Persistent fifth aortic arch: the “great pretender” in clinical practice

Abstract

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.

Fifth arch artery – a case of mistaken identity?

“…At that time, however, we did not know as much as we do now about the fate, during development, of the arteries running through the pharyngeal arches. And, as Lloyd et al describe at length, 1 we have collectively now cast significant doubt on the role of the putative fifth arch arteries as the basis of the lesions they now review. 3,4 In this regard, we also questioned the interpretation of a vessel as a fifth arch artery in a case recently described by Naimo and Konstantinov.…”

“…A recently published article, 1 Lloyd et al interpret several rare cardiac malformations on the basis of persistence of the artery of the fifth pharyngeal arch. Following the precedent of Gerlis et al, 2 they continue to accord the artery the role of the “great pretender”.…”

Fetal Diagnosis of Tetralogy of Fallot, Major Aortopulmonary Collateral Arteries, and an “Inverted” Pulmonary Valve Causing a Circular Shunt

“…This vessel functioned as a systemic-to-systemic shunt in our patient, rather than a systemic-to-pulmonary shunt that may be seen with severe right-sided obstructive lesions. 13 Thus, the finding did not significantly affect hemodynamics.…”

A case report: stent implantation to treat coarctation of persistent 5th aortic arch associated with interrupted 4th aortic arch

“…Persistent 5th aortic arch is a rare congenital heart disease first described in 1969 by Van Praagh in a patient with a ‘congenital double-lumen aortic arch’ 1 . Subsequent cases have exhibited variable anatomy and pathophysiology 2 , 3 . The most common abnormalities are interruption or severe coarctation of the 4th aortic arch with or without coarctation of the 5th aortic arch 3 .…”

“…Subsequent cases have exhibited variable anatomy and pathophysiology 2 , 3 . The most common abnormalities are interruption or severe coarctation of the 4th aortic arch with or without coarctation of the 5th aortic arch 3 . It is usually diagnosed and repaired in paediatric patients, especially when coarctation of the systemic arch is clinically significant.…”