0.077; hospital stay, rho = −0.429, p = 0.126) in the hybrid group, but not in the Norwood group. Conclusions Hybrid palliation does not have a significant adverse impact on PA development, with comparable PA growth and hemodynamics. The demonstration of equivalent survival, diminished hospital utilization, and trends indicating ongoing refinement of the hybrid strategy warrants a prospective randomized trial.