OBJECTIVETo observe the clinical and pathological characteristics of brain arteriovenous malformations (BAVM) embolized with the non-adhesive aqueous embolic agent Onyx and evaluate its application in comprehensive treatment of BAVM.

METHODSThirty-four patients underwent BAVM embolization using Onyx, and their clinical manifestations, architecture of the malformed vessels, emblization procedure, and complications associated with the procedures were recorded. The resected tissues after embolization with Onyx were observed with electron microscope, and the prognosis of the patients was estimated with modified Rankin Score (mRS).

RESULTSThese patients included 21 male and 13 female patients with a mean age of 30.45-/+11.81 years and an estimated mean size of the nidus of 3.98-/+1.43 cm. The patients received a total of 52 endovascular treatment procedures with Onyx to embolize 86 feeding pedicals, which resulted in an average estimated size reduction of the nidus of (72.35-/+21.26)%. Complications associated with the procedure occurred in 7 patients, and 23 patients received surgical resection or radiosurgery after embolization. Follow-up of the patients for 6 months to 4 years showed that the mRS was below 3 in 32 cases and > or =3 in 2 cases. Vasodilatation, brain tissue edema surrounding the nidus, and inflammatory cell infiltration were observed in the resected tissues after embolization. In some major feeding pedicals, thrombus recanalization was observed after embolization with Onyx (diameter> or =3 mm).

CONCLUSIONEndovascular treatment of BAVM with Onyx can achieve high occlusion rate, enhance the safety of operation and radiosurgery, and improve the clinical prognosis of the patients.