Treatment and management of the Chiari II malformation: an evidence-based review of the literature

Multiple surgical strategies exist for the management of the symptomatic Chiari II malformation. To date, no comprehensive analysis of this medical literature in an attempt to seek out standards or guidelines has been performed, thus serving as the impetus for this present review. A computerized search of the database of the National Library of Medicine was performed on the English-language medical literature between 1966 and 2003. Terms searched for included hindbrain hernia, Chiari II, Arnold-Chiari, surgery, decompression, syringomyelia, and CSF shunts. All literature found was reviewed with associated references from these sources. Each piece of literature reviewed was scrutinized and guidelines developed utilizing the methodology used by the Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injuries. All data reviewed were deemed to be Class III in nature. No standards or guidelines could be established from the available literature. There is significant debate and variable results in the current neurosurgical literature regarding the evaluation of shunt function vs. Chiari II decompression in patients with symptomatic hindbrain herniation. Multi-institutional prospective randomized trials are needed before any conclusions can be drawn regarding symptomatic Chiari II and its treatment paradigm. Until this time, clinical practice will be based on individual surgeons’ experience, training, and personal beliefs.