Isolation of arch vessels: Imaging characteristics and associations on multidetector computed tomography angiography

Aim To evaluate the imaging characteristics and associations in patients with isolation of arch vessels on multidetector computed tomography angiography (CTA). Materials and Methods We retrospectively reviewed all multidetector CTA studies performed for the evaluation of congenital heart diseases (CHDs) at our institution from January 2014 to June 2020. Cases with isolation of arch vessels were identified. The isolated arch artery and its relationship with patent arterial duct, pulmonary artery, and aortic arch were characterized in addition to other associated intra- and extracardiac anomalies. Results Isolation of arch vessels was seen in 14/3926 (0.36%) patients. Left subclavian artery (SCA) was the commonest isolated arch vessel, involved in 7/14 (50%) cases. Isolation of right SCA, left brachiocephalic artery, and left common carotid artery was seen in 4 (28.6%), 2 (14.3%), and 1 (7.1%) patient, respectively. The isolated arch vessel was seen associated with right aortic arch in 10/14 (71.4%) cases and was on the opposite side of aortic arch in all 14 (100%) patients. Right-sided nonrestrictive patent arterial duct was seen in 3/14 (21.4%) cases, left-sided nonrestrictive patent arterial duct was seen in 1/14 (7.1%) while a left-sided restrictive patent arterial duct was seen in 3/14 (21.4%) cases. Tetralogy of Fallot (ToF) was the commonest associated anomaly seen in 8/14 (57.1%) patients. Conclusion Isolation of aortic arch branch vessels is rare, seen most commonly associated with ToF. Left SCA is the commonest involved vessel. CTA is useful not only in the diagnosis of isolation of arch vessels, but also in the presence or absence of associated anomalies which may impact the symptomatology, prognosis, and surgical management.