Abstract: Microsurgical anatomy of internal auditory canal (IAC) and cerebellopontine angl e that were related to suboccipital retrosigmoid approach were studied to put fo rward anatomic parameters for the operation of acoustic neuromas. Ten cadaveric head s were dissected using 5 to 25× magnification and ten dry skulls provided 20 te m poral bone for measurment of the osseous relationships in the region. The anatom ic distances were measured and the anatomic structures were photographed wi th microphoto camera. The anatomic relationship and data of structures in cerebe llopontine angle and IAC that was related to acoustic neuromas were obtained. Fa miliarity with the microanatomical relationship of the structures around IAC may be helpful to improve the surgical outcome of acoustic neuromas.

Key words: internal auditory canal, cerebellopontine angle, acoustic neuromas, microanatomy