Impact of Extent of Resection and Surgical Approach on Outcomes of Insular Gliomas

Abstract Background: The surgical treatment of gliomas in the insular region is considered a challenge for neurosurgeons. The insular cortex represents only 2% of the whole cortex, but gliomas in this area reach up to 25% of all low-grade gliomas (LGG) and 10% of all high-grade gliomas (HGG). Aim of Study: This study aimed to discuss the different modalities in the surgical management of insular gliomas to obtain favorable surgical outcomes (maximum resection with no deficits) and to identify the different variants affecting the outcomes. Material and Methods: The data of 21 patients with insular gliomas who had surgery at our institute between August 2018 and August 2020 were retrospectively evaluated in this study. The obtained data included age, gender, preoperative and postoperative clinical conditions, radiological features, ap-proach of surgery, extent of resection of the tumor, and histopathology. Results: Based on the immediate postoperative clinical outcomes, six cases (28.6%) showed new neurological deficits. Moreover, 9 tumors (42.9%) were treated via the trans-sylvian approach and 12 (57.1%) via the transcortical approach. Awake craniotomy was performed in four cases (19%). Of all cases, six (28.6%) had an extent of resection (EOR) of <90%, five (23.8%) had an EOR of >!90%, and ten (47.6%) underwent gross total removal. Conclusion: Overall, a significant statistical correlation between the EOR and the pathological grade of the tumor was observed, but no statistical difference between the transcor-tical and trans-sylvian approaches in relation to the outcome or the extent of resection. Gliomas in zone 2 and gliomas extending via the superior limiting sulcus showed more postoperative deficits.