A double aoic arch is due to persistency of the following segment:

Double aoic arch is the result of persistence and continued patency of the segment of the right dorsal aoa between the origin of the right seventh intersegmental aery and its junction with the left dorsal aoa. Affected infants have a characteristic inspiratory and expiratory wheeze, stridor, or crouplike cough. Echocardiography, CT, and MRI can demonstrate the anomalous anatomy. Ref: Keller B.B., Markwald R.R., Hoying J.B. (2011). Chapter 9. Molecular Development of the Hea. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.