Membrane ventilating tube for the middle ear.

A pilot study was conducted to evaluate the efficacy of a membrane ventilating tube as a Eustachian tube prosthesis in 20 patients with otitis media. The design was based partly on assumptions since many of the physiological parameters required to calculate the gas transport processes have not been previously reported. An elementary gas transport model with assumed partial pressures of gases was developed. A semipermeable membrane covering a tympanostomy tube was fashioned and used to ventilate the middle ear cavity. From this preliminary investigation, the device successfully maintained atmospheric pressures in the tympanum, compensated for Eustachian tube malfunction, prevented otorrhea and recurrence of middle ear effusions.