The vascular system of the inner ear was investigated in 18-21 weeks old human fetuses, using the corrosion cast technique in scanning electron microscopy. At that developmental stage, vascularization of the cochlea and semicircular canals shows a pattern very similar to that described for adults. The most important differences which can be regarded as fetal features include: (1) denser limbus vessels, (2) the marginal vessels of the spiral lamina appearing as irregular network which shows a less clear arcade-like arrangement, (3) some radiating arterioles of the spiral lamina and marginal vessels possessing connections with the vascular system of the external wall, and (4) a dense, sinusoidal network of draining venules at scala tympani. These features apparently disappear during the final remodelling of the inner ear microvasculature in the last trimester.
Miodoński, A. J.; Gorczyca, J.; Nowogrodzka-Zagórska, M.; Litwin, J. A.; and Składzień, J.
"Microvascular System of the Human Fetal Inner Ear: A Scanning Electron Microscopic Study of Corrosion Casts,"
Scanning Microscopy: Vol. 7
, Article 15.
Available at: https://digitalcommons.usu.edu/microscopy/vol7/iss2/15