Management of aortopulmonary collateral arteries in Fontan patients: routine occlusion is not warranted.

Aortopulmonary collaterals (APCs) are common in patients undergoing a Fontan operation and are typically identified at cardiac catheterization. However, this is a qualitative approach and has important limitations. Previous catheterization-based studies of the effects of APCs have produced conflicting results. We have recently carried out a study directly measuring APC flow at the time of Fontan operation. This study showed that patients undergoing a Fontan operation have APC flow many-fold higher than controls, the extent of APC flow varies widely from patient to patient, APC flow does not increase in a linear fashion over time, and that APC flow has no detectable effect on the outcome of the Fontan operation. Thus, routine preoperative APC identification and occlusion does not appear indicated. A randomized study of preoperative coil occlusion could clarify this issue further. Aortopulmonary collaterals may exert a "threshold" effect, increasing risk in patients who also have other risk factors. Preoperative coil occlusion may decrease overall risk in such patients. Postoperative APC occlusion is a reasonable option in the patient with prolonged effusions after a Fontan operation, with no other correctable anatomic defects.