Repair of a cerebrospinal fluid fistula using a muscle pedicle flap: technical case report
As a late complication of radiation therapy and a transoral approach, a cerebrospinal fluid (CSF) fistula between an oropharyngeal cavity and the ventral dura of the cervical spine is an extremely rare event. There are often difficulties in repairing ventral dural defects. Herein, we describe a technique that assists in feasible repair of a CSF fistula associated with ventral dural defects. A 36-year-old man was admitted to our institution with postnasal drip and a progressive spastic gait disturbance. Eleven years earlier, he had a recurrent chordoma of the cervical spine, which was treated by 5 open surgeries, including a transoral operation, and 6 rounds of radiation therapy. A neuroradiological examination revealed a CSF fistula between a posterior pharyngeal wall and the ventral dura of the cervical spine. We performed a repair operation of the CSF fistula using a conventional direct posterior approach. However, we were unable to repair the fistula using a dural-substitute suturing procedure. Therefore, we used a semispinalis cervicis muscle pedicle flap. The muscle pedicle flap was brought through the dural defect in the anterior part of the posterior pharyngeal wall, to which it was fixed. It was then used to reinforce the suture line that closed the fistula and to fill the fistula tract. After posterior surgery, a transoral endoscopic approach was used to augment the muscle pedicle flap with a bovine pericardial patch graft. No postoperative complications occurred, and CSF leaking ceased after surgery. There was no CSF leakage during the 1-year follow-up period. This novel muscle pedicle flap technique for repairing a CSF fistula can be used as an alternative to the direct "water-tight" closure of ventral cervical dural defects.