E-109 Precipitating hydrophobic injectable liquid (PHIL) in endovascular treatment of brain arteriovenous malformations: initial experience

Abstract

<h3>Background</h3> Non-adhesive embolization compositions are a method of choice in endovascular treatment of a brain arteriovenous malformation (AVM). Non-adhesive precipitating hydrophobic injectable liquid (PHIL) is a relatively new material for treating such pathologies. The objective of this paper is to demonstrate our initial experience in using of PHIL for treatment of brain AVMs. <h3>Materials and Methods</h3> Between May 2015 and January 2021, E.Meshalkin National Medical Research Center and Federal Center of Brain and Neurotechnologies treated 131 AVM patients using PHIL. By January, the treatment had been completed in 70 of the patients; 59 were undergoing a staged embolization, and 2 patients had died between stages due to an AVM rupture. The data for analysis were accumulated in a prospective database. <h3>Results</h3> The cohort for analysis included the 70 patients whose treatment was finalized. Total occlusion was achieved in 50 patients (71.4%). Among them, 28 underwent a single-stage embolization. In 14 patients (28%), the procedure was performed using PHIL only. A procedure, where using PHIL was combined with a single-stage microsurgical resection was performed in 2 (4%) cases. The remaining 35 patients (70%) underwent embolization with a combination of embolizing agents (Onyx, Squid, N-BCA) as during a single as during a multi-stage treatment. Seven patients (10%) underwent a subtotal embolization with single-stage microsurgical resection. In 6 patients (8.6%) subtotal embolization was followed by radiosurgery. Partial AVM occlusion with microsurgical resection and partial embolization with radiosurgical treatment were performed in 1 (1.4%) and 3 (4.3%) patients, respectively. Partial AVM occlusion only was performed in 3 patients (4.3%). Intra-and postoperative complications were registered in 37 cases (53%). Persistent neurological deficiency developed in 4 patients (5.7%), including the two after partial embolization. The mortality rate comprised 1.4% to be 1 patient after partial AVM embolization. <h3>Conclusion</h3> PHIL is an effective tool for treatment of brain AVMs. The agent has a high degree of initial occlusion and is safe if compared to the other liquid embolization materials. However, large-scale multicenter studies are required to determine the embolizer’s safety profile and to estimate its long-term efficacy. <h3>Disclosures</h3> <b>K. Orlov:</b> None. <b>N. Strelnikov:</b> None. <b>V. Berestov:</b> None. <b>A. Somova:</b> None.