Treatment of Ruptured Intracranial Aneurysms with Parent Artery Flow Diverter Devices: A Comprehensive Systematic Review and Meta-Analysis

Background: Surgical clipping and endovascular coiling are well-established treatments for acutely ruptured intracranial aneurysms leading to acute subarachnoid hemorrhage (aSAH). However, these modalities have limitations, particularly in cases involving wide-necked, bifurcating, or dissecting aneurysms. Flow diverter (FD) devices, initially used for unruptured aneurysms, have emerged as an alternative treatment for ruptured aneurysms despite concerns about hemorrhagic complications. Aims: This study aimed to perform a comprehensive systematic review and meta-analysis to assess the efficacy and safety of parental artery FD devices in treating ruptured intracranial aneurysms. Methods: A systematic search was conducted in Medline, Embase, and Cochrane databases from inception to July 2024. The inclusion criteria focused on studies involving patients with acutely ruptured aneurysms treated with parental artery FDs, with or without adjunctive coiling. Studies were required to report clear, stratified data specific to the population of interest, and include more than five patients. Exclusion criteria included studies on non-ruptured aneurysms, intrasacular flow diversion devices, or previously clipped aneurysms treated with FD. Data extraction was performed independently by two authors, and statistical analysis included single proportion analysis with 95% confidence intervals under a random-effects model, using R Studio. The primary outcome was the rate of aneurysm occlusion at follow-up. Summary of Review: Sixty studies encompassing 1300 patients were included. The primary outcome analysis revealed a 90% (95% CI: 87% - 92%; I2= 51%) rate of total occlusion at follow-up. Subgroup analysis indicated an occlusion rate of 89% for anterior circulation aneurysms and 96% for posterior circulation aneurysms. Intraoperative complications occurred in 6% of cases, while postoperative complications were observed in 13%. Rebleeding rates were low at 1%, with a 2% need for retreatment. Good functional outcomes (mRS ≤ 2) were achieved in 82% of patients, and the overall mortality rate was 4%. Conclusions: FD devices demonstrated high rates of aneurysm occlusion and favorable functional outcomes in patients with acutely ruptured intracranial aneurysms. However, the low mortality rate and favorable outcomes observed may reflect selection bias toward patients with less severe SAH. Despite a modest complication rate, the overall safety and efficacy of FD devices suggest they may be a viable alternative to traditional treatments for specific aneurysm types. Further studies, including a broader spectrum of SAH severities, are warranted to optimize their use in clinical practice.