Alternative hybrid access in endovascular neurosurgery: Scoping review and technical considerations

Background The common femoral artery and radial artery constitute the most common access sites in contemporaneous endovascular neurosurgery. Oftentimes, it may be impossible to reach the vascular target safely due to different circumstances, necessitating alternative approaches. We aim to review these “last resource” access sites described in the literature, focusing on the technical aspects as a convenient reference. Methods We performed a comprehensive literature search of PubMed capturing articles from 1958 to 2022. Results We identified nine alternative approaches for endovascular access, after excluding direct carotid stick: superficial temporal artery access in 60 patients, calvarial foramina access in five patients, occipital artery access in seven patients, middle meningeal artery access in six patients, vertebral artery access in 23 patients and external carotid artery, internal maxillary artery, facial artery or lingual artery in 40 patients. Indications for the use of alternative access points included tortuous or occluded vessels, small vessel calibers, or anatomic variation. Pathologies treated included dural arteriovenous fistulas, arteriovenous malformations, intracranial aneurysms, acute stroke, and intracranial stenosis. Diagnostic brain angiograms were also performed. Conclusions Alternative vascular access routes expand the proceduralists' toolkit, enhancing the capability to manage complex cerebrovascular interventions. This review advocates for a broader understanding and consideration of these techniques, given their potential to significantly increase treatment options in neuroendovascular surgery.