Postoperative Communicating Hydrocephalus Following Grade 2/3 Glioma Resection: Incidence, Timing and Risk Factors

In diffusely infiltrating gliomas, the maximum extent of tumor resection is an important predictor of overall survival, irrespective of histological or molecular subtype or tumor grade. For glioblastoma WHO grade 4 (GBM), it has been shown that resection-related events, such as ventricular opening and ventriculitis, increase the risk for development of communicating hydrocephalus (CH) requiring cerebrospinal fluid (CSF) diversion surgery. Risk factors for the development and the incidence of hydrocephalus following resection of other types of infiltrating gliomas are less well established. In this study, we evaluated the incidence and timing of occurrence of different types of hydrocephalus and potential risk factors for the development of CH following resection of grade 2 and 3 gliomas.

346 patients who underwent tumor resection (WHO grade 2: 42.2%; 3: 57.8%) at our department between 2006 and 2019 were analyzed retrospectively. For each patient, age, sex, WHO grade, histological type, IDH mutation and 1p/19q codeletion status, tumor localization, number of resections, rebleeding, ventriculitis, ventricular opening during resection and postoperative CSF leak were determined. Uni- as well as multivariate analyses were performed to identify associations with CH and independent risk factors.

24 out of 346 (6.9%) patients needed CSF diversion surgery (implantation of a ventriculoperitoneal or ventriculoatrial shunt) following resection. Nineteen patients (5.5%) had CH, on median, 44 days after the last resection (interquartile range: 18-89 days). Two patients had obstructive hydrocephalus (OH), and three patients had other CSF circulation disorders. CH was more frequent in grade 3 compared to grade 2 gliomas (8.5 vs. 1.4%). WHO grade 3 (odds ratio (OR) 7.5, p = 0.00468), rebleeding (OR 5.0, p = 0.00984), ventriculitis (OR 4.1, p = 0.00463) and infratentorial tumor localization (OR 6.6, p = 0.00300) were identified as significant independent risk factors for the development of post-resection CH. Ventricular opening was significantly associated with CH, but it was not an independent risk factor.

Physicians treating brain tumor patients should be aware that postoperative CH requiring CSF shunting occurs not only in GBM but also after resection of lower-grade gliomas, especially in grade 3 tumors. It usually occurs several weeks after resection. Rebleeding and postoperative ventriculitis are independent risk factors.