A nonadhesive liquid embolic agent of ethylene vinyl alcohol copolymer and ethanol mixture for cerebral arteriovenous malformations. Clinical experience.

We report our experience using our new nonadhesive liquid embolic agent, an ethylene vinyl alcohol copolymer (EVAL)/Ethanol mixture, to treat human arteriovenous malformations (AVM). Between June 1995 and April 2001, 57 patients with confirmed AVM underwent embolization with the EVAL/Ethanol mixture. Using 87 procedures consisting of one to three stages, we embolized 185 feeding arteries to occlude as much of the AVM as possible. Repeated injections under fluoroscopic control could be performed smoothly without encountering cementing of the catheter in the vessel wall. Among 87 procedures undertaken in 57 patients, seven (8.0%) procedures in six patients produced new postembolization symptoms. Resolution of these symptoms occurred within hours or days following four of the seven procedures; permanent neurological deficits remained after three embolization procedures (3.4%). Of the 57 patients, three underwent postembolization radiosurgery, 54 were radically treated with microsurgical extirpation. Histopathological examinations of the 54 specimens disclosed mild inflammation within the embolized lumen without inflammatory reactions in the media or adventitia. Follow-up angiograms obtained three years after they underwent radiosurgery showed that in all three patients the nidus had completely disappeared. The EVAL/Ethanol mixture is handled easily and appears to be an effective and safe embolic agent for the preoperative embolization of AVM.