Awake Craniotomy for Resection of Brain Metastases: A Systematic Review

Background Surgery for brain metastases aims to reduce mass effect and achieve local control through maximizing resection. There is increasing recognition that awake craniotomy (AC) is especially relevant for resection of brain metastases in eloquent areas. This study seeks to examine the neurologic outcomes of using AC for brain metastases resection. Methods A systematic search for studies examining the role of AC in patients with brain metastases was conducted via PubMed without limitations on the year of publication, language, or study design, using the following search terms: (cerebral OR brain) and (metastases OR tumor) and (awake OR intraoperative OR eloquent OR supramarginal). Studies were included if patients underwent AC for resection of brain metastases and data on pre- and postoperative neurologic function were available. Results Seven studies published between 2001 and 2017 with 104 patients who underwent 107 ACs were identified. Gross total resection was achieved in 61% of patients, supramarginal resection was achieved in 32%, and subtotal resection was achieved in 7%. Immediately after operation, 73% of patients experienced no change or improvement in neurologic outcomes, whereas 27% experienced worsening. In the long term, 96% of those with postoperative worsening of function experienced improvements in neurologic function. Conclusions Most patients experienced improvements in neurologic function immediately after AC, and most patients that experienced short-term worsening of neurologic function after the procedure showed excellent recovery. AC should be considered as a technique to optimize outcomes in brain metastases in eloquent areas.