An unusual aortic coarctation.

From the time that coarctation of the aorta was first described by Morgagni in 1771 (cited by Evans, 1933) until 1944, when Crafoord and Nylin (1945) and Gross (1945) independently managed the lesion successfully by a surgical procedure, the lesion remained a curiosity which challenged the descriptive powers of anatomists and pathologists and which proved a diagnostic exercise for clinicians. The literature during that period was confined to descriptions of the clinical and pathological features of the disease and its natural course, and to statistical evaluation of its various facets. Boniet (1903) offered a classification which recognized an infantile and an adult type of coarctation. Fawcett (1905), Blackford (1928), and Evans (1933) recorded the necropsy incidence of the disease, which varied from 0-6 to 0-14%. A constant finding in these series was that males were affected twice as commonly as females. In an analysis of 200 necropsy cases, Abbott (1928) recorded that only 28 had been diagnosed in life. Bonnet's original classification has been modified by Hudson (1965), who relates infantile coarctation to a persistent ductus arteriosus, recognizes pre-ductal and post-ductal varieties, and includes an extreme form in which the whole ascending aorta is involved. This last-mentioned variety is a form of the hypoplastic left heart syndrome and is generally incompatible with life. Adult coarctation is classified in relation to the subclavian artery, and the usual type occurs beyond the origin of the left subclavian artery. Coarctation at or proximal to the left subclavian artery is uncommon. Bayley and Holoubek (1940) described a case of coarctation proximal to the left subclavian artery and were able to compare this with only 15 previously recorded examples. Since their description a number of cases of coarctation at this level have been described. In Fig. 1 are illustrated the varieties of infantile and adult coarctation, including the last-mentioned anomaly. The rare varieties of coarctation previously reported are illustrated in Figure 2. Fawcett (1905) described coarctation of the aorta distal to the left subclavian artery in a patient in whom there was an aberrant right subclavian artery which arose proximal to the coarctation (Fig. 2a). Similar anomalies have since been described by East (1932) and by DeBoer, Grana, Potts, and Lev (1961). Gross (1950) quotes a case described by Stephens in which an aberrant right subclavian artery arose distal to the site of aortic coarctation (Fig. 2b). This anomaly has been recorded by others (Griffith, Oblath, and Jones, 1955; English, 1965). An anomalous right subclavian artery which arose at the site of the coarctation and was associated with a left innominate artery proximal to the coarctation was described by Partyka et al. (1958) (Fig. 2c). Aortic coarctation proximal to both the left subclavian artery and an anomalous right subclavian artery was first described by McGregor and Medalie (1952) (Fig. 2d). Since then D'Abreu, Aldridge, Astley, and Jones, (1961), Dodrill and Benson (1962), and Nathoo (1965) have described similar cases. That described by McGregor and Medalie (1952) had an associated small persistent ditctus arteriosus. In the same year Brynolf, Crafoord, and Mannheimer (1958) recorded an example of coarctation of the aorta with a right aortic arch and a left descending aorta with the coarctation proximal to both subclavian arteries (Fig. 2e). Efskind and Sanderud (1955) described a patient with a double aortic coarctation, the coarcted segments being proximal and distal to a vessel from which left subclavian and left common carotid arteries arose (Fig. 2f). Clarke and Dodrill (1952) described a 'functional' coarctation; a single vessel was the source of both common carotid arteries and the right subclavian artery (itself a not uncommon anomaly), and during systole the distal lip of the origin of the left subclavian artery was displaced caudally and produced the syndrome of aortic coarctation (Fig. 3).