Intraoperative precautionary insertion of external ventricular drainage catheters in posterior fossa tumors presenting with hydrocephalus

IntroductionHydrocephalus in association of posterior cranial fossa tumors (PFT) remains a matter of controversy; whether to perform cerebrospinal fluid (CSF) diversion prior to tumor resection, or to perform direct tumor resection.ObjectiveThe aim of this study is to assess the risks and benefits associated with routine intraoperative insertion of external ventricular drainage (EVD) catheters in patients with PFT presenting with hydrocephalus.MethodsForty two patients with PFT with secondary hydrocephalus had intraoperative insertion of an external ventricular drainage catheter, it was kept closed, unless intraoperative lowering of the intracranial tension was needed, or opened postoperatively in cases of persistent hydrocephalus, CSF leak, in certain cases throughout and after the procedure.ResultsEight cases (19%) needed opening of the drainage system during surgery to lower the intracranial tension. In the postoperative period, twelve cases (28.5%) needed opening of the EVD for the persistence of hydrocephalus, occurrence of CSF leak or bloody CSF. Only eight cases (19%) needed permanent CSF shunting, seven of which were ependymomas and medulloblastomas. None of the cases in this series acquired any EVD related infection, nor did those who required subsequent permanent CSF diversion.ConclusionIntra-operative insertion of EVD catheter during surgery of posterior fossa tumors, as it allows better control of the ICT during surgery if needed, provides a life saving emergency CSF drainage outlet if tumor resection fails to resolve HC or for the occurrence of de novo HC, and finally it provides adequate control of CSF leak in cases with supratentorial ventriculomegaly, where the use of lumbar drains may be hazardous. Intraoperative drainage prevents possible complications met with early CSF diversion. But the application of this technique should better be restricted to midline posterior fossa tumors related to the ventricular system.