| The role of embolization of cerebral arteriovenous malformations (AVMs) by liquid embolic agents has increased in recent years. One commonly used agent is n-butyl 2-cyanoacrylate (NBCA). The key to success of embolization of an AVM is to achieve complete glue casting of the lesion. We have previously investigated the accurate estimation of transit times through the malformation by injection of insoluble contrast that can be used for proper selection of glue mixture ratio. Albeit, precise polymerization kinetics of NBCA are still unknown.; We have used the swine rete to create a model of a human AVM. In our model embolizations were performed acutely as well as in chronic preparations. For the chronic preparation, flow was redirected through the rete by creating an arteriovenous fistula. After a period of at least six months, the retia were harvested and connected to a perfusion loop driven by a peristaltic pump.; For the acute preparation a legation of the left common carotid artery was performed. A cannula, open to atmospheric pressure, was positioned into the left ascending pharyngeal artery, thereby, providing the desired flow through the rete.; A total of thirty swine were used for both preparations with the following mixtures of Lipiodol/NBCA+Glacial Acetic Acid (%volume/%volume+μl) were used for embolization: 80/20+0, 50/50+0, 50/50+5, 50/50+10, and 50/50+20. For each mixture a group of six retia were used for analysis. In each experiment, flow, pressure-drop across the rete, and glue injection profile were recorded. Radiographic images obtained from the harvested retia were used to correlate the dispersion and depth of the penetration of the glue mixtures into retia with the hemodynamics. Also, the effect of different amount of glacial acetic acid (GAA) on the kinetics of the mixtures is studied.; Our results show that the addition of GAA resulted in a more complete cast of the AVM with better dispersion of the glue into the smaller vessels without increasing the initial viscosity of the mixture. Addition of 20 μl of GAA to a 50/50 glue mixture resulted in a penetration and dispersion of the glue three times higher than the one without the acid while the mean pressure gradient across the retia for these two groups were almost the same. |
