OBJECTIVES To analyse the results of hybrid palliation of hypoplastic left heart syndrome (HLHS) patients and its variants with an emphasis on the long-term fate of the pulmonary arteries. METHODS We analysed 28 neonates (2006-11) with HLHS and its variants, who underwent bilateral pulmonary artery banding, patent ductus arteriosus (PDA) stenting and balloon atrial septostomy using a true hybrid approach. Median age and weight were 4 (0-36) days and 3 (1.9-3.7) kg respectively. Diagnoses included 23 HLHS and 5 variants. The fate of all surviving branch pulmonary arteries (PA) after a hybrid approach were compared with their counterparts in 29 Norwood I survivors (2002-11). RESULTS Four of 28 hybrid procedures needed to be converted to a Norwood procedure. Mortality after stage I hybrid palliation was 3/24 (12.5%). All 21 acute survivors underwent a comprehensive stage II at a median age of 4 (2.3-5.7) months, without any mortality (0%). Eleven of 21 comprehensive stage II survivors have undergone extracardiac Fontan; including 1 who underwent a rescue Fontan at 7 months of age and died (1/11: 9%). While 18/21 (86%) needed branch PA intervention in the hybrid group during the median follow-up duration of 39 (10-81) months, 9/29 (31%) needed the same in the Norwood group during a median follow-up duration of 58 (16-128) months (P < 0.001). Eight of 21 (38%) needed stenting [all on the left pulmonary artery (LPA)] in the hybrid group vs 5/29 (17%) in the Norwood group (P = 0.097). Ten of 21 (48%) patients had surgical/catheter intervention on both branch PA in the hybrid group vs 2/29 (7%) in the Norwood group (P = 0.001). Pre-Fontan Nakata index was significantly better in the Norwood group 206 (118-406) compared with the hybrid group 153 (56-230) mm2/m2 (P = 0.01). The comparable lower lobe indices were 149 (103-333) and 137 (45-178) mm2/m2 (P = 0.04), respectively. CONCLUSIONS Hybrid approach can be pursued with a low mortality. However, the high frequency of catheter and/or surgical interventions, and the sluggish growth of the branch PA pre-Fontan need innovative solutions. A comparison of the neurodevelopmental outcome for the hybrid vs the Norwood cohort would define the role of the hybrid strategy in the treatment of HLHS and its variant
