Histology of synthetic ossicular prostheses

Idiopathic, Infectious and Reactive Lesions of the Ear and Temporal Bone

A number of infectious, inflammatory and idiopathic lesions develop within otologic tissues that may share similar clinical and/or microscopic features. This review first provides a working classification for otitis externa, and then otitis media and includes two recently described entities, eosinophilic otitis media and otitis media with ANCA-associated vasculitis. Next, the microscopic findings of a spectrum of otopathologic conditions are described, including post-inflammatory conditions such as tympanosclerosis and aural polyps, an overview of animate aural foreign body as well as iatrogenic aural foreign body reactions. Finally, a review of fungal disease affecting the ear with a brief synopsis of Candida auris, a recently described and virulent organism, is presented.

Histopathology of ossicular grafts and implants in chronic otitis media

OBJECTIVES

We describe the histopathology of ossicular grafts and implants so as to provide insight into factors that may influence functional results after surgery for chronic otitis media.

METHODS

Histopathologic observations were made on 56 cases: 50 surgical specimens and 6 temporal bone cases in which the graft was sectioned in situ.

RESULTS AND CONCLUSIONS

Autogenous malleus, incus, and cortical bone grafts behaved in a similar manner and maintained their morphological size, shape, and contour for extended periods of time, at least up to 30 years. These histopathologic observations support the continued use of autograft ossicular and cortical bone grafts for middle ear reconstruction. Cartilage grafts developed chondromalacia with resulting loss of stiffness and showed a tendency to undergo resorption. Synthetic prostheses made of porous plastic (Plastipore, Polycel) elicited foreign body giant cell reactions with various degrees of biodegradation of the implants. Prostheses made of hydroxyapatite and Bioglass were enveloped by a lining of connective tissue and mucosal epithelium. The Bioglass material was broken down into small fragments and partially resorbed by a host response within the middle ear. These results warrant caution in the use of prostheses made of porous plastic or Bioglass.