Otologic characteristics of individuals with deletions of distal 18q

Measurement method for external auditory canal and clinical application in congenital aural stenosis

OBJECTIVE

To describe a measurement method for external auditory canal (EAC), especially in congenital aural stenosis (CAS).

METHODS

High-resolution CT (HRCT) datasets of CAS were imported into the MIMICS 15.0 software for image processing. We used two methods to evaluate the degree of CAS. One is sagittal reconstruction measurement method, the minor axis of the bony ear canal was measured in each layer using sagittal reconstruction. The other is Matlab procedure calculation, we calculated the midpoint axis values of the EAC in each Frankfurt plane. Finally, we compared the minimum value of each method, and verified the sagittal reconstruction measurement method retrospectively in the CAS cases without cholesteatoma who had undergone meatoplasty.

RESULTS

Twenty CAS cases were selected using the sagittal reconstruction measurement method and Matlab procedure calculation to evaluate the degree of CAS. The mean age was 9.55 ± 2.85 years old (range: 6-15). The mean degree of CAS was 2.09 ± 0.50 mm by sagittal reconstruction measurement method and 2.03 ± 0.58 mm by Matlab procedure calculation. There were no significant differences in the two groups (t = -1.371, p = 0.186). A total of 94 HRCT datasets were imported into MIMICS for verification. The mean age was 11.66 ± 6.56 years old (range: 6-39). Mean stenosis of EAC at surgery was 2.88 ± 0.93 mm (range: 1-4) by using sagittal reconstruction measurement method.

CONCLUSIONS

Matlab procedure calculation is precise but relatively complicated and is only for scientific research. The sagittal reconstruction measurement method to calculate the most stenotic part of the bony ear canal is relatively simple and accurate to evaluate the degree of CAS. In cases of CAS without cholesteatoma, the precise measurement was critical for the next consultation.

Congenital Aural Stenosis: Clinical Features and Long-term Outcomes

The aim of the present study was to comprehensively evaluate the clinical features and long-term outcomes of congenital aural stenosis (CAS). This study presents a retrospective review of patients who underwent meatoplasty for CAS at a tertiary referral hospital from 2008 to 2015. A total of 246 meatoplasty procedures were performed on 232 patients in the present study. We performed multivariate regression analysis. Except in the age < 6 years group, no significant difference was observed among different age groups for cholesteatoma formation, p > 0.05. Except for the stenosis of the external auditory canal (EAC) (>4 mm) group, the other stenosis of EAC groups were not associated with cholesteatoma formation, p > 0.05. Postoperative air-bone gaps (ABG) less than 30 dB occurred in 77.3% (99/128) of the patients, and the Jahrsdoerfer score was associated with postoperative ABG, p < 0.001. The complication rate of CAS was 13.8% (20/144), and males showed a higher risk for postoperative complications (OR, 6.563; 95% CI, 1.268-33.966, p = 0.025). These results indicate that meatoplasty was an effective surgical intervention for CAS, showing a stable hearing outcome with prolonged follow-up. There was no significant difference between the cholesteatoma and no cholesteatoma groups for hearing outcomes, p > 0.05.