Anatomical Variations of the Left Subclavian Artery and Their Significance in Clinical Practice.

We study variations of the aortic arch (AA) and its first branches, the brachiocephalic, common carotid, and subclavian arteries. Specifically, we describe anatomical variations of the left subclavian artery (LSA) and their significance in clinical practice. Such variations are commonly associated with congenital anomalies of the right-sided AA (RAA) and/or great vessels. A systematic search of the PubMed online database for studies of LSA variations and RAA, published between 2000 and 2020, produced a total of 73 articles for our study (n = 258 cases). Three of the most common variants were aberrant LSA (32.9%), RAA with mirror-image branching (49.6%), and isolated LSA (17.4%). Although RAA and LSA variations are rare, they may give rise to symptoms during the first stages of life or adulthood and may require surgical repair. Patients can remain asymptomatic, but incidental findings on imaging studies may lead to surgical interventions in areas of the neck or thorax. In such cases, planning the surgical procedure can be challenging, and possible implications must be considered.