Mechanisms responsible for postnatal middle ear amniotic fluid clearance

Newborn Hearing Screening in Infants With Cleft Palates

“…There is also evidence for temporary CHL in neonates immediately after birth because of residual liquid derived from amniotic fluid in the ME cavity (13,14). Although the prevalence of ME effusion in healthy neonates is unknown, a 1973 autopsy study disclosed that 60% or more of full-term newborns who died on the first day of life had f luid in the ME (15).…”

In vivo demonstration of the absorptive function of the middle ear epithelium

“…All these data demonstrate the disappearance of fluid from the middle ear, but they do not ascertain whether this occurs through the ET or through the mucosa. Priner et al (2003b) have conducted experiments in guinea pigs to support the role of the trans-mucosal transport. They introduced various solutes into the middle ear cavity and observed the animals over several days by tympanometry and otoscopy.…”

Mechanism and Rate of Middle Ear Fluid Absorption

“…Fluids can be present in the middle ear cavity as part of normal physiological processes, such as residual amniotic fluid shortly after birth [Priner et al, 2003]. Fluid is also present in serous otitis media.…”

“…In both cases, normal middle ear function and hearing require the clearance of this incompressible fluid and its replacement by compressible air. Several mechanisms have been implicated in this clearance: a pumping action through the eustachian tube following contraction of the tensor veli palatini muscle [Cantekin et al, 1979;Honjo et al, 1981Honjo et al, , 1985; removal by the beating cilia of the mucosal lining (mucociliary mechanism) of the middle ear and eustachian tube [Sade, 1967;Nuutinen et al, 1983]; osmotic outflow of water from the middle ear as a consequence of osmotic pressure gradients between the middle ear fluid and blood [Priner et al, 2003]; active transport of sodium by middle ear epithelium from the middle ear fluid, driving water absorption [Herman et al, 1992;Yen et al, 1993;Li et al, 2005].…”