[Aneurysm of the internal carotid artery bifurcation. Technical reflections apropos of a series of 10 cases].

Cerebral aneurysms at the bifurcation of the internal carotid artery are uncommon and represent less than 10% of intracranial aneurysms. A recent series of 10 cases (out of a total of 221 aneurysms over a period of five years, from 1983 to 1988, i.e. 4.5%) treated via a microsurgical approach is presented. Anatomical and operative aspects are discussed. These malformations are located at the point of union of the carotid artery, sylvian and lamina terminalis cisterns. They are close to perforating vessels which usually lie on their deep aspect. Surgery is performed via the standard pterional approach and, as Yasargil points out, two specific dissecting times are required for the opening of the sylvian and lamina terminalis cisterns, in order to avoid dangerous traction on the brain. In our experience, deep hypotension was used in the four cases of large malformations, and there was no need for a temporary dip. All aneurysms were clipped at the neck and the sac then punctured or removed. Post-operative evolution was completely asymptomatic in 9 cases (grade I-II--Hess and Hunt), one patient (grade IV) died from an apparent vascular spasm, confirmed by CT scan.