Hearing Results of Surgery for Acquired Atresia of the External Auditory Canal

Objective: To evaluate short- and long-term hearing results of surgery for acquired atresia of the external auditory canal (EAC) in a large patient cohort and to define preoperative audiometric conditions useful for patient counseling. Study Design: Retrospective cohort study. Setting: Academic tertiary referral center. Patients: Seventy-eight ears from 72 patients with postinflammatory acquired atresia of the EAC who underwent canal- and meatoplasty were included. Patients with involvement of the ossicular chain, (syndromic) external ear malformations, or congenital aural atresia were excluded. Intervention: Canal- and meatoplasty. Main Outcome Measures: Mean pure-tone averages of thresholds at 0.5, 1, 2, and 3 kHz (PTA(0.5,1,2,3)) for air conduction (AC), bone conduction, and air-bone gap (ABG) were calculated preoperatively and at short-term (<= 0.55 yr) and long-term follow-up (>0.55 yr). Additionally, the numbers of ears with a closed ABG <= 10 dB and <= 20 dB, and with Social hearing (defined as: AC PTA(0.5,1,2,3) <= 35 dB) were assessed. Results: At short-term follow-up AC PTA(0.5,1,2,3) improved by 18 dB. Social hearing was obtained in 81% of the ears. Postoperatively, 35% of the ears had a closed ABG <= 10 dB, 83% was closed <= 20 dB. During follow-up, significant deterioration of 5 to 7 dB occurred for AC thresholds at 0.25, 0.5, and 1 kHz. Conclusions: Surgery for acquired atresia of the EAC is often beneficial. This study suggests overall advantageous surgery when the preoperative indication criteria ABG PTA(0.5,1,2,3) >20 dB and AC PTA(0.5,1,2,3) >35 dB are applied.