Efficacy and low vascular toxicity of embolization with radical versus anionic polymerization of n-butyl-2-cyanoacrylate (NBCA) - An experimental study in the swine

Background and purpose: To compare the efficacy and vascular toxicity of embolization with radical (NBCA+metacryloxysulpholane = CS) versus conventional anionic (NBCA alone = CA) polymerization of NBCA. Materials and methods: Under continuous digital subtracted angiography (DSA) recordings, a 0.2 mL volume of identical glue mixtures were injected in a single-step procedure, concomitantly, in left and right (with CS and CA, respectively) renal arterial branches (RAB) and ascending pharyngeal arteries (APA) in 8 swines. Arterial histopathology and morphometry of inflammation were investigated at 2 weeks. Results: Complete embolization was achieved with equivalent cast homogeneity on DSA with both NBCA mixtures in RAB and APA. Inflammatory crowns in APA and RAB were significantly lower in CS - than in CA-treated sites (P<0.001). CS plug was scarcely adhesive to the vascular wall, and pulled apart from the wall by a residual thrombotic lining; in contrast with CA casts that were strongly adhesive to walls with endothelium stripping. Conclusions: Anionic and radical polymerization of NBCA embolization was identical with regards to occlusion rate; whereas radical pathway of polymerization with cyanoacrylates lowered histotoxicity with a less sustained adhesiveness of casts against vascular walls.