Clinical application of intraoperative MRI navigation in microsurgical resection of cerebral arteriovenous malformations located near the main functional areas

Objective To evaluate the efficacy and safety of intraoperative MRI navigation in the microsurgical treatment of arteriovenous malformations (AVM) located near the main functional areas of brain. Methods A total of 53 patients with AVM in the adjacent functional areas were treated by microsurgical operation with intraoperative MRI navigation and electrophysiological monitoring. Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) and diffusion tensor imaging (DTI) examinations were performed before and during operation. We fused BOLD-fMRI and DTI images to form three-dimensional images containing lesions, important functional areas and pyramidal tract so as to study the relationship between them and their changes before and after operation. Results The diameter of malformations in 53 patients was 2-7 cm, on average of (3.41 ± 0.85) cm. There were 6 patients involved in sensory areas, 7 patients in motor areas, 10 patients in pyramidal tract, 14 patients in language areas, 2 patients in visual cortex, 9 patients in optic radiation, 2 patients in basal ganglia and 3 patients in brain stem. Gross total resection was achieved in 49 patients while full functionality was retained. The other 4 patients with intraoperative MRI navigation were found that malformations and functional areas were closely related, so the lesions were partially resected. There were 8 patients with new-onset postoperative neurological dysfunction, among whom one case was found bilateral visual field defects, 3 patients' muscle tone was lower than before, one case of facial paralysis, 2 cases of aphasia, one with decreased muscle tone and motor aphasia. Follow-up period varied from 3 to 60 months [median 19.37 (6.00, 30.00) months], and 2 cases died (one died of respiratory failure after one year, and the other was agnogenic). Glasgow Outcome Scale (GOS) score was 5 in 45 cases (84.91%), 4 in 3 cases (5.66%), 3 in 2 cases (3.77%), 2 in one case (1.89%) and one in 2 cases (3.77%). Conclusions With the application of intraoperative MRI navigation and electrophysiological monitoring, it may be appropriate to expand the surgical indications of AVM located near the main functional areas of brain. DOI: 10.3969/j.issn.1672-6731.2016.12.006