Stapes Release in Tympanosclerosis
Tympanosclerosis in the middle ear space is common in Ethiopia and often involves the ossicles and particularly the stapes. Ear operations in Ethiopia are relatively expensive in this country of limited medical resources and a low average living wage. In this setting, 2-stage operations using prostheses become prohibitively expensive. Therefore, the recommended 2-stage approach for tympanic membrane perforation with tympanosclerosis and stapes fixation is impractical for Ethiopia.
We present a series of 67 patients who had a single stage tympanoplasty, removal of tympanosclerosis from the stapes suprastructure, and ossicular chain reconstruction using ossicular interposition. Crucial is the surgical technique employed for peeling the mound of tympanosclerotic plaque off of the stapes, which we term the stapes release. Controls were 67 patients with similar perforations and air-bone gap, but no tympanosclerosis. Most controls had ossciular discontinuity and were reconstructed with type III tympanoplasty.
Air-bone gap improved in both groups: 18 dB (11 dB standard deviation) in the stapes release group, and 23 dB (11 dB standard deviation) in the control group. Paired t test found these improvements in each group significant at p < 0.001. Among the preoperative subjects there were 40 with air-bone gap greater than 45 dB, and none less than 20 dB. Among the postoperative subjects, none had air-bone gap worse than 45 dB, while 25/67 (37%) stapes release and 44/67 (66%) controls had air-bone gap better than 20 dB. Three patients in each group failed to close their perforations completely (96% closure rate).
The only complications were two early cases of transient facial nerve weakness, which was avoided in subsequent cases by an alteration in technique. There was no deterioration of sensorineural hearing levels in either group's subjects postoperatively.
In conclusion, stapes release with ossicular interposition can be performed at the same time as tympanoplasty without exacerbation of sensorineural hearing loss. Tympanic membrane closure and hearing levels were similar between patients with and without stapes fixation from tympanosclerosis.