Microanatomy and clinical significance of the oculomotor nerve

Objective To study the running of oculomotor nerve and its relationship with surrounding structures,and to provide the guideline for the clinical practices.Methods A total of 10 adult cadaver heads with intravascular dye perfusion were observed under the operating microscope to study the morphology of bilateral oculomotor nerve and adjacent and feeding blood vessels,and measure the distance between the oculomotor and vital surrounding structures in 20 cases.Results The oculomotor nerve was 5.13 mm±1.26 mm away from posterior clinoid process,2.42 mm ± 0.43 mm away from anterior clinoid process,10.20 mm ± 2.71 mm away from oculomotor and trochlear nerve tentorial entrance.The average diameter of oculomotor nerve was 2.41 mm ± 0.37 mm.Conclusion Because the complicated adjacent neurovascular structures of oculomotor nerve,it is easily be injured during operation.Good understanding the adjacent structures of oculomotor nerve is helpful for the clinical practice.