Intraoperative detection of residual arteriovenous malformation using narrow-band imaging: illustrative case

Complete obliteration of the nidus is the primary goal of microsurgical treatment for arteriovenous malformations (AVMs), yet small residual components may be difficult to detect under conventional white-light visualization.

A 46-year-old man presented with a ruptured Spetzler-Martin grade III AVM with a large temporoparietal intracerebral hemorrhage. After endovascular embolization, microsurgical resection was performed using a 4K 3D ORBEYE exoscope system. Although the nidus appeared completely removed under white light, narrow-band imaging (NBI) revealed a small vascular lesion within the resection cavity. Indocyanine green videoangiography (ICG-VA) confirmed residual blood flow, and the suspected remnant was additionally resected. Histopathological analysis demonstrated arterialized vessels with irregular internal elastic laminae consistent with residual AVM components. Postoperative angiography confirmed complete obliteration. The patient was transferred for rehabilitation on hospital day 70 with mild aphasia and sensory disturbance (modified Rankin Scale score 2).

NBI served as a useful adjunct for detecting small residual AVM components during microsurgical resection. Combined use with ICG-VA may improve intraoperative assessment of nidus removal. https://thejns.org/doi/10.3171/CASE26265.