The proximal portion of the vestibular aqueduct. A radioanatomical investigation.

Purpose: To obtain information on the morphology of the proximal portion of the vestibular aqueduct.

Material and methods: One hundred plastic casts of temporal bone were examined with a dissection microscope at high magnifications in order to evaluate the proximal portion of the vestibular aqueduct. The difficulties in reproducing these minute structures were solved by light scanning photography.

Results: There is usually more than one paravestibular canaliculus (PVC) around the proximal portion of the vestibular aqueduct closely related to an intra-and a periaqueductal vascular network. An estimate was made of the number of PVCs and their widths measured. The origins of the PVCs at the wall of the vestibule were identified and their widths were measured. Numerous vascular sulci and impressions of a vascular network on the inside of the bony wall of the vestibule were revealed close to the internal aqueductal aperture. The pattern of the channels and the number of the paravestibular canaliculi were not influenced by the pneumatization of the temporal bone.

Conclusion: The significance of these vascular structures and their influence on the radiographic reproducibility of the proximal portion of the vestibular aqueduct is discussed.