Abstract
To identify the causes of failure after the primary stapes surgery and to evaluate the hearing outcome of the revision stapes surgery, we retrospectively reviewed a series of 10 revisions surgery after stapes surgeries for otosclerosis between January 1994 and May 2011. Pre- and intra-operative findings, causes of failure, and pre- and postoperative audiometric results were evaluated retrospectively.
Eight cases were primary revision surgery and two cases were secondary revision surgery. Average duration between the primary and revision surgeries was 4 years and 9 months. The reasons of the revision surgery were conductive hearing loss (nine cases) and dizziness (one case). Temporal bone CAT scans were performed before revision surgery in all cases to evaluate the status of the piston. We confirmed displacement of the piston only in five cases. The causes of the failure that we found during revision surgery were displacement of the piston from the incus (five cases) and from the oval window (four cases). In one case, we found that both causes occurred. In all cases of dislocation of the piston from the oval window, the oval window was closed by soft tissue and no case had bony closure of the oval window. Then, it was easy to re-open the oval window and insert a piston again. In cases of the displacement of the piston from the incus, we crimped the hook to incus again when incus erosion was slight or was not found. Seven cases had successful hearing results (more than 15dB improvement in the threshold of air conduction) in nine cases of conductive hearing loss. Among six cases we followed up for more than six months, five cases maintained good hearing level.
As a conclusion, when conductive hearing loss remains or appears after primary stapes surgery, it would be better to choose positive attitude to perform revision surgery.
