Risk of Aspiration Increased by Post-swallow Residue in Infant Fiberoptic Endoscopic Evaluation of Swallowing (FEES)

Objective: To assess the risk of aspiration associated with post-swallow residue subsites in Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in bottle-fed infants <1 year of age. Methods: This is a retrospective matched-pairs cohort study at an academic tertiary children's hospital. FEES and Videofluoroscopic Swallowing Study (VFSS) trials performed within the same infant <5 days apart were paired by matching bolus consistency and bottle flow rate. Positive aspiration was defined by the "or rule" in which aspiration is positive when either FEES or VFSS within a matched pair is positive. Results: Eighty-seven FEES-VFSS matched pairs from 29 patients (16 males; mean [SD] age, 2.9 [2.8] months) were included. The rate of positive aspiration, as defined by the "or rule", was 59% (51/87). In FEES, post-swallow pyriform sinus residue was present in 16% (14/87) and anterior commissure residue 27% (31/87). Risk of positive aspiration was increased by pyriform sinus residue (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.9-19.3, p < 0.01) and anterior commissure residue in FEES (OR 2.5, 95% CI 1.1-6.1, p = 0.03). In the neonate subgroup, <1 month of age, multivariate-adjusted analysis showed that anterior commissure residue had better diagnostic accuracy for aspiration than in older infants (overall 70% vs. 42%, p < 0.01; sensitivity 60% vs. 10%, p < 0.01), whereas pyriform sinus residue had worse accuracy (overall 41% vs. 70%, p = 0.02; sensitivity 13% vs. 43%, p = 0.02). Conclusion: This study demonstrates that pyriform sinus and anterior commissure residue during infant FEES were associated with fivefold and twofold increased risk of aspiration, respectively.