Preoperative Tympanometry and the Presence of Middle Ear Effusion at the Time of Tympanostomy Tube Placement

Objective(s) To evaluate the relationship between preoperative tympanometry and intraoperative middle ear effusion in children undergoing tympanostomy tube placement. Methods Retrospective cohort study of children undergoing tympanostomy tube placement at a tertiary academic medical center from January to April 2021. Preoperative tympanometry was categorized as Type A, B, or C per Jerger classification. The primary outcome was middle ear effusion visualized at myringotomy. Secondary outcomes included effusion resolution among Type B ears and effusion development among Type A and C ears. Risk ratios with 95% confidence intervals were estimated using modified Poisson regression fit via generalized estimating equations, clustered by patient, with robust standard errors. Results A total of 268 children contributing 520 ears were included. Effusion was present at surgery in 44.0% of Type A ears, 72.4% of Type B ears, and 68.3% of Type C ears. Effusion risk was significantly higher for Type B (RR 1.65, p < 0.001) and Type C (RR 1.55, p = 0.002) compared with Type A. Among Type A and C ears, 51.2% had effusion at surgery. Differences in effusion rates across tympanogram types were no longer significant at intervals greater than 60 days. Type A ears were more commonly from children with recurrent AOM, among whom 41.2% had effusion intraoperatively. Conclusions Tympanogram type predicted intraoperative effusion probability, though nearly half of Type A ears had effusion confirmed at surgery. The predictive value of tympanogram type diminished at intervals greater than 60 days between assessment and surgery, suggesting tympanometry is most informative when surgery follows promptly after evaluation. Level of Evidence 4.