Efficacy of diluted NBCA mixture for embolization of arteriovenous malformations

The purpose of this study is to evaluate the efficacy and problems of the embolization for cerebral arteriovenous malformations (AVMs) with diluted cyanoacrylate adhesives. Twelve consecutive AVM cases were treated with N-butyl-2-cyanoacrylate (NBCA) glues between January 1997 and July 1998. The mean age of the patients was 37 years old. Intracerebral hemorrhage was the presenting symptom in seven cases, seizure in three, headache in one and mental deterioration in one. According to the classification of Spetzler and Martin, seven were Grade II, five were Grade III. We used a mixture of NBCA (normally 25% Histoacryl, 75% Ethidol) for embolization. Microcatheter was navigated into the nidus and the tip of the catheter was set in a wedged position. Then the glue was injected using complete column technique. Nineteen sessions of embolization were performed in 12 patients. The mean volume of each nidus was reduced from 22.5 ml to 3.4 ml (85%) after embolization. Four cases were cured by embolization alone. Surgical resection was performed after embolization without any residual nidus in three cases. Five were treated with stereotactic radiosurgery following embolization. One was completely cured in 18 months after and the other four have been decreasing their sizes of nidus. One case was suffered from delayed intracerebral hemorrhage three days after embolization, and resulted in mild hemiparesis and memory disturbance. The others had no complications and were clinically improved or unchanged after embolization. It is possible to embolize the nidus of AVMs more accurately and safely with diluted mixture of NBCA, compared with the method using relatively higher concentration of NBCA glues. This technique is useful and effective method for the treatment of AVMs.