Comparison of Traditional and Wideband Tympanometry Between the Mastoidectomy Posterior Tympanotomy Approach (MPTA) and Transcanal Wall (VERIA) Surgical Approach in Children with Cochlear Implantation

Abstract

Aim: The current study aimed to find and compare the effect of cochlear implantation (CI) on middle ear mechanics in terms of wideband absorbance (WBA) and resonance frequency (RF) using wideband tympanometry in children who underwent different surgical approaches, i.e., mastoidectomy posterior tympanotomy approach (MPTA) and transcanal wall (Veria) approach. The study also compared the WBA across frequencies and RF between Normal and MPTA group, Normal and Veria group and MPTA and Veria group. Further, it also compared the conventional 226 Hz tympanometry and wideband tympanometry (WBA & resonant frequency) between MPTA and Veria groups. Methods: The present study was conducted using a standard group comparison design. A total of 40 participants ranging from 3 to 10 years were involved in the present study, which was separated into three groups: Group I had 20 normal-hearing children, Group II, comprised 10 children with CI operated with MPTA, and Group III involved 10 CI children operated with the Veria technique. All the participants underwent the wideband tympanometry testing across frequencies at peak pressure and ambient pressure. Furthermore, 226 Hz tympanometry was performed only on the MPTA group and the Veria group. Results: The results of the present study indicated that a comparison of WBA between the Normal and MPTA groups showed a significant difference in WBA at 1000 Hz and 1250 Hz frequencies for both peak pressure and ambient pressure. Further, a comparison of WBA between the Normal and Veria groups showed a significant difference in WBA at 2000 Hz, 3000 Hz, 4000 Hz, 5000 Hz, 6000 Hz, and 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz, 5000 Hz,6000 Hz frequencies at peak pressure and ambient pressure respectively. Also, a comparison of WBA between the MPTA and Veria groups showed a significant difference for frequencies 1250 Hz, 1500 Hz, 3000 Hz, 4000 Hz, and 5000 Hz at peak pressure and 3000 Hz and 4000 Hz frequencies at ambient pressure. A comparison of resonance frequency showed that the mean resonance frequency was found to be higher in MPTA group compared to Veria group and Normal group. However, there was no significant difference noted for resonance frequency between Normal and MPTA, Normal and Veria, and MPTA and Veria group. Further, a comparison of 226 Hz tympanometry and WBT between the MPTA and Veria groups revealed that the conventional 226 Hz tympanometry did not exhibit any significant difference among the MPTA and Veria groups. However, there were significant differences noted in WBA at certain frequencies (1250 Hz, 1500 Hz, 3000 Hz, 4000 Hz, & 5000 Hz at peak pressure and 3000 Hz & 4000 Hz at ambient pressure) between MPTA and Veria groups. Conclusions: From the results of the study it can be concluded that cochlear implantation has an effect on the middle ear mechanics, which can be measured in terms of WBA using wideband tympanometry. These differences are also noted differently across frequencies for different types of cochlear implant surgical approaches (MPTA & Veria approaches). However, resonance frequency did not show any difference between MPTA and Veria groups. It can also be concluded that conventional 226 Hz tympanometry has limitations in showing the differences between the MPTA and Veria surgery approaches. Thus, compared to 226 Hz tympanometry, WBT has the potential to study the effect of cochlear implantation on middle ear mechanics across frequencies.