Clipping of Basilar Perforator Pure Arterial Malformation Aneurysm: 2-Dimensional Operative Video.

Pure arterial malformations are rarely-encountered intracranial lesions, often mistaken for arteriovenous malformations. A minority of these lesions may harbor associated aneurysms. In a recent series of 12 patients with pure arterial malformations, 3 patients had associated aneurysms.1 As the authors describe, the presentation and natural history of pure arterial malformations generally are considered benign. In over 85% of cases reported in the literature, they are discovered incidentally and in cases with documented follow-up the angio-architecture tends to remain stable.1  However, here we present the case of an aneurysm associated with a pure arterial malformation managed with microsurgical clipping. The patient presented to us with the development of hemorrhage within and/or around the lesion and the development of a partial CN III palsy. Using a cranio-orbital approach, we successfully performed clipping of the offending vessel in the region of the basilar apex. Critical to the successful treatment of this lesion were: the correct identification of the offending vessel, recognition of the presence of perforating arteries, and clipping of the offending artery distal to the origin of the perforating arteries. This case represents a rare instance of a symptomatic pure arterial malformation with associated aneurysm.  Verbal consent was provided by the patient for reproduction and publication of her case.