Abstract:

Objective　To discuss the anatomic features of Kawase approach based on virtual reality image model.　Methods　Image data of CT and MRI scan performed to fifteen adult cadaver heads were used to establish virtual reality three-dimensional anatomy model of skull base. The lines between landmark points of craniotomy and petrous bone drilling were used as axis to outline cylinders simulating surgical routes of Kawase approach. Anatomic exposures in two surgical routes were observed and measured.　Results　Route 1 of Kawase approach involved superior petrous sinus and the end of route involved pon at the root entry zone of trigeminal nerve. Route 1 involved partial trigeminal nerve and superior cerebellar artery. Route 2 of Kawase approach involved superior petrous sinus, inferior petrous sinus and basal sinus. And then, ipsilateral trigeminal nerve, ipsilateral abducent nerve, basal artery, contralateral abducent nerve and trigeminal nerve were passed through. The end of route 2 was the intersection between axial line of cylinder and the root of contralateral trigeminal nerve. The volumes of route 2 and osseous structures, brainstem, artery, vein, greater superficial petrosal nerve and ipsilateral trigeminal nerve involved were more than those of route 1 with statistical significance. The volume difference of the temporal lobe between the two route did not reach statistical significance.　Conclusions　Kawase triangle forms a surgical window through which the direction of route will change the operative range. The route which passes through the superior edge at the root of the temporal bone zygomatic process will be helpful to expose the brainstem ventral space.

Key words: Kawase approach; , Virtual reality; , Three-dimensional anatomy; , Skull base;  , Petrous bone