[Stapedectomy and micro-stapedotomy in the treatment of otospongiosis. A comparative study].

This is a comparative study of 622 patients undergoing either stapedectomy or stapedotomy for otosclerosis. 379 underwent stapedectomy, which in the majority of cases employed interposition of the posterior crus of the stapes into a venous graft placed over the newly created fenestra. The results of this technique are compared with 243 microwindow stapedotomies performed since 1976. For all patients a minimum of 5 years had elapsed between surgery and evaluation of outcome. In some instances, this time period was 20 years. One month post-surgery the closure of the air-bone gap was more frequently superior with stapedectomy, particularly in the low frequencies. The degree of an incidence of overclosure was comparable for both techniques. However, at 4,000 Hz, bone threshold levels deteriorated more usually following stapedectomy. The air-bone gap widened progressively over the proceeding years post-stapedectomy. This was in contrast to the effect seen during the same period after stapedotomy, namely a narrowing of the air and bone threshold levels. Additionally a progressive loss of bone thresholds was noted after the latter technique. The incidence of sudden total deafness, either immediate or delayed, was less than 1% for both procedures. Even after 15 years or more poststapedectomy, the air-bone gap (13 dB average) and bone thresholds remained stable. Revision surgery was necessary in 8% of stapedectomies and in 4% stapedotomies. However, the post-operative follow up period is much shorter for the latter.