In neonatal Ebstein’s anomaly of the tricuspid valve, prolonged ductal patency in patients without anatomic pulmonary valve atresia can be deleterious. Circular shunts may develop in patients with different degrees of pulmonary and tricuspid insufficiency. Closure of the arterial duct may result in haemodynamic improvement in particular scenarios. The transcatheter approach is a valuable closure alternative despite some technical difficulties in large-sized arterial ducts and low birth weight neonates. Herein, we report on two consecutive term newborns with Ebstein’s anomaly and large arterial ducts in whom mechanical stimulus of the arterial duct during failed attempts of transcatheter closure led after two days to definitive closure followed by good clinical outcomes.

We present an uncommon challenging case of spontaneous thrombosis of the arterial duct and with alloimmune thrombocytopaenia in a full-term newborn who presented with respiratory distress, hypoglycaemia dispersed petechiae on the trunk, and significant haemorrhage of the umbilical venous catheter.

In the accompanying article appearing in this issue of the Journal, Prabhu and his colleagues, from Bengalaru in India, describe their experience with patients having a right aortic arch. They discuss the fact that the anomalous arrangements they encountered can all be interpreted on the basis of the hypothetical double arch proposed by Edwards. They point to the fact that interpretation of the developmental changes underscoring the production of the double arch is currently confused by reference to the so-called Rathke diagram, in which six sets of arteries are shown extending through the mesenchyme of the pharyngeal arches. As the authors point out, Graham and his associates have now shown that the alleged fifth set of pharyngeal arches do not exist. Based on our own observations, we endorse this statement. It means that new explanations must now be provided for the lesions previously described on the basis of persistence of the alleged artery of the fifth pharyngeal arch. We have previously claimed to have observed such an artery in a human fetus. We now believe, on the basis of our latest findings, that our earlier observation is better explained on the basis of presence of a collateral channel. We suggest that the so-called “fifth arch arteries” are themselves then best explained either on the basis of existence of such collateral channels, or remodelling of the aortic sac, which is the manifold, during development, that gives rise to the pharyngeal arch arteries.

Persistence of the embryonic “fifth aortic arch” in postnatal life is a rare, enigmatic – and at times controversial – condition, with variable anatomical forms and physiological consequences. First described in humans over 40 years ago by Van Praagh, the condition was labelled the “great pretender” by Gerlis 25 years later, because of its apparent propensity to mimic anatomically similar structures. Despite many subsequent case reports citing the condition, the true developmental origin of these structures remains unresolved, and has been the subject of debate among embryologists for more than a century. A persistent fifth aortic arch has been defined as an extrapericardial structure, arising from the ascending aorta opposite or proximal to the brachiocephalic artery, and terminating in the dorsal aorta or pulmonary arteries via a persistently patent arterial duct. This description may therefore encompass various anatomical forms, such as a unilateral double-lumen aortic arch, an unrestrictive aortopulmonary shunt, or a critical vascular channel for either the systemic or pulmonary circulation. The physiological properties of these vessels, such as their response to prostaglandins, may also be unpredictable. In this article, we demonstrate a number of cases that fulfil the contemporary definition of “persistent fifth aortic arch” while acknowledging the embryological controversies associated with this term. We also outline the key diagnostic features, particularly with respect to the use of new cross-sectional imaging techniques.

Although usually shown in embryology textbooks, the presence of the fifth pair of pharyngeal arch arteries has long been controversial. To the best of our knowledge, six pairs of bilaterally symmetrical arteries developing within the pharyngeal arches are yet to be found in any mammalian or avian species. Collateral channels between the distal ends of the fourth and sixth arch arteries, in contrast, have been found in up to half of all developing mouse embryos. In only one human embryo, again to the best of our knowledge, has a channel been found that extends from the aortic sac to the dorsal aorta, and hence qualifies as an arch artery. Despite these confounding factors in terms of the developmental heritage of the fifth arch arteries, the purported channels are invoked with increasing frequency to describe various lesions discovered in the setting of the congenitally malformed heart. Persistence of the artery of the fifth arch was initially proposed to explain double-barrelled aorta. It was subsequently proposed to account for various systemic-to-pulmonary channels feeding the pulmonary circulation in the setting of pulmonary atresia. It has also been claimed to persist so as to explain abnormal branching of the brachiocephalic arteries from the aortic arch. In the light of the ongoing doubts concerning the existence of the arteries of the fifth arch themselves, we have reviewed the various descriptions of purported fifth arch arteries within the world literature. We have then sought to validate the descriptions on the basis of our own understanding of development, for this purpose providing images of the remoulding arch arteries in the mouse so as to substantiate our conclusions. While accepting that our own interpretations are speculative, we suggest that more convincing alternative explanations can be advanced to account for the majority of lesions currently interpreted on the basis of persistence of the arteries of the fifth arches. Although the interpretations do not necessarily change the therapeutic approaches to the channels, appropriate description is important in terms of their classification.

We present a case of double aortic arch with a predominant right and a double arterial duct detected by echocardiogram in a 28-week gestation foetus. The first evaluation revealed that both arches were perfused; the 1-month postnatal echocardiogram showed the closure of both arterial ducts and the partial obliteration of the left aortic arch between the left subclavian artery and the dorsal aorta. In our case, the postnatal obliteration of the left arch in a double aortic arch was probably due to the closure of the left-sided arterial duct.

Pulmonary atresia with intact septum is itself a rare congenital abnormality, albeit known to be associated with other cardiac and non-cardiac anomalies. The combination of right- and left-sided obstructive lesions, however, is extremely rare. We describe a patient having pulmonary atresia with intact septum associated with aortic coarctation, which to the best of our knowledge has been previously described on but one occasion.

Deletion of chromosome 22 and DiGeorge syndrome are associated with inappropriate development of the neural crest and abnormalities of the ventricular outflow tracts. Bis-diamine induces comparable cardiac anomalies by inhibiting the normal development of the neural crest. In order to clarify the effect of damage on the development of the neural crest and its relation to the cardiac anomalies, the effects of giving a small dose of bis-diamine were compared with the results of a large dose of bis-diamine. A small dose of bis-diamine (20 mg), therefore, was administered to 40 pregnant rats on the 10th day of pregnancy, and 330 fetal hearts were studied on the 21st day with the rapid whole-body freezing method. Intracardiac anomalies were rare, being found in only 55 fetuses. The anomalies discovered were: aberrant origin of the subclavian artery in 88 fetuses, right aortic arch in 26 fetuses, interruption of the aortic arch in 23 fetuses, and high location of the aortic arch in 8 fetuses. Anomalies of the arterial duct were also common; with a vascular ring formed by the aortic arch and contra-lateral duct being seen in 21 fetuses, isolation of the right subclavian artery associated with either bilateral ducts (9 fetuses) or a right duct and absent left duct (9 fetuses), absent duct with tetralogy of Fallot in 7 fetuses, and with common arterial trunk in one fetus. In conclusion, a small dose of bis-diamine induced extra cardiac anomalies of the aortic arch and arterial duct, indicating a greater susceptibility of the aortic arch and the duct to inappropriate formation of the neural crest cells in the early developing embryo. Clinically, these anomalies of the aortic arch and the duct should be searched for in all patients suspected of having deletion of their 22nd chromosome.

To check a possible mechanism for residual patency of arterial ducts closed with umbrellas, we studied retrospectively all 25 implantations of the Rashkind device carried out in our institution. In all instances, the smaller umbrella had been used. Residual patency occurred in 40%. There was a significant correlation (p<0.001) between the way the umbrella was rotated and the rate of residual patency. In the larger subgroup, the residual patency was 75% when two arms were pointing towards the aortic blood stream. In contrast, when only one arm pointed upwards, there was only one patient (8.3%) with residual shunt. This potential precipitating mechanism should be considered when implanting the Rashkind devices in future.

A hydropic neonate, born at 28 weeks gestation, died 45 minutes after birth. Autopsy showed an abnormally long and tortuous arterial duct which wasoccluded by laminated thrombus. The right heart chambers and the left ventricle were dilated, but there was no other structural cardiac abnormality. Apart from the abnormal ductal morphology, there was no evident cause for the intrauterine thrombosis of the arterial duct, which appeared to be the sole cause of fatal heart failure.

We describe an infant with congenitally corrected transposition, ventricular septal defect and severe pulmonary stenosis. The heart occupied a midline position. Extension of ductal tissue had resulted in occlusion of the left pulmonary artery. As far as we are aware, this is the first report of an association of coarctation of the left pulmonary artery with corrected transposition.

Doppler echocardiography revealed a characteristic pattern of flow in four neonates with postductal coarctation of the aorta. There was a continuous left-to-right shunt at the level of the patent arterial duct with simultaneous measurement of a large gradient across the site of coarctation with a pandiastolic gradient and prolonged pressure half-time. Infusions of prostaglandin produced no hemodynamic improvement, and urgent surgical correction was performed.

A 5-week-old male, born with an aneurysm of the arterial duct forming part of a vascular ring, underwent successful surgery without cardiopulmonary bypass. From our search of the literature, it seems, that this combination of rare congenital malformations has not previously been reported.

Aneurysm of the arterial duct is well described when presenting in infants and children. The case we present were detected by fetal echocardiogram in late pregnancy, indicating the congenital nature of this lesion and excluding widely accepted explanations of the pathogenesis. Spontaneous closure may occur more frequently than the literature suggests. We recommend a conservative approach in asymptomatic patients.

To assess the prevalence and role of the arterial duct in hearts with incomplete development of the aorticopulmonary septum, 110 autopsy specimens, comprising 100 examples of common arterial trunk and 10 cases with aorticopulmonary window, were studied. In addition to intracardiac malformations, these specimens were analyzed to determine the side of the aortic arch, the presence and location of any interruption of the arch, the presence of any anomaly of origin and course of the subclavian arteries, and the status of the arterial duct. The arterial duct was present in 33 cases, absent in 63 cases and undetermined in four cases with common arterial trunk. The duct provided an essential pathway for flow in the 20 cases with interrupted aortic arch, and in two cases with interruption of the proximal portion of the left pulmonary artery. The presence of the duct in 11 cases, in functional terms, was not essential. In the 10 hearts with aorticopulmonary window, the duct was present in eight. It was an obligatory part of the circulatory pathways in three cases where the aortic arch was interrupted. The prevalence of non-obligatory ducts was 71% in hearts with aorticopulmonary window compared to 15% in hearts with common arterial trunk. The prevalence of the duct in cases with aorticopulmonary window suggests this lesion is a later developmental defect. The functional role of an arterial duct in these hearts should be properly assessed in the clinical situation.

Clinical and Doppler echocardiography were performed in 65 patients who had undergone ligation of the arterial duct between January 1978 and December 1991. Of the patients, 12 (18%) patients had residual patency as demonstrated by color Doppler, while three (4.6%) of these had continuous murmurs. There was no association between residual patency and the age at surgery, the weight at surgery or the follow-up interval.