Clin Exp Otorhinolaryngol.  2025 Feb;18(1):14-20. 10.21053/ceo.2024.00189.

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

• Lee Y
• Park MK
• Lee JH
• Lee SY
• Suh MW

• KMID: 2565229
• DOI: http://doi.org/10.21053/ceo.2024.00189

Abstract

Objectives
. Congenital aural atresia (CAA) is a complex condition that manifests in various forms, including Schuknecht type B stenosis, which is 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 Schuknecht type B CAA.
Methods
. The study included 21 ears diagnosed with Schuknecht type B CAA, all of which underwent canal-tympanoplasty. Reconstruction of the large EAC and tympanic membrane involved conchal flap meatoplasty, bony EAC drilling, ossicular reconstruction, and overlay tympanoplasty. Standard pure-tone audiometry was analyzed at multiple post-surgery time points: 3, 6, 12, and 24–60 months. Additionally, the incidence of postoperative complications was assessed.
Results
. The hearing outcomes of canal-tympanoplasty in this case series were satisfactory. Serviceable hearing was achieved in all patients after 3 months and was maintained in 85% of patients for 1 year. The air-bone gap improved from a preoperative average of 39.3±15.1 dB 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 required revision canal-tympanoplasty due to hearing deterioration, representing 14.3% of the cases. There were no instances of postoperative infection, facial nerve weakness, vertigo, deterioration of bone conduction thresholds, or complete restenosis of the EAC.
Conclusion
. Canal-tympanoplasty proved to be a satisfactory surgical intervention for patients with Schuknecht type B CAA. This procedure led to significant improvements in hearing outcomes, providing serviceable hearing that lasted for several years. Moreover, the risk of postoperative hearing deterioration and/or the need for revision surgery within 1 year was considered acceptable.

Keyword

Tympanoplasty; Hearing; Canal; Patients; Schuknecht; Congenital Aural Atresia

Figure

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  Fig. 1. Preoperative hearing threshold. Before surgery, the weighted four-tone average of the air conduction (AC) threshold was 49.4±14.4 dB HL, and that of the bone conduction (BC) threshold was 10.7±6.4 dB HL. The air-bone gap was 39.3±15.1 dB.

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  Fig. 2. (A) Postoperative changes in the hearing threshold and air-bone gap over time. The air conduction (AC) threshold improved significantly after canal-tympanoplasty at all time points, from 3 months to 2–5 years. (B) Similar findings were identified for the air-bone gap (ABG) at all time points. When individual ears were evaluated, a successful outcome (AC ≤40 dB HL, ABG ≤30 dB, indicated by the red broken line) was achieved in all patients (100%) at 3 months. (C) Three patients underwent revision canal-tympanoplasty, and the surgical outcome was good in two ears (indicated by the orange lines). (D) The bone conduction (BC) threshold was preserved or improved in all patients. *P<0.05 by the paired t-test.

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  Fig. 3. Postoperative air conduction hearing threshold at four different frequencies. Hearing improved across all four frequencies. Regardless of the time point (3 months, 6 months, 12 months, and 2–5 years postoperatively), the mean hearing threshold was less than 32 dB HL for every tested frequency.

Reference

1. Casazza GC, Jonas RH, Kesser BW. Congenital aural stenosis with cholesteatoma. Otol Neurotol. 2022; Mar. 43(3):320–7.

2. Jahrsdoerfer RA. Congenital atresia of the ear. Laryngoscope. 1978; Sep. 88(9 Pt 3 Suppl 13):1–48.

3. Chan CY, Karmali SA, Arulanandam B, Nguyen LH, Duval M. Cholesteatoma in congenital aural atresia and external auditory canal stenosis: a systematic review. Otolaryngol Head Neck Surg. 2023; Sep. 169(3):449–53.

4. Nadaraja GS, Gurgel RK, Kim J, Chang KW. Hearing outcomes of atresia surgery versus osseointegrated bone conduction device in patients with congenital aural atresia: a systematic review. Otol Neurotol. 2013; Oct. 34(8):1394–9.

5. Farnoosh S, Mitsinikos FT, Maceri D, Don DM. Bone-anchored hearing aid vs. reconstruction of the external auditory canal in children and adolescents with congenital aural atresia: a comparison study of outcomes. Front Pediatr. 2014; Jan. 2:5.

6. Morrison D, Kesser B. Congenital anomalies of the ear canal. Otolaryngol Clin North Am. 2023; Oct. 56(5):933–48.

7. Suh MW. Canalotymapnoplasty: nomenclature of the surgical procedure for correcting congenital aural atresia. J Int Adv Otol. 2023; Jan. 19(1):74–5.

8. Kim HA, Namavarian A, Khan U, Levy BB, Ziai H, Talei B, et al. Reconstructive techniques in pediatric congenital microtia: a systematic review and meta-analysis. Facial Plast Surg. 2024 Feb 23 [Epub]. https://doi.org/10.1055/a-2247-5109.

9. Li CL, Li J, Guo Y, Zhang TY. Measurement method for external auditory canal and clinical application in congenital aural stenosis. Int J Pediatr Otorhinolaryngol. 2020; Oct. 137:110233.

10. Zhang TY, Bulstrode N, Chang KW, Cho YS, Frenzel H, Jiang D, et al. International consensus recommendations on microtia, aural atresia and functional ear reconstruction. J Int Adv Otol. 2019; Aug. 15(2):204–8.

11. Lasminingrum L, Mahdiani S, Makerto RD. Surgical treatment of external auditory canal cholesteatoma in congenital malformation of the ear: a case series. Ann Med Surg (Lond). 2021; Sep. 70:102880.

12. Chen K, Liu L, Shi R, Wang P, Chen D, Xiao H. Correlation among external auditory canal anomaly, temporal bone malformation, and hearing levels in patients with microtia. Ear Nose Throat J. 2017; Jun. 96(6):210–7.

13. Han SA, Lee SY, Park MK, Lee JH, Oh SH, Suh MW. Comparison of hearing outcomes in patients with congenital aural atresia managed with canaloplasty and bone conduction hearing devices. Acta Otolaryngol. 2022; Jan. 142(1):23–9.

14. Chang H, Song JJ, Choi BY, Lee JH, Oh SH, Chang SO. Partial ossicular replacement versus type II tympanoplasty in congenital aural atresia surgery: a matched group study. Otol Neurotol. 2009; Aug. 30(5):609–13.

15. Chang SO, Choi BY, Hur DG. Analysis of the long-term hearing results after the surgical repair of aural atresia. Laryngoscope. 2006; Oct. 116(10):1835–41.

16. Chang SO, Lee JH, Choi BY, Song JJ. Long term results of postoperative canal stenosis in congenital aural atresia surgery. Acta Otolaryngol Suppl. 2007; Oct. (558):15–21.

17. Chen Y, Zhang T. Modified meatoplasty for external auditory canal stenosis with endoaural-conchal incision. Otol Neurotol. 2015; Jan. 36(1):1–3.

18. Sakamoto T, Kikkawa YS, Kikuta S, Kinoshita M, Ueha R, Suzukawa K, et al. Favorable prognostic factors for long-term postoperative hearing results after canal tympanoplasty for congenital aural stenosis. Otol Neurotol. 2014; Jul. 35(6):966–71.

19. Li CL, Chen Y, Chen YZ, Fu YY, Zhang TY. Congenital aural stenosis: clinical features and long-term outcomes. Sci Rep. 2016; Jun. 6:27063.

20. Ahn J, Baek SY, Kim K, Cho YS. Predictive factors for hearing outcomes after canaloplasty in patients with congenital aural atresia. Otol Neurotol. 2017; Sep. 38(8):1140–4.

21. Park SM, Kim HJ, Son SE, Cho YS. Taste changes after atresioplasty in patients with congenital aural atresia. Otol Neurotol. 2023; Mar. 44(3):e166–70.

22. Chen K, Lyu H, Xie Y, Yang L, Zhang T, Dai P. Morphological characteristics of round window niche in congenital aural atresia and stenosis patients. J Comput Assist Tomogr. 2015; Jul-Aug. 39(4):547–51.