Flow Diverter Devices for Treatment of Intracranial Aneurysms in Small Parent Vessels—A Systematic Review of Literature

The overall safety and efficacy of flow diverting stents (FDSs) deployed in small caliber parent arteries (≤2.5 mm) for the treatment of intracranial aneurysms remains unclear. Recent studies have provided additional outcomes data to assess the use of FDSs for such arteries. In the present review, we have summarized the reported clinical and angiographic outcomes of FDS-treated brain aneurysms in small parent arteries.A systematic literature review was performed for outcomes data related to FDS-treated intracranial aneurysms using PubMed, Ovid Medline, and Web of Science. Procedural data, angiographic outcomes, and clinical outcomes at various time points were collected and summarized.The 19 studies included 580 patients with 604 aneurysms, of which 6.1% had been acutely ruptured and 28.3% had been previously treated. The procedural complication rate and symptomatic stroke rate was 9.8% and 7.5%. The complete occlusion rate at the last radiographic follow-up (mean, 12.1 months) was 73.6%. At the last clinical follow-up (mean, 10.6 months), the FDS-associated mortality was 2.5%.FDSs for the treatment of intracranial aneurysms located in small caliber arteries was associated with rates of long-term complete aneurysm occlusion, mortality, and permanent neurologic deficit comparable to the rates with FDS-treated aneurysms in larger parent arteries. However, the relatively increased risk of symptomatic stroke of these FDS-treated aneurysms should not be ignored. Direct comparisons with alternative endovascular approaches are necessary to further define the optimal use of FDS for these aneurysms.