Experimental and clinical aspects of carbon as a middle ear prosthesis

Abstract

The biocompatibility of vitreous carbon and carbon fibre reinforced carbon (CFRC) as middle ear implants was investigated. In separate animal model systems, vitreous carbon was implanted in the middle ear of 20 DA rats for up to 6 months, whilst 3 varieties of CFRC (basic or crude, ultrasonically cleaned, glazed) were implanted in 98 guinea-pig middle ears for up to 4 months. Tissue reactions to implantation were assessed by means of stereoscopic and standard light microscopy, and scanning electron microscopy with chemical analysis facilities (EDAX, WDAX). Vitreous carbon and glazed CFRC were considered suitable for human implantation and a trial of the latter was started in 23 patients (14 partial, 9 total ossicular implants). At 9 months, only 52% of the implants were still in situ; 40% had been extruded and 8% had elicited inflammatory responses which would undoubtedly result in extrusion. Carbon particle dissemination with carbon fibre destruction and exposure as a result of peroperative prosthesis drilling were considered the likely causes for the failure of this implant.

Literature review of alloplastic materials in ossiculoplasty

“…12 Furthermore, in a small clinical study using carbon bre reinforced carbon as the ossicular prosthesis, Blayney et al reported a 40 per cent extrusion rate at nine months and a further eight per cent with in ammatory responses around the implant. 50 Titanium (Ti) was established as an excellent biocompatible material by Branemark in the 1970s. 51 It was rst introduced as an alloplastic material for ossiculoplasty in 1993.…”

Application of carbon fibers to biomaterials: A new era of nano-level control of carbon fibers after 30-years of development

“…A wide variety of implants, including artificial joints, plates and screws for treatment of fractures, maxillofacial implants, and middle ear implants have been developed, and some of these are now clinically applied. [76][77][78]…”

Passive und aktive Mittelohrimplantate

“…Bei Humanexplantaten fanden sich mehrkernige, fremdkörperhaltige Riesenzellen, was als Fremdkörperreaktion mit Degradation des Implantates angesehen wird [97]. Reiner Glaskohlenstoff als Implantatmaterial ist wegen starker Fremdkörperreaktionen mit konsekutiver Abstoßung in Tierversuchen und im klinischen Einsatz nicht zu empfehlen [98,99]. Flex H/A ist ein Komposit, welches aus Hydroxylapatit und Silastik zu gleichen Teilen besteht.…”