The Poly-L-Lactide Eustachian Tube Stent: Tolerability, Safety and Resorption in a Rabbit Model

Objective: To ascertain the tolerability and resorption of a poly-l-lactide Eustachian tube stent in a rabbit animal model. Materials and Methods: In a prospective, controlled animal study, a poly-l-lactide stent was implanted into one Eustachian tube of ten female New Zealand white rabbits. The remaining ear of each animal served as a matched control. Serial otoscopy was performed to assess any manifestation of foreign body reaction. The rabbits were sacrificed at 24 weeks post implantation. Blinded histological sectioning was performed to determine degree of inflammatory response. The degree of stent resorption was evaluated by weight measurement of the stent prior to implantation and following extraction of the temporal bone from the cadaver. Results:. Follow-up was available for all ten animals at time of sacrifice. Of these ten animals, five developed otitis media in the test ear, and one of these four animals also developed facial cellulitis. All infections resolved with treatment relatively quickly. The stent was completely resorbed at 6 months post implantation in all test animals. None of the tympanic bullae demonstrated histologic evidence of acute or chronic inflamation. Conclusions: The poly-l-lactide Eustachian tube stent was well tolerated by the test animals. This technology merits further evaluation for efficacy in animals.