Surgical treatment of apical petrositis through the anterior transpetrosal approach: A case report

Background: Apical petrositis is a rare but serious infection, often accompanied by osteomyelitis, that may cause cranial neuropathies and typically responds to antibiotics. However, surgical intervention may be required when medical therapy fails or when complications such as trigeminal neuralgia develop. Case Description: We report a rare case of apical petrositis that was successfully treated using the anterior transpetrosal approach. The patient was a 74-year-old woman who presented with pain in the distribution of the right mandibular division of the trigeminal nerve. A cystic lesion was identified in the right petrous apex, demonstrating low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging, with slight enhancement of the cyst wall, findings suggestive of apical petrositis. Antibiotic therapy was ineffective and her pain was not relieved with analgesics. Furthermore, imaging showed that the trigeminal nerve was displaced superiorly by bone expansion inside the petrous apex. Therefore, a right petrous apicectomy through an anterior transpetrosal approach was performed. During the operation, the dura mater was opened to examine the trigeminal nerve, which was surrounded by thickened and opaque arachnoid. The arachnoid was incised to decompress the nerve. Conclusion: This report highlights the importance of considering surgical intervention for apical petrositis, which may be necessary when antibiotic therapy fails.