Localization and Microsurgical Resection of Left Postcentral Gyrus Spetzler-Martin Grade 3 Arteriovenous Malformation by Intraoperative Neuronavigation and Tracing of Subcortical Draining Vein: 3-Dimensional Operative Video.

This 42-yr-old man presented with a history of sudden right-sided facial and right arm weakness and dysarthria. Head computed tomography showed a left frontal-parietal blood clot. An intra-arterial digital subtraction angiography demonstrated a left subcortical postcentral, Spetzler-Martin Grade 3 arteriovenous malformation (AVM) with a diffuse nidus, measuring 2.1 × 1.5 cm, supplied by branches of the left MCA, and draining into a cortical vein and a deep vein, which was going toward the ventricle. Preoperative embolization was not possible.  The patient underwent left frontal-parietal craniotomy with intraoperative motor and sensory mapping. No arterialized veins were visible on the cortical surface. Neuronavigation localized the AVM in the subcortical postcentral gyrus. Through an incision in the postcentral sulcus, microdissection led to a yellowish gliotic plane. The large cortical vein was in the gliotic area and traced to the AVM. Circumferential microdissection was performed around the AVM. It had a very diffuse nidus; the arterial feeders were cauterized and divided, and the superior superficial and inferior deep draining veins were finally occluded, and AVM was removed.  Postoperative angiogram showed total removal of the AVM. At discharge, his right arm weakness had improved (power 5/5), and facial weakness and dysarthria were improving (modified Rankin Scale (mRS) 2). At 1-yr follow-up, facial weakness and dysarthria had improved considerably, and patient returned to work (mRS 1).  This video shows microsurgical resection of an AVM by neuronavigation and tracing of the subcortical draining vein. The technique of cauterizing the perforating arteries after temporary clipping with flow arrest is shown in the video. Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.