[Proximal aneurysms of the postero-inferior cerebellar artery. Therapeutic consideration upon a multicenter retrospective study of 24 cases].

Aneurysms of the postero inferior cerebellar artery (PICA) are relatively rare as it accounts for only 0.5% to 3% of all intracranial aneurysms, even though this localization is in second place for frequency in the posterior fossa, after aneurysms of the basilar artery. Among them, origin from the anterior or latero-medullary segment of PICA would account for 80% of cases. In this retrospective multicenter study, we report 24 cases of PICA aneurysms with their clinical and anatomic features as well as either their surgical or endovascular treatment. We also carried out an exhaustive review of the literature in order to propose the typical clinical features of this type of lesion. Of particular significance: a predominance of female patients of approximately 50 years of age ; posterior direction; constancy of hemorrhage in the fourth ventricle in case of ventricular involvement of subarachnoid hemorrhage. The various therapeutic possibilities are discussed and their results are analyzed. The prognosis for PICA aneurysms would seem to be favorable, depending, of course, on initial clinical grade.