Page 1 of 4 Case report Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY) For citation purposes: Shetty P, Nayak BS, D’Souza MR, Thangarajan R, Prabhu GS. Variation in the morphology and branching pattern of the aortic arch: A case report. OA Case Reports 2013 Sep 10;2(10):99. Competng interests: none declared. Confict of interests: none declared. All authors contributed to concepton and design, manuscript preparaton, read and approved the fnal manuscript. All authors abide by the Associaton for Medical Ethics (AME) ethical rules of disclosure. Anatomy Variation in the morphology and branching pattern of the aortic arch: A case report P Shetty, BS Nayak*, MR D’Souza, R Thangarajan, GS Prabhu Abstract Introduction The arch of the aorta is situated in the superior mediastinum and it normally branches into three: the brachiocephalic trunk, left common carotid artery, and the left subclavian artery. Variations in its morphology and branching pattern are mainly due to the errors in its embryologic development. Here, we report con- current variation in the morphology and branching pattern of the aortic arch. Case report The first branch of the aortic arch was a common trunk which divided into the brachiocephalic trunk and the left common carotid artery. There was a constriction in the aortic arch immediately to the left of this com- mon trunk. The left vertebral artery arose from the aortic arch, dorsolat- eral to the origin of the left subclavi- an artery. At the root of the neck, the left vertebral artery passed behind the first thoracic and inferior cervical sympathetic ganglia. Conclusion Knowledge of these variations may be very useful to surgeons involved in the cervical and thoracic sympa- thectomies, vascular surgeries, and cardiac catheterization procedures. Introduction The arch of the aorta is the continu- ation of the ascending aorta. It is situated in the superior mediastinum and usually branches into three: the brachiocephalic trunk, left common carotid, and left subclavian arteries. This branching pattern is found in 65%–80% of population 1 . Variation in the aortic arch branches occurs mainly due to the abnormal fusion or disappearance of aortic arch ar- teries during the embryonic period 2 . Variations, such as its coarctation, might result in decreased blood flow to certain regions of the body de- pending on where the coarctation is situated. Variations in the branching pattern may result in iatrogenic in- juries of the variant branches; their compression by adjacent structures or problems in the catheterization procedures 3 . Knowledge of these concurrent vascular variations in the superior mediastinum may be very important to various medical dis- ciplines and we discuss the clinical importance of these variations in this article. Case report During routine dissection classes for medical undergraduates, we ob- served the following variations in the morphology and branching pattern of the arch of the aorta. The aortic arch was situated in the superior me- diastinum, behind the manubrium sterni. Its first branch was a common trunk for the brachiocephalic trunk * Corresponding Author E-mail: nayaksathish@gmail.com Melaka Manipal Medical College (Manipal Campus), Manipal University, Manipal, Karnataka State, India 567104 Figure 1: Dissection of the major vessels in the superior mediastinum. (AA – aortic arch; CT – common trunk; C – constriction/coarctation of the aorta; SVC – superior vena cava; BCT – brachiocephalic trunk; LCC – left common carotid artery; LS – left subclavian artery; LV – left vagus nerve; RS – right subclavian artery; RCC – right common carotid artery; TRC – trachea; THR – thyroid gland; LVA – left vertebral artery).