Basilar trunk perforator artery aneurysms. Case report and literature review.

Perforator artery aneurysms of the basilar trunk are rarely described in the literature. In addition to presenting our own case, we performed a PubMed search to comprehensively illustrate demographics, hemorrhage patterns, and treatment outcomes for these lesions. We found 12 patients with basilar perforator artery aneurysms. Mean patient age was 47.3, and there was a 3:1 male to female predominance. All patients had ruptured aneurysms, though all were clinically low or medium grade (I-III). Six patients had diffuse subarachnoid hemorrhage (SAH), and six had prepontine and/or perimesencephalic hemorrhage patterns. All aneurysms arose off middle or rostral basilar perforator arteries; mean aneurysm size was 4.5 mm. All except one was partially thrombosed, and 4 out of 12 patients did not have their aneurysms detected on initial angiography (33%). Seven were treated surgically, two were coiled, and three were observed. At last follow-up, all were occluded, and 8 out of 12 patients were neurologically intact (67%). Of seven patients that were not treated with early intervention, one suffered a rebleed over a combined total of 37.3 months of observation. Two aneurysms amenable to coiling were occluded without complication. Three of seven patients treated surgically had transient complications, though five were neurologically intact at follow-up. Basilar perforator artery aneurysms may be sources of hemorrhage in diffuse or perimesencephalic/prepontine SAH. While endovascular coiling is an excellent option if parent vessel anatomy allows for catheterization, many are unamenable to endovascular treatment. Surgical obliteration via proximal occlusion or trapping is a safe and effective means of treating these aneurysms.