Endovascular treatment of a ruptured posterior fossa pure arterial malformation: illustrative case

BACKGROUNDPure arterial malformations (PAMs) are rare vascular anomalies that are commonly mistaken for other vascular malformations. Because of their purported benign natural history, PAMs are often conservatively managed. The authors report the case of a ruptured PAM leading to subarachnoid hemorrhage (SAH) with intraventricular extension that was treated endovascularly.OBSERVATIONSA 38-year-old man presented with a 1-day history of headaches and nausea. A computed tomography scan demonstrated diffuse SAH with intraventricular extension, and angiography revealed a right posterior inferior cerebellar artery–associated PAM. The PAM was treated with endovascular Onyx embolization.LESSONSTo the authors’ knowledge, only 2 other cases of SAH associated with PAM have been reported. In those 2 cases, surgical clipping was pursued for definitive treatment. Here, the authors report the first case of a ruptured PAM treated using an endovascular approach, showing its feasibility as a treatment option particularly in patients in whom open surgery is too high a risk.

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.