Histological study of inactivated/preserved ossicular homograft in New Zealand rabbits

ObjectivesHistological evaluation of the fate of implanted ossicular homografts in adult New Zealand white rabbits after inactivation/preservation procedure.DesignThe study was conducted on 10 pathogen free adult NZ white rabbits at the animal laboratory of Alexandria University Hospitals. Under general and local infiltrative anesthesia middle ear ossicles (incus and malleus) were collected bilaterally from another five rabbits. These ossicles underwent inactivation/preservation procedure using sodium hydroxide followed by autoclaving at 134 °C for 8 min and kept in a sterile autoclavable package. The treated ossicles were randomly implanted in the middle ear cavity of recipient rabbits. After one month, both the homograft and the ossicle of the same rabbit were retrieved and histologically examined.ResultsAll the harvested control ossicles from the same ear showed the regular histological structure of the compact bone. All harvested specimens of inactivated/preserved ossicular homograft maintained their shape, contour, size and physical integrity and were surrounded by a variable layer of fibro-vascular tissue. There was bone proliferative activity with new bone formation at the periphery underneath the periosteum and remodeling was evident around the bone marrow spaces. All harvested ossicular homografts did not show any granulomatous foreign body reaction.ConclusionInactivated/preserved ossicular homograft can be considered for partial ossicular reconstruction in some selected indications for patients lacking suitable autograft ossicles.