A series of 309 awake surgeries with transcortical approach for IDH-mutant low-grade glioma involving the insula: long-term onco-functional outcomes in 253 consecutive patients

Hugues Duffau

Journal of Neurosurgery +

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April 18, 2025

View abstract on PubMed

Summary

Awake surgery (AS) for insular low-grade gliomas (LGGs) through the opercula offers high functional preservation and return to work rates. This approach demonstrates excellent extent of resection (EOR) and overall survival, even for gliomas invading multiple lobes.

Area Of Science

Neurosurgery
Oncology
Neurology

Background

Low-grade gliomas (LGGs) involving the insula present unique surgical challenges.
Awake surgery (AS) with intraoperative functional mapping is crucial for minimizing morbidity and maximizing resection in LGGs.
The efficacy of AS via a transcortical approach for insular LGGs, particularly comparing pure insular versus multi-lobar involvement, requires further investigation.

Purpose Of The Study

To investigate the long-term outcomes of AS via a transcortical approach for LGGs within the insula.
To compare functional and oncological results between pure insular gliomas and those also invading other lobes.
To evaluate the role of AS in preserving function and achieving maximal tumor resection in this specific patient cohort.

Main Methods

Retrospective analysis of patients with isocitrate dehydrogenase-mutant grade 2 gliomas involving the insula who underwent AS by the author (June 2002-January 2024).
Patients were categorized into two groups: pure insular gliomas (group 1) and insular-centered gliomas involving other lobes (group 2).
Functional outcomes (Karnofsky Performance Scale, epilepsy control, return to work) and oncological outcomes (extent of resection, survival) were analyzed and compared between groups.

Main Results

A cohort of 253 patients (309 ASs) demonstrated excellent functional preservation, with 99.2% having no permanent postoperative deficit and 96.6% returning to work.
The mean extent of resection (EOR) was 89.4%, with a high overall survival rate of 80.2% at a mean follow-up of 7.1 years.
Both groups showed similar EOR and rates of intractable postoperative seizures, with group 2 (multi-lobar involvement) having a higher rate of return to work.

Conclusions

This study represents the largest homogeneous experience of AS for insular LGGs via the opercula using awake mapping.
AS provides high functional preservation, significant return-to-work rates, and favorable long-term survival for LGGs involving the insula.
The approach is effective for both pure insular and multi-lobar insular-centered gliomas, supporting its role in managing these complex tumors.

Keywords:

awake mapping epilepsy functional neurosurgery functional outcomes insula low-grade glioma return to work survival tumor