Middle Ear Pressure Changes Following Endoscopic Sinus Surgery in Chronic Rhinosinusitis with Nasal Polyposis: An Observational Cohort Study

Background: Chronic rhinosinusitis with nasal polyposis (CRSwNP) can alter sinonasal physiology and influence Eustachian tube (ET) function, yet postoperative changes in middle ear pressure (MEP) after functional endoscopic sinus surgery (FESS) remain poorly studied, particularly in asymptomatic patients. This study aims to evaluate the pre- and postoperative middle ear function in CRSwNP patients undergoing FESS and examines whether polyp severity or residual disease affects middle ear ventilation. This observational cohort study was conducted at a tertiary care center in South India between September 2022 and August 2024. Patients (> 18 years) diagnosed with CRSwNP and scheduled for FESS were enrolled. Tympanometry was performed using a calibrated ANSI 1991 GSI-TympStar immittance meter (226 Hz probe tone) preoperatively, at 1 week, and at 3 months postoperatively. Results: Among the 30 patients (median age 48.5 years; 63% male), 63.3% of ears showed Type A tympanograms preoperatively. Median MEP improved significantly from –12.50 daPa to –10.00 daPa at 1 week (p = 0.01). At 3 months, MEP remained slightly improved (–11.00 daPa), though not statistically significant compared with baseline (p = 0.07). Residual disease was associated with markedly negative MEP (–34.00 daPa) compared with patients without residual polyposis (–10.00 daPa), showing a strong trend (p = 0.06). However, preoperative polyp grade did not correlate with MEP (p = 0.167). Conclusion: The study shows that successful sinus clearance results in only a transient postoperative rise in MEP. This short-lived improvement underscores the need for continued monitoring