A CASE OF IATROGENIC INTRATEMPORAL MENINGOENCEPHALOCELE AFTER MIDDLE EAR SURGERY

Abstract

　We describe the case of a patient who underwent middle ear surgery and subsequently developed a bone defect in the middle cranial fossa, resulting in the occurrence of a meningoencephalocele and cerebrospinal fluid otorrhea due to a traumatic defect of the arachnoid membrane. The patient was a 19-year-old man who had previously undergone two middle ear surgeries for chronic otitis media at the ages of 9 and 10 years old. He developed unilateral hearing loss in the right ear, as well as headache and watery otorrhea after these surgeries. A pulsating tumor lesion was identified in the ear canal, and temporal bone computed tomography revealed the presence of a bone defect in the right middle cranium, as well as dense soft tissue in the right canal and mastoid cavity. Furthermore, magnetic resonance imaging revealed herniation of the brain parenchyma. Based on these findings, the patient was diagnosed as having a meningoencephalocele in the right temporal bone and underwent surgery. An extensive bone defect was identified in the base of the middle cranial fossa. Furthermore, loss of the dura mater and herniation of the brain tissue into the mastoid cavity were observed. Following resection of the meningoencephalocele, the bone defect was closed in a multi-layered fashion using a pedicled temporalis muscle flap, temporal fascia, rectus fascia, adipose tissue, and an absorbable plate for internal fixation. At 2 years 5 months after the surgery, the patient has not developed meningitis or recurrence of the cerebrospinal fluid otorrhea. Iatrogenic meningoencephalocele is a relatively rare condition, and an appropriate treatment approach should be selected taking into account multiple factors, such as the size and location of the fistula and the level of residual hearing.