Longitudinal Response to Epipharyngeal Abrasive Therapy (EAT) in Chronic Nasopharyngitis With Outcome Redefinition and Stratified Analysis by Tissue Type and Baseline Severity.

Objective This study aimed to evaluate longitudinal changes in nasopharyngeal findings in patients undergoing epipharyngeal abrasive therapy (EAT) and to examine differences in treatment responsiveness according to macroscopic tissue type and baseline severity. In addition, outcome definitions were reconstructed using reproducible criteria based on EAT and bleeding scores, and factors associated with complete resolution were investigated. Methods A total of 546 patients undergoing EAT with nasopharyngeal evaluations from baseline up to 12 months were retrospectively analyzed. Inflammation and bleeding were quantified using EAT and bleeding scores. Longitudinal trends (0-12 months) were assessed using mixed-effects models with Restricted Maximum Likelihood (REML) and Holm correction for multiple comparisons. Primary analyses focused on patients with complete data at 0-3 months (n=238), stratified by macroscopic tissue type (proliferative/hypertrophic vs edematous) and baseline severity (EAT score ≥20 vs <20), using Generalized Estimating Equations (GEE). Complete and incomplete resolutions were compared using Welch's t-test and χ² tests. Results Both EAT and bleeding scores decreased significantly from 1 month onward, with improvements maintained up to 12 months. Stratified analyses suggested differential improvement patterns by tissue type and baseline severity, with edematous tissue and higher baseline scores demonstrating faster initial improvement. Complete resolution (n=76) was associated with lower baseline EAT scores, longer treatment duration, higher number of EAT sessions, and higher prevalence of edematous tissue compared to incomplete resolution (n=470). Redefining outcome criteria increased the number of complete resolution cases from 55 in the previous report to 76. Multivariate logistic regression analysis identified age, tissue type, and baseline severity as independent factors associated with complete resolution. Conclusions EAT leads to early and sustained improvement in inflammation and bleeding in chronic nasopharyngitis. Stratification by tissue type and baseline severity provides clinically relevant insights for predicting treatment response. Outcome re-definition enhances reproducibility and may inform treatment planning and follow-up strategies.