The Posterior Wall of the Cavernous Sinus: A Microanatomical Study

The posterior wall of the cavernous sinus was studied in 15 cadaver heads (20 specimens) fixed in formalin. The heads were placed in a Sugita head holder and turned 45* from the side of dissection. The posterior wall of the cavernous sinus belongs to the dura mater of the petroclival region. It is limited superolaterally by the posterior petroclinoid ligament, medially by the dorsum sellae, and inferiorly by the petrous apex and Dorello canal. Similar to the lateral and superior wall of the sinus, the posterior wall was found to be formed by two layers: a smooth superficial dural layer and a thin less defined deep layer. This wall covers not only the posterior aspect of the cavernous sinus but a venous confluence joint also by the basilar sinus and the inferior petrosal sinus. Other anatomical structures related to the posterior wall and posterior end of the cavernous sinus are: Dorello canal, the abducens nerve, the posterior bend of the ICA with the meningo-hypophyseal trunk and its branches. The anatomy of this wall becomes important when dealing with lesions in the petroclival area.