Interplay Between Rhinosinusitis and Eustachian Tube Dysfunction in Patients Undergoing Functional Endoscopic Sinus Surgery

Objectives To evaluate the association between chronic rhinosinusitis (CRS) and Eustachian tube dysfunction (ETD) using subjective and objective measures, and the relationship between disease laterality and Eustachian tube function (ETF). Study Design Prospective cohort study. Setting Single tertiary medical institution. Methods Eighty‐five CRS patients who were candidates for FESS underwent comprehensive evaluation. Subjective assessments utilized the Eustachian Tube Dysfunction Questionnaire‐7 (ETDQ‐7) and Sino‐Nasal Outcome Test‐22 (SNOT‐22). Objective evaluations comprised a 9‐step inflation–deflation tympanometric test scored by maximal peak pressure difference (MPD), nasal endoscopy using the modified Lund‐Kennedy (MLK) system, sinus CT scored via the Lund‐Mackay (LM) system, and acoustic rhinometry measuring the second minimal cross‐sectional area (MCA 2 ). Patients were stratified into fair (<14) and poor (≥14) ETF groups based on ETDQ‐7 scores. Correlations were analyzed using Pearson coefficients, receiver operating characteristic (ROC) curves, and Bland‐Altman plots, with additional assessment of CRS lateralization effects. Results Poor ETF (ETDQ‐7 ≥ 14) occurred in 36.5% of patients and was associated with higher SNOT‐22 (median 48.0 vs 31.5, P < .001). ETDQ‐7 correlated moderately with SNOT‐22 total ( r = 0.65). No significant differences in MPD, MLK, LM, or MCA 2 were found between fair and poor ET function groups. ROC analysis identified optimal cut‐offs of ETDQ‐7 > 15 (AUC 0.761) and SNOT‐22 > 45 (AUC 0.802). Laterality analysis showed no significant side‐specific associations. Conclusion In CRS, sinonasal symptom burden shows only a moderate association with patient‐reported ETD. Higher ETDQ‐7 scores often parallel greater SNOT‐22 severity, suggesting that PROMs may help identify patients in whom ETD symptoms are partly influenced by CRS.