High-frequency hearing, tinnitus and patient satisfaction with stapedotomy: A randomized prospective study

Abstract

Otosclerosis is a common disorder that leads to conductive hearing loss. Most patients with otosclerosis also have tinnitus, and surgical treatment is known to improve hearing as well as tinnitus. Some patients however experience worsening of tinnitus after the operation, but there are no known factors that allow surgeons to predict who will be at risk. In this prospective observational study on 133 patients undergoing stapedotomy, we show that postoperative air conduction thresholds at very high stimulus frequencies predict improvement of tinnitus, as assessed with proportional odds logistic regression models. Young patients were significantly more likely to experience reduction of tinnitus and patients whose tinnitus became better were also more satisfied with the outcome of the operation. These findings have practical importance for patients and their surgeons. Young patients can be advised that surgery is likely to be beneficial for their tinnitus, but a less positive message should be conveyed to older patients.Otosclerosis is a common disorder 1,2 , where one of the ossicles in the middle ear, the stapes, gradually fuses with surrounding bone, producing conductive hearing loss. This hearing impairment can be treated surgically 3 , commonly by replacing the diseased stapes with a prosthesis that improves sound transmission through the middle ear to the sensory cells in the inner ear. The usual result is great enhancement of low-frequency hearing 4 . At frequencies below 1000 Hz, the average improvement is around 30 dB, which substantially enhances speech perception and frequently means patients no longer need hearing aids.Despite being a generally successful procedure that improves hearing in a large majority of patients, stapes surgery is associated with some risk. The risk for complete hearing loss on the operated ear is very low, on the order of 1% 5 . However, many studies have shown that the benefit from surgery declines with stimulus frequency and at 6 and 8 kHz, some loss of both air and bone conduction thresholds is commonly seen [6][7][8][9] . In two previous studies 10,11 , where the frequency range of audiometry was extended beyond the standard 8 kHz, a mean threshold loss ranging from 9 to 23 dB was evident across the frequencies 10-14 kHz, despite robust improvement of low-frequency hearing. The relevance of changes in hearing thresholds at these very high stimulus frequencies is unclear, although tinnitus patients often have elevated thresholds at 10 kHz and higher, which may correlate with the pitch of their tinnitus 12 .

Surgical technique in stapedotomy hearing outcome and complications

“…The difference was, however, not significant. Other risk factors for worsened tinnitus are preoperative HF hearing loss and older age, according to a study by Bagger‐Sjöbäck . In this study, preoperative HF hearing, postoperative HF hearing deterioration, and tinnitus did not reveal such patterns.…”

“…Other risk factors for worsened tinnitus are preoperative HF hearing loss and older age, according to a study by Bagger-Sjöbäck. 13 In this study, preoperative HF hearing, postoperative HF hearing deterioration, and tinnitus did not reveal such patterns. In contrast, we found that patients with better preoperative HF hearing had an increased risk of new or worsened tinnitus.…”

“…In the same way, it can be proposed that the HF hearing deterioration revealed in this study reflected the natural progression of the disease to cochlear otosclerosis rather than resulting from damage from either the acoustic and mechanical trauma of the microdrill or the potential heat effects of the laser. In contrast, several studies have reported an immediate postoperative deterioration of HF hearing that would be difficult to argue as being related to anything other than the surgical procedure itself …”

“…In contrast, several studies have reported an immediate postoperative deterioration of HF hearing that would be difficult to argue as being related to anything other than the surgical procedure itself. 13 A meta-analysis of different surgical techniques in stapedotomy has previously suggested superior results using laser stapedotomy compared to conventional stapedotomy with a microdrill only, in relation to both hearing outcomes and complications. 14,15 We found differences in hearing outcome among the investigated surgical techniques.…”

New chamber stapes prosthesis – A preliminary assessment of the functioning of the prototype

“…Some authors report worsening of tinnitus in 1–11% of patients [44–46], and declining high-frequency hearing, after stapes surgery [47]. This may be caused by surgical trauma of sensory hair cells due to sound generated by drilling and stimulation of the perilymph by the piston being too low.…”