Brain involvement in extracranial internal carotid artery aneurysms

Background: No prospective study of extracranial internal carotid artery an eurysms (EICAA) has been reported to date. The aim of this study was to eva luate central nervous system complications associated with surgical interve ntion for EICAA. Patients and methods: A total of seven patients, rep resenting all cases ob served at our institution from December 1997 to December 1998, ere entered in this prospective study. Three patients had bilateral involvement. The an eurysms were both atherosclerotic and dysplastic. All patients were males, with mean age of 70 years (range 65 to 74). Internal or common carotid arte ry to EICAAs diameter ratios were calculated on the angiograms. The transve rse diameter as well as the craniocaudal extension of the lesions were accu rately measured intraoperatively. Follow-up evaluations were performed at t hree, six and twelve months postoperatively, and consisted of a clinical ev aluation by both a neurologist and a vascular surgeon who were not part of the primary surgical team. Results: Six patients presented with neurological symptoms ranging from non -hemispheric TIAs to hemispheric stroke. One patient was asymptomatic. The severity of symptoms was correlated with the size of the aneurysm. Preopera tive symptoms were more severe in EICAAs of greater than or equal to 3 cm i n transverse diameter. One case had a postoperative stroke, no perioperativ e deaths occurred All the internal carotid arteries operated on were patent during follow-up evaluations. No new neurologic event was observed during follow-up. Conclusions: The severity of central neurologic symptoms seems to depend on the size of the aneurysmatic lesion. Pro,npt surgical management of small EICAAs may reduce the occurrence of severe CNS complications, both preopera tively and postoperatively, due to the lower risk of embolization associate d with small aneurysms compared to larger lesions.