Development of an In Vivo Model for Eustachian Tube Dysfunction

Area of Science:

• Otolaryngology
• Medical Engineering
• Animal Models

Background:

• Otitis media frequently correlates with Eustachian tube dysfunction (ETD).
• A significant gap existed in large animal models for evaluating novel Eustachian tube (ET) treatments, such as stenting.

Purpose of the Study:

• To establish a reproducible large animal model for inducing ETD without permanent Eustachian tube (ET) closure.
• To develop and validate a method for testing new therapeutic interventions for ETD.

Main Methods:

• Development of specialized tools for safe hyaluronic acid (HA) injection near the Eustachian tube (ET) in blackface sheep.
• Utilizing cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI) for visualizing HA depots and guiding stent placement.
• In vivo validation through tympanometry to assess middle ear ventilation and induction of ETD.

Main Results:

• Successful induction of ETD in sheep using 2.5 mL or higher of HA, with no observed complications or animal distress.
• The induced ETD persisted for 3 to 13 weeks and was associated with middle ear effusion.
• Demonstrated feasibility of stent placement within the ET following HA injection.

Conclusions:

• A reliable and reproducible large animal model for Eustachian tube dysfunction (ETD) has been successfully established.
• This model provides a platform for preclinical evaluation of innovative treatments, including Eustachian tube (ET) stents.
• The HA injection technique offers a temporary and controllable method for studying ETD and its management.