Treatment of syringomyelia with a syringosubarachnoid shunt.

The surgical results in 40 patients with syringomyelia, treated with a syringosubarachnoid shunt or other procedures are reviewed. The principal indication for surgery was that of significant neurological deterioration. There were 12 patients with idiopathic syringomyelia without tonsillar ectopia, 12 with an associated Chiari malformation, 11 with post-traumatic syringomyelia and five patients with spinal arachnoiditis. There were 38 syringosubarachnoid shunts performed in 35 patients, and an excellent or good result was achieved in 26 patients (74.3%). In terms of the type of syringomyelia, the best results were obtained in the idiopathic group without tonsillar ectopia and in the post-traumatic group. A short duration of pre-operative symptoms favoured a better outcome, and in our opinion, early surgical treatment is indicated for all patients with neurological deterioration. All eight patients in whom a posterior fossa decompression was performed as the initial surgical procedure required a second operation, either a syringosubarachnoid or syringoperitoneal shunt to achieve neurological improvement or stabilization. Thus, the syringosubarachnoid shunt is an effective therapeutic modality for patients with syringomyelia, particularly for the idiopathic and post-traumatic groups. More than one surgical procedure may be required to achieve cessation of deterioration. Overall, excellent or good results were achieved in 29 (72.5%) of the 40 patients.