Modified Norwood procedure with a high-flow cardiopulmonary bypass strategy results in low mortality without late arch obstruction

Objective: The results of our modification of the stage I Norwood procedure , in which we use only autologous tissue to reconstruct the aortic arch, we re reviewed. A high-flow, low-pressure cardiopulmonary bypass protocol (wit h phenoxybenzamine), before and after a period of deep hypothermic circulat ory arrest, was used. Methods: Between 1993 and 1999, 59 patients, aged 1 to 353 days (median 4 d ays) and weighing 1.7 to 6.8 kg (median 3.2 kg), underwent a modified Norwo od procedure. The ascending aortic diameter ranged from 1.5 to 8 mm (median 3 mm). The modified Blalock-Taussig shunt was 3 mm in 21 patients (36%) an d 3.5 mm or larger in 38 patients (64%). Results: Deep hypothermic circulatory arrest and cardiopulmonary bypass tim es ranged from 15 to 64 minutes (median 37 minutes) and 44 to 144 minutes ( median 88 minutes), respectively. Early postoperative survival was 83%. By univariate analysis, early mortality was associated with an ascending aorti c diameter of 2.5 mm or less (P = .01). Weight, circulatory arrest and bypa ss times, diagnosis (hypoplastic left heart syndrome vs variant), shunt siz e, and date of the procedure did not affect survival. For a median followup period of 37 months (range 4-63 months), 42 (61%) patients underwent bidir ectional cavopulmonary shunts, 10 (17%) had Fontan operations, and 1 patien t underwent transplantation after a bidirectional cavopulmonary shunt. Eigh t patients subsequently died, for a 1-year actuarial survival of 72% (95% c onfidence interval: 60%-84%). Neoaortic arch obstruction was corrected in 3 patients (5%). Conclusions: At intermediate-term follow-up, our modification of the Norwoo d procedure together with our perioperative strategies has resulted in acce ptable outcomes with a low incidence of neoaortic arch obstruction. Patient s with a small ascending aortic diameter have emerged as a high-risk group, but a recent technical modification may improve the outlook for these pati ents.