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

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

Prospective experimental.

Experimental animal study.

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.

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.

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.