Surg-36. evaluation of surgical results and predictive factors of hydrocephalus in pediatric patients with posterior fossa tumors

Abstract INTRODUCTION Infratentorial tumors represent 45 to 60% of all brain tumors in children and are associated with hydrocephalus in 70 to 90% of cases. The aim of this study is to describe and analyze the surgical results and correlate them with the incidence of hydrocephalus, as well as identify predictive factors of hydrocephalus in pediatric patients underwent to a surgical treatment of posterior fossa tumors. METHODS This is a retrospective observational study, based on demographic, clinical and radiological information of pediatric patients underwent to surgical resection of posterior fossa tumors by a single group between 2011 and 2019. RESULTS We included 135 patients with a mean age of 7.56 years, mean follow-up of 35.7 months and overall survival of 18.8 months. Considering the histology, most tumors were pilocytic astrocytomas (34.1%), followed by medulloblastomas (27.4%) Total resection was achieved in 77.8% and tumor recurrence was observed in 16.2%. The rate of hydrocephalus was 36.3%, with most shunt procedures performed preoperatively. There was a high rate of complications associated with shunting (42.9%), mostly represented by infection (71.5%). Patients with hydrocephalus were younger (p = 0.001), showing a faster evolution between the onset of symptoms and diagnosis (p = 0.008). Tumor volume (p = 0.1) and location (p = 0.32) were not statistically significant for hydrocephalus, however, the presence of leptomeningeal disease (p = 0.001) was. The resection rate was also significant, with lesions totally resected showing the best results (p = 0.009). Regarding tumor histology, 33.3% of patients with medulloblastoma and 62.5% of patients with ependymoma were shunted. CONCLUSION One third of children with posterior fossa tumors will require a shunt procedure. Some factors should guide the neurosurgeon during patient counseling and surgical planning to minimize the use of permanent shunts and avoid related complications.