A39-04 Impact of Esophageal Dilation on Non-Scleroderma Interstitial Lung Disease (ILD)

Rationale Esophageal dilation (EoD) is linked to systemic sclerosis (SSc) and gastroesophageal reflux disease, where impaired motility and esophageal sphincter dysfunction promote chronic reflux and microaspiration. Similar mechanisms are suggested in idiopathic pulmonary fibrosis. However, the role and magnitude of EoD in non-scleroderma ILD remains unclear. Methods We performed a retrospective single-center study of ILD patients receiving care at a large quaternary care center. Patients were identified using an ILD registry and convenient sampling allowing for two-year follow-up was performed. Demographics were abstracted from the electronic health record. Inclusion required more than two high-resolution or non-contrast CT scans and more than two pulmonary function tests (PFTs), with CTs more than six months apart and PFTs within one month of each scan. Patients were excluded if CT-PFT intervals exceeded two years. Esophageal dimensions were measured using Sectra integrated diagnostic software (IDS7) with multi-planar reconstruction, manual volumetry, and diameter tools. EoD was defined as greater than 10mm. Descriptive statistics were performed using student’s t-test and Fischer’s exact test. Correlation analyses were performed using pearson and spearman coefficients. Results In this non-scleroderma ILD cohort (n = 100), 50% of patients demonstrated more than 10mm esophageal air on cross-sectional imaging. Baseline esophageal volume was smaller in patients with less than 10mm of esophageal air (mean ± SD = 4.82 ± 4.98) compared to those with greater than 10mm (8.28 ± 8.89; p = 0.018). Baseline pulmonary function showed an inverse correlation between esophageal measurements and both FVC and DLCO. Patients with less than 10mm of esophageal air had higher FVC% (75.49 ± 21.13) and DLCO% (55.51 ± 17.24) compared to those with greater than 10mm (FVC% 64.90 ± 15.45, p = 0.005; DLCO% 46.81 ± 15.02, p = 0.009), suggesting reduced baseline function with greater esophageal dilation. Increased esophageal airway column (cm3) was inversely related to baseline lung function as measured by FVC% predicted (r=-0.21, P = 0.08) and DLCO% predicted (r=-0.27, p = 0.00079). Inter-rater agreement on volume measurement was performed between two primary readers and a third expert radiologist which was excellent (ICC ≈ 0.89, 95% CI 0.68-0.97, p < 0.001). Conclusion In this cohort of patients with non-scleroderma ILD, increased esophageal diameter and volume were associated with lower baseline FVC and DLCO, supporting a potential link between EoD and impaired pulmonary function. We demonstrated an inverse relationship between the volume of air to severity of baseline lung function. These findings suggest that structural and functional esophageal abnormalities are associated with functional limitation in non-scleroderma ILD. This abstract is funded by: None