Abstract:Objective To present more details for treating sacral canal cyst by open surgery, and to probe into the pathogenesis. Methods The patients with symptomatic sacral canal cyst from 2010 to 2014 were treated with laminectomy and decompression, incision and drainage of the cyst, rotating erector spinae pedicle flap and full padding. Appropriate wall tissue was removed for pathological examination. Results All patients received an open surgery, 76.0% (19/24) of the patients showed complete remission of the symptoms, 12.0% (3/24) showed partial improvement, and 4.0% (1/24) had no improvement. There was no nervous tissue under microscope, but a thin layer of hyaline-degenerated collagen fibers with hemorrhage lined with monolayer squamous epithelial cells. The immunofluorescence analysis showed glial fibrillary acidic protein and S100 were negative. Conclusions Sacral canal cyst is not derived from congenital defect of dura mater spinalis, but from an expansion of perineurium-like structure (similar to peripheral perineurium) covering the surface of cauda equina. The curative effect of open surgery is accurate and the management could be used as a favorable surgical option.