THE UTRICULO-ENDOLYMPHATIC VALVE IN PEDIATRIC TEMPORAL BONES

The utriculo-endolymphatic valve (UEV) is located in the posterior wal l of the utricle at its junction with the utricular duct and was first described in a human fetus by East in 1928. Although different theori es about its normal position and function have been postulated, the fu nction of the UEV remains unclear. In the present investigation we stu died 118 temporal bones from 70 children to determine whether there we re differences in the position of the valve and by inference, its func tion between children and adults. Premortem ages ranged from newborn t o 10 years (mean age, 11.6 months). All temporal bones were fixed in 1 0% formalin, decalcified and processed by the celloidin technique. Spe cimens were sectioned in a horizontal plane at a thickness of 20 mu m. Every tenth section was stained with hematoxylin-eosin and studied by light microscopy. The position of the UEV was then classified as clos ed or open. Valves damaged by preparation or having an uncertain posit ion were classified as artifact. The chi-square test was used to deter mine a correlation between the position of the valve and the status of the rest of the endolymphatic system and whether or not endolymphatic hydrops was present in the cochlear and vestibular systems. The UEV w as closed in 39 temporal bones (33.1%) and open in 13 (11.0%). Artifac ts were found in 66 bones (55.9%). In the group of patients with a col lapsed ductus reuniens the UEV was closed in 38% of the specimens, sug gesting that the UEV prevented loss of endolymph from the pars superio r, but these findings were not statistically significant.