Association of aberrant subclavian arteries with aortic pathology and proposed classification system.

Abstract Objective Aberrant subclavian artery (aSCA) is a rare anatomic variant whose association with other aortic branch variations and aortic pathology has yet to be established. Knowledge of such an association could be relevant to recommendations for screening and awareness as associated variations are important for operative planning. We describe the incidence of aSCA variations, its association with aortic pathology, and a proposed classification system. Methods The thoracic cross-sectional imaging database at Keck Hospital of the University of Southern California from 2006 to 2018 was queried for presence of aSCA. Studies were evaluated for aSCA laterality, variant anatomy, and aortic and branch vessel disease. Medical records were reviewed for associated symptoms and diagnoses. The primary outcome was association of aSCA with aortic pathology (aneurysm or dissection). Secondary outcomes were comparison of right and left aSCA, comparison between the sexes, and creation of a proposed classification system. Results Of 98,580 axial imaging studies, 810 studies (0.82%) were identified with aSCA in 312 unique patients. Right aSCA made up the majority of cases (90.1%). All aSCAs had a retroesophageal course. Kommerell’s diverticulum (KD) was present in 184 (59%) with an average diameter of 1.67 cm (range, 1.2-3.3 cm). KD was more frequent (84% vs 56%; P = .0003) and larger (2.05 cm vs 1.61 cm; P  Conclusions aSCAs are frequently symptomatic and commonly associated with aortic dissection and aneurysm. Our proposed classification scheme depicts all four aSCA arch variants and accounts for vertebral artery origin variation. These variants are common, and vertebral anatomy can differ greatly. Knowledge of these anatomic variations is critical to planning for endovascular and open repair of aortic arch pathology.