Inhibition of experimentally induced endolymphatic hydrops by middle ear ventilation.

The tympanic membrane was perforated (n = 19) or a tube was inserted into the middle ear through the wall of the tympanic bulla (n = 6) immediately after blockage of the endolymphatic duct in guinea pigs. Total cochlear endolymph volume and volumes in each cochlear turn were determined from serial sections of the temporal bones and volume changes were analyzed statistically by comparison with hydropic controls without treatment (n = 12). Results showed that both middle ear ventilation procedures significantly reduced the subsequent development of endolymphatic hydrops. This inhibition of hydrops was presumed to be due to pressure release into the middle ear and/or improved oxygenation of the middle and inner ears. Findings suggest the possible merit of a tympanostomy as a treatment for Meniere's disease in carefully selected patients refractory to medical management.