Descriptions of temporal lobe arteriovenous malformations (AVMs) are inconsistent. To standardize reporting, the authors blended existing descriptions in the literature into an intuitive classification with 5 anatomical subtypes: lateral, medial, basal, sylvian, and ventricular. The authors' surgical experience with temporal lobe AVMs was reviewed according to these subtypes.
Eighty-eight patients with temporal lobe AVMs were treated surgically.
Lateral temporal lobe AVMs were the most common (58 AVMs, 66%). Thirteen AVMs (15%) were medial, 9 (10%) were basal, and 5 (6%) were sylvian. Ventricular AVMs were least common (3 AVMs, 3%). A temporal craniotomy based over the ear was used in 64%. Complete AVM resection was achieved in 82 patients (93%). Four patients (5%) died in the perioperative period (6 in all were lost to follow-up); 71 (87%) of the remaining 82 patients had good outcomes (modified Rankin Scale scores 0–2); and 68 (83%) were unchanged or improved after surgery.
Categorization of temporal AVMs into subtypes can assist with surgical planning and also standardize reporting. Lateral AVMs are the easiest to expose surgically, with circumferential access to feeding arteries and draining veins at the AVM margins. Basal AVMs require a subtemporal approach, often with some transcortical dissection through the inferior temporal gyrus. Medial AVMs are exposed tangentially with an orbitozygomatic craniotomy and transsylvian dissection of anterior choroidal artery and posterior cerebral artery feeders in the medial cisterns. Medial AVMs posterior to the cerebral peduncle require transcortical approaches through the temporo-occipital gyrus. Sylvian AVMs require a wide sylvian fissure split and differentiation of normal arteries, terminal feeding arteries, and transit arteries. Ventricular AVMs require a transcortical approach through the inferior temporal gyrus that avoids the Meyer loop. Surgical results with temporal lobe AVMs are generally good, and classifying them does not offer any prediction of surgical risk.
Abbreviations used in this paper:AChA = anterior choroidal artery; ACoA = anterior communicating artery; ATA = anterior temporal artery; AVM = arteriovenous malformation; BA = basilar artery; BVR = basal vein of Rosenthal; DSA = digital subtraction angiogram; ICA = internal carotid artery; LSA = lenticulostriate artery; MCA = middle cerebral artery; MMA = middle meningeal artery; mRS = modified Rankin Scale; MTA = middle temporal artery; PCA = posterior cerebral artery; PCoA = posterior communicating artery; PTA = posterior temporal artery; STA = superior temporal artery; UCSF = University of California, San Francisco; VA = vertebral artery.
Address correspondence to: Michael T. Lawton, M.D., Department of Neurological Surgery, University of California at San Francisco, 505 Parnassus Ave., M780, San Francisco, CA 94143-0112. email: email@example.com.
Please include this information when citing this paper: published online July 12, 2013; DOI: 10.3171/2013.6.JNS122333.
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