Collateral circulation in coarctation of aorta in infancy and childhood.

Forty patients with coarctation of the aorta under the age of 2 years were studied, and a well-developed collateral circulation was present when the coarctation was severe and the sole lesion. In those with an associated congenital heart lesion a collateral circulation was seen in rather more than half. It is suggested that in many patients, the collateral circulation develops during fetal or early postnatal life.