Outcome in infants less than 3 kilograms for placement of saphenous venous homografts as systemic-to-pulmonary arterial shunts

Background: Establishing stable and adequate flow of blood to the lungs using a systemic-to-pulmonary arterial shunt in infants with low birth weight may involve significant morbidity and mortality. We reviewed our experience with this procedure in patients weighing less than 3 kilograms. Methods: Between June, 2002, and June, 2007, we placed systemic-to-pulmonary arterial shunts in 32 infants weighing less than 3 kilograms, the range being 1.8 to 2.86 kg, with a median of 2.5 kg. The median age at placement of the shunt was 8 days, with a range from 2 to 70 days. In 17 patients (53%), the anatomic defects had produced a functionally univentricular heart, while 15 (47%) had defects which permitted staging to biventricular repair. Patients staged to univentricular palliation were much more likely to have a circulation dependent on the arterial duct as compared with those staged to biventricular palliation (p < 0.001). The latter patients tended to have smaller pulmonary arteries, significantly the left pulmonary artery, which has a median diameter of 3.6 versus 2.0 mm, p = 0.01. In all patients a saphenous venous homograft was used as the conduit, its size ranging in diameter from 2.5 to 4 mm, with a median of 3.0 mm. Results: The overall hospital mortality rate for the entire cohort was 6.25%, with 2 patients dying. There was no significant difference between the two groups with regard to length of stay in intensive care or hospital. Follow-up has ranged from 3 months to 4.7 years, with a mean of 2.1 years). Of those with functionally univentricular hearts, 3 have subsequently died, along with 1 patient having a biventricular circulation (p = 0.3). All deaths occurred before takedown of the shunt. A trend toward longer survival was noted in those with biventricular as compared to functionally univentricular circulations (p = 0.06). Conclusion: Systemic-to-pulmonary arterial shunts can be constructed safely in infants with biventricular physiology born with low weight. Those having functionally univentricular circulations carry an increased rate of mortality for the period of shunting. Using the saphenous venous homograft permits use of smaller grafts, which does not significantly increase the risk for thrombosis or survival when compared to previous studies using polytetrafluoroethylene grafts.