Spinal arachnoiditis as a complication of peridural anesthesia

Seven patients who received epidural anesthesia for gynecological (5 cases), cosmetic (1 case) or general surgery (1 case) developed spinal arachnoiditis leading to subarachnoid cyst in all 7 and cord cavitation in 5. MRI was useful to show the subarachnoid and intramedullary cysts, as well as to monitor lesion extent and progress. Associated MRI findings were a Chiari anomaly in one case, a tethered cord in another and spinal cord atrophy in a third. One patient refused surgery but improved spontaneously while the other six were treated by a shunting procedure, with a satisfactory outcome in three. Meningeal inflammation may have left scars which later induced ischemia and subsequent cavitation. Alternatively, CSF circulation blockade may have dilated the central spinal canal causing ischemia by compression, followed by myelomalacia and cavitation. Careful handling of this procedure is urged in order to avoid such severe complications.