Revision surgery in otosclerosis--an investigation of the factors which influence the hearing result.

The hearing improvement obtained by revision surgery for otosclerosis has been assessed in 163 patients with a conductive hearing loss. Several different surgical techniques had been used at the primary operation. On average at revision a hearing improvement of 11 dB was obtained. The hearing improvement was related to the surgical technique of the primary operation, the middle ear abnormalities and the surgical technique used at revision. Patients in whom a small-fenestra-technique had been used for the primary as well as the revision procedure, had a better result than patients who had total removal of the footplate. Patients with adhesions and an eccentric prosthesis only showed a small hearing improvement. Patients with necrosis of the long process of the incus were also difficult to manage. Since the complication rate was low it does not seem to be more dangerous to perform a revision than to perform a primary operation. The results obtained by revision are poorer than can be obtained by the primary procedure. This indicates that in stapes surgery the greatest chance for hearing improvement is the first operation, therefore centralization of this type of operation should be considered.