Posterior fossa decompression in pediatric Chiari malformation type I: a meta-analysis and meta-regression of outcomes with and without duraplasty

OBJECTIVE The role of duraplasty in posterior fossa decompression for pediatric Chiari malformation type I (CM-I) remains controversial. Proponents of posterior fossa decompression with duraplasty (PFDD) argue that it improves CSF flow and syrinx regression, while posterior fossa decompression only (PFDO) is thought to offer a less invasive alternative with fewer complications. The authors investigated whether adding duraplasty provides patient-relevant clinical benefit in children with CM-I. METHODS A systematic review and meta-analysis of comparative pediatric studies (PFDD vs PFDO) was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcomes were overall clinical improvement, syrinx regression, Chicago Chiari Outcome Scale (CCOS) score, complications, and reoperation. Random-effects models, study-level meta-regression, graft-type subgroup analyses, and prespecified sensitivity analyzes were performed, including restriction to rigorously defined congenital CM-I cohorts and studies routinely using intraoperative ultrasound. Formal assessments of risk of bias, publication bias, and certainty of evidence were also conducted. RESULTS Twenty-six studies consisting of 5977 pediatric patients (2641 PFDO, 3336 PFDD) were included. Clinical improvement (70.8% PFDO, 80.0% PFDD; p = 0.13), syrinx improvement (55.4% PFDO, 63.5% PFDD; p = 0.11), CCOS scores (p = 0.39), and reoperation (risk ratio [RR] 1.54, 95% CI 0.93–2.54; p = 0.09) showed no significant intergroup difference. PFDD was associated with substantially higher CSF-related morbidity (RR 0.47, 95% CI 0.28–0.78; p < 0.01) and longer operative time (mean difference [MD] 63.9 minutes) and hospital stay (MD 1.22 days). No consistent differences emerged by graft type. Meta-regression showed that higher cohort-level syrinx prevalence correlated with greater clinical improvement after PFDD (p < 0.05) but not PFDO. Sensitivity analyses restricted to rigorously defined congenital CM-I cohorts and studies routinely performing intraoperative ultrasound reproduced all primary findings. Most studies were retrospective with moderate to serious risk of bias and overall certainty of evidence graded as moderate. No significant publication bias was detected (p = 0.36). CONCLUSIONS PFDD and PFDO yielded broadly comparable clinical and radiographic outcomes in pediatric CM-I, although PFDD was associated with higher CSF-related morbidity and greater operative burden. Current evidence does not clearly define patient subgroups that derive additional benefit from duraplasty, and observed differences are likely influenced by underlying cohort heterogeneity. Prospective trials incorporating standardized phenotyping and patient-reported outcomes are needed. Systematic review registration no.: CRD420251112828 ( www.crd.york.ac.uk/prospero/ )