Abstract 1122‐000048: Endovascular Treatment for Spetzler‐Martin Grade III Pediatric Arteriovenous Malformations

Abstract

Introduction : Grade III Spetzler‐Martin (SM) brain arteriovenous malformations (AVMs) presents high variability in terms of size (S), angioarchitecture, flow characteristics, a frequent involvement of eloquent areas (E), and presence of central venous drainage (V). Therefore, this specific group fall into a gray zone in which the best treatment option is not stablished. Here, we aimed to assess the safety and efficacy of intent‐to‐cure embolization in pediatric grade III AVM management at two institutions. Methods : Pediatric patients (<18 years of age) with grade III AVMs treated with intent‐to‐cure embolization in two institutions between 2010 and 2019 were included. These two centers primarily perform endovascular treatment with intention to cure, which means that they attempt to occlude the maximal volume of nidus in a single session. Then, if the first session is not curative or the result is partial, a subsequent embolization is planned to completely occlude the AVM nidus. The clinical features, obliteration rates, and intraoperative complications were retrospectively collected from the clinical records. We categorized the AVMs based by the SM features: Type 1 = S1E1V1, Type 2 = S2E1V0, Type 3 = S2E0V1, and Type 4 = S3E0V0. The Institutional Review Boards approved this study. Results : Twenty‐seven children (19 females; mean age: 12 years, standard deviation: 3.9 years) with grade III AVMs underwent 47 embolization sessions. The most common presentation was intracranial hemorrhage (66%), and the majority (48%) were deep lesions (basal ganglia, corpus callosum, ventricle). The size of AVMs was <3 cm in 16 patients, 3 – 6 cm in 9, and >6 cm in 2; 21 AVMs were in eloquent cortex and 20 had deep venous drainage. The AVMs were Type 1 in 16 cases, Type 2 in 5, Type 3 in 4, and Type 4 in 2. Complete obliteration was achieved in 12 patients (44%), including 37% of AVMs exclusions after a single session. Eight (30%) patients had multiple embolizations. The AVM was obliterated after a single session in 10 patients (63%) with Type 1 AVMs (small lesions). The most common embolic agent employed was Squid (17/44), followed by Onyx (14/44) and Histoacryl (6/44). Intraoperative complications were reported in 5 (4 microperforations, 1 microcatheter rupture) out of 47 sessions (11%), with only one complication in the large AVM group (Types 2 ‐ 4). Deaths were not reported. Conclusions : Endovascular treatment with intent‐to‐cure of grade III SM AVMs in the pediatric population has demonstrated adequate complete obliteration rates with acceptable intraoperative complication rates. Therefore, long‐term follow‐up in this population is necessary in order to assess the real impact of embolization in terms of cure rates.