Posterior circulation perforator aneurysms: a proposed management algorithm

Subarachnoid hemorrhage (SAH) from posterior circulation perforator aneurysms (PCPAs) is rare and its natural history is unknown. Diagnosis may be difficult, acute management is poorly defined, and long-term recurrent SAH rates and clinical outcome data are lacking.

We searched our institution's records for cases of PCPA rupture and analyzed patient demographics, Hunt and Hess (HH) grades, diagnostic imaging, management, and clinical outcomes. We conducted telephone interviews to calculate modified Rankin Scale (mRS) scores.

We identified 9 patients (6 male, 3 female) with a ruptured PCPA who presented to the University of Virginia Health System (Charlottesville, VA, USA) between 2010 and 2016. Median and mean ages were 62 and 63 years, respectively. Median HH grade was 3. Seven of nine (78%) PCPAs were angiographically occult on initial imaging and median time to diagnosis was 5 days. Three conservatively managed patients had a mean mRS score of 0.67 (range 0-1) at mean follow-up of 35.3 months. Antifibrinolytic therapy was administered to all conservatively managed patients without thrombotic complication. Six patients receiving endovascular treatment had a mean mRS score of 2.67 (range 0-6) at mean follow-up of 49.2 months. No cases of recurrent SAH were seen in the study.

The rarity of PCPA has precluded long-term clinical follow-up until now. Our experience suggests low recurrent SAH rates. Until further studies are performed, conservative management, possibly combined with antifibrinolytic therapy, may be a viable treatment with acceptable long-term outcome.