Historical Considerations The first description of aortic coarctation is generally attributed to Johann Freidrich Meckel, the Prussian anatomist, who presented the case of an 18-yearold female to the Royal Academy of Sciences of Berlin in 1750 At postmortem, she was found to have an aorta that was “so narrow that its diameter was smaller by half than that of the pulmonary artery, which it should have exceeded or at least have equaled in caliber.” Some argue, however, that it was Morgagni who should be given priority.1 As pointed out by Craigie,2 a more recognizable description was published in Desault's Journal de Chirurgie in 1791 According to Craigie, Monsieur Paris, Prosector of the Amphitheatre at the Hotel-Dieu, described, in the winter of 1789, the postmortem of “a very emaciated woman about 50 years old.” In addition to recognizing that the thoracic arteries were thicker and more tortuous than normal, he gave the following description “The part of the aorta which is beyond the arch, between the arterial ligament and the first inferior intercostal, was so greatly narrowed that it had at most the thickness of a goosequill Hence, in taking apart its walls, which had not decreased in this place, there remained only a small lumen The part of the vessel which was above the constriction was slightly dilated; the distal part was of normal calibre The most careful dissection did not reveal either in the aorta or in its vicinity any cause to which this extraordinary condition could be attributed.” With regard to interruption of the aortic arch, which can be considered as the severest end of the spectrum of aortic coarctation (see Fig 45.1), Celoria and Patton3 classified this lesion into alphabetic subtypes (Fig 45.2) FIG 45.2 Categorization of interruption of the aortic arch introduced by Celoria and Patton In each pattern, the descending component of the aortic arch is supplied through the persistently patent arterial duct Interruption at the aortic isthmus had been the first pattern described, being recognized in 1778 by Stiedele in Vienna.4 The more common variety, with interruption between the left common carotid and left subclavian arteries, was described some 40 years later by Siedel.5 The least frequent variant, with interruption between the brachiocephalic and left common carotid arteries, was not seen until 1948.6 Prevalence and Etiology Aortic coarctation accounts for 7% of liveborn children with congenitally malformed hearts,7 with a higher incidence in stillborn infants.8 The overall incidence is in the region of 1 in 12,000, with a slightly increased occurrence in males.9 Coarctation is generally said to show multifactorial inheritance, although genetic factors are clearly important in certain groups The lesion was found in 10% of a large Danish series of patients with Turner syndrome, albeit with a lower incidence in patients with mosaicism or those with structural anomalies of the X chromosome.10 Inheritance has also been reported as an autosomal dominant trait.11 It is now known that cells migrating from the neural crest populate the aortic arches, and a 22q11.2 deletion is well recognized as being associated with interruption between the left common carotid and subclavian arteries.12 Coarctation is also found with 22q11.2 deletion, supporting an association with abnormal migration of cells from the neural crest.13 There is a reported seasonal incidence, with paucity of males born between April and August but without identification of an exogenous etiologic agent.14 Interruption of the aortic arch accounts for just over 1% of cases of so-called critical congenital cardiac disease.9 As already emphasized, there is a known association between deletion of chromosome 22q11.2, specifically DiGeorge syndrome, and interruption between the left common carotid and subclavian arteries.12 As many as one-third of those with the DiGeorge phenotype have an interruption of this type; conversely, two-thirds of those with interruption between the left common carotid and subclavian arteries have DiGeorge syndrome.12 Taking those with interruption as a group, interruption between the left common carotid and subclavian arteries accounts for between 50% and 75% of such cases, interruption as the isthmus for 40%; interruption between the carotid arteries is rare.15,16 Interruption as an isolated lesion is also rare.17 The combination of congenital absence of the aortic isthmus, patency of the arterial duct, and ventricular septal defect, however, is very common, occurring in 75% of patients with interruption.18 The incidence is equal between the genders.15