Characterization of N-butyl Cyanoacrylate (NBCA) Glue Polymerization for the Embolization of Brain Arteriovenous Malformations (AVMs)

Abstract

Brain AVMs are abnormal connections between arteries and veins. Endovascular glue embolization with NBCA is an accepted form of treatment. The reported complication rates of NBCA embolization varies widely from 2-15%, and timing of polymerization plays a major role. Polymerization time was measured for mixtures of lipiodol/NBCA of 50/50, 70/30, 60/40. The influence of pH, temperature and presence of biological catalysts on polymerization time was investigated in-vivo. PVA-C, silicone and endothelium surfaces were compared. High-speed video analysis of glue injection through a microcatheter was performed. Polymerization rate increases with pH and temperature. A hydrophilic surface such as PVA-C better mimics endothelium. Biological substrates including endothelium and blood products dramatically increase the polymerization rate. Characterization of coaxial flow shows dripping to jetting transition with significant wall effect. The determinants of NBCA polymerization rate are multifactorial and dependent mainly upon the presence of biological substrates coupled with flow-related wall interaction