Persistence of third aortic arch with fourth aortic arch agenesis.

Abstract

SUMMARY This report describes a case in which a persistent third aortic arch connection partly palliated interruption of the aortic arch. The malformation occurred without other cardiovascular abnormality in a newbom infant in whom the principal diagnostic clinical finding was the absence of all peripheral pulses except for those of the right brachial and carotid arteries. Echocardiographic and angiocardiographic examination showed a continuation of the left internal carotid artery to the descending aorta by way of an arching communication.Interruption of the aortic arch is an unusual anomaly which most frequently occurs in association with other, often complex, cardiac malformations.1`4 In such cases the condition is invariably ductus dependent and is associated with a high mortality rate in infancy.23Only rarely does the abnormality occur as a solitary malformation that is not associated with other cardiac defects and is not ductus dependent.5`7 In such instances the circulation is adequately maintained, as in simple coarctation of the aorta, by collateral vessels.8We describe an infant with aortic arch interruption in whom the descending aorta was supplied only by a small persistent third aortic arch. Case reportWhen we first saw this three day old female infant (4300 g) she was in a state of shock. She was pale and mottled, tachypnoeic, and pulseless-although when she had been discharged from the nursery 36 hours before she had been thought to be healthy. After admission and stabilisation procedures, which included peritoneal dialysis for anuria and azotaemia, we found that only the right carotid and axillary pulses were palpable. Blood pressure in the right arm was 130/70 mm Hg. A systolic ejection murmur radiating only to the right carotid artery was heard.The electrocardiogram showed biventricular hy-

Persisting carotid duct and proximal external carotid artery agenesis in an adult

“…No segmental agenesis of any ECA was found then. In a different case of interrupted AA, the descending aorta was supplied only by a small persistent 3rd AA artery [ 6 ].…”

“…The 4th AA evolves in an asymmetrical fashion: on the left, it forms part of the arch of the aorta, between the left common carotid and the left subclavian arteries (SAs), and on the right, it forms the most proximal segment of the right SA [ 3 ]. The dorsal aorta between the entrance of the 3rd and 4th AAs is known as the carotid duct (CD, ductus caroticus ), and it normally regresses [ 3 , 5 - 8 ].…”