Histopathology of Ossicular Grafts and Implants in Chronic Otitis Media

Abstract

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