Total Intravenous Versus Inhalational Anesthesia in High-Grade Glioma Surgery: A Systematic Review and Meta-Analysis

<i>Background and Objectives</i>: High-grade gliomas (HGGs) are aggressive primary brain tumors with a poor prognosis despite multimodal treatment. The anesthetic technique used during surgery may influence tumor progression and survival, but its role in HGGs remains unclear. This meta-analysis evaluated the effect of total intravenous anesthesia (TIVA) versus inhalational anesthesia (INHA) on overall survival (OS) and progression-free survival (PFS) in HGG patients. <i>Materials and Methods</i>: A systematic search was conducted in PubMed, Scopus, and Cochrane databases for studies assessing the impact of TIVA versus INHA on OS and PFS in HGG patients. Statistical analysis was performed using R version 4.3.1. Heterogeneity across studies was quantified using the Cochrane Q test alongside the I² statistic. A random-effects model was employed to derive the pooled hazard ratios (HRs). <i>Results</i>: A total of five studies involving 827 participants (mean age 58 years, mean females 38%) were included, of whom 406 (49%) received TIVA. No statistically significant differences were observed in OS (HR 0.77; 95% CI [0.58-1.02]; <i>p</i> = 0.07; I² = 67%) or PFS (HR 0.88; 95% CI [0.70-1.10]; <i>p</i> = 0.27; I² = 51%) between the groups. A subgroup analysis revealed that TIVA was associated with improved OS in patients with grade IV tumors (HR 0.70; 95% CI [0.51-0.96]; <i>p</i> = 0.03), while no significant effect was observed in the mixed grade III-IV subgroup. However, the test for subgroup differences was not statistically significant (<i>p</i> = 0.0669), and this finding should be interpreted with caution. No significant differences were observed in median OS or PFS, or in single-arm meta-analyses. <i>Conclusions</i>: This meta-analysis found no statistically significant differences in overall or progression-free survival between TIVA and INHA in patients undergoing surgery for HGGs. Although a subgroup analysis suggested a possible survival advantage of TIVA in grade IV tumors, the lack of a statistically significant subgroup difference test limits the strength of this finding. Further investigation is needed to determine whether anesthetic technique influences outcomes in this subgroup.