AWAKE CRANIOTOMY TO MAXIMIZE GLIOMA RESECTION: METHODS AND TECHNICAL NUANCES

OBJECTIVE: Awake craniotomy is the gold standard for the identification and preservation of functional areas. The goal of this study was to analyze a single surgeon's experience and the evolving methodology of awake language and sensorimotor mapping for glioma surgery to maximize perioperative safety. METHODS: We retrospectively studied patients from 1986-2013 undergoing awake brain tumor surgery. Perioperative risk factors and complications were assessed using 611 cases. RESULTS: Median patient age was 42 years (range, 13-84 years). Sixty percent of patients had KPS scores of 90-100, and 40% had KPS scores under 80. Fifty-five percent of patients received surgery for high-grade gliomas, 42% for low-grade gliomas, 1% for metastatic lesions, and 2% for other lesions (cortical dysplasia, encephalitis, necrosis, abscess, hemangioma). The majority of patients were ASA class 1 or 2 (mild systemic disease). Laryngeal mask airway (LMA) was used in 8 patients (1%), and was most commonly used for large vascular tumors with more than 2 cm of mass effect. The most common sedation regimen was propofol plus remifentanil (PR; 54%); however, 42% required an adjustment to the initial sedation regimen before skin incision. Mannitol was used in 54% of cases. Twelve percent of patients were active smokers at the time of surgery, which did not impact intraoperative mapping procedure failure. Stimulation-induced seizures occurred in 3% of patients and were rapidly terminated with ice-cold Ringer's solution. Preoperative seizure history and tumor location were associated with an increased incidence of stimulation-induced seizures. Mapping was aborted in 3 cases (0.5%) due to intraoperative seizures and patient emotional intolerance. The overall perioperative complication rate was 10%. CONCLUSIONS: Awake brain tumor surgery can be safely performed with low complication and failure rates regardless of ASA classification, Mallampati score, body mass index, smoking status, psychiatric history, seizure history, tumor site, or tumor pathology.