[The small fenestra vs large stapedectomy: comparative evaluation of failures and complications]

The Authors discuss post-operative failures and complications detected in their case-report of 1857 patients, operated for otosclerotic disease between 1982 and 1993 (399 large fenestra and 1458 small fenestra stapedotomies), with reference to the data from international literature. Their study reveals that the most frequent clinical event caused by complications arising is still hypoacusia of various degree, both conductive (2.7%) and sensorineural (6.6%); more precisely, conductive hearing loss points to revision surgery, while sensorineural lesions, often limited to high frequencies (5.7%), may unfortunately take the form of anacousia (0.9%). Some extra-auditory complications (temporary facial paralysis, ear drum perforation, disgeusia, tinnitus) are also present with relative frequency in stapes surgery (4.2%); among them, however, only impairment or appearance of tinnitus (0.6%) turn out to be a persistent disorder. Analysis of the results underlines that the complications rate is higher in the case of coexisting morphological anomalies (such as stenosis of the external ear canal, disjointing or amputation of the incus, difficulty in approaching the oval window, reobliteration of the oval window, facial nerve prolapse) or when intraoperative problems arise (excessive bleeding, profuse perylymph flow), which make the operation more difficult to perform. The data obtained in this study show that stapedotomy (using a 0.6 mm diameter prosthesis), gives a significantly lower rate of sensorineural complications (4.1%), than platinectomy (15.6%), because of the reduction of labirinthine traumatism. Lastly, the Authors performed 64 revision operations, evaluating intraoperative findings and hearing recovery rate. Causes of failure most frequently detected during revision surgery were: incus necrosis (24.6%) and prosthesis displacement (21.3%) with possible reobliteration of the oval window (23%); however it has not always been possible to detect pathogenesis of a postoperative conductive hearing loss. All things considered, results of revision surgery seem to be less satisfactory (56% improvements, 4.9% severe sensorineural hearing loss) than those obtained after the first operation.