Flow-Diversion for Complex Posterior Communicating Artery Aneurysms Associated With a Fetal Posterior Circulation.

Background: Flow-diverting stents (FDSs) are effective in treating complex intracranial aneurysms, including posterior communicating artery aneurysms. However, some studies have suggested FDSs have limited efficacy for posterior communicating artery aneurysms associated with a fetal posterior communicating artery (FPCoA). Methods: A retrospective analysis of patients with FPCoA aneurysms treated using FDS intervention alone was performed. Only aneurysms in which the FPCoA originated from the neck or dome of the aneurysm, which were therefore not amenable to standard coil embolization, were included. Results: Stand-alone, single-device FDSs were placed in 16 patients with unruptured posterior communicating artery aneurysms associated with an FPCoA. The device was sized to ensure excellent wall apposition, with a focus on expanding the device across the aneurysm neck to optimize flow diversion. Excellent angiographic results were achieved in 12 patients (75%), and all patients had satisfactory clinical outcomes, with complete obliteration of the aneurysm in 10 (62.5%). No patients required additional treatment. Nine patients had complete patency of the FPCoA, 4 had mildly decreased flow, 2 had markedly diminished flow, and 1 had FPCoA occlusion. In all 7 cases with decreased FPCoA flow, there was coincident increased flow in the P1 segment of the posterior cerebral artery. No patient developed posterior circulation ischemia. Mean follow-up was 19.9 months. Conclusion: Contrary to previous reports, the placement of FDSs was found to be a safe and effective treatment option for FPCoA aneurysms. The deployment technique of maximizing device expansion across the neck of the aneurysm may contribute to successful outcomes. Treatment using an FDS may be particularly useful for complex FPCoAs.