Middle ear dimensions in congenital aural atresia and hearing outcomes after atresiaplasty.

OBJECTIVE: To determine if middle ear dimensions in congenital aural atresia (CAA) patients can predict early postoperative audiometric outcomes in order to establish specific parameters that facilitate stratification of surgical candidates.

STUDY DESIGN: Retrospective case review.

SETTING: Tertiary referral center.

PATIENTS: Twenty-five patients with CAA (28 atretic ears and 22 nonatretic ears) and 12 controls (24 ears).

INTERVENTION: Primary repair of congenital aural atresia.

MAIN OUTCOME MEASURES: Measure and compare middle ear dimensions in controls, atretic ears, and nonatretic ears in unilateral CAA. Determine correlations between the dimensions and best speech reception threshold during the first postoperative year (SRT-1).

RESULTS: The epitympanic depth, medial canal diameter, and the mesotympanic height, area, and estimated volume measurements in atretic ears differ significantly with those in control ears. The mesotympanic length, area, and estimated volume measurements each correlate significantly with SRT-1. Atretic ears with a mesotympanic volume estimate measurement greater than or equal to 42 mm3 are 24 times more likely to have an SRT-1 of 25 dB or better than those measuring less than 42 mm3 (odds ratio = 24.5; 95% confidence interval, 2.826-212.4; Fisher's exact test, p = 0.0022).

CONCLUSION: Middle ear measurements in appropriately selected patients may help predict successful early hearing outcomes after atresiaplasty, thus offering a valuable tool for the surgical decision-making process.