Limitations of Flow Diverters in Posterior Communicating Artery Aneurysms

Background: Treatment of intracranial aneurysms with flow diverters (FDs) showed promising results. However, a subset of patients treated for posterior communicating artery (PComA) aneurysms has variable occlusion rates. Especially the fetal type-associated PComA aneurysms seemed to respond differently to treatment. We analyze our series of fetal type PComA aneurysms treated with a FD. The literature on this subject is reviewed. Methods: Data from patients treated with FD for all PComA aneurysms at the RadboudUMC Nijmegen were retrospectively analysed. Primary end-point was complete aneurysm occlusion at six months. Secondary end-points were clinical outcome, treatment safety, and results of secondary treatment after non-closure. The results for the fetal PComA aneurysms were compared to the literature. Results: Nineteen consecutive patients harboring 21 PComA aneurysms were treated. Three aneurysms had ipsilateral fetal type PCA (14.3%). Overall, none of the fetal type PcomA aneurysm showed complete occlusion versus 77.8% of the others (p = 0.03). Mortality and permanent morbidity rates were respectively 5.3% and 0%. Conclusions: FD treatment for PComA aneurysm with fetal type circulation seemed to be less effective compared to other types of PComA aneurysms. Flow characteristics at the PComA bifurcation are thought to be causative Alternative strategies should be considered as first line treatment.