Current outcomes of the Glenn bidirectional cavopulmonary connection for single ventricle palliation

The Glenn bidirectional cavopulmonary connection (BCPC) is an established procedure in multistage palliation of various single ventricle (SV) anomalies. We aimed to report the current outcomes following BCPC and to examine risk factors affecting survival and progression to the next palliation stage. Two hundred and twenty-seven consecutive children with variable SV pathologies underwent BCPC from 2002 to 2007. Competing risk analyses were performed to model events after BCPC (death and transition to Fontan) and subsequently after Fontan (death and cardiac reoperation) and to examine the associated risk factors for poor outcomes. There were 139 males (61%) with a median age of 7.6 months [interquartile range (IQR) 6.0-10.8] and median weight of 6.2 kg (IQR 5.2-7.4). Forty-three patients (19%) had primary BCPC and 184 (81%) had prior palliation: aortopulmonary shunt (APS) (n = 83), Norwood (n = 55), pulmonary artery (PA) band (n = 48), atrial septectomy (n = 25), PA reconstruction (n = 14), anomalous pulmonary venous connection repair (n = 7) and other (n = 8). Predominant ventricle was left morphology (n = 122, 54%), right morphology (n = 95, 42%) and two equally developed ventricles (n = 10, 4%). Twenty-six patients (12%) had bilateral superior vena cava. Concomitant surgery included atrioventricular valve repair (n = 18), PA augmentation (n = 80), percutaneous Fontan preparation (n = 34) and other (n = 24). Competing risk analysis showed that 5 years following BCPC, similar to 17% have died, 76% have undergone Fontan and 7% were alive awaiting or not qualifying for Fontan. On multivariable analysis, risk factors for death prior to Fontan were pulmonary vascular resistance (PVR) index of > 3 WU/M-2 [hazard ratio (HR) 3.9, P = 0.001], dominant right ventricle (HR 2.1, P = 0.03) and prior palliation other than APS (HR 0.4, P = 0.03). Competing risk analysis showed that 3 years following 172 Fontan operations, similar to 10% have died, 6% have undergone further cardiac surgery and 84% were alive and free from reoperation. Overall, 8-year survival following BCPC was only 74%. Despite established selection criteria and improved surgical technique and medical management, there is a continuous failure and attrition risk following BCPC. Outcomes are influenced by underlying cardiac anomaly; patients with dominant left ventricle (i.e. tricuspid atresia, double inlet left ventricle) having the best survival while those with dominant right ventricle (i.e. hypoplastic left heart syndrome, double outlet right ventricle with heterotaxy) having the worst survival. Increased PVR remains a significant factor affecting mortality.