Which of the following embolic agents is considered a permanent, non-resorbable liquid agent commonly used for high-flow arteriovenous malformations (AVMs) due to its ability to penetrate deeply into the nidus and polymerize in situ?

Explanation

N-butyl cyanoacrylate (NBCA) glue is a liquid embolic agent that polymerizes rapidly upon contact with ionic solutions like blood. This property allows it to be injected and flow deeply into the complex nidus of high-flow AVMs, providing permanent occlusion. Gelfoam is a temporary, resorbable particulate agent. Polyvinyl alcohol (PVA) particles are permanent particulate agents but may not penetrate as deeply or provide as cohesive an occlusion as liquid embolics for AVMs. Coils are permanent mechanical occlusive devices primarily used for larger vessels, aneurysms, or fistulas, rather than the diffuse nidus of an AVM.