Coarctation of the Aorta

Abstract

Coarctation of the aorta is a congenital malformation in which a segment of the aorta is constricted. Classically, the narrowing occurs between the origin of the left subclavian artery and just distal to the site of insertion of the ductus or ligamentum arteriosum, involving only a relatively short segment of the aorta (1). While there may be any degree of narrowing of the aortic lumen at the site of the coarctation, there is usually a marked stenosis, or less frequently an atresia, in the clinically significant cases. Rarely, coarctation occurs in other areas (2–8), either proximally in the aortic arch or in the distal thoracic or abdominal aorta, and in some instances the involved segment may be of considerable length. Coarctation in individual cases carries a variable prognosis, but it has been clearly established that the overall life expectancy of a group of patients with coarctation is much shorter than that of the population at large (1, 9). Frequently, coarctation occurs in association with other serious cardiovascular malformations, and in such cases the life expectancy is generally quite short. In 13,000 consecutive autopsies at The Johns Hopkins Hospital, coarctation was noted in 24 instances, or roughly once per 500 autopsies. Twenty-one of these 24 coarctations were in stillborn or young infants, and almost invariably other significant cardiovascular anomalies were present. Of more clinical importance, although statistically less frequent, are cases in which the coarctation is either the only cardiovascular anomaly, or other anomalies, if present, are of a relatively minor nature. Here the life expectancy is greater, but still below that of the general population. The increased mortality in this group may be due to several causes. Classically there is hypertension proximal to the site of coarctation, with relative hypotension distally. Hence, the more common causes of death are cardiac failure and the other complications associated with hypertension. In a significant number of these patients a dissecting aneurysm may develop or rupture of the aorta may ensue. This usually occurs in the ascending aorta and rarely in the post-stenotic segment or adjacent intercostal arteries. Bacterial endocarditis and endarteritis, frequently superimposed upon an anomalous bicuspid aortic valve or the coarctation site, also occur in these patients, and an increased incidence of congenital intracranial aneurysms has been observed. Prior to 1945, coarctation was a clinical curiosity of academic interest only. In that year, Crafoord and Nylin (10) and Gross (11) independently reported successful resections of coarctations with re-establishment of the continuity of the aortic lumen. Since that time surgery has been performed on many cases of coarctation and the practicality and effectiveness of this method of treatment have been clearly demonstrated.