Neurosurgery 66:1074-1084, 2010 DOI: 10.1227/01.NEU.0000369514.74284.78
Awake craniotomy with intraoperative electrical mapping is a reliable method to minimize the risk of permanent deficit during surgery for low-grade glioma located within eloquent areas classically considered inoperable. However, it could be argued that preservation of functional sites might lead to a lesser degree of tumor removal. To the best of our knowledge, the extent of resection has never been directly compared between traditional and awake procedures.
OBJECTIVE: We report for the first time a series of patients who underwent 2 consecutive surgeries without and with awake mapping.
METHODS: Nine patients underwent surgery for a low-grade glioma in functional sites under general anesthesia in other institutions. The resection was subtotal in 3 cases and partial in 6 cases. There was a postoperative worsening in 3 cases. We performed a second surgery in the awake condition with intraoperative electrostimulation. The resection was performed according to functional boundaries at both the cortical and subcortical levels.
RESULTS: Postoperative magnetic resonance imaging showed that the resection was complete in 5 cases and subtotal in 4 cases (no partial removal) and that it was improved in all cases compared with the first surgery (P = .04). There was no permanent neurological worsening. Three patients improved compared with the presurgical status. All patients returned to normal professional and social lives.
CONCLUSION: Our results demonstrate that awake surgery, known to preserve the quality of life in patients with low-grade glioma, is also able to significantly improve the extent of resection for lesions located in functional regions.
Neurosurgery 66:523-529, 2010 DOI: 10.1227/01.NEU.0000364996.97762.73
During the past decade, numerous reports have supported the contribution of awake mapping in surgical removal of brain lesions in eloquent areas, with a significant increase of the extent of resection while minimizing the risk of permanent deficit—and even improving quality of life.
METHODS: Most of these awake procedures were performed in patients with lesions in language areas, to avoid postoperative aphasia. Surprisingly, mapping of nonlanguage functions received less attention, despite the possible consequences of deficits other than aphasia on daily life. Visuospatial and cognitive deficits are reported after brain surgery, because of more objective and extensive neuropsychological assessments.
RESULTS AND CONCLUSION: This review provides new insights into the indications of awake craniotomies for nonlanguage mapping in surgery for lesions in areas not related to language processing.
Neurosurg Focus 28 (2):E8, 2010. DOI: 10.3171/2009.12.FOCUS09236
Recent surgical studies have demonstrated that the extent of resection is significantly correlated with median survival in WHO Grade II gliomas. Consequently, thanks to advances in intraoperative functional mapping, the authors questioned whether it is actually necessary to leave a “security” margin around eloquent structures.
Methods. The authors first reviewed the classic literature, especially that based on epilepsy surgery and functional neuroimaging techniques, which led them to propose the rule of a security margin. Second, they detailed new developments in the field of intrasurgical electrical mapping, especially with regard to subcortical stimulation of the projection and long-distance association pathways. On the basis of these advances, the removal of gliomas according to functional boundaries has recently been suggested, with no margin around eloquent structures.
Results. Comparative results showed that the rate of permanent deficit was similar with or without a security margin, that is, < 2%. However, a higher rate of transient neurological worsening in the immediate postsurgical period was associated with the absence of a margin, with recovery following adapted rehabilitation. On the other hand, the extent of resection was in essence improved with no margin.
Conclusions. This no-margin technique, based on the subpial dissection, and the repetition of both cortical and subcortical stimulation to preserve eloquent cortex as well as the white matter tracts (U-fibers, projection pathways, and long-distance connectivity) allow optimization of the extent of resection while preserving the quality of life (despite transitory impairment) thanks to mechanisms of brain plasticity.
Neurosurg Focus 27 (2):E7, 2009
Despite the report of recent experiences of insular surgery in the past decade, there has been no series specifically dedicated to studying functional outcome following resection of insular WHO Grade II gliomas involving the dominant hemisphere, in patients with no or only mild preoperative language deficit. In this article, the authors analyze the contribution of awake mapping for preservation of brain function, especially language, in a homogeneous series of 24 patients who underwent surgery for insular Grade II gliomas within the dominant insular lobe.
Methods
Twenty-four patients underwent surgery for an insular Grade II glioma involving the dominant hemisphere (22 left, 2 right), revealed by seizures in all but 1 case. The preoperative neurological examination result was normal in 17 patients (71%), whereas 7 patients presented with language disorders detected using an accurate language assessment performed by a speech therapist. All surgeries were performed on awake patients utilizing intra-operative language mapping involving cortical and subcortical stimulation.
Results
There were no intrasurgical complications or postsurgical sensorimotor deficits. Despite an immediate postoperative language worsening in 12 cases (50%), all patients recovered to a normal status within 3 months, and 6 cases even improved in comparison with their preoperative examination results. The 24 patients returned to normal social and professional lives. Moreover, the surgery had a favorable impact on epilepsy in all but 4 cases (83%). On control MR imaging, 62.5% of resections were total or subtotal. Three patients underwent a second or third awake surgery, with no additional deficit. All but 2 patients (92%) are alive after a mean follow-up of 3 years (range 3–133 months).
Conclusions
Although insular surgery was long believed to be too risky, the present results show that the rate of permanent deficit, especially dysphasia, following resection of Grade II gliomas involving the dominant insula has been dramatically reduced (none in this patient series), thanks to the systematic use of intraoperative awake mapping, even in cases of repeated operations. Furthermore, patient quality of life may be improved due to a decrease of epilepsy after surgery. Thus, the authors suggest systematically considering resection when an insular Grade II glioma is diagnosed after seizures in a patient with no or mild deficit, even a glioma invading the dominant hemisphere.
