[An endoscopic-assisted technique for the enlarged middle cranial fossa approach to the petroclival region: an...

Objective:Through the observation and measurement of the adjacent anatomical structures exposed by the pure microscope and endoscopic-assisted technique for the enlarged middle cranial fossa approach to the petroclival region, quantitative compare the advantages of endoscopic-assisted technique and the pure microscope exposure. Method:The enlarged middle cranial fossa approach was performed on 10 cases (20 sides) fresh adult cadaveric head specimens in which the vessels were injected with colored silicone. At the end of every enlarged middle cranial fossa approachs, endoscope assisted technique was applied. The effective working areas were measured under pure microscope and endoscopic-assisted technique. Result:The distance between the trigeminal nerve root entering the pons and the upper limit of exposure to the middle of the ventral brainstem under the microscope was（15.95±0.48）mm；the distance from the initial point of the acoustic-facial bundle to the lower bound of exposure to the middle of the ventral brainstem under the microscope was（10.79±0.51）mm；The distance between the trigeminal nerve root entering the pons and the upper limit of exposure to the middle of the ventral brainstem under endoscopy was（18.88±0.36）mm；the distance from the initial point of the acoustic-facial bundle to the lower bound of exposure to the middle of the ventral brainstem under endoscopy was（14.56±0.64）mm. Conclusion:In the anatomic study of the enlarged middle cranial fossa approach to the petroclival region, the endoscopic assistance has a larger effective exposure space and flexible perspective compared with the operation under the microscope, which is helpful to accurately locate the position and size of the lesion during surgery, accurately identify the important nerves and blood vessels surrounding the lesion, so as to improve the resection rate and reduce the recurrence rate.