Dorello's canal: a microanatomical study.

The microsurgical anatomy of Dorello's canal has been studied in 20 specimens obtained from 10 cadaver heads fixed in formalin. The bow-shaped canal through which courses the abducens nerve before reaching the cavernous sinus is located inside a venous confluence which occupies the space between the dural leaves of the petroclival area. The petrosphenoidal ligament (Gruber's ligament), which forms the posteromedial wall of the canal, appears as a fibrous trabecula surrounded by venous blood. Canal measurements were performed and its anatomical relationship with the sixth cranial nerve is described. Angulations of variable degrees were observed in the course of the nerve inside and outside the canal. The influence of this relatively tortuous course of the abducens nerve upon its vulnerability in some pathological conditions is discussed.