Postoperative ischemic lesions are a significant concern for neurosurgeons performing resections for diffuse low-grade glioma (dLGG). Recent data from a Scandinavian multicenter study highlights that these lesions occur much more frequently than previously estimated. Understanding the patterns of ischemic injury is essential for improving functional outcomes and minimizing iatrogenic neurological deterioration in oncology patients.

Characteristics of Postoperative Ischemic Lesions

The study analyzed 286 patients using diffusion-weighted MRI (DWI) to detect ischemia following surgery. Surprisingly, researchers identified a postoperative ischemic lesion in 85.7% of cases. These injuries were categorized into two primary types: rim-type lesions, which are limited to the resection border, and sector-type lesions, which extend deeper into the brain tissue. While rim-type lesions occurred in about 30.4% of patients, sector-type lesions were more prevalent, affecting 55.2% of the cohort.

Correlation with Neurological Deficits

The clinical impact of these lesions depends heavily on their morphology and total volume. Sector-shaped lesions showed a stronger correlation with transient neurological deterioration compared to rim lesions. Furthermore, patients experiencing permanent major deficits typically had significantly larger lesion volumes. Specifically, the mean volume for major deficits was 4.2 cm³ compared to 1.6 cm³ in those without such deficits.

Consequently, the use of advanced imaging or intraoperative monitoring did not significantly reduce the incidence of these lesions. This suggests that the mechanical and vascular challenges inherent in dLGG surgery remain the primary drivers of ischemic injury. Surgeons must focus on vascular preservation to enhance the safety profile of glioma resections and ensure better long-term recovery for their patients.

Frequently Asked Questions

How common are postoperative ischemic lesions after glioma surgery?

Research indicates that ischemic lesions are very common, appearing in over 85% of patients following diffuse low-grade glioma resection when assessed by postoperative MRI.

Which type of ischemic lesion is more dangerous?

Sector-shaped ischemic lesions, which extend further into the brain tissue, are more frequently associated with neurological deficits than rim-shaped lesions that remain limited to the resection border.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or a professional recommendation. Always consult with a qualified healthcare provider for diagnosis and treatment. Refer to the latest local and national guidelines for clinical practice.

References

Dunås T et al. Epidemiology of ischemic lesions after diffuse low-grade glioma resection: a Scandinavian multicenter study. J Neurosurg. 2026 Mar 13. doi: 10.3171/2025.10.JNS25658. PMID: 41825065.