The Prognostic Impact of Ventricular Opening in Glioblastoma Surgery: A Retrospective Single Center Analysis.

Abstract

Ventricular opening during glioblastoma (GBM) resection is controversial. Sufficient evidence regarding its prognostic role is missing. We investigated the impact of ventricular opening on overall survival (OS), hydrocephalus development, and postoperative morbidity in patients with GBM. Patients who underwent primary GBM resection between 2006 and 2013 were assessed retrospectively. Established predictors for overall survival (age, Karnofsky Performance Status, extent of resection, O-6-methylguanine-DNA methyltransferase promoter methylation status, isocitrate dehydrogenase mutation status) and further clinical data (postoperative status, further treatment, preoperative tumor volume, proximity to the ventricle) were included in univariate and multivariate analyses. Thirteen (5.7%) of 229 patients developed a hydrocephalus. Multivariate logistic regression showed that neither ventricular opening, tumor size, proximity to the ventricle, nor extent of resection were significant risk factors for hydrocephalus. Ventricular opening did not delay postoperative therapy and was not associated with neurological morbidity. Kaplan-Meier analysis demonstrated that patients who underwent ventricular opening (n= 114) exhibited a median OS of 14.3 months (12.9-16.5), whereas patients who did not undergo ventricular opening (n= 115) exhibited a median OS of 18.6 months (16.1-20.8). However, multivariate Cox regression (n= 134) did not confirm ventricular opening as an independent negative predictor of OS (risk ratio 1.09, P= 0.77). Instead, it showed that a greater preoperative tumor volume >22.8 cm3 was a negative predictor of OS (risk ratio 1.76, P= 0.02). Because extent of resection is a strong independent predictor of OS and ventricular opening is safe, neurosurgeons should consider ventricular opening to achieve maximal tumor resection.