Persistent fifth aortic arch in a neonate with interrupted aortic arch: an unexpected intraoperative finding.

Persistent fifth aortic arch (PFAA) is a rare variant of the aortic arch that may be associated with coarctation or interrupted aortic arch. We report the case of a neonate initially referred for coarctation repair. After a left thoracotomy was performed, a rare diagnosis of PFAA associated with interrupted aortic arch was made. Despite this unusual anatomy, the repair was successfully performed via a lateral approach. This unusual anatomy of the aortic arch deserves special consideration in case of association with coarctation. Indeed, repair from the side may not be possible due to the common origin of the neck-vessels, and resection should be extended as far as possible to eliminate remaining ductal tissue and prevent recoarctation.