Discussion
TCS presents various symptoms depending on age and its cause. Neurologic symptoms, sensory or motor dysfunction, dysuria, and deformation of the feet or spine are usually developed by progressive stretching of and increased tension in the spinal cord in children.[4] Cutaneous stigmata, hair tufts, skin tags, dimple, nevi, hemangioma, lumps, lipomas, etc. could be surface (cutaneous) findings that suspect TCS.[4] Our patient had subcutaneous fluid collection following the caudal approach and it looked like it was concealing the existence of a subcutaneous lipoma. If a physician at a local clinic had performed a physical examination of the procedure site before the practice, he would have found a lesion suspected as a lump or lipoma. We suspected that she had a CSF leakage based on physical examination and bedside US and finally confirmed a rare case of TCS and subarachnoid-cutaneous fistula by MRI. Based on our experience, it is difficult to predict dural puncture before caudal epidural block without expensive imaging studies such as CT or MRI.
In children, an inelastic filum is attached to the caudal end of the spinal cord which adds continuous tension to the spinal cord causing severe neurological symptoms. Surgical treatment of TCS should maintain neural functions and circulation of CSF, and reconstruct the dural sac; additionally, there should be no adverse effects, such as infection or adhesion.[5] Major symptoms of TCS, such as pain, bowel or urinary dysfunction, may not improve after surgery in adults, and postoperative complications of old age may be three times higher than that in young patients. Asymptomatic adult TCS patients could be followed up only for symptoms, and conservative management could be applied to non-aggressive and bearable symptoms.[6-8] There is a controversy over the superiority of conservative management and surgical management. This case showed that conservative management could improve symptoms in adult TCS patients, therefore, we should be careful in our decision about employing surgical treatment.[6-8] In our patient, surgical release of the filum terminale anchored to the spinal cord could be considered, but we decided to maintain the conservative management with an abdominal binder and observation of the symptoms because her mild neurologic symptoms (pain of the left leg and foot) improved and PDPH decreased.
In the structures of the epidural cavity, the incomplete lateral wall could cause peritoneal pressure to be transmitted to the epidural cavity through the intervertebral foramina. Therefore, increased abdominal pressure could induce an increase in the epidural pressure.[9] In this respect, the compression of the abdomen with an abdominal binder would be helpful to decrease the PDPH after spinal tapping in postpartum patients by increasing the peritoneal pressure. The preventive effects of an abdominal binder in PDPH’s occurrence were similar to that of the injection of normal saline into the epidural space.[10] We applied an abdominal binder obliquely for two main purposes. First, we tried to maintain high epidural pressure by increasing peritoneal pressure to reduce pressure variations due to change in posture. Second, compressive dressing with gauze and adhesive tape was insufficient, especially in the coccyx area because the movable and soft buttocks would offset the adhesive tape’s compression. Considering these points, we applied an abdominal binder to surround the lower abdomen, buttocks, and coccyx, obliquely from the upper anterior pelvis to the lower posterior pelvis. This placement, fastening the binder around the pelvis, prohibited lateral movement of the buttocks and provided evenly distributed compression of the lipoma and large subcutaneous CSF collection. The abdominal binder was able to compress a surface area of 8 × 7 cm2.
The EBP was a very effective treatment for spontaneous intracranial hypotension; therefore, 90% of the patients showed improvement regardless of the presence or location of CSF leakage.[11] However, complications and/or side effects—ranging from mild to severe—make EBP a challenging procedure for anesthesiologists. Mild events include temporary nerve compression syndrome, dizziness, vertigo, or tinnitus, while the rare, severe adverse effects include epidural abscess or cord compression.[12] Our patient had a history of body fluid leakage, which could be expected as the puncture site had swelling and fluctuation on physical examination of the coccygeal area, which appeared as a subcutaneous fluid collection. Because we confirmed that this fluid collection communicated with the intrathecal space via MRI (Fig 3A and B), we thought that the EBP through the sacral hiatus had a high risk of meningitis. It was reported that the large volume of blood infused into the epidural space ran in the cephalad direction during EBP in MRI,[13] and thus, the lumbar site for EBP in our patients seemed ineffective and large volumes of blood would be needed in contrast to that in the sacral approach if it was performed.
Based on the findings of this case, the following points should be kept in mind during the caudal procedure.
  1. Careful physical examination of the procedure site before the caudal pain procedure should be performed because it could show the patient’s abnormal anatomical conditions.
  2. When a subcutaneous fluid collection after a neuraxial procedure is suspected by peripheral swelling or fluctuation, fluid collection can be examined by easily accessible US. If it has been proven, CSF leakage must be ruled out by an MRI scan, and then EBP should be considered later.
  3. An abdominal binder could be used effectively in a patient showing CSF leakage in the coccygeal area, which is not controlled by conventional compressive dressing.