Hydrocephalus Associated with Posterior Fossa Tumors: How to Manage Effectively?

Background: Hydrocephalus associated with posterior fossa tumor (PFT) is a common neurosurgical problem, the management of which is still controversial. Aim: To provide an overview of the advantages and limitations of different management strategies for hydrocephalus associated with PFT both before and after resection of these tumors. Methods: Structured review of the literature on the management of hydrocephalus in PFT both in children and adults. Results: The incidence of hydrocephalus associated with PFT at the time of presentation is more in children (70-90%) than adults (10-21%). This difference is maintained for hydrocephalus after the resection of PFT (~30% for children and 1.2-6.9% for adults). Preresection hydrocephalus is obstructive while emerging evidence in the literature suggests that postresection hydrocephalus may have a communicating component. The treatment of preresection hydrocephalus associated with PFT has undergone a paradigm shift in the past two decades. Preoperative Cerebrospinal Fluid (CSF) diversion is less commonly used except when required by the clinical condition of the patient. Preresection hydrocephalus may be treated by steroid use and early tumor removal, perioperative use of external ventricular drainage, or endoscopic third ventriculostomy in selected patients. Various prediction scales are available to assess the risk of postresection hydrocephalus in PFT. Certain histological tumor types and molecular phenotypes of PFT are more commonly associated with hydrocephalus. CSF diversion through endoscopic third ventriculostomy or ventriculoperitoneal shunts remains the management strategies for postresection hydrocephalus. The failure rates and the time-to-failure of both endoscopic third ventriculostomy and CSF shunts in PFT are variable and surgeons should be aware of these while taking management decisions. Conclusions: Hydrocephalus associated with PFT affects the quality of life of patients with such lesions. Routine preoperative CSF diversion is not necessary for the vast majority of patients with posterior fossa tumor-related hydrocephalus. A high index of suspicion and aggressive surveillance is required for the early identification and appropriate management of postresection hydrocephalus. Future studies are needed to address several unanswered questions pertaining to the management of this condition.