A scanning electron-microscopic study of different tympanic grafts

Area of Science:

• Otolaryngology
• Biomaterials Science
• Surgical Pathology

Background:

• Temporalis fascia autografts and tympanic allografts are used in ear surgery.
• Understanding graft surface architecture is crucial for surgical outcomes.
• Preservation methods can alter graft structure.

Purpose of the Study:

• To investigate and compare the surface architecture of dried temporalis fascia autografts and preserved tympanic allografts.
• To evaluate the structural changes induced by storage and dehydration.
• To assess the potential implications of these changes for graft integration and middle ear pathology.

Main Methods:

• Scanning electron microscopy (SEM) was employed to examine graft surfaces.
• Grafts were subjected to standard preservation (formaldehyde-cialit) and dehydration processes.
• Surface morphology, including epithelial layers and underlying structures, was analyzed.

Main Results:

• Tympanic allografts showed progressive detachment of epithelial and mucosal layers during storage, leaving the lamina propria.
• Dried temporalis fascia autografts displayed irregular, crater-like defects due to dehydration.
• These defects presented an amorphous surrounding structure.

Conclusions:

• Preservation and dehydration significantly alter the surface architecture of both graft types.
• The observed defects in dried fascia autografts may facilitate epithelial migration towards the middle ear.
• This finding provides novel support for the immigration theory of cholesteatoma development.