Comparison of Medial Underlay and Lateral Underlay Endoscopic Type I Tympanoplasty for Anterior Perforations of the Tympanic Membrane

Objectives: To compare the outcomes of medial and lateral underlay endoscopic type I tympanoplasty for anterior tympanic membrane (TM) perforations. Study Design: Retrospective chart review. Setting: Tertiary care academic referral center. Patients: Patients who were diagnosed with either chronic otitis media with dry and stable anterior TM perforations or traumatic anterior TM perforations and underwent endoscopic type I tympanoplasty between 2017 and 2019. Interventions: Medial or lateral underlay type I endoscopic tympanoplasty. Main Outcome Measures: Patient demographics, size, and location of TM perforation, graft success rate, and hearing outcome. Results: Of the 170 patients, 68 and 102 patients underwent the medial and lateral underlay techniques, respectively. Patient demographics were not significantly different between groups, except the middle ear mucosa status. Graft success rates were significantly different between groups regardless of the perforation size (85.3 and 95.1%, p < 0.001). The lateral underlay group had a significantly better outcome (p < 0.001) when anterior superior quadrant TM perforation was included than the medial underlay group (p = 0.552). Hearing outcomes did not significantly differ between groups, but a significant audiological improvement was observed in both groups (p < 0.05). Conclusion: Lateral underlay type I endoscopic tympanoplasty can be challenging as it requires dissection of the malleus. However, the lateral underlay group had a high graft success rate without sensorineural hearing loss in the repair of anterior TM perforations. Thus, lateral underlay type I endoscopic tympanoplasty should be considered for repairing anterior TM perforations, especially when the anterior superior quadrant is involved.