Modified Surgical Technique for the Safe Anterior and Posterior Combined Petrosectomy

Objective: The anterior and posterior combined petrosal approach has been widely recognized as a useful approach to lesions at the clivus and petroclival junction. Nevertheless, the time-consuming and complicated petrosectomy procedure sometimes inhibits non–skull-base surgeons in selecting this approach. Hence, we modified the procedure to enhance safety and simplify the combined approach.

Material and Methods: Between January 2007 and October 2011, the modified techniques were applied to 68 patients with petroclival and clival lesions. After accomplishment of temporo-occipito-suboccipital craniotomy, the wall of the sigmoid sinus was carefully dissected from the overlying inner cortical bone at the mastoid process, and the mastoid bone was removed with a rongeur. The next step was complete dissection of the dura matter off the superior and posterior surface of the petrous bone. At the middle fossa, the middle meningeal artery was sacrificed, and the greater superficial petrosal nerve was carefully dissected for full exposure of the superior surface of the petrous bone. Then, presigmoid dura was also peeled to the dural reflection into the internal auditory canal, with coagulation and transaction of endolymphatic duct. Through this extradural procedure, the petrous bone was entirely exposed and could be safely and easily drilled out though a wider surgical corridor compared with that obtained via a standard petrosectomy.

Results: All 68 petrous bones were safely drilled out without any injury of the sigmoid sinus and the other crucial structures.

Conclusions: Our modification of the combined petrosectomy effectively shortened the surgical time and increased the safety of the approach.