Match with operational treatment of petroclival cholestatoma by presigmoid approach;

Modified transpetrosal presigmoid approach for microsurgical removal of petroclival tumors;

The anatomic study of the superior petrosal vein during the endoscope-assisted presigmoid approach;

Methods Adopting presigmoid sinus approach and using micro neurosurgery technique,deblocking the petroclival meningioma and then making total tumor resection or partial tumor resection.

Objective: : To provide anatomical basis for drilling the po sterior wall of the petrous pyramid through transpetrous presigmoid approach.

Objetive: To supply relevant anatomy basis for transpetrous presigmoid approach by the way of measuring the distance among the important bone structures of petrous bone of cadaveric adult heads and combining CT thin tomographic scan, and reduce the emergence of operation complications.