Rat Model of External Auditory Canal Stenosis

Area of Science:

• Otolaryngology
• Regenerative Medicine
• Animal Models

Background:

• Acquired external auditory canal (EAC) stenosis results from trauma or inflammation, causing narrowing, debris, and hearing loss.
• Surgical treatment for EAC stenosis is prone to restenosis.
• A reliable, inexpensive animal model for EAC stenosis is needed, with no prior studies correlating injury extent to stenosis severity.

Purpose of the Study:

• To establish a reproducible animal model of acquired external auditory canal (EAC) stenosis.
• To correlate the degree of electrocautery injury to the EAC with the resulting stenosis.
• To provide a model for studying preventative therapies for EAC stenosis.

Main Methods:

• Rats underwent 25%, 50%, or 75% circumferential electrocautery injury to the external auditory canal (EAC).
• Stenosis was quantified 21 days post-injury.
• Histological analysis assessed the injury and healing response.

Main Results:

• A 25% injury caused 4-34% stenosis (mean 13%), 50% injury caused 43-100% stenosis (mean 73%), and 75% injury caused 94-100% stenosis (mean 99%).
• The 50% injury group showed significant stenosis (30-100%).
• Histology revealed intact cartilage/epithelium, thickened subepithelium, and fibrosis.

Conclusions:

• Electrocautery injury to the rat EAC reliably induces stenosis.
• This model is valuable for investigating therapies to prevent acquired EAC stenosis.
• The correlation between injury extent and stenosis severity can inform clinical EAC injury management.