Comparison of two surgical approaches for petroclinic lesions

Abstract

Objective: to compare the methods of petrous apical bone removal and to explore the applicable scope of Kawase approach and retrosigmoid sinus-internal auditory canal approach. Methods: one group of cadaveric head specimens simulated Kawase approach to measure the data of “Kawase triangle”, the other group simulated retrosigmoid sinus-internal auditory canal approach to measure the safety range of the grinding bone window. Then we explored the clinical indications of the two surgical approaches. Result: the grinding depth of Kawase triangle was 11.6±0.14mm, and the range of clival exposed after grinding Kawase triangle was 22.4±1.22mm, which could effectively expose the ventrolateral brainstem, the midline of clivus and the area above the facial acoustic nerve. The diameter of the anterior and posterior of the grinding bone window in the retrosigmoid sinus-internal auditory canal approach was 21.95±2.23mm. In front of the exposure area were the internal carotid artery, the cavernous sinus, and the upper trigeminal nerve; the lower part was the connection between the facial acoustic nerve and the abducent nerve. Conclusion: Kawase approach is suitable for lesions of ventrolateral brainstem, middle superior clivus, with or without invasion of middle cranial fossa; the retrosigmoid sinus-superior internal auditory canal approach is suitable for lesions mainly in cerebellopontine angle area and only slightly invading Meckel’s cavity.

Keywords

cadaveric head anatomy / petrous tip / Kawase approach / retrosigmoid sinus-superior internal auditory canal approach