Bilateral Abnormal Origin of the Anterior Branches of the External Carotid Artery Theodore Troupis, Adamantios Michalinos, Ioannis Dimovelis, Theano Demesticha, Konstantinos Vlasis, and Panayiotis Skandalakis, Athens, Greece Background: Description of a rare variation is provided alongside with a review of the literature with special references to anatomic, embryologic, and clinical issues it may create. Methods: This was a cadaveric dissection conducted during a pregraduate anatomy course that is accompanied by short review of the literature and critical appraisal. Results: During dissection of the neck region of a male cadaver, the superior thyroid artery occurred from the common carotid artery bilaterally and the lingual artery occurred from the carotid bifurcation on the left side. Conclusions: Superior thyroid artery originating from common carotid artery or carotid bifurca- tion is a common variation, but the lingual artery originating from the common carotid artery or carotid bifurcation is very rare (<1%). Its existence can have a significant impact on treatment success and potentially lead to errors during interventions at the neck region. A high level of suspicion is required. The superior thyroid artery (STA) is usually described as the first branch of the external carotid artery (ECA). STA descends in an oblique course until reaching the superior pole of the thyroid gland, parallel to the superior laryngeal nerve. The origin of the STA from the carotid bifurcation (CB) or common carotid artery (CCA) is not uncommon (incidence of 30% of the general population). 1,2 The lingual artery (LA) is the main artery supplying the tongue and the floor of the mouth. The LA usually originates from the ECA at the level of the posterior tubercle of the hyoid bone. The LA is classically described as the second branch of the ECA. The LA rarely occurs from the CCA or CB (inci- dence of <1%). 2 We describe a case where the STA occurred from the CCA and the LA from the CB at the left side and the STA from the CCA at the right side. We also provide a brief review of these anatomic characteris- tics, their embryologic origin, and their potential clinical significance. CASE REPORT During dissection of the neck region of a wholly preserved in 10% formalin male cadaver, an anatomic variation concerning the origin of branches of the ECA on both sides was observed. The dissection was carried out as part of an undergraduate anatomy teaching course. Partial dissec- tions were made by students and further dissections by the authors. Variations were photographed and micro- metric values were measured using an 0.01-mm accuracy electronic caliper. For all measurements, cadavers remained in the supine position and no tension was exercised. On the left side, the STA was found to occur from the CCA and the LA from the CB (Fig. 1). The distance of the STA origin from the CB was 10.1 mm. The STA diameter was 1.04 mm, and the LA diameter was 2.39 mm. The ECA was measured at 6.0 mm, the internal carotid artery (ICA) at 4.67 mm, and the CCA at 7.17 mm. On the right side, the STA was found to occur from the CB. The LA was the first branch of the ECA, and the distance from the LA to the CB was 7.48 mm. The diameter of the STA was 1.36 mm and the diameter of Department of Anatomy, Faculty of Medicine, National and Kapo- distrean University of Athens, Athens, Greece. Correspondence to: Theodore Troupis, MD, Department of Anatomy, School of Medicine, National and Kapodistrian University, 75 Mikras Asias Street, 11527 Athens, Greece; E-mail: ttroupis@med.uoa.gr Ann Vasc Surg 2014; 28: 494.e5–494.e7 http://dx.doi.org/10.1016/j.avsg.2013.04.020 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: January 16, 2013; manuscript accepted: April 3, 2013; published online: December 2, 2013. 494.e5