Early experience with a modified Norwood procedure using right ventricle to pulmonary artery conduit.

BACKGROUND: A recent modification to the Norwood procedure involves the use of a right-ventricle (RV) to pulmonary artery (PA) conduit to provide pulmonary blood flow for patients with hypoplastic left heart syndrome (HLHS). This modification is thought to provide more stable hemodynamics by avoiding the diastolic "run-off" that occurs with a Blalock-Taussig shunt.
METHODS: We reviewed our experience with the first 11 patients undergoing the RV-PA conduit modification of the Norwood operation and compared their outcomes with those of the preceding 22 patients who underwent a conventional Norwood procedure.
RESULTS: Between July 1999 and March 2002, 33 patients with HLHS underwent the Norwood procedure at a median age of 5 days (range 1 to 31 days). Aortic atresia was present in 28 (85%). No significant difference was noted between the RV-PA (n = 11) and conventional Norwood (n = 22) groups with respect to measures of morbidity such as duration of mechanical ventilation or hospital stay. Patients who underwent the conventional Norwood procedure did have significantly lower diastolic blood pressure in the early postoperative period (38.4 +/- 4.4 mm Hg versus 49.5 +/- 4.3 mm Hg, p = 0.001). The operative and 1-year survival rates were 81% and 81%, respectively, for patients with the RV-PA modification, which was not significantly different from those of patients who underwent the conventional procedure, 81% and 73% (p = 1.00 and p = 0.36). Two patients developed a pseudoaneurysm of the RV infundibulum after placement of RV-PA conduit. Four sudden deaths occurred after hospital discharge, all occurring in the conventional Norwood group.
CONCLUSIONS: The RV-PA conduit modification of the Norwood procedure results in excellent early survival. By avoiding low diastolic blood pressure this modification may provide superior perfusion to the coronary vascular bed and potentially reduce the risk of sudden unexpected death.