Conductive hearing loss after surgical treatment of otosclerosis - long-term observations.

<b>Introduction:</b> For many years, surgical treatment of otosclerosis has been a widely accepted approach. Hearing improvement following stapes surgery is sometimes spectacular, and good treatment results are obtained in many centers in over 90% of patients. However, in the subsequent years after the treatment, some patients develop permanent or progressive conductive hearing loss. <br><b>Aim:</b> The aim of the study is to present a group of patients with conductive hearing loss after the first otosclerosis surgery and to analyze the causes of its occurrence. <br><b>Materials and Methods:</b> The retrospective review covered patients who underwent the initial surgery in the years 2000-2009. We analyzed the patients' medical records from before the end of 2019, which provided results of at least 10 years of postoperative follow-up. The group consisted of 1118 patients aged 14-82, including 802 women and 316 men.<br><b> Results:</b> Reoperations due to conductive hearing loss were performed on 93 patients, who accounted for 8.3% of the originally operated patients. They were much more common in patients after stapedectomies (19.7%) than in patients after stapedotomy (5.5%). Prosthesis dislocation was found to be the most frequent intraoperative observation (44.1%) and was often associated with erosion or necrosis of the long process of incus (28%). Less frequent reasons for hearing loss were: adhesions around the prosthesis (10.8%), too small hole in the stapes footplate (8.6%), too short prosthesis (8.6%), progression of otosclerosis (7.5%), too long prosthesis (6.4%), presence of a granuloma around the prosthesis (5.4 %), and displacement of incus (4.3%). <br>Conclusions:</b> Surgical treatment of otosclerosis is a widely accepted and good method. It allows to achieve an improvement in hearing in the vast majority of patients treated in this way. Unfortunately, over the years some patients develop recurrent conductive hearing loss. Reoperation creates an opportunity for finding the cause and improving hearing in the majority of cases.