Surgery for brain arteriovenous malformations (BAVMs): The role of intraoperative imaging and neuromonitoring

Object This study sought to determine the role of different intraoperative imaging modalities and intraoperative neuromonitoring in BAVM surgery, describing a current prospective surgical series. Methods Prospective series of 23 BAVMs treated with the adjunct of intraoperative MRI (iMRI) (n = 12), intraoperative angiography (iOA) (n = 11), intraoperative Indocyanine green (ICG) videoangiography (n = 23) and intraoperative neuromonitoring (IOM) (n = 13). Assessment of each imaging modality in view of resection control for BAVMs. Illustration of peculiar aspects of the various imaging modalities in neurovascular surgery. Correlation of IOM and postoperative patient course. Results We observed a marked drop of signal-to-noise ratio in intraoperative TOF-MRA, due to the effects of general anaesthesia on cerebral blood flow velocity. 2 false negative MRI-findings occurred (16.7%). IOA turned out as safe, time-efficient with standard diagnostic image quality. ICG appeared not suitable to assess residual BAVM due to infratentorial or deep-seated location in 3 patients. It helped to detect residual AV-Shunt in 3 patients, invariably SM 3 and 4. 3 false-negative ICG-findings occurred (15.0%). IOM allowed correct localization of the central sulcus in 3 cases and reliable motor monitoring in the whole study group. No complications occurred attributable to the applied intraoperative imaging or monitoring techniques. Conclusions Our results demonstrate that iMRI currently does not appear appropriate to detect residual nidus in BAVM surgery. DSA remains the intraoperative imaging modality of choice in BAVM surgery even in times of ICG. ICG can be regarded as valuable complementary tool. IOM, at least in our small series proved to reliably localize and monitor the motor system.