抄録
Chiari malformations are often associated with congenital anomalies. The authors evaluated several surgical procedures for Chiari malformations associated with basilar impression and/or syringomyelia. Twenty patients with Chiari malformations with and without congenital anomalies were treated by various surgical procedures. Associated anomalies were atlantoaxial dislocation in one, basilar impression in eight, and syringomyelia in 11. There were 11 males and nine females, ranging in age from 6 to 63 years. Nine patients were treated by foramen magnum decompression (suboccipital craniectomy and upper cervical laminectomy), one by foramen magnum decompression combined with terminal syringostomy, one by anterior decompression via the transoral approach, and nine by syringosubarachnoid shunting. The period of follow-up ranged from 5 months to 21 years (mean, 7 years). Seventeen of the 20 patients showed neurological improvement, one was unchanged, and two deteriorated. One of the patients who deteriorated had undergone syringosubarachnoid shunting, and the shunt malfunctioned because of arachnoiditis. A patient with basilar impression died of respiratory failure after suboccipital craniectomy and upper cervical laminectomy.
On the basis of their results, the authors recommend posterior decompression for patients with Chiari malformations alone. If a foramen magnum lesion is responsible for the neurological manifestations and the clivoaxial angle is narrow in Chiari malformations associated with basilar impression and/or syringomyelia, anterior decompression with fusion should be performed. If the clivoaxial angle is within normal limits, the authors perform posterior decompression. Syringosubarachnoid shunting appears effective in patients in whom syringomyelia is the main cause of neurological symptoms.
