Hearing results after stapedotomy: role of the prosthesis diameter

To evaluate the functional results obtained after stapedotomy in patients affected by otosclerosis, according to the prosthesis diameter.

A retrospective case review was performed. Two hundred and twelve consecutive ears in 132 patients affected by otosclerosis were operated on. All patients underwent primary small-fenestra stapedotomy. In 112 of the 212 stapedotomies (52.83%) the 0.6-mm piston (group A) and in 100 of the 212 stapedotomies (47.16%) the 0.4-mm piston (group B) were employed.

After surgery, the difference between the two groups in the air conduction improvement (21.04 dB group A vs. 11.14 dB group B) reached statistical significance (p < 0.05). In group A, the postoperative air conduction pure-tone average improvement obtained at 0.5, 1, and 2 kHz was statistically greater as compared with group B (p < 0.05). In group A the postoperative bone conduction pure-tone average decreased by 5.19 dB, whereas in group B it increased by 2.95 dB (p > 0.05). The incidence of ears with a postoperative bone conduction worsening >10 dB (sensorineural hearing loss) was lower in group B than in group A: 5 of 100 ears (5%) versus 9 of 112 ears (8.03%) (p > 0.05). The postoperative air-bone gap was smaller in group A than in group B for all frequencies, but the difference can be considered significant at 1 and 2 kHz. The air-bone gap improvement in group A if compared with group B was statistically greater at 0.5, 1, and 2 kHz (p < 0.05).

Our study suggests that an increase in piston diameter gives better results, especially at lower frequencies. The functional results obtained after stapedotomy confirm the advantageous effect of a larger piston diameter on hearing of the speech frequencies and support the opinion of a better clinical effect.