Bidirectional cavopulmonary connection without additional pulmonary blood flow in patients below the age of 6 months

The bidirectional cavopulmonary connection (BCPC) has shown excellent results as an intermediate step towards permanent palliation in functional single ventricle morphology. The optimal timing of the BCPC, though, remains unclear. This investigation focuses on results in a subgroup of patients under 6 months of age.

Between 2001 and 2006, 124 patients received a BCPC followed by an extracardiac total cavopulmonary connection (TCPC). Review of 84 angiograms before BCPC and before TCPC allowed for analysis of haemodynamic findings and measurement of the diameters of the pulmonary arteries. Twenty-eight patients were below 6 months of age at the time of BCPC (group 1), whereas 56 were above 6 months of age (group 2).

Age at time of BCPC was 4.6+/-1 months (range 2-6 months) for group 1, compared to 16.6+/-17 months (range 6-98 months) for group 2 (p<0.001). The most common diagnosis was a hypoplastic left heart syndrome (HLHS) in 16 patients (19%). The rate of patients with HLHS was higher in group 1 than in group 2 (p=0.006). There was a significant increase in oxygen saturation from 73+/-11% prior BCPC to 83+/-6% prior to TCPC in group 1 (p=0.001) and from 75+/-8% to 83+/-6% in group 2 (p=0.003) respectively. The mean pulmonary artery pressure decreased from 18+/-10 mmHg before BCPC to 9+/-2 mmHg before TCPC in group 1 (p<0.001) and from 14+/-7 mmHg to 8+/-3 mmHg in group 2 (p=0.001). The pulmonary artery diameters increased in both groups between BCPC and TCPC, except for the left pulmonary artery in group 2. Nevertheless, the pulmonary arteries remained too small for the given body surface area.

Early unloading of the functional univentricular heart by means of BCPC without additional pulmonary blood flow is feasible even in very young patients. Favourable haemodynamics and reasonable increase in pulmonary artery size allow for good condition prior to completion to TCPC.