The sinus of the dorsum sellae.

Dissections of cadaver heads and studies of specimens sectioned in horizontal (axial), coronal, or sagittal planes at low (5 X) magnification revealed a frequent venous sinus within the bone of the dorsum sellae in addition to the true dural sinuses. This sinus interconnected the cavernous sinuses on either side of the sella turcica and was continuous with the superior and inferior petrosal sinuses and the basilar plexus. The sinus was quite evident on venograms of five patients. In sagittal sections of 37 adult cadaver heads, the sinus was identified in 28 (76%) and was absent in nine (24%) in which there was pneumatization of the dorsum sellae by the sphenoid sinus. The intracranial sinus of the dorsum sellae is not a true dural sinus but is comparable to the basivertebral veins of the spine.