The advantages of naming rather than numbering the arteries of the pharyngeal arches

Controversies continue as to how many pharyngeal arches, with their contained arteries, are to be found in the developing human. Resolving these controversies is of significance to paediatric cardiologists since many investigating abnormalities of the extrapericardial arterial pathways interpret their findings on the basis of persistence of a fifth set of such arteries within an overall complement of six sets. The evidence supporting such an interpretation is open to question. In this review, we present the history of the existence of six such arteries, emphasising that the initial accounts of human development had provided evidence for the existence of only five sets. We summarise the current evidence that substantiates these initial findings. We then show that the lesions interpreted on the basis of persistence of the non-existing fifth arch arteries are well described on the basis of the persistence of collateral channels, known to exist during normal development, or alternatively due to remodelling of the aortic sac.

Automated summary

There are ongoing controversies regarding the number of pharyngeal arches and their contained arteries in developing humans. Resolving these controversies is crucial for pediatric cardiologists as abnormalities in the extrapericardial arterial pathways are often interpreted based on the persistence of a fifth set of arteries. However, the evidence supporting this interpretation is questionable. In this review, the authors present the history of six such arteries, emphasizing that initial accounts of human development only provided evidence for the existence of five sets. They summarize the current evidence that supports these initial findings and suggest alternative explanations for lesions based on collateral channels or remodeling of the aortic sac.