A 47-year old man suffering from aphasia and mild rt hemiparesis was disclosed to have lt front-parietal subcortical hematoma in CT and cerebral arteriovenous malformation (AVM) angiographically which was placed in sensory-motor area fed by three cortical branches of lt middle cerebral artery. Lt front-parietal craniotomy was performed under general anesthesia. The main feeder and one other feeder were exposed under surgical microscope. After the minor feeder was temporarily clipped to reduce the flow of AVM, the main feeder was cannulated by a 22 gauge Tephlon catheter and isobutyl-2-cyanoacrylate (IBCA) was injected through the catheter. During the injection of IBCA, the operative field was observed carefully under surgical microscope and injection was stopped immediately when IBCA filled the fine venous portion of the AVM. The AVM was obliterated immediately and no blood flow was observed when the temporary clip on the minor feeder was released. Since angiography in the operating room revealed the disappearance of the AVM, the main feeder was coagulated and sacrificed, then the operation was completed. The postoperative neurological course was good and CT showed no drawbacks, such as remarkable cerebral swelling, in the use of this procedure. Postoperative angiography revealed complete obliteration of the AVM and preservation of the normal vascular network.
Although advances in microsurgical techniques have made possible the complete, surgical resection of AVMs in the speech and sensory-motor regions without disabilities, some risks and difficulties still remain. Since embolization with IBCA can permanently obliterate AVMs without surgical removal, invasion toward the surrounding brain could be less than a surgical excision. Recently the technique of interventional radiology has been applied to embolization of AVMs, but occasionally percutaneous navigation of the balloon catheter to a feeding artery near the nidus may be impossible, especially with low flow AVMs. In such cases, exposure of the feeding artery under craniotomy is useful to prevent accidental embolization of normal vascular channels. Partial embolization is a major problem in this method. In the present case, complete embolization of AVM was performed successfully by temporary occlusion of the minor feeder to reduce the blood flow of the AVM; however, this procedure may not be available where some feeders cannot be exposed in the same operating field. In such cases, stepwise embolization may be considered. Providing on adequate amount of embolization materials and monitoring during embolization to prevent stray embolization are problems to be resolved.