Abstract: Objective To investigate the surgical techniques and clinical efficacy of removing tumors in the petroclibal region through preauricular subtemporal keyhole approach. Methods The microsurgery via preauricular subtemporal keyhole approach was performed based on preoperative imaging characteristics of the tumors. Results In all 18 cases, total removal of the tumors was achieved in 15 (83.3%) and subtotal in 2 (11.1%) cases, and in 1 case the major part of tumor was removed (5.6%). After surgery, oculomotor paralysis occurred in 1 patient, who completely recovered in 9 days; ambiopa was observed in 2 patients, who recovered 4 and 6 months later, respectively; facial hypesthesia was found in 3 patients, 1 of whom returned to normal in 2 months and another 2 recovered 6 months later; facioplegia occurred in 1 patient, who recovered 6 months later. No CSF leakage, hemiplegia, aphasia or death occurred. Conclusion Preauricular subtemporal keyhole is a reasonable approach to remove tumors in the petroclibal region. Intraoperative electrophysiologic monitoring of cranial nerves and brain stem function is useful for the protection of neurological function.

Key words: Subtemporal approach, Electroneurophysiological monitoring, Petroclibal region, Keyhole