Microvasculature of normal and hydropic labyrinth.

The microvasculature of the inner ear in guinea pigs and humans was observed with a scanning electron microscope using corrosion casting method. Alterations in the inner ear vasculature which occurred in association with experimental endolymphatic hydrops were also investigated. The results thus obtained are summarized as follows: 1. In the cochlea and vestibule, the arteries, coiled arterioles, and the veins are endowed with their respective characteristic morphologic features and play a role in the regulatory mechanisms of circulation. 2. The point in humans which is most different from guinea pigs was that coiled arterioles in the cochlea and the coil-like traveling of the anterior vestibular artery is not outstanding. 3. Arteriovenous anastomoses were demonstrated to exist in lateral wall of cochlea and utricular macula, a finding suggesting the existence of a regulatory mechanism for local blood flow. 4. Endolymphatic hydrops was noted to be preferentially associated with vascular abnormalities in the lateral wall of the cochlear duct and in the saccular macula, among other vestibular structures.