A bicarotid trunk in association with an aberrant right subclavian artery. Report of two cases, clinical impact, and review of the literature.

A combination of an aberrant right subclavian artery (ARSA) and a bicarotid trunk (BCT) appears in up to 2.5% of the population. The aim of this study is to report the higher total and male incidence of this variation in the literature and to summarise its clinical impact, providing useful knowledge to anatomists, radiologists, cardiologists, and vascular and thoracic surgeons in order to avoid diagnostic pitfalls and therapeutic complications. A total of 72 (43 female and 29 male) Greek Caucasian formalin-embalmed cadavers were studied. The international literature was reviewed along with the dissection archives of the Department of Anatomy from 1986 to 2009. Two male cadavers were found to have an ARSA combined with a BCT (incidence: total 2.78%, males 6.9%, females 0%). Both aortic arches consisted of three branches: (1) the BCT, (2) the left subclavian artery, and (3) the ARSA. The common carotids followed a normal route to the neck; the ARSA passed between the trachea and the oesophagus in the first case and behind the oesophagus in the second case, and was accompanied by a non-recurrent laryngeal nerve. In the second cadaver the ARSA formed a sharp angle (kinking/buckling) on its route to the right arm. The ARSA is associated with several congenital cardiovascular anomalies and some chromosomal and other syndromes. It is occasionaly responsible for causing dysphagia, dyspnoea, or acute ischaemia to the right upper limb, and it may present as a superior mediastinal mass in cases of aneurysm formation.