The Microscopic Anatomical Study With The Improved Sinus Sigmoideus-into The Internal Acoustic Meatus Road

[Objective] Based on the cross-section images of the datasheet of the firstchinese digital visible female, and reconstruct the cyber-three-dimensionalmodel of the temporal bone and petrous internal carotid artery(PICA)which would then help to explore the way by which the modern imagingtechnology combined with neuronavigation device to use the improvedsinus sigmoideus-into the internal acoustic meatus road (retrosigmoidalsuprameatal approach, RSSMA) to quantify the ampliative mill range ofthe internal acoustic meatus and the apex partis petrosae as well as itssafety, effectiveness and practicality.[Materials] the cross-section images of the datasheet of the first chinesedigital visible female, Adobe photoshop CS3software、Amira software andMaya software;15cases of adult dead heads (both bilateral have30sets ofdata) which were primed by10%formalin、64-slice spiral CT (0.625mmthick)、Mimics V10.0software、neuronavigation systems and so on.[Methods] Based on the cross-section images of the datasheet of the firstchinese digital visible female, and reconstruct the cyber-three-dimensionalmodel of the temporal bone and petrous internal carotid artery(PICA) which has been realized by using Adobe photoshop CS3software、Amirasoftware and Maya software. Using the accurate neuronavigation systemsto simulate the surgical approach and dissect microscopicly layer by layer,mill(from back to front) the internal acoustic meatus and the apex partispetrosae securely, in order to improve security of the milling, and using CTmeasurements to observe and measure the grinding scope of the internalacoustic meatus and the apex partis petrosae and then measure the exposurerange of trigeminal nerve; Using Mimics V10.0software to reconstruct thethree-dimensional inner ear and temporal bone, and then estimate therelatively safe grinding range of the petrous bone.[Results] The three-dimentional images reconstructed by Amira softwaredemonstrated clearly the spatial shapes and adjacent relationships of thetemporal bone and petrous internal carotid artery(PICA), and thesurrounding structures. These images could be visualized independently,collocated randomly or demonstrated as a whole. Reconstructed parts couldbe re-dissected serially from coronal,sagittal and horizontal directions,andinner structures of reconstructed parts were displayed clearly.Through thisexperimental study by the improved RSSMA, the front-back、middle-sideof the internal acoustic meatus can all be worn out completely; theup-down (8.22mm bone can be worn out)、front-back、middle-side of thepetrous bone can be partially worn out; the trigeminal nerve can be exposedampliatively9.26±1.25mm; the surgical field of the anterior and posterior wall of the auditory canal can expand33.06±5.75degree; the superiorclivus can be exposed93.08±7.50mm2, the middle fossa is about148.76±8.21mm2.[Conclusion] Tri-dimentional reconstructions and visible displays of thetemporal bone and petrous internal carotid artery(PICA) has significantvalue for the clinic imaging diagnosis and skull base neurosurgery aroundthis area, and for the improvement of teaching effect of anatomy.Theimproved RSSMA approach which combined with neuronavigation deviceand modern medical imaging technology is much more simple、practical、minimally invasive and safer than the traditional, and it is a better optionfor the petroclival tumor surgery.