Simulation of petrous bone drilling in subtemporal approach utilizing virtual reality system

Abstract

Objective To evaluate the utilizing value of virtual reality technique for microanatomy of petrous bone by comparing the anatomic characteristics and data measurement between virtual reality and cadaveric head specimens in subtemporal approach. Methods CT scan data of 15 adult cadaveric heads were inputted into the Dextroscope virtual reality system to build three⁃dimensional model of petrous bone. Petrous bone drilling was performed on cadaveric heads and virtual reality models respectively to expose anatomic structures step by step, and the distance and angle was measured based on selected mark points. Bland⁃Altman method was used for the uniformity of checking. Results Visibility effect of simulation of petrous bone drilling in virtual reality system was good. The anatomical structure of facial nerve in petrous bone, greater superficial petrosal nerve, cochlea, semicircular canal, internal carotid artery and glomus jugulare, were displayed clearly. Comparative analysis between cadaveric head and virtual reality by Bland⁃ Altman method showed that bias for distance between geniculate ganglion and start point of common osseus crus of semicircular canal bony, geniculate ganglion and vertex of cochlea, and vertex of cochlea and start point of horizontal segment of internal carotid artery in petrous bone, were 0.020, 0.020, and ⁃ 0.010 respectively, and 95% confidence intervals were ⁃ 0.240-0.270, ⁃ 0.190-0.220, and ⁃ 0.170-0.150, respectively. Good consistency was demonstrated in scatter diagram. For the limitation of visual angle in cadaveric head, the angle between internal acoustic meatus and groove of great superficial petrosal nerve and the distance between start point of common osseus crus of semicircular canal and superior margin of glomus jugulare could not be measured, while data measurement of petrous bone model in virtual reality system was convenient and quick, without limitation of visual angle. The distance between start point of common osseus crus of semicircular canal and superior margin of glomus jugulare was measured as (4.74 ± 0.20) mm, and the angle between internal acoustic meatus and groove of greater superficial petrosal nerve was (51.34 ± 3.29)° . Conclusion Accurate, objective and measurable results can be obtained in the simulation of petrous bone drilling in subtemporal approach utilizing virtual reality system, and could guide surgical practice in dealing with petroclival lesions．

DOI：10.3969/j.issn.1672⁃6731.2012.06.019