Brain involvement in extracranial internal carotid artery aneurysms

Background: No prospective study of extracranial internal carotid artery aneurysms (EICAA) has been reported to date. The aim of this study was to evaluate central nervous system complications associated with surgical intervention for EICAA. Patients and methods: A total of seven patients, rep resenting all cases observed at our institution from December 1997 to December 1998, ere entered in this prospective study. Three patients had bilateral involvement. The aneurysms were both atherosclerotic and dysplastic. All patients were males, with mean age of 70 years (range 65 to 74). Internal or common carotid artery to EICAAs diameter ratios were calculated on the angiograms. The transverse diameter as well as the craniocaudal extension of the lesions were accurately measured intraoperatively. Follow-up evaluations were performed at three, six and twelve months postoperatively, and consisted of a clinical evaluation 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. Preoperative symptoms were more severe in EICAAs of greater than or equal to 3 cm in transverse diameter. One case had a postoperative stroke, no perioperative 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 preoperatively and postoperatively, due to the lower risk of embolization associated with small aneurysms compared to larger lesions.