Pneumolabyrinth is characterized by the presence of air in the inner ear due to intrusion from the tympanic cavity. It is a rare complication of stapedoplasty. Currently, there is no clear algorithm for treatment of this complication. The paper reports two cases of pneumolabyrinth being the short-term and long-term postoperative complications. In the first case, the patient, who had undergone stapedoplasty in the left ear, suddenly developed rapid hearing loss and tinnitus in the left ear with dizziness three weeks after physical activity. Physical examination revealed no evidence of the tympanic membrane defect. Audiometry revealed left-sided IV degree of sensorineural hearing loss. Pneumolabyrinth was detected on the temporal bone CT scans. In the second case, vestibulocochlear symptoms developed three days after stapedoplasty in the right ear. Pure tone audiometry revealed right-sided IV degree of mixed hearing loss. CT scan of the temporal bone confirmed the diagnosis of pneumolabyrinth. In both cases the correct position of the stapedial prosthesis, "empty" vestibule and perilymphatic fistula were found during revision tympanotomy. The prosteses were removed during surgery, Dexamethasone solution was introduced into the vestibule; stapedoplasty with autocartilage on the perichondrium was performed. After surgery, vestibular symptoms disappeared, and hearing improved.

The review of papers, focused on studying various neoplasms, diagnosis, selection of surgical approach, complications, and recurrence rates of the petrous apex lesions, that have been published in 2008–2022, is provided. Effusion, mucocele, cholesterol granuloma, cholesteatoma are the most common benign lesions of the petrous apex. Such surgical approaches as translabyrinthine, transcochlear, endoscopic endonasal approach and the middle cranial fossa approach are most often used during treatment. The middle cranial fossa approach, infracochlear approach and endoscopic transnasal approach are recommended for patients with preserved hearing. In case of disseminated lesions, when the carotid artery and the jugular bulb should be additionally controlled, transcochlear and translabyrinthine surgical corridors could be used.