Paravestibular canaliculus in Meniere's disease. A histopathological study.

The paravestibular canaliculus (PVC) and its contents were studied in 27 temporal bones from individuals with Meniere's disease and in the same number of controls. The specimens were examined by the medial view graphic reconstruction method and/or histologically under a light microscope. In most of these bones (88.9% of controls and 85.2% of Meniere's bones) only one PVC was noted; in the remaining bones (11.1% of controls and 14.8% of Meniere's bones) two PVCs were recognized. Most of the PVCs (88.9%) in both control and Meniere's bones were located in the petrous bone anterolateral to the vestibular aqueduct (VA). In one third of both control and Meniere's bones the PVC extended below the inferior margin of the posterior semicircular canal. In 74.1% of the Meniere's bones the PVCs were noted to exit directly to the posterior cranial fossa, whereas such a course was present in only 40.7% of controls. The difference in this parameter between control and Meniere's disease bones is statically significant and appears to be related to the size of the VA. The length of the PVC, however, seems to be independent of both the size of the VA and the degree of development (thickness) of the petrous bones surrounding the PVC. In four Meniere's bones a part of the main vein in the PVC was absent; this was never observed in a control bone. We found no other evidence in this study to link the function or anatomy of the PVC to Meniere's disease.