Safety and efficacy of staged primary coiling followed by delayed flow diversion of ruptured intracranial aneurysms: A systematic review and meta-analysis

Background Ruptured intracranial aneurysms lead to significant mortality and morbidity. Recent advancements have suggested staged coiling with subsequent flow diverter stent placement may reduce the risk of hemorrhage with dual antiplatelet therapy (DAPT) or stent thrombosis in the acute inflammatory phase after aneurysm rupture while still appropriately mitigating risk of aneurysmal rehemorrhage. Materials and Methods A systematic review and single-arm meta-analysis was conducted. Studies reporting patients receiving coiling followed by delayed flow diverter placement on a separate day were included. Results Five studies, comprising 94 patients, were included for meta-analysis. Average time between procedures ranged from 9.8 to 169 days; 24% (95% CI: 10–41%) of patients had a poor functional neurologic outcome (modified Rankin Scale > 2) at discharge compared to 4% (0–11%) at last follow-up. There was one incidence of rehemorrhage between treatments, 0% (0–4%). Vasospasm after coiling was the most common adverse event, 16% (1–41%). There was low risk of ischemic complications [1% (0–8%) with coil placement and 5% (1–11%) with stent placement]. Intraprocedural intracranial hemorrhage was also rare (two patients during coil placement; no cases during stent placement). There were no significant differences if flow diversion was performed less than or greater than 100 days from coiling. Conclusions Our study highlights the benefit of primary coiling with staged flow diversion for the management of ruptured intracranial aneurysms with a low risk for complications. Namely, the rate of rebleeding between treatments was exceptionally low. We advocate for the greater consideration of this treatment combination in the treatment of ruptured intracranial aneurysms.