Hearing results following endoscopic type I tympanoplasty in medium and large perforations

Objectives

To clarify the hearing outcomes after endoscopic type I tympanoplasty for medium and large perforations due to chronic otitis media.

Methods

We examined the clinical records of patients who underwent endoscopic type I tympanoplasty for medium and large perforations of the eardrum resulting from chronic otitis media between January 2019 and December 2021. We analyzed the changes in hearing pre- and post-operation in patients with healed eardrums and assessed the impact of tympanosclerosis on hearing. Patients with incomplete follow-up data, middle ear cholesteatoma, stapes fixation, severe lesions in the tympanic antrum and mastoid necessitating mastoidectomy and/or ossicular chain reconstruction were excluded.

Results

A total of 156 patients underwent analysis for audiological outcomes. Among them, 63 had medium tympanic membrane perforations, with 18 cases showing calcification of the tympanic membrane and 20 cases with calcification in the tympanic cavity. Additionally, 93 cases had large tympanic membrane perforations, with 25 cases showing tympanic membrane calcification and 32 cases with tympanic cavity calcification. Prior to surgery, the Air Conduction threshold (AC) in the large perforation group was higher than in the medium perforation group, particularly at low frequencies, measuring (47.4 ± 13.3 dB) and (41.2 ± 14.7 dB), respectively (p-value < 0.05). Following surgery, both groups experienced an improvement in AC, measuring (33.6 ± 13.9 dB) and (32.6 ± 12.8 dB), respectively, with no significant difference noted (p-value > 0.05). There was no significant change in Bone Conduction threshold (BC) before and after surgery in either the large or medium perforation groups (all p-values > 0.05). Except for 4000 Hz an increase, bone conduction did not increase post-surgery, instead showing further improved. Pre-surgery, the Air-Bone Gap (ABG) in the large and medium perforation groups was (27.7 ± 8.5 dB) and (21.8 ± 8.3 dB), respectively, mainly affecting low frequencies, with a statistically significant difference noted (p-value < 0.05). Following surgery, ABG in both groups improved to (16.3 ± 7.6 dB) and (15.7 ± 8.4 dB), respectively, with no significant difference observed (p-value > 0.05). There was no significant difference in hearing pre-surgery among the groups with No calcification (No), Tympanic Membrane Calcification (TM), and Tympanic Cavity Calcification (TC). However, TC significantly impacted low frequency (250–500 Hz) AC and ABG. The differences in AC and ABG pre-surgery between TC and No group, and TC and TM group (at 250–500 Hz) were statistically significant (all p-values < 0.05). Preoperative ABG in TM group was better than in No group and TC group, suggesting minimal impact of tympanic membrane calcification on hearing. No interaction was observed between tympanic membrane perforation size and tympanosclerosis on hearing. Post-surgery, both large and medium tympanic membrane perforation groups, regardless of tympanosclerosis presence, showed good AC and ABG, with no statistically significant difference in △ABG (all p-values > 0.05).

Conclusion

Preoperative AC and ABG were increase in cases of large tympanic membrane perforations and medium tympanic membrane perforations with tympanic cavity calcification. Surgical intervention led to more significant hearing improvement in these patients. However, irrespective of tympanic membrane perforation size and the presence of tympanosclerosis, as long as the ossicular chain remains intact and functional, postoperative AC and ABG outcomes are satisfactory. Endoscopic type I tympanoplasty proves effective in achieving improved hearing outcomes for patients with medium to large tympanic membrane perforations and tympanosclerosis, provided there is no ossicle chain fixation.

Level of evidence

Level 4.