Balancing the Extent of Resection and Ischemic Complications in Insular Glioma Surgery: Technical Nuances and Proposal of a Novel Composite Postoperative Outcome Index

• Published in: Neurology India Vol. 70; no. 3; pp. 983 - 991
• Main Authors: Das, Kuntal, Gosal, Jaskaran, Khatri, Deepak, Singh, Amanjot, Datta, Aanchal, Kumar, Abhishek, Bhaisora, Kamlesh, Verma, Pawan, Srivastava, Arun, Jaiswal, Awadhesh, Behari, Sanjay
• Format: Journal Article
• Language: English
• Published: Mumbai Wolters Kluwer India Pvt. Ltd 01.05.2022; Medknow Publications & Media Pvt. Ltd
• Subjects: Glioma; Medical prognosis; Postoperative period; Surgery; Surgical outcomes; Tumors; complications; lenticulostriate artery; composite postoperative outcome index; trans-basisulcal planeKey Message: Despite the increasing application of operative adjuncts; Approach; insular glioma; outcome; surgery; the anatomy and topography-based surgical approach to insular gliomas remains quintessential. The novel postoperative surgical outcome index proposed in this paper objectifies the concept of onco-functional balance
• ISSN: 0028-3886; 1998-4022
• DOI: 10.4103/0028-3886.349642

Background: Maximal safe resection remains the most desired goal of insular glioma surgery. Intraoperative surgical adjuncts provide better tumor visualization and real-time "safety" data but remain limited due to a high cost and limited availability. Objective: To highlight the importance of anatomical landmarks in insular glioma resection and avoidance of vascular complications. We also propose to objectify the onco-functional balance in insular glioma surgery. Methods: Forty-six insular gliomas operated upon by a single surgeon between January 2015 and February 2020 were reviewed, focusing on the operative technique and clinical outcomes. A novel composite postoperative outcome index (CPOI) was designed, comprising the extent of resection and permanent postoperative deficits, and utilized to assess the surgical outcomes. Results: Gross-total, near-total, and subtotal resections were achieved in 10.9%, 52.1% (n = 24), and 36.9% (n = 17) patients, respectively. The median overall survival (OS) was 20 months (95% CI = 9.56-30.43). CPOI was optimal in 38 patients (82.6%). A well-defined tumor margin (P = 0.01) and surgeon's experience (P = 0.04) were significantly associated with an optimal CPOI. Out of seven (15.2%) patients who developed permanent neurological deficits, three (6.5%) patients had severe disability. Favorable prognostic factors of survival included younger age (<40 years) (P = 0.002), tumors with only frontal lobe extension (P = 0.011), tumors with caudate head involvement (P = 0.04), and non-glioblastoma histology (P = 0.006). Conclusion: Tumor margin and increasing surgeon experience are critical to an optimal postoperative outcome. Respecting the basi-sulcal plane is key to lenticulostriate artery preservation. Caudate head involvement is a new favorable prognostic factor in insular gliomas.