Elsevier

World Neurosurgery

Volume 106, October 2017, Pages 615-624
World Neurosurgery

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

https://doi.org/10.1016/j.wneu.2017.07.034Get rights and content

Objective

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.

Methods

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.

Results

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).

Conclusions

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.

Introduction

Glioblastoma (GBM) is among the most common primary brain tumors.1 Given the current standard of care, patients diagnosed with GBM exhibit a median overall survival (OS) of approximately 16 months.2, 3, 4, 5 OS is dependent on patient age, O-6-methylguanine-DNA-methyltransferase (MGMT) methylation status, isocitrate dehydrogenase (IDH) mutation status, Karnofsky Performance Status (KPS), and the extent of resection (EOR).6, 7, 8

Tumor resection is one of the strongest predictors of OS.9, 10, 11, 12, 13 Much effort has been made to increase the extent of GBM resection as far as safely possible. Fluorescence-guided surgery with 5-aminolevulinic acid has enabled surgeons to accomplish supramarginal resections well beyond the enhancing mass appreciated on preoperative scans.14 Moreover, intraoperative methods, such as electrophysiological monitoring, cortical mapping, and awake surgery, have been used to achieve maximal safe resection even in eloquent areas.15, 16, 17, 18

In many cases, tumor infiltration of the ventricular wall represents an obstacle that many surgeons are reluctant to surpass during GBM resection. Avoidance to open the ventricular system is based on 2 concerns: the development of a communicating hydrocephalus and ependymal tumor spread (Figure 1). Both are believed to be associated with reduced quality of life and decreased OS.

Previous studies, reporting ventricular opening in 59%19 and 18.9%20 of cases, discussed these scenarios in detail, although neither investigation determined their impact on patient prognosis. These studies performed univariate analyses and thus did not examine the impact of established prognostic factors on OS after GBM resection.19, 20 Another study has observed that the rate of hydrocephalus after GBM resection increased from 3.4% to 15.2% if the ventricle was opened during surgery. However, postoperative hydrocephalus had no negative prognostic effect on OS if treated appropriately.21, 22

A most recent retrospective analysis by John et al.23 assessed the role of ventricular opening in a variety of tumor entities including 74 GBMs. The authors showed that the complication rate in patients with ventricular opening (19%) increased to 46% compared with 21% in patients without ventricular opening. The authors further suggested that ventricular opening is associated with shorter OS in patients with GBM, but they did not perform a multivariate analysis to confirm univariate observation and did not conclude clear recommendations. So far, the question whether ventricular entry during GBM surgery impacts OS and causes lasting increased morbidity remains still unanswered. In many cases ventricular opening is necessary to achieve complete macroscopic tumor resection. This study assessed the independent prognostic impact of ventricular opening on the incidence of postoperative complications, length of hospital stay, adjuvant treatment delays, and OS in patients who underwent primary GBM resection.

Section snippets

Study Design

This retrospective observational single-center analysis was performed to determine whether ventricular opening during primary GBM resection influences OS and postoperative hydrocephalus occurrence. We also investigated the impact of tumor proximity to the ventricle and ventricular opening and the impact of intraoperative ventricular opening on the postoperative neurological outcome as well as the length of hospital stay and adjuvant treatment delays.

We analyzed primary GBMs of 229 patients who

Participants

Overall, 326 patients were screened for inclusion into this study, all primary GBMs surgically treated in the author's institution between January 2006 and December 2013. Ninety-seven patients were excluded from this study since they only received a biopsy (n = 68) or postoperative images were not available (n = 29). 229 patients were eligible for the analysis of the impact of ventricular opening on postoperative morbidity (hydrocephalus, CSF fistula, postoperative deficits, the length of

Key Results

The prognostic role of ventricular opening during GBM resection remains a matter of debate. In this retrospective study, we analyzed 229 patients with GBM to determine the relation of ventricular opening, with postoperative hydrocephalus and CSF fistula development, postoperative neurologic deficits, the length of hospital stay, adjuvant treatment delay, and OS including all established prognostic covariates. The rate of CSF fistula development was significantly greater in patients who

Conclusions

Ventricular opening during GBM resection has no independent negative prognostic effect and should therefore not prevent neurosurgeons from attempting safe and feasible maximal tumor resections. This finding is critically important, as the extent of tumor resection is one of the strongest independent predictors of OS. This study also has demonstrated that ventricular opening does not increase neurological morbidity, nor does it delay adjuvant therapy.

Acknowledgments

We thank the editors at American Journal Experts for editing the manuscript for nonintellectual content.

References (32)

  • M.R. Gilbert et al.

    A randomized trial of bevacizumab for newly diagnosed glioblastoma

    N Engl J Med

    (2014)
  • C. Hartmann et al.

    Patients with IDH1 wild type anaplastic astrocytomas exhibit worse prognosis than IDH1-mutated glioblastomas, and IDH1 mutation status accounts for the unfavorable prognostic effect of higher age: implications for classification of gliomas

    Acta Neuropathol

    (2010)
  • M.E. Hegi et al.

    Correlation of O6-methylguanine methyltransferase (MGMT) promoter methylation with clinical outcomes in glioblastoma and clinical strategies to modulate MGMT activity

    J Clin Oncol

    (2008)
  • M. Lacroix et al.

    A multivariate analysis of 416 patients with glioblastoma multiforme: prognosis, extent of resection, and survival

    J Neurosurg

    (2001)
  • N. Sanai et al.

    An extent of resection threshold for newly diagnosed glioblastomas

    J Neurosurg

    (2011)
  • M.E. Oppenlander et al.

    An extent of resection threshold for recurrent glioblastoma and its risk for neurological morbidity

    J Neurosurg

    (2014)
  • Cited by (0)

    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

    View full text