Abstract
BACKGROUND: Standard impedance catheters and balloon-based mucosal impedance catheters (BBMI) have been used to assess mucosal integrity and diagnose mucosal diseases. The goal of this study was to determine the age-related technical issues associated with mucosal balloon inflation, validate the BBMI measurement against a standard impedance probe, and compare software-generated diagnoses to histologic diagnoses. METHODS: We prospectively recruited patients undergoing endoscopy, during which patients underwent standard mucosal impedance catheters and BBMI measurements. Measurements were compared to each other, to the histologic diagnoses, and to the number of eosinophils per high power field. We then compared the patients' diagnosis to that assigned by the BBMI software. KEY RESULTS: Sixty-two patients (mean age: 62 ± 62 months) were recruited, including non-GERD (N = 40), GERD (N = 15), and EoE (N = 7) patients. There were significant differences between the impedance values measured by the two technologies at each esophageal height (p < 0.003). There were significant correlations between the mean impedance values taken by the two catheters in the distal (r(2) = 0.272, p = 0.04), mid (r(2) = 0.371, p < 0.001), and proximal (r(2) = 0.259, p = 0.05) esophagus. There were significant differences in BBMI impedance values across diagnoses in the mid and proximal esophagus (p = 0.024 and 0.025, respectively). While not statistically significant (p = 0.061-0.073), the standard catheter showed similar trends by diagnosis. Using the BBMI diagnostic prediction software, 33%-72% of patients were misclassified. CONCLUSION AND INFERENCES: While there was significant variability in impedance values between technologies within patients, regional measurements were consistent across catheters. Automated analyses lacked the sensitivity to diagnose inflammatory disorders.