Repair of Spontaneous Cerebrospinal Fluid Otorrhea from Defect of Middle Cranial Fossa
A 49-year-old woman was referred to our hospital because of right pulsatile otorrhea after myringotomy. Initially, she had experienced right ear fullness and hearing disturbance for 2 weeks. When a local otolaryngologist examined her ear, there was visible fluid through the tympanic membrane. Thus, she was diagnosed as right serous otitis media and treated with antibiotics. However, the fluid remained despite a 2-week treatment. Myringotomy was attempted but failed due to profuse pulsatile clear discharge from the myringotomy site.\nThe pure tone audiogram of the right ear revealed conductive hearing loss of 40 dB (air-bone gap 32 dB). Her body weight was 70 kg and body mass index was 27.7 kg/m2. She had no specific past medical history and family history. High resolution computed tomography (HRCT) scan and magnetic resonance imaging (MRI) of temporal bone were performed for further evaluation of the otorrhea. The HRCT scan revealed a large, bony, anteromedial defect from the anterior wall to the roof of the right epitympanum (). The right middle ear cavity and mastoid cavity were filled with soft tissue density. T2 weighted MRI demonstrated high signal intensity in right middle ear and mastoid cavity, consistent with CSF ().\nRepair of CSF leak was planned through a transmastoid approach. First, lumbar drainage was done after general anesthesia. Temporalis muscle fascia was harvested. Several pieces of bone chips were taken from mastoid cortex. A cortical mastoidectomy was performed. On entering the antrum, a profuse clear discharge from epitympanum was noted. To further evaluate the tegmen tympani, the incus and head of malleus were removed. An approximately 8 mm bony defect was apparent from the anterior roof of the epitympanum extending to the anterior wall. There was no identifiable any healthy dura or brain tissue herniation along with the CSF leak site.\nCovering the defect began with insertion of prepared temporalis fascia into the bony defect. After that, large piece of bone chip was inserted into the defect to cover the fascia. The bony defect was still visible because of the large defect size. Other bone chips were placed in the defect, unless there was no evidence of the CSF leak. Surgical glue was applied around bone chips and gelfoams were packed in the cavity.\nA postoperative CT scan demonstrated that the defect had sealed and revealed a pneumocephalus in the right temporal lobe (). The patient did not complain of headache or any neurologic deficits. Lumbar drainage was maintained for 6 days. Two weeks later, the pneumocephalus had disappeared and the patient was discharged. One year later, CT scan showed a well-healed defect (). There has been no evidence of recurrent CSF leak up to date.