Abstract
OBJECTIVE: Pediatric posterior fossa tumor (PFT) resection is frequently complicated by postoperative hydrocephalus. Previous hydrocephalus risk stratification tools demonstrate limited performance in external validation and do not account for important intra- and post-operative variables. We aimed to evaluate additional risk factors for post-resection hydrocephalus to improve risk-stratification. METHODS: We conducted a retrospective analysis of pediatric patients who underwent resection of primary PFT's at our institution (January 2016-June 2024). We collected perioperative variables thought to influence hydrocephalus risk. The primary outcome was permanent CSF diversion within 6 months after resection. We used univariable and multivariable logistic regression with bidirectional stepwise selection to identify predictors of post-resection hydrocephalus. RESULTS: A total of 112 patients were included. We identified age < 5 years, moderate/severe hydrocephalus, and subtotal resection (STR; ≥ 1.5 cm(2) residual tumor) as independent predictors of post-resection hydrocephalus on multivariable regression. STR exhibited an odds ratio of 8.25 (95% CI 2.72-26.84; p < 0.001), highlighting its strong association with the need for permanent CSF diversion. A scoring tool that incorporated STR and an age cutoff of < 5 years improved the discriminative performance (area under the ROC curve = 0.826) compared to the modified Canadian Preoperative Prediction Rule for Hydrocephalus (AUC = 0.720). CONCLUSIONS: These findings suggest STR is associated with increased risk of persistent hydrocephalus and emphasize careful intraoperative decision-making when pursuing incomplete resection. Future multicenter studies will be necessary to validate this framework and to further elucidate how STR, in conjunction with age and hydrocephalus severity, can be leveraged to optimize treatment strategies in diverse healthcare settings.