Anatomic characteristics of the right aortic arch with aberrant left subclavian artery in patients who do and do not undergo vascular ring repair

Introduction: It is unclear if certain anatomic characteristics in patients with a right aortic arch with aberrant left subclavian artery (RAA ALSCA) are associated with undergoing surgical repair. Methods: This was a single-center retrospective study of patients with RAA ALSCA and computed tomography or cardiovascular magnetic resonance from July 2013–September 2023. The size of the proximal ALSCA or diverticulum of Kommerell (DoK), thoracic inlet index, angle of the proximal ALSCA/DoK from the aortic arch, the position of descending aorta, location of the DoK, and tracheal size were compared between patients who did or did not undergo surgery. Results: Of 163 patients meeting inclusion criteria, 56 ​% underwent surgery. Surgical patients had a larger indexed proximal ALSCA/DoK diameter and area, a higher indexed distance between the tip of the DoK and the opposite aortic wall, a greater proximal-to-distal LSCA ratio, a less acute angle of the proximal ALSCA/DoK from the aortic arch, a more leftward DoK location, and a lower thoracic inlet index compared to non-surgical patients. A larger indexed proximal ALSCA/DoK diameter, with an optimal threshold of ≥13.78 ​mm/m², and a more leftward DoK location were independently associated with surgery. The reoperation rate was 11 ​%, and was associated with a less acute angle of the proximal ALSCA from the aortic arch. Conclusions: A larger proximal ALSCA/DoK size and a more leftward DoK location were associated with surgical repair of RAA ALSCA, while a less acute angle of proximal ALSCA from the aortic arch was associated with reoperation.