Surgical experience in 130 pediatric patients with Chiari I malformations.

OBJECT: The aim of this study was to present the long-term findings of a surgical series of pediatric patients with Chiari I malformations.

METHODS: One hundred thirty symptomatic pediatric patients with Chiari I malformations underwent posterior fossa decompression. The age in this group of patients ranged from 2 months to 20 years (mean 11 years). The length of the hospital stay extended from 2 to 7 days (mean 2.7 days), and follow up was from 3 months to 15 years (mean 4.2 years). Patients most often presented with headache/neck pain (38%) and scoliosis (18%). Examples of associated diagnoses included neurofibromatosis Type 1 (5.5%), hydrocephalus (11%), idiopathic growth hormone deficiency (5.5%), and Klippel-Feil anomaly (5%). Syringes were present in 58% of patients. Seventeen percent of patients had caudal displacement of the brainstem and fourth ventricle. Postoperative relief of preoperative pathologies was experienced in 83% of patients. Of the most common presenting symptoms--headache/neck pain and scoliosis--12 and 17%, respectively, were not alleviated postoperatively. Complications occurred in 2.3% of this group and included the development of acute hydrocephalus postoperatively and severe life-threatening signs of brainstem compression that necessitated a transoral odontoidectomy. Nine patients have had to undergo repeated operations for continued symptoms or persistent large syringes. During surgery 10 patients (7.7%) were found to have arachnoid veils occluding the fourth ventricular outlet, and nine of these had syringomyelia. In our experience almost all syringes will stabilize or improve with posterior fossa decompression and duraplasty.

CONCLUSIONS: The authors believe this to be the largest reported series of pediatric patients who have undergone posterior fossa decompression for Chiari I malformations.