Distal aortic arch aneurysm associated with persistent fifth aortic arch.

Persistent fifth aortic arch (PFAA) associated with interruption of the fourth aortic arch is a rare malformation, usually requiring surgical intervention in childhood. A 51-year-old woman developed a distal aortic arch aneurysm associated with PFAA after patch aortoplasty for coarctation of the aorta at the age of 18. To our knowledge, this is the first reported case of a distal aortic arch aneurysm associated with PFAA. Residual tissues of the ductus and PFAA, which is not a definitive aortic arch, and the implanted synthetic patch may have been related to the development of the aneurysm. Graft interposition between the proximal border of PFAA and the descending aorta was performed because severe adhesions impeded the application of the fourth aortic arch as a proximal anastomotic site of the graft. Accurate diagnosis and sufficient understanding of PFAA allow an appropriate surgical treatment in childhood with a good result over the long term.