Sustained Inner Ear Steroid Delivery via Bioabsorbable Stent: A Tolerability and Feasibility Study on Guinea Pigs.

Objective: To determine the feasibility and tolerability of a steroid-eluting middle ear device on an animal model.

Study Design: Prospective experimental.

Setting: Experimental animal study.

Subjects And Method: Mometasone furoate (MF)-eluting miniature sticks were implanted through a myringotomy incision into the middle ear of 10 guinea pigs. Two additional ears of 2 animals served as controls. Fourteen days after implantation, perilymphatic fluid was collected through an endaural cochleostomy. MF concentrations were measured with high-performance liquid chromatography, and the middle ear mucosal inflammation was graded with hematoxylin and eosin colorations.

Results: Fourteen days after implantation, all tympanic membranes had fully healed. An average of 165 ng/mL of MF was detected in the perilymphatic fluid of the experimental ears, and none was measured in control ears. Microscopic residues of the ministicks were found in 90% of the samples, confirming the bioabsorbable properties of this device. Histologic analysis of the middle ear mucosa found similar inflammation profiles in both groups, thereby suggesting middle ear tolerability.

Conclusion: MF-coated bioabsorbable miniature stick allows for prolonged delivery over 14 days without injuring the middle ear mucosa. Middle ear-sustained steroid delivery may prove to be beneficial in numerous neurotologic conditions.