Disintegration of porous polyethylene prostheses.

A Plastipore (porous polyethylene) Total Ossicular Replacement Prosthesis gave an excellent initial hearing result which was maintained for 14 years. Hearing then began to deteriorate and revision surgery showed disintegration of the prosthesis and a defect in the stapes footplate. Histological examination confirmed previous findings in porous polyethylene with multinucleated foreign body giant cells and breakdown of the material.

Myringotomy and ventilation tube insertion: a ten-year follow-up.

Eighty children who had myringotomy performed for otitis media with effusion in 1984 were reviewed in 1994. This had involved surgery on 158 ears. Three aspects of ear condition were studied: hearing loss, tympanic membrane perforation, and tympanosclerosis. Hearing losses were present in 13 ears (8.2 per cent), involving 10 children (12.5 per cent), although losses were under 20 dB in seven of these ears (five patients). Of the six ears with losses more than 20 dB (3.8 per cent), in five patients bilateral losses of 30 dB were due to a recurrence of effusions, a large dry posterior perforation was the cause of a 30 dB loss, an infected anterior perforation had caused a 30 dB loss, an ear which had a cholesteatoma, and had a mastoidectomy and ossiculoplasty in 1987, had a 30-40 dB loss, and one ear which had a Type 1 tympanoplasty in 1994 had a 50 dB loss. Therefore in only three ears (1.9 per cent) could hearing loss be associated directly with myringotomy and ventilation tube insertion. Perforations had persisted unilaterally in seven patients, three having had tympanoplasties. Of the remaining perforated tympanic membranes, two were free of symptoms, one had only a slight hearing loss, and one had a more significant loss with recurrent infection. Tympanosclerosis was only found in those ears which had ventilation tubes inserted (and not those which had myringotomy only), occurring in 48 ears (31 per cent, of 39 per cent of those which had a ventilation tube inserted). There was no link between tympanosclerosis and hearing loss. The site of tympanosclerosis was not restricted to the site of myringotomy, and in many cases was present only in other areas of the tympanic membrane. There was a tendency for more extensive tympanosclerosis to occur in those ears which had more ventilation tube insertions. The risk of perforation in particular lends support to a policy of 'watchful waiting'.