A New Method to Evaluate Lower Esophageal Distension Capacity in Eosinophilic Esophagitis by using functional lumen imaging probe (Endoflip™)

Abstract

Background Endoluminal functional lumen impedance planimetry (EndoflipTM) has become the gold standard to evaluate esophageal distensibility, although the study itself and its analysis present challenges. We propose here a new method to assess lower esophageal distension capacity, which overcomes several limitations of prior approaches including incomplete and corrupted EndoflipTM recordings. Methods Esophageal distension capacity was evaluated with a 16-channel EndoflipTM in 10 controls and 14 patients with Eosinophilic Esophagitis (EoE). Controls were evaluated once. EoE patients were evaluated at baseline and after at least six weeks treatment with budesonide orodispersible tablet 1mg bd. Balloon volumes were increased 5-mL stepwise either reaching maximum volume of 60 mL, or maximum balloon pressure of 60mmHg. Recordings were analyzed with a home-made R script. The mean esophageal diameter at 60 mL D(60mL) was calculated or extrapolated depending on whether the 60 mL volume was reached. Results By fitting a Michaelis-Menten curve across all measured diameters throughout all constant volume steps, mean D(60mL) was estimated. For control subjects, the mean±SD value of diameter at D(60mL) was 17.08±1.69 mm and for EoE patients at baseline D(60mL) was 14.51±2.68 mm. After six weeks of treatment of EoE patients, D(60mL) significantly increased to 16.22±1.86mm (paired Wilcoxon signed test: p=0.0052), although the values for control subjects were not reached. Conclusions Estimated mean esophageal diameter at 60 mL is a good proxy for esophageal distension capacity, which correlates with clinical outcomes in EoE. The method presented in this study overcome difficulties encountered during the standard measurement protocol, allowing analysis of recordings from incomplete and corrupted registries.