Postoperative Outcomes of Interlay Versus Underlay Tympanoplasty: A Randomized Controlled Trial

Postoperative Outcomes of Interlay Versus Underlay Tympanoplasty

Abstract

One of the main causes of conductive hearing loss is still chronic otitis media with tympanic membrane perforation. Surgical repair aims to restore hearing and membrane integrity. Objective: To compare the postoperative anatomical and functional outcomes of interlay versus underlay tympanoplasty techniques in patients with chronic otitis media. Methods: This randomized controlled trial was carried out at the Department of Otorhinolaryngology, Shaikh Zayed Medical Complex, Lahore, from January to June 2025 after approval by the institutional ethical review board. Consecutive Sampling of Patients with Chronic Otitis Media and Large Central Tympanic Membrane Perforations. At the conclusion of the trial period, 78 patients who had both substantial central tympanic membrane perforation and chronic otitis media were included. Post-enrolment, participants were randomly assigned to either underlay or interlay tympanoplasty using simple randomization to minimize allocation bias. Standardized endoscopic procedures using temporalis fascia grafts were performed under general anesthesia. Outcomes were assessed at 12 weeks, and 62 patients completed follow-up and were analyzed. Results: Analysis was done on 62 patients in total. The baseline features of the groups were similar (p>0.05). The mean air-bone gap was 25.08 ± 4.07 dB before surgery, compared to 26.27 ± 4.03 dB (p=0.254). At 12 weeks, postoperative air–bone gap improved to 15.95 ± 4.03 dB versus 11.79 ± 3.70 dB (p < 0.001), with greater mean hearing gain in the interlay group (14.48 ± 4.48 dB vs 9.14 ± 3.12 dB; p<0.001). Conclusions: Interlay tympanoplasty resulted in significantly greater hearing improvement than the underlay technique, with comparable anatomical success.