Object: Most pediatric patients that present with a posterior fossa tumor have concurrent hydrocephalus. There is significant debate over the best management strategy of hydrocephalus in this situation. The objectives of this paper were to review the pathophysiology model of posterior fossa tumor hydrocephalus, describe the individual risks factors of persistent hydrocephalus, and discuss the current management options. Specifically, the debate over preresection cerebrospinal fluid diversion is discussed.
Results: Only 10-40 % demonstrate persistent hydrocephalus after posterior fossa tumor resection. It appears that young age, moderate to severe hydrocephalus, transependymal edema, the presence of cerebral metastases, and tumor pathology (medulloblastoma and ependymoma) on presentation predict postresection or persistent hydrocephalus. The Canadian Preoperative Prediction Rule for Hydrocephalus (CPPRH), a validated prediction model, can be used to stratify patients at point of first contact into high and low risk for persistent hydrocephalus.
Conclusions: A protocol is proposed for managing hydrocephalus that utilizes the CPPRH. Low-risk patients can be monitored conservatively with or without an intraoperative extraventricular drain, while high-risk patients require the use of an intraoperative extraventricular drain, higher postoperative hydrocephalus surveillance, and even consideration for a preoperative endoscopic third ventriculostomy.
Keywords: CPPRH; Cerebrospinal fluid diversion; Endoscopic third ventriculostomy; Extraventricular drain; Hydrocephalus; Intratumoral hemorrhage; Oncology; Pediatric; Posterior fossa tumor; Upward tentorial herniation; Ventriculoperitoneal shunt.