Emerging Neurovascular Interventions for the Prevention of Cerebral Vasospasm and Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review.

Aneurysmal subarachnoid hemorrhage remains a major cause of neurological morbidity and mortality, with delayed cerebral ischemia and cerebral vasospasm representing important contributors to secondary brain injury and unfavorable functional recovery. Although conventional management strategies such as nimodipine administration, hemodynamic augmentation, and endovascular rescue therapy remain central to clinical practice, growing evidence suggests that delayed cerebral ischemia is a multifactorial neurovascular process extending beyond isolated large vessel vasospasm. This systematic review evaluated emerging neurovascular interventions for the prevention and management of cerebral vasospasm and delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage. A comprehensive literature search was conducted across PubMed/MEDLINE, Scopus, and Web of Science databases for studies published between January 2020 and February 2026 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Nine studies met the eligibility criteria and were included in the qualitative synthesis. The included interventions encompassed endothelin receptor antagonists, localized nicardipine release implants, intra-arterial nimodipine infusion, microcirculatory targeted pharmacologic therapies, anti-inflammatory neuroprotective agents, and autonomic neuromodulatory approaches. Several interventions demonstrated reductions in angiographic vasospasm, delayed cerebral ischemia incidence, rescue therapy utilization, or cerebral infarction burden. However, consistent improvement in long-term neurological recovery remained variable across studies. Emerging evidence increasingly supports a broader pathophysiological model of delayed cerebral ischemia involving endothelial dysfunction, microcirculatory impairment, neuroinflammation, and autonomic dysregulation in addition to proximal arterial narrowing. Contemporary neurovascular interventions may therefore represent an important shift toward more targeted and mechanistically informed therapeutic strategies after aneurysmal subarachnoid hemorrhage, although further large-scale multicenter investigations remain necessary to establish definitive clinical benefit.