Objective: Postoperative ischemia is a major complication of neurosurgical procedures. Perforator territory ischemia has been related to poor postoperative neurological outcome. This study aimed to investigate the incidence and clinical severity of postoperative perforator territory ischemia in patients with intra-axial or extra-axial tumors.
Methods: Between 2019 and 2022, records of all patients who underwent craniotomies for intra-axial or extra-axial tumors at the authors' brain tumor center were retrospectively reviewed. Patient and disease characteristics, abnormalities identified on early postoperative MRI diffusion-weighted imaging (DWI) sequences, and neurological status measured using the full-scale National Institutes of Health Stroke Scale (NIHSS) at the preoperative time and postoperative follow-up were extracted. Groups were compared based on NIHSS score deterioration at discharge and were stratified for intra-axial tumor subtypes and extra-axial tumor locations. Postoperative DWI abnormality assessment was divided into different territories (perforator territory, cortex, insular, white matter, and multiple locations). The authors distinguished between "anticipated" ischemia directly bordering the resection cavity and iatrogenic injury related to vessel injuries. Multivariable linear regression analyses were performed with full-scale NIHSS scores at discharge as the dependent variable while adjusting for preoperative NIHSS scores and the territories where DWI abnormalities were detected.
Results: In total, 1012 patients underwent craniotomies at the authors' institution. Ultimately, 548 patients with intra-axial tumors and 188 patients with extra-axial tumors were included. The overall incidence of DWI abnormalities in the perforator territory in patients with intra-axial tumors was 14% (n = 74). In the intra-axial group, multivariable linear regression analysis showed that patients with postoperative perforator territory DWI abnormalities (β coefficient 0.72, 95% CI 0.18-1.27; p = 0.01), insular ischemia (β coefficient 0.95, 95% CI 0.08-1.81; p = 0.03), or cortical ischemia (β coefficient 0.43, 95% CI 0.06-0.81; p = 0.02) on DWI had a higher total NIHSS score at discharge. The overall incidence of perforator territory DWI abnormalities in patients with extra-axial tumors was 12% (n = 22). No association was found between NIHSS score at discharge and the territories showing DWI abnormalities.
Conclusions: The overall incidence of perforator territory DWI abnormalities suggesting ischemia was found to be around 13% in both patients with intra-axial and extra-axial tumors. Patients with intra-axial tumors, who had postoperative perforator territory or insular DWI abnormalities, performed worse neurologically at discharge, compared with patients with cortical and/or white matter ischemia.
Keywords: cerebral perforators; extra-axial tumor; glioma surgery; intra-axial tumor; postoperative ischemia; skull base surgery; surgical technique; vascular disorders.