Embolization of brain arteriovenous malformations with squid co-polymer embolic material: Initial experience

To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer (EVOH) liquid embolic agent Squid (Emboflu, Switzerland) for the treatment of brain arteriovenous malformations. Between April 2015 and July 2017, 46 embolization treatments for brain arteriovenous malformations (BAVM) were performed in 25 patients using two Squid formulations (18 and 12). Six female and 19 male patients with a mean age of 34 years (range, 9–62 years) were included. A total of 46 procedures were performed. The BAVMs were classified as Spetzler-Martin grade II in 4 procedures, III in 27 procedures, and 1V in 15 procedures. Among the 25 patients, 15 presented with hemorrhage, 5 with seizures, and 5 with headache and neurology. The BAVMs were located in the temporal lobe in 5 patients, parietal lobe in 7 patients, frontal lobe in 3 patients, posterior fossa in 6 patients, basal ganglia in 3 patients, and parasagittal lobe in 1 patient. The obliteration rate of the BAVMs ranged from 10% to 100%, with a mean of 33%. Most patients underwent their first or second embolization procedure. Four patients (8%) developed intracranial bleeding post procedure, with one death (2%). One patient (2%) experienced a seizure during the procedure; however, no intracranial bleeding was observed. Seven patients (15%) experienced perforations during catheter manipulation. One case (2%) of fractured catheter was recorded, but no significant complications were observed. The average volume of copolymer injected was 0.6 ​ml per nidus. Thirteen procedures used the Squid-12 formulation, 29 procedures used the Squid-18 formulation, and 3 procedures used a combination of Squid-12 and -18 formulations. Squid is a safe and effective embolic agent for treating BAVMs.