Hybrid Procedure for Neonates With Hypoplastic Left Heart Syndrome at High-Risk for Norwood: Midterm Outcomes

Background: Hybrid procedure offers patients with severe congenital heart disease an alternative initial procedure to conventional surgical reconstruction. We report the midterm outcomes of a cohort of neonates who had a hybrid procedure for variants of hypoplastic left heart syndrome because they were at high risk for the Norwood procedure.

Methods: Between December 2005 and January 2013, 41 neonates underwent bilateral pulmonary artery banding followed by ductal stenting by means of a sternotomy at a median age of 6 days (range, 2 to 18 days) and weight of 2.6 kg (range, 1.5 to 3.7 kg). Thirty-five patients had hypoplastic left heart syndrome, and 6 patients had critical aortic stenosis with hypoplastic left ventricle. Primary indications for the hybrid procedure were low birth weight in 17 patients, hypoplastic left ventricle with the possibility of later biventricular repair in 6 patients, intact or near-intact atrial septum in 5 patients, and poor patient condition in 13 patients. Echocardiographic, angiographic, operative, and clinical data were reviewed. Outcomes were summarized with descriptive statistics and risk factors for mortality identified.

Results: All but 6 patients had an antenatal diagnosis, and 24 patients were from other congenital cardiac centers. Nine patients had perioperative balloon aortic valvuloplasty, 1 patient had fetal balloon aortic valvuloplasty, and 17 patients had intervention to their atrial septum (41.4%). There were 9 inpatient deaths (21.9%) and 4 interstage deaths (9.8%) after the hybrid procedure. Twenty-eight patients subsequently underwent either the Norwood procedure (11 patients), combined stage I and II (14 patients), or biventricular repair (3 patients). No patient had heart transplantation. Among the patients who had combined stage I and II as a second procedure after the hybrid procedure, there were 2 early deaths, 1 late death before the Fontan, and 1 late death after the Fontan completion after combined stage I and II. All patients who had subsequent Norwood procedure were midterm survivors. Three of the 4 patients who had biventricular repair were midterm survivors. Overall survival was 56.1% at a median follow-up of 32.0 months. By univariate analysis, patient factors, intact or near-intact atrial septum, and aortic atresia were associated with nonsurvival.

Conclusions: Hybrid procedure as an alternative to the Norwood procedure offers good midterm survival in patients deemed at high risk for neonatal reconstruction.