Iatrogenic intradural arachnoid cyst following tethered cord release in a child.

Iatrogenic arachnoid cysts represent uncommon complications of intradural spinal procedures. Here we present the case of a 7-year-old girl who was found to have a symptomatic, pathologically proven, intradural arachnoid cyst 3 years following tethered cord release. The patient originally presented with abnormal urodynamics testing and was found to have fatty infiltration in her filum terminale. She underwent sectioning of the filum terminale without complications. The patient presented 3 years later with pain and neurogenic claudication. The patient was successfully treated with subarachnoid cyst fenestration with resolution of her bilateral lower extremity pain. Spinal intradural arachnoid cysts represent an important, though rare, postoperative complication of dural opening.