Different surgical treatment techniques used by neurosurgeons and orthopedists for syringomyelia caused by Chiari I malformation in Japan

Abstract

Object Syringomyelia is a rare disease commonly caused by Chiari I malformation. Surgery by neurosurgeons and orthopedists is a critical treatment for symptomatic patients, and surgical techniques are associated with improved symptoms for these patients. The aim of this study was to determine the different surgical techniques used by neurosurgeons and orthopedists in Japan to treat syringomyelia caused by Chiari I malformation. Methods Patients who had undergone a surgical treatment were identified from a 2-stage postal survey conducted in late 2009. The authors compared the type of surgery performed and its association with cavity size reduction, on the basis of whether patients were receiving care in a neurosurgery or orthopedics department. Results A total of 232 patients with syringomyelia caused by Chiari I malformation were included in this study. Two-thirds of patients were treated in a neurosurgery department and the other third in an orthopedics department. Neurosurgeons preferred foramen magnum decompression (FMD) with dural patch grafting, and orthopedists preferred FMD with dural dissection. Foramen magnum decompression with dural patch grafting was associated with better outcomes than was dural dissection with regard to the following: motor impairment (66% vs 39%, p < 0.05), sensory disturbance (60% vs 43%, p = 0.051), pain (67% vs 47%, p < 0.05), and cavity size (74% vs 58%, p < 0.05). Improved motor function was associated more with cavity size reduction than with sensory disturbance and pain. Conclusions Surgical procedures and outcomes differed, depending on whether the patient's care was managed in a neurosurgery or orthopedics department. Outcomes were better after FMD with dural patch grafting.