Long Term Surgical Outcome of Canal-Tympanoplasty in Patients with Schuknecht Type B Congenital Aural Stenosis.

Abstract

Background: Congenital aural atresia (CAA) is a complex condition that can present in various forms, including Schuknecht type B stenosis, characterized by a congenitally narrow bony external auditory canal (EAC). This study aims to evaluate the long-term surgical outcomes of canal-tympanoplasty in patients with CAA Schuknecht type B.

Methods: The study included 21 ears diagnosed with CAA Schuknecht type B that underwent canal-tympanoplasty. The large EAC and tympanic membrane were reconstructed using conchal flap meatoplasty, bony EAC drilling, ossicular reconstruction, and overlay tympanoplasty. Standard pure-tone audiometry was analyzed at various time points post-surgery: 3, 6, 12, and 24-60 months. The incidence of postoperative complications was evaluated.

Results: The hearing outcomes of canal-tympanoplasty were satisfactory in this case series. Serviceable hearing was achieved in all patients after 3 months and was sustained for 1 year in 85% of patients. The air-bone gap (ABG) improved from 39.3 ± 15.1 dB preoperatively to 13.7 ± 7.4 dB at 3 months, 16.4 ± 10.5 dB at 6 months, 19.1 ± 11.7 dB at 12 months, and 21.5 ± 16.1 dB at 2-5 years postoperatively. Three patients underwent revision canal-tympanoplasty due to hearing deterioration (14.3%). There were no cases of postoperative infection, facial nerve weakness, vertigo, deterioration of bone conduction thresholds, or complete restenosis of the EAC.

Conclusion: Canal-tympanoplasty was a satisfactory surgical intervention for patients with CAA Schuknecht type B. The procedure resulted in significant improvements in hearing outcomes, with serviceable hearing that lasted for several years. The risk of postoperative hearing deterioration and/or revision surgery within 1 year was acceptable.