SURG-45. Predictive Factors for Awake Surgery Failure

Abstract BACKGROUND Awake surgery (AS) has demonstrated utility in the resection of brain tumors and in epilepsy surgery. However, due to risks such as intraoperative seizures and difficulties in securing the airway, it is desirable to avoid unnecessary AS in cases where poor intraoperative awakening is anticipated, as this may result in insufficient neurological monitoring (AS failure). In the present study, we retrospectively analyzed predictive factors for AS failure. METHODS A total of 78 consecutive cases of AS performed for brain tumors and epilepsy at our institution between January 2021 and December 2024 were retrospectively reviewed. We evaluated previously reported predictive factors and contraindications for AS, as well as the presence or absence of basal ganglionic involvement. RESULTS The mean age was 45.4 years, and 46 patients were male. The median MoCA-J score was 26. Preoperative aphasia was present in 26 cases, and the median preoperative KPS was 90. Left hemisphere lesions were present in 52 cases. Diagnoses included high-grade glioma (47), low-grade glioma (17), and epilepsy (11). Repeated surgeries were performed in 30 cases, midline shift was observed in 19, and basal ganglionic involvement in 18. Successful AS, defined as sufficient intraoperative neurological monitoring under awake conditions, was achieved in 65 cases (83.3%). Failed AS, defined as insufficient monitoring due to poor awakening, occurred in 13 cases (16.7%). A comparison between the two groups revealed the following: left hemisphere lesions were present in 60% of the successful group and 100% of the failure group (p=0.0035); midline shift was observed in 16.9% vs. 61.5% (p=0.0019); and basal ganglionic involvement in 9.2% vs. 92.3% (p<0.0001), respectively. CONCLUSIONS Left hemisphere involvement, midline shift, and basal ganglionic involvement were significantly more frequent in the AS failure group. Among these, basal ganglionic involvement may serve as a novel predictive factor for AS failure.