Delayed Diagnosis of Cauda Eqina Syndrome with Perineural Cyst after Combined Spinal-Epidural Anesthesia in Hemodialysis Patient
A 53-year-old female who had been on maintenance hemodialysis due to diabetes mellitus developed an infection in her left femoral prosthesis and needed removal surgery.\nIn consideration of her general status, general anesthesia was not undertaken. We performed removal surgery successfully under combined spinal-epidural anesthesia by puncturing L3/4, 3 mL of 0.5%-bupivacaine was administered into the subarachoid cavity and continuous injection of 2%-mepivacaine was performed at a rate of 3.3 mL per hour for 24 hours postoperatively. Pain relief was quite satisfactory during and after operation as this combination technique provides a rapid onset and spinal block reliability with high-quality analgesia by supplemented by the epidural catheter during and after surgery. Postoperative rehabilitation was started on the seventh postoperative day as no paresis of the four extremities was observed.\nFor the first time, on the 14th postoperative day, she complained that she was feeling hypoesthesia in the perianal area and loss of stool sensation. The client noted that she recognized the inability to sense stool but hesitated to inform us due to embarrassment. She seemed to manifest the symptom of fecal incontinence.\nWe immediately conducted neurological and radiological examinations to determine the source of her symptoms.\nThe plain MRI revealed at least two perineural cysts inside the spinal canal at the L5/S1 level, that were considered to be S2 root cysts (). The myelography showed a blockade of the contrast medium (). Afterward, the computed tomography was taken which showed a delayed filling of the right S2 root cysts and an inflated dural sheath of the S2 or S3 roots which could be expressed as cysts.\nWe supposed that her symptoms were caused by a volume effect or a prolonged analgesic effect entrapped in root cysts [,]. We conducted an S1 to S5 laminectomy in order to decompress whole root cysts and sampled spinal fluid captured in left-side S2 root cyst then irrigated it with extracellular fluid. The intraoperative finding gave the impression that the blockage of the spinal flow due to stenosis had been alleviated ().\nSensation loss and urinary incontinence caused by sphincter disturbance subsided gradually and on the fifth postoperative day, her symptoms had almost disappeared. However, the residual existence of analgesics was not detected in the sampled spinal fluid.