Onyx embolization of a cerebellar arteriovenous malformation fed by the posterior inferior cerebellar artery originating from a vertebral artery fenestration: illustrative case.

Because the vessel wall near the proximal end of a fenestration is fragile, careful manipulation is required during microcatheter insertion and withdrawal to avoid mechanical stress. https://thejns.org/doi/10.3171/CASE25790.