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.