Surgical Techniques for Insular Glioma Management

Insular gliomas present a formidable challenge due to their deep-seated location, proximity to critical vascular structures and eloquent cortex, and intimate involvement with white matter tracts. Surgical strategies aim to maximise tumour removal while preserving neurological function. Two principal corridors—the trans-Sylvian and transcortical approaches—offer complementary advantages: the former provides direct access through the sylvian fissure for vascular control, whereas the latter via opercular corticotomies permits awake mapping of sensorimotor, language and cognitive pathways. Advances in microsurgical anatomy have refined the understanding of insular zones, as classified by Berger-Sanai, guiding tailored resection based on tumour extent and relation to lenticulostriate arteries. Awake craniotomy, direct electrostimulation mapping and intraoperative neurophysiological monitoring work in concert to delineate functional boundaries. Concurrently, intraoperative imaging technologies—such as magnetic resonance imaging and ultrahigh-resolution angiography—enable real-time assessment of residual disease and perforator preservation. Multimodal integration of these techniques has driven extent-of-resection rates beyond 90 per cent in specialised centres, with minimised permanent deficits and improved seizure control, quality of life and return-to-work outcomes.

Research from Nature Portfolio

Recent studies have demonstrated the efficacy of intraoperative magnetic resonance imaging (IoMRI) in guiding microsurgical resection of non-dominant fronto-temporo-insular gliomas under general anaesthesia without routine cortical or subcortical mapping. In a series of consecutive patients, serial IoMRI scans permitted incremental debulking until a median extent of resection of 92 per cent was achieved. Early postoperative assessments revealed transient motor deficits in a minority of cases and preserved neuropsychological profiles, including sociocognitive functions. Most patients were symptom-free at discharge and regained high Karnofsky Performance Scores at three months, with nearly half resuming professional activities. These findings underscore the potential of IoMRI as an adjunct to microsurgical technique in selectively challenging insular lesions.

Surgical Techniques for Insular Glioma Management publication trend

The graph below shows the total number of articles in surgical techniques for insular glioma management across all publications each year (not limited to Nature Index journals).

Technical terms

Extent of Resection (EOR): The percentage of tumour volume removed during surgery, a predictor of survival and seizure control.

Transcortical Approach: Corticotomy through frontal, temporal or parietal opercula to access the insula while mapping functional cortex.

Trans-Sylvian Approach: Dissection along the sylvian fissure to expose insular cortex and middle cerebral artery branches for vascular preservation.

Intraoperative MRI (IoMRI): Real-time magnetic resonance imaging used during surgery to assess residual tumour and guide further resection.

Intraoperative Neurophysiological Monitoring (IONM): Continuous recording of electrical responses (e.g. motor-evoked potentials) to detect and prevent functional injury.

Lenticulostriate Arteries (LSAs): Deep perforating vessels arising from the middle cerebral artery essential for basal ganglia and internal capsule perfusion.

Berger-Sanai Classification: A zonal system dividing the insula into four regions to guide surgical planning and risk assessment.

References

1. Anatomical aspects of the insula, opercula and peri-insular white matter for a transcortical approach to insular glioma resection. Neurosurgical Review (2021).
2. Awake Surgery for Left Posterior Insular Low-Grade Glioma Through the Parietorolandic Operculum: The Need to Preserve the Functional Connectivity. A Case Series. Frontiers in Surgery (2022).
3. Incidence of ischemic complications and technical nuances of arteries preservation for insular gliomas resection. Frontiers in Surgery (2022).
4. Microsurgical resection of fronto-temporo-insular gliomas in the non-dominant hemisphere, under general anesthesia using adjunct intraoperative MRI and no cortical and subcortical mapping: a series of 20 consecutive patients. Scientific Reports (2021).
5. Factors affecting the extent of resection and neurological outcomes following transopercular resection of insular gliomas. Acta Neurochirurgica (2024).
6. Visualization of the lenticulostriate arteries, long insular arteries, and long medullary arteries on intra-arterial computed tomography angiography with ultrahigh resolution in patients with glioma. Acta Neurochirurgica (2023).