E-082 Initial experience of combined phil™ and ONYX® brain AVM embolization

Introduction DMSO-based non-adhesive embolic devices nowadays are the mainstay of multimodality treatment for brain arteriovenous malformations (AVMs). Ethylene vinyl alcohol copolymer (Onyx) pioneered on the market and quickly became the unofficial gold standard for AVM embolization. Recently appeared polylactide-co-glycolide and polyhydroxyethylmethacrylate copolymer (PHIL) was thought as primary competitor for Onyx. But due to its different intrinsic properties in some cases PHIL may be a valuable addition rather than substitute. Hereby we want to present our experience in combined PHIL and Onyx AVM embolization. Materials and methods The group (n=8) consisted of 3 males and 5 females aged from 14 to 67 years old. 3 patients had hemorrhagic manifestation of the disease, 3 patients had secondary epilepsy and two patients had only a headache at presentation. The patients were graded by Spetzler-Martin as grade II (n=3), grade III (n=3) and grade IV (n=2). The principle of this technique is primary PHIL injection (aiming to occlude high-flow compartments) followed by slow delivery of Onyx into small-vessel relatively low-flow parts of the nidus via the same microcatheter. In 5 cases the technique has been implied as the first session of multi-stage treatment. In 4 of them complete occlusion was instantly achieved. Results No intraoperative complications were observed. There were two cases of postoperative complications: transient neurological deficiency and parenchymal hemorrhage that did not require surgery. In one case AVM related aneurysm required immediate clipping following complete nidus occlusion. By the results of histological examination of the removed nidus we can suppose that PHIL penetrates into lower caliber vessels in comparison with Onyx (see figure 1). Conclusion Combined injection of PHIL and Onyx via the same micro catheter is technically possible and safe. Proposed method has a potential to increase treatment radicality with similar complication risk, though due to low presented sample size further investigations are required. Due to the fact that precipitation of PHIL takes less times, there is a possibility that some parts may left non-embolized. Onyx, at the same time, penetrates those compartments with high radicality. Disclosures A. Tasenko: None. P. Seleznev: None. A. Moskalev: None. K. Orlov: None.