Gliomas are one of the most common type of intracranial malignant tumours. Although the incidence of gliomas is relatively low (approximately 661/100,000), disability and mortality rates associated with it are very high.17 As a high-grade glioma, glioblastomas are characterized by highly invasive growth, difficulty to perform a complete surgical resection, high recurrence rate, and poor prognosis.18 Therefore, methods to achieve a breakthrough in the treatment of glioblastoma and improve the prognosis of glioblastoma patients have become an area of intense clinical research.
At present, the main treatment strategy for glioblastoma is to remove as much of the lesion as possible and provide comprehensive treatment such as chemo-radiotherapy to prevent neurological dysfunction. Surgical resection usually includes total, subtotal, or partial resection. Therefore, maximal safe resection of tumours has become the consensus for surgical treatment of glioblastoma.19,20 Although the effects of glioblastoma prognosis vary, the amount of residual postoperative tumour is an important factor affecting prognosis. Total resection of tumours directly affects the recurrence and survival time, and the extent of resection may determine subsequent treatment.21 Retaining sensation, speech, movement, and other important neurological functions while maximizing tumour removal is a goal of many neurosurgeons.
New technologies are being used to increase the safety and effectiveness of surgery. In particular, performing an awake craniotomy using neuronavigation, cortical electrical stimulation, intraoperative ultrasound, tumour luciferin, and other auxiliary means, has greatly expanded the neurosurgeon's expertise in tumour surgery of eloquent eloquentregions, which promotes tumour removal as thoroughly as possible.22 Initially, when the neuronavigation system became standard, it allowed surgeons to preoperatively create a "desired range" of excision, whether total, subtotal, or partial. However, due to the complication of intraoperative brain displacement, neurophysiological monitoring was added to improve the safety of the operation.23
We first identified tumour boundaries with navigation-guided catheterization, assisted neurophysiological monitoring as projection guidance to determine neural function, and "fine-tuned" tumour resection. 5-ALA only provided a relative boundary for glioblastoma, and the surgeon decided to further remove the tumour tissue or to terminate resection based on neurophysiological monitoring results, as well as the patient's condition, family support, patient's occupation, and prior discussion with the patient. Since iUS and iMRI cannot provide the "expected excision range", they can only be used as post-excision verification tools.
This study explored the application of awake craniotomy combined with neuronavigation, neuroelectrophysiological monitoring, iUS, and tumour fluorescence for glioblastoma resection to achieve tumour resection with maximum safety. Awake craniotomy had been performed as a routine strategy in our centre, and more than 300 cases had been performed to achieve maximum safety removal while minimizing the rate of neurological damage.24 In our initial experience, 80 patients had total or near total resection, which represents a good resection range, comparable to or better than the 91% of total or near total resection reported thus far.25 The rate of new neurological damage has been reported to be 18–23% has been reported.26,27,28 In our study, 91% of patients had either improved or no change in their neurological status. Only 7 patients experienced new neurological dysfunction and a reduced KPS score after surgery, including worsening of their pre-existing neurological dysfunction. This decline was most likely due to mechanical manipulation and heat damage to the functional brain tissue. However, intraoperative neuroelectrophysiological monitoring and DTI imaging localization were used to protect the eloquent structures of brain tissue, and 6 patients recovered within 3 months after surgery, avoiding permanent neurological damage.
In our patient cohort, all operations were successfully completed, and conversion to general anaesthesia was not required during the operation. The rate of conversion to general anaesthesia or failure has been reported to range from 2.4 to 6.4%.29 In addition, during the study period, awake craniotomy patients were hospitalized for an average of 6.89 days and had fewer postoperative complications. Intraoperative epilepsy is one of the most common complications of awake craniotomy. In our study, 2 patients experienced brief seizures during motor localization, and we quickly controlled the symptoms with cold saline and propofol and continued the surgery. It is currently believed that seizures may be caused by cortical stimulation and localization. Patients with a long history of seizures undoubtedly have a higher probability of intraoperative seizure. Thus, we used cortical stimulation very carefully for intraoperative localization to reduce the risk of intraoperative seizures. We optimized the control of epileptic seizures with the preoperative and intraoperative use of sodium valproate to prevent epilepsy.
Here, a retrospective analysis was conducted on patients undergoing an awake craniotomy. Although the number of cases was limited, our results suggest the promising prospects for performing awake craniotomy to remove glioblastomas. These results at least partly confirmed the effectiveness of awake surgery combined with multimodal techniques in the protection of intraoperative neurological function. Among the 81 glioblastoma patients studied, the median survival time was 12 months, which was higher than the median survival time of glioblastoma patients studied at home and abroad. This partly confirmed the improvement in prognosis and survival rate of glioblastoma patients after total resection and expanded resection. We found that awake craniotomy improved surgical safety and reduced neurological deficits, consistent with past reports. The next step is to study this technique in other patients (e.g., thalamus, basal ganglia, internal capsule, etc.) and establish a control group for comparison in order to demonstrate the direct impact of the technique on the extent of resection, postoperative nerve status, or overall survival. In addition, patients' coordination and tolerance during awake craniotomy were enhanced by ensuring comfort during surgery, appropriate use of sedatives to minimize fatigue, and the use of long-duration anaesthetics to block local scalp surgery. Therefore, we were able to achieve the goal of maximum safe resection in the vast majority of patients.