Initial management of hydrocephalus associated with Chiari malformation Type I-syringomyelia complex via endoscopic third ventriculostomy: an outcome analysis

J Neurosurg. 2008 Jun;108(6):1211-4. doi: 10.3171/JNS/2008/108/6/1211.


Object: The aim of this study was to evaluate the efficacy of endoscopic third ventriculostomy (ETV) in patients with Chiari malformation Type I (CM-I) and hydrocephalus with or without syringomyelia.

Methods: The authors identified, in a prospective endoscopy database, 16 adults and children (age range 2-68 years) with CM-I and hydrocephalus that had been managed with ETV. They reviewed the clinical features and radiographic findings for all patients. Fifteen patients underwent ETV as a primary treatment, whereas 1 patient underwent the procedure at the time of shunt failure. All patients had symptomatic hydrocephalus with either aqueductal or fourth ventricular outflow obstruction. The mean duration of follow-up was 42 months.

Results: Fifteen patients (94%) remain shunt free following ETV for CM-I. Five (83%) of the 6 patients with a syrinx had improvement or resolution of the syrinx following ETV. Six patients (37.5%) underwent foramen magnum decompression for persistent CM-I -- or syrinx-related symptoms. There was no cerebrospinal fluid leakage or intracranial pressure-related problem following foramen magnum decompression.

Conclusions: Endoscopic third ventriculostomy provides a durable method of treatment for hydrocephalus associated with CM-I. It is effective as a primary treatment, and the authors advocate its use as a replacement for routine ventriculoperitoneal shunt insertion in these patients. Management of the hydrocephalus alone is often sufficient and may obviate decompression, although a significant proportion of patients will still need both procedures.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Arnold-Chiari Malformation / complications*
  • Arnold-Chiari Malformation / pathology
  • Arnold-Chiari Malformation / surgery
  • Child
  • Child, Preschool
  • Cohort Studies
  • Decompression, Surgical
  • Endoscopy*
  • Humans
  • Hydrocephalus / etiology
  • Hydrocephalus / pathology
  • Hydrocephalus / surgery*
  • Middle Aged
  • Retrospective Studies
  • Syringomyelia / complications*
  • Syringomyelia / pathology
  • Syringomyelia / surgery
  • Third Ventricle / surgery*
  • Treatment Outcome
  • Ventriculostomy*