At autopsy on a 72-year-old woman, the aortic arch showed an unusual a
rrangement, passing behind the trachea and esophagus and descending on
the left side. The heart was normal, and death was due to unrelated c
auses. The nature of this anomaly is considered in respect of embryolo
gical development. (C) 1998 Wiley-Liss, Inc.