International survey on the management of Chiari I malformation and syringomyelia

Introduction. The availability of magnetic resonance imaging (MRI) has resulted in an increasing number of asymptomatic, minimally symptomatic, and doubtfully symptomatic patients being diagnosed with a Chiari I malformation with or without syringomyelia. In an attempt to clarify how neurosurgeons manage these clinical problems, an international survey on the Chiari I malformation and related syringomyelia was undertaken. Method. A questionnaire on the expected natural course of the disease and on aspects of the surgical technique for a number of hypothetical cases relating to Chiari I malformation with and without syringomyelia was used to survey Pediatric Neurosurgeons worldwide. Results. Of 246 questionnaires distributed, 76 (30.8%) were completed and returned. There was a consensus that no operation should be carried out in asymptomatic patients with a Chiari I malformation, unless there is associated syringomyelia. There was a consensus that decompression of the Chiari malformation should be performed in patients with scoliosis when syringomyelia is present, and the majority decompressed the Chiari malformation in scoliotic patients even in the absence of syringomyelia. Suboccipital decompression was the standard surgical procedure for Chiari I malformations. The majority of respondents favored routine dural opening at surgery and closure with a pericranial or synthetic patch graft. In the case of a persistent or progressive syrinx after suboccipital decompression, the majority recommended shunting of the syrinx to the subarachnoid space or to the pleural cavity. Conclusion. There continues to be much variation in the management of the Chiari I malformation.