P-001 A simple animal model for the pre-clinical evaluation of liquid embolic agents and adjunctive devices used in transvenous retrograde embolization of arteriovenous malformations

Objective Traditionally, embolization of cerebral AVMs has been performed by trans-arterial injection of liquid embolic agent (LEA) into the nidus of the AVM. Recently transvenous retrograde embolization (TvRE) has been reported to be successful in the treatment of some AVMs. An appropriate animal model might be useful for pre-clinical testing of newer LEAs as well as any adjunctive devices, which are being developed for TvRE. Flow reversal in the Swine rete mirable (RM) has been shown to result in conditions mimicking AVM physiology. 1 Herein, we report on the feasibility of using an Swine model with flow reversal for pre-clinical evaluation of a LEA with an adjunctive embolic containment device (ECD) for the performance of TvRE. Methods The experiments were carried out in two adult Yorkshire Swine specimens. General anesthesia was induced, and following femoral arterial access, an 8 French Flow Gate (Stryker, USA) Balloon Guide catheter (BGC) was advanced into the left internal carotid artery. A Headway Duo Microcatheter and a 0.021’ microcatheter were advanced through the BGC into the ascending pharyngeal artery supplying the RM. The BGC was inflated to produce flow reversal in the RM, and a novel ECD was deployed through the 0.021’ microcatheter and positioned proximal to the tip of the Duo Microcatheter. An LEA (PHIL, Microvention, USA) was then retrogradely injected into the RM, through the Duo Microcatheter. The ECD was left detached at the end of the procedure. Results In both specimens, there was good retrograde flow of the LEA into the RM and LEA was not seen to reflux below the proximal ECD marker (figure 1). Conclusion Flow reversal in the Ovine RM, produced by endovascular balloon occlusion can provide a simple model for the pre-clinical testing of LEAs and adjunctive devices used for TvRE in cerebral AVMs. Reference Siekmann R, Wakloo AJ, Brauch B, et al . Modification of previously described arteriovenous malformation model in the swine: Endovascular and combined surgical/endovascular construction and hemodynamics. Am J Neuroradiol 2000;21:1722–1725. Disclosures B. Jagadeesan: 1; C; Microvention, Medtronic. 2; C; Microvention, CvRx. S. Moen: None. R. Tummala: None. A. Grande: None.