Background and Objectives: Posterior fossa tumors (PFTs) are common pediatric brain tumors and frequently present with obstructive hydrocephalus. Although tumor resection restores cerebrospinal fluid (CSF) circulation in many patients, a subset subsequently requires ventriculoperitoneal shunt (VPS) placement. This systematic review and meta-analysis aimed to identify factors associated with postoperative VP shunt placement following PFT resection in children. Materials and Methods: This systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was prospectively registered with PROSPERO (CRD420261455396). A comprehensive search of major electronic databases was conducted from inception to April 2025. Observational studies evaluating factors associated with postoperative VP Shunt placement in children undergoing PFT resection were included. Risk of bias was assessed using the Quality In Prognosis Studies (QUIPS) tool, and certainty of evidence was evaluated using the modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework for prognostic factor research. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects meta-analysis. Results: Nine retrospective cohort studies comprising 922 children were included. Higher odds of postoperative VP shunt placement were observed with preoperative hydrocephalus (OR = 7.62, 95% CI 2.19–26.47), midline tumor location (OR = 4.75, 95% CI 1.21–18.69), ependymoma (OR = 2.56, 95% CI 1.38–4.76), subtotal resection (OR = 3.04, 95% CI 1.92–4.79), postoperative intraventricular hemorrhage (OR = 4.36, 95% CI 1.16–16.44), postoperative infection (OR = 4.96, 95% CI 1.77–13.91), and pseudomeningocele (OR = 6.17, 95% CI 3.12–12.19). Astrocytoma was associated with lower odds of VP shunt placement (OR = 0.47, 95% CI 0.27–0.85), whereas sex, medulloblastoma, and postoperative CSF leakage were not significantly associated. EVD exposure was associated with higher odds of subsequent VP shunt placement (OR = 4.79, 95% CI 2.11–10.87), although this association is susceptible to confounding by indication. Certainty of evidence ranged from very low to low, with most pooled estimates derived from unadjusted data. Conclusions: Several clinical and perioperative characteristics may help identify children requiring closer surveillance for persistent hydrocephalus after posterior fossa tumor resection. The observed relationship with EVD likely reflects underlying hydrocephalus severity rather than an independent prognostic effect. Given the limited certainty and predominantly unadjusted evidence, these findings should support risk-informed surveillance rather than decisions for permanent CSF diversion. Future prospective studies with standardized definitions and multivariable adjustment are needed to develop reliable prediction models.

Background and Objectives: Postoperative fatigue (POF) is a frequent complication that negatively affects recovery and quality of life following surgery. Ketamine and esketamine, as N-methyl-D-aspartate (NMDA) receptor antagonists, may reduce postoperative fatigue; however, current evidence remains inconclusive. This systematic review and meta-analysis aimed to evaluate the effects of perioperative ketamine and esketamine on postoperative fatigue in adult surgical patients. Materials and Methods: A systematic search of major electronic databases was conducted to identify randomized controlled trials comparing perioperative ketamine or esketamine with placebo or standard care in adult surgical patients. Fatigue outcomes during the first postoperative week were analyzed using random-effects meta-analyses and reported as standardized mean differences (SMDs) with 95% confidence intervals (CIs). Subgroup analyses were performed according to NMDA antagonist type, surgical procedure, and administration regimen. Sensitivity analyses included exclusion of studies using patient-controlled intravenous analgesia (PCIA) and leave-one-out analyses. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and certainty of evidence was evaluated using the GRADE approach. Results: Eight randomized controlled trials (n = 906 participants) were included in the qualitative and quantitative synthesis. No significant overall reduction in postoperative fatigue was observed at POD1 (SMD −0.37, 95% CI −0.87 to 0.13), although esketamine demonstrated a significant benefit in subgroup analysis. Ketamine/esketamine significantly reduced postoperative fatigue at POD3 (SMD −0.58, 95% CI −0.86 to −0.30) and POD7 (SMD −0.38, 95% CI −0.65 to −0.12). Subgroup analyses demonstrated greater reductions in fatigue among patients undergoing colorectal surgery. Sensitivity analyses excluding PCIA studies and leave-one-out analyses confirmed the robustness of the findings at POD3 and POD7. The certainty of evidence was rated as low for POD1 and moderate for POD3 and POD7. Conclusions: Perioperative ketamine and esketamine were associated with reduced postoperative fatigue from POD3 onward in adult surgical patients, with more consistent benefits observed in colorectal surgery populations. Further high-quality studies are needed to determine the clinical significance of these findings and their impact on postoperative recovery outcomes.