Dorello's canal
This canal was first described by Gruber in 1859 as an osteo fibrous canal situated at the petrous apex containing the abducent nerve. This canal is named after the famous Italian anatomist Primo Dorello who proved the existance of this canal after a series of meticulous dissections.
It is found close to the petrous apex.It lies below Gruber's ligament (petrosphenoidal ligament) betweenthe petrous apex and clivus. In majority of cases it is found atthe medial most end of petrous ridge at the confluence of inferiorpetrosal sinus, basal sinus and posterior end of cavernous sinus. Gruber and Dorello described this canal as the anatomic region between petrous apex and petrosphenoidal ligament. They also included inferior petrosal sinus along with 6th cranial nerve as contents of this canal.
Nathan defined this canal as a little space limited by the apex of the petrous bone, petroclinoid ligament and dorsum sellae. Dolenc beleived that this canal extended from the entrance of 6th cranial nerve into the interdural space, up to its entrance into the cavernous sinus.Involvment of air cells around petrous apex due to mastoid infections can lead to oedema of abducent nerve which lies within this canal.