Tympanum Reconstruction in Lateral Skull Base: Preliminary Report on Classification-Based Technique.

Abstract

To introduce a classification system and corresponding surgical techniques for tympanum reconstruction in patients with lateral skull base lesions, aiming to restore tympanic wall structure, maintain aeration, and preserve air conduction hearing. We retrospectively reviewed 17 patients (mean age 38.9 ± 10.1 years) with benign lateral skull base tumors requiring extensive tympanectomy between 2015 and 2023. Based on defect location, tympanum reconstruction could be classified as Type 1 (posterior and inferior walls) or Type 2 (anterior and superior walls), using pedicled sternocleidomastoid or temporalis muscle flaps, respectively. Surgical cavity stability, complications, and audiological outcomes were evaluated. Ten patients underwent Type 1 reconstruction, four received Type 2, and three required both. The mean follow-up was 16 months. Based on postoperative CT scans, well-aerated tympanic cavities without significant adhesions were observed in all cases. The median postoperative air conduction threshold was 40.0 (IQR = 28.8) dB HL, with a median air-bone gap of 25.0 (IQR = 11.3) dB HL. No statistically significant differences were observed compared to preoperative hearing (p > 0.05). Postoperative air-bone gaps were < 30 dB HL in 82% of patients, and < 20 dB HL in 41%. This classification-based reconstruction approach enables tailored repair of tympanic defects using autologous pedicled flaps, offering structural stability, resistance to infection, and a well-epithelialized auditory canal. Though consistent hearing gains were not achieved, most patients maintained acceptable postoperative hearing, and profound hearing loss was avoided. This approach provided more options for hearing rehabilitation for these patients.