[Applied anatomy of the cerebelloponotine angle through retrosigmoid approach].

Objective: To privde anatomical basis for the surgical operation of endoscope-assisted retrosigmoid approach. Method: In 20 adult head cadavers fixed with formalin (40 sides), the surgery via retrosigmoid approach was simulated. The anatomic features of the cerebellopontine angle were examined and measured. Result: The distance from the midpoint of posterior border of sigmoid sinus to acoustic nerve near internal acoustic pore, trigeminal nerve near Meckel's cave, glossopharyngeal nerve near jugular foramen and the posterior margin of internal acoustic meatus were (32.8±1.7)mm, (46.3±1.8)mm, (29.4±3.0)mm, (31.2±2.0)mm. The tracks of degree of angle of median sagittal plane were (32.6±7.7)°, (31.4±4.1)°, (40.2±6.9)°, (32.7±4.9)°. Conclusion: The measurement provides some useful references for defining the position in operating.