Incidental Aberrant Right Subclavian Artery (ARSA) In Adults: Can Computed Tomography (CT) Imaging Features Predict Development Of Late Onset Dysphagia?

Abstract

Aim: To evaluate the role of CT in diagnosing ARSA and assess the part of CT morphometric features, including size, angle and atherosclerosis, in predicting the development of late-onset dysphagia lusoria.

Methods:  A total of 38 patients with ARSA were evaluated. Nine patients were excluded based on age <18 years and associated diseases causing dysphagia. CT features, including size, take-off angle, and the presence or absence of atherosclerosis, were assessed using curved Multiplanar Reformation (MPR) images. Any difference in the size and angle between patients with and those without difficulty swallowing was sought. Patients were followed over a mean period of 18 months for the need for surgery.

Results:  Most of the patients were females (n=17 59%). Dysphagia was present in 6 (20%) patients with ARSA, while the remaining 80% had no swallowing difficulty. The mean size and take-off angle of ARSA in patients with some degree of dysphagia were 11.4 ± 1.5 mm and 62.9 ± 3.4 degrees, while in those with no history of difficulty in swallowing was 9.4 ± 1.3 mm and 81 ± 8.1 degrees respectively. Atherosclerosis of ARSA was seen in 13 (45%) of our patients, which included 5 (17%) patients with dysphagia, 2 (7%) patients with aortic dissection and 6 (21%) patients with no symptoms related to ARSA.

Conclusion:  CT scan is the gold standard for diagnosis of ARSA. CT morphometric features (size, angle and atherosclerosis) can suggest future development of dysphagia and help earmark patients who require follow-up. Most cases of dysphagia lusoria respond to conservative management.