Type III persistent fifth aortic arch in association with transposition of great arteries and pulmonary atresia—An unreported case

Imaging of the spectrum of abnormal systemic arterial supply to the lungs using dual-source CT

Abnormal systemic arterial supply to the lungs can be seen in various congenital and acquired diseases. Identification and characterisation of aberrant vascular supply is essential for further management and treatment. Multidetector computed tomography (CT) with its multiplanar capabilities and volume-rendering techniques provides precise information regarding the anatomy and spatial relationship of arterial vascular channels. The following concise review elucidates the characteristic imaging findings of conditions in which systemic arteries are seen supplying the lung parenchyma on dual-source CT.

Persistent fifth arch anomalies - broadening the spectrum to include a variation of double aortic arch vascular ring

Fifth arch anomalies are rare and complex and frequently misdiagnosed or mistaken for other entities. We report a double arch vascular ring that is thought to consist of right fourth arch and left fifth arch components, a previously undescribed persistent fifth arch variant. The currently recognized spectrum and classification of fifth arch vascular anomalies are expanded along with illustrative images to justify the proposed changes. Reviewing and expanding the classification of fifth arch anomalies to include a double arch ring variant will promote recognition, correct diagnosis and appropriate management of these anomalies.

Clarifying the anatomy of the fifth arch artery

The artery allegedly forming in the fifth pharyngeal arch has increasingly been implicated as responsible for various vascular malformations in patients with congenitally malformed hearts. Observations from studies on developing embryos, however, have failed to provide support to substantiate several of these inferences such that the very existence of the fifth arch artery remains debatable. To the best of our knowledge, in only a solitary human embryo has a vascular channel been found that truly resembled the artery of the fifth arch. Despite the meager evidence to support its existence, the fifth arch artery has been invoked to explain the morphogenesis of double-barreled aorta, some unusual forms of aortopulmonary communications, and abnormalities of the brachiocephalic arteries. In most of these instances, the interpretations have proved fallible when examined in the light of existing knowledge of cardiac development. In our opinion, there are more plausible alternative explanations for the majority of these descriptions. Double-barreled aorta is more likely to result from retention of the recently identified dorsal collateral channels while abnormalities of brachiocephalic arteries are better explained on the basis of extensive remodeling of aortic arches during fetal development. Some examples of aortopulmonary communications, nonetheless, may well represent persistence of the developing artery of the fifth pharyngeal arch. We here present one such case - a patient with tetralogy of Fallot and pulmonary atresia, in whom the fifth arch artery provided a necessary communication between the ascending aorta and the pulmonary arteries. In this light, we discuss the features we consider to be essential before attaching the tag of "fifth arch artery" to a candidate vascular channel.

How frequent is the fifth arch artery?

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.

Coarctation of persistent 5th aortic arch: first report of catheter-based intervention

Persistent 5th aortic arch, originally called double-lumen aortic arch, is a rarely reported cardiac developmental anomaly that results in systemic-to-systemic or systemic-to-pulmonary shunting. When this malformation occurs, other intracardiac defects are almost always present. We report the case of a 7-month-old girl who presented with a heart murmur; she was found to have an interrupted 4th aortic arch and coarctation of a persistent 5th aortic arch, with no other defects. To our knowledge, this is the 3rd report of a pediatric patient with this condition in isolation, and the first report of its diagnosis and treatment by means of cardiac catheterization and balloon angioplasty.

Persistent fifth aortic arch diagnosed by echocardiography and confirmed by angiography: Case report and literature review

Persistent fifth aortic arch is a rare congenital anomaly that can be discovered incidentally or at postmortem exam. It can be associated with major congenital heart malformations involving the systemic or the pulmonary circuits. It usually has no clinical significance but can be either, beneficial as in systemic outflow tract obstructions or cause hemodynamic compromise when associated with a significant left to right shunt. We report an infant with persistent fifth aortic arch associated with Shone's complex diagnosed accurately by transthoracic echocardiography and confirmed by cardiac catheterization and computed tomography.

Aortic coarctation with persistent fifth left aortic arch

A neonate with severe aortic coarctation showed a double lumen transverse aorta (persistent fifth aortic arch) with both channels joining at the isthmus where the obstruction was confirmed by echocardiography and cardiac catheterization. Surgical repair was performed with a pantaloon-shaped patch. Persistent fifth aortic arch does not result in a vascular ring and, per se, is not hemodynamically significant unless associated with other cardiac malformations.

Surgical Treatment of Persistent Fifth Aortic Arch Associated with Interrupted Aortic Arch

This study describes two cases of the rare congenital anomaly, persistent fifth aortic arch. Both cases involve boys (1 at 9 years of age and another at 7 months of age). To detect persistent fifth aortic arch with interrupted aortic arch, the following methods were used: echocardiogram, angiocardiography, and magnetic resonance imaging. In both cases the blood pressure between the upper and lower limbs differed. To relieve the obstruction of blood flow, each case was surgically repaired using patching or conduit interposition. Postoperative courses were uneventful. Two-year to 5-year follow-up examinations were positive showing that the anastomosis was unobstructed and the velocity of blood flow to the descending aorta was normal.