Aneurysms of the Extracranial Carotid Arteries

Carotid artery aneurysm can be defined as a more than 50% localized increase of carotid calibre diameter when compared to reference values: Internal carotid: 0.55±0.06 in men and 0.49±0.07 in women Carotid bulb: 0.99±0.10 in men and 0.92±0.0 in women. Unlike occlusive or ulcerated atherosclerotic lesions carotid aneurysms are quite uncommon, with very few cases reported in the literature, which influences the correct knowledge of the natural history of this entity. In 1808 Sir Ashley Cooper made history when he per- formed, at Guy’s Hospital in London, the first success- ful treatment of a carotid aneurysm. The operation consisted of ligation of the common carotid artery, and the patient, a 50-year-old man, left the hospital after a 3-month period of recovery (because of a “smoulder- ing wound infection”)[4,5]. The patient died 14 years later from a cerebral haemorrhage. Through autopsy, Sir Ashley Cooper noticed that the haemorrhage was on the same side as the previous ca- rotid ligation, and there was a large posterior commu- nicating artery supplying collateral circulation to the ipsilateral middle cerebral artery. In 1936 Nathan Winslow and colleagues reported an exhaustive review of 124 cases published in the litera- ture. Surgical ligation of the carotid was the main ther- apeutical option (82 patients) with cure or improve- ment in 71%, and a mortality rate of 28%, while the conservative approach (42 patients) carried a mortal- ity of 71% with 12% cure or improvement [16]. Ligation remained the main therapeutical option until the late 1960s, when direct arterial reconstruction and/ or autogenous vein grafting had definitely become the best surgical option irrespective of the aetiology. Since then several series have been published, such as those of McCollum and deBakey with 37 cases oper- ated in 20 years, representing 0.5% of all aneurysms performed in the same period [3]. More recently El Sabrout and Cooley [2] published, in 2000, the largest single centre series of 67 carotid an- eurysms operated between 1960 and 1995. Nowadays endovascular techniques are being used particularly for lesions that are inaccessible to sur- gery.