Aortic aneurysm: aortic arch aneurysm

Thoracic aortic aneurysm (TAA) is defined as aneurysmal degeneration that occurs in the thoracic aorta. The incidence of TAA is increasing with improvements in screening, as well as advances in imaging. They are often asymptomatic but in some cases, they may compress the innominate vein or airway or they may stretch the left recurrent laryngeal nerve, causing hoarseness. TAA often results from cystic medial degeneration and when it occurs at younger ages, it is classically associated with connective tissue disorders, such as Marfan syndrome or, less commonly, Ehlers–Danlos syndrome and Loeys–Dietz syndrome. Mycotic aneurysms, once the predominant cause of ascending and arch aneurysms, are rare today. Diagnosis is often casual and can be suspected on the basis of chest X-ray or as for ascending aortic aneurysms, diagnosed by transthoracic echocardiogram. However, the computed tomography angiography scan represents the gold standard examination for diagnosis. The aortic arch operation consists of the replacement of the arch with reimplantation of the supra-aortic vessels. Effective methods of cerebral, myocardial, as well as visceral protection are necessary to obtain acceptable results in terms of hospital mortality and morbidity. The ‘elephant trunk’ procedure can be an alternative technique for total arch repair; however, a recent evolution of the ‘elephant trunk’ procedure is the ‘frozen elephant trunk’ technique. This technique consists of the implantation of the stented distal segment of the hybrid prosthesis into the descending aorta through the opened aortic arch, while the proximal, non-stented segment is used for conventional replacement of the aortic arch.