ABSTRACT
Objective To investigate the surgical techniques of the modified presigmoid trans-partial bony labyrinth approach and the advantages in exposure of the petroclival region and in treat the lesion of this area.Methods By simulate the modified presigmoid trans-partial bony labyrinth approach in 15 adult cadaveric heads with the aid of an operating microscope and record important structures in the petroclival region.Results The petroclival region,the posterior cavernous sinus,Meckel cave,the vertebral-basilar artery,the anterior inferior cerebellar artery,the superior cerebellar artery,ipsilateral Ⅲ-Ⅹ cranial nerve nere fully exposured and contralateral Ⅵ cranial nerve were fully exposured.The range of presigmoid exposure was (19.41 ± 1.58)mm,the exposurein of inferior temporal was (14.18 ± 1.88) nun,the maximum exposure angle of slope center depression was (60.54 ± 6.93) °,the depth of operation was (55.87 ± 4.34) mm.Conclusion The advantages of the modified presigmoid trans-partial bony labyrinth approach can earn enough exposures of deep part of petroclival region and posterior part of cavernous sinus,improved petroclival exposure,multiple axes of visualization,preservation of hearing and facial nerve function,and early devascularization of the tumor.