T32 Predoctoral Research Trainee Washington University School of Medicine St. Louis, Missouri
Educational Objective: At the conclusion of this presentation, participants should understand the technical nuances and potential advantages of endoscopic over-under tympanoplasty for challenging large or anterior tympanic membrane perforations.
Objectives: To compare the indications and efficacy of endoscopic over-under tympanoplasty versus endoscopic underlay tympanoplasty.
Study Design: Retrospective chart review.
Methods: Patients who underwent a type I endoscopic tympanoplasty via either an underlay or over-under technique by a single surgeon from 2017-2021 were included in this study. Patients were excluded if they had a concurrent mastoidectomy, ossiculoplasty, or advanced cholesteatoma defined by more than two middle ear subsites. Patient demographics, perforation size and location, middle ear status, preoperative and postoperative audiograms, and perforation closure were reviewed. Middle ear status was scored using the Ossiculoplasty Outcome Parameter Score (OOPS). The main outcome measures were graft take, postoperative pure tone average (PTA) and air bone gap (ABG).
Results: Of 56 patients, 33 underwent endoscopic underlay tympanoplasty and 23 underwent endoscopic over-under tympanoplasty. Tragal cartilage perichondrium was used in 91%. OOPS was not significantly different between groups. Over-under technique addressed significantly larger perforations (median size of 50% vs. 30%, p = .002) and a higher rate of anterior extension (96% vs. 24%, p < .001) than underlay technique. Graft success rate was not significantly different between groups, both overall (94.7% vs. 96.3%) and when stratified by perforation size and anterior extension. Patients experienced significant improvement in PTA and ABG in both groups. The only complications included a superficial keratin pearl in each group.
Conclusions: The endoscopic over-under tympanoplasty is noninferior to endoscopic underlay tympanoplasty in terms of graft take and audiologic improvement. The over-under technique is effective for repairing larger perforations or those with anterior extension.