Anatomy and radiology of the variations of aortic arch branches in 1,266 patients.

BACKGROUND The most reliable data about arterial variations, which are very important in surgery and radiology, can be obtained from a large series of patients. MATERIALS AND METHODS We examined angiographic and multislice computerised tomography (MSCT) images in a group of 1,265 patients and in 1 dissected specimen. RESULTS While in 946 (74.72%) of the patients a normal vascular pattern (type I) was noticed, in the remaining 320 (25.28%) patients variations of the branches of the aortic arch were found, which were classified into types II through VIII and a few subtypes. Type II (2.84%) comprised a common origin of the left commoncarotid and subclavian arteries. Type III (15.56%) was related to an origin of the left subclavian artery from the brachiocephalic trunk. Type IV (0.55%) included the aortic origin of both common carotid and subclavian arteries, with the right subclavian artery having a retroesophageal course. Type V (0.24%) included the same 4 supra-aortic branches, which, however, arose from a double or a right--sided aortic arch. Type VI (3.63%) comprised the aortic origin of the left vertebral artery, type VII (0.24%) the same origin of the right vertebral artery, and type VIII(2.22%) the aortic origin of the thyroideaima artery. A corresponding embryological background and clinical implications of the described aberrant vessels were presented. CONCLUSIONS In more than one quarter of the cases, the branching pattern of the examined arteries did not follow the classical pattern. Detailed knowledge of aortic branch variations is of great significance in anatomy, embryology, and clinical medicine, especially in radiology and thoracic surgery.