The potentially beneficial role of an aortic arch anatomical variant

We dis-cuss a case of acute type-A aortic dissection requiringa complex repair of the aorta wherein an unexpectedanatomic variant of the innominate artery allowed imme-diate institution of bilateral antegrade cerebral perfusion(ACP).A previously healthy 57-yr-old man was admitted to adistrict hospital after he had suffered a syncopal episode ona ski run. He was found unconscious in the snow after anunknown time period had elapsed. After recovering con-sciousness, he complained to the rescue team of severechest pain. Transthoracic echocardiography revealed alarge pericardial effusion and moderate aortic regurgita-tion. This medical condition along with other clinical signs(syncope, pulse asymmetry, and chest pain) led to a ten-tative diagnosis of type-A aortic dissection. Withhemodynamics deteriorating and acute respiratory failureimminent, the computed tomography scan in the districtfacility was cancelled. While the patient was on high-dosevasoactive support, his trachea was intubated and his lungswere ventilated prior to urgent transfer to our centre. In theoperating room, a transesophageal echocardiographyexamination confirmed the diagnosis of type-A aortic dis-section. Extracorporeal circulation was established with thearterial inflow cannula inserted in the right axillary arteryand a two-stage venous drainage cannula inserted in theright atrium. On reaching the targeted nasopharyngealtemperature (20 C), hypothermic circulatory arrest wasinstituted. By cross-clamping the innominate artery at itsorigin, the surgeon sought to establish a continuous uni-lateral right axillary ACP via the right-sided carotid andvertebral artery. The exploration of the aortic arch revealeda circumferential dissection with multiple intimal tearsextending beyond the ostium of the innominate artery.However, only one additional arch vessel ostium could beidentified. Further preparation of the distal aortic archshowed that the second arch ostium did not, as previouslyassumed, represent the left common carotid artery, but