A retrospective single-center series on the surgical management and postoperative outcomes of pediatric Chiari malformation type I. Part 1: presentation, operative management, and complications

OBJECTIVE: Posterior fossa decompression is the main surgical treatment for Chiari malformation type I (CM-I). The authors present findings on patient presentation, surgical methods, and postoperative complications from a large cohort of pediatric patients with the aim of utilizing this institutional experience to guide evidence-based management of pediatric CM-I. METHODS: A departmental operative database was queried for patients who underwent a posterior fossa decompression for CM-I between 1992 and 2021. The charts of identified patients were reviewed. Data regarding demographics, presentation, operative details, and complications were collected. RESULTS: A total of 510 patients were identified. The mean patient age was 10.2 ± 5.2 years, and 57% of patients were female. The most common presenting clinical symptoms or associated signs were exertional suboccipital headaches (65%), syringomyelia (55%), and scoliosis (18%). The mean cerebellar tonsillar descent was 14.2 ± 6.4 mm below the foramen magnum. At surgery, 20% of the patients with a preoperative syrinx had documented arachnoid veils obstructing the outflow tract of the fourth ventricle. Operatively, 99% of patients underwent cervical laminectomy; of these laminectomies, 89% were C1 only. Ninety-seven percent of all patients underwent suboccipital craniectomy with expansile duraplasty (PFDD), while 3% underwent bone-only decompression (PFD). Eighty-seven percent of the patients with PFDD received tonsillopexy and/or tonsillar resection. The median postoperative hospital stay was 2 days for PFD patients and 3 days for PFDD patients (p < 0.01). Postoperative complications developed in 12% of cases, with CSF leakage (5%) and aseptic meningitis (4%) being most common. CSF leakage and aseptic meningitis were also the most common reasons for early readmission after surgery. There were no intraoperative or postoperative deaths. CONCLUSIONS: The authors demonstrate an institutional preference for PFDD and tonsillopexy. Exertional suboccipital pain and syringomyelia were the most common indications for surgery. Complications tended to be more common with PFDD. There was a significant difference in postoperative length of stay between patients who underwent PFD (median 2 days) versus PFDD (median 3 days). CSF leakage and aseptic meningitis were the most common reasons for readmission.