Interarterial Coronary Anastomoses in Neonatal Pigs.

Abstract

The coronary arteries in the hearts of 29 neonatal pigs were examined for interarterial anastomoses by a postmortem technique of unilateral injection with a radio-paque mass (BaSO4 in gelatin), at a pressure of 150 mm Hg. The mass advances quite regularly into vessels with a diameter of 40[mu] and irregularly into still smaller ones. In none of the hearts was there any evidence of interarterial coronary anastomoses 40[mu] or larger. This was in contrast to the findings in human neonates which were born at or beyond term and which had been shown previously to be endowed with collaterals of varying grades in the majority of the cases. It is concluded that interarterial coronary anastomoses in neonatal hearts are not a general characteristic of the mammalian phylum but rather of man. Whether they are unique to the latter requires the study of neonatal hearts in other species.