Measuring esophageal compliance using functional lumen imaging probe to assess remodeling in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is associated with fibrostenotic remodeling that can be objectively assessed using the functional lumen imaging probe (FLIP). This is typically done using a metric called distensibility plateau (DP). We aimed to describe a novel measure of compliance of the esophageal body and evaluate the associated clinical characteristics in EoE.

One hundred seventy-one adult patients with EoE (mean (SD) age 38 (12) years), 31% female and 35 healthy, asymptomatic controls who completed 16-cm functional luminal imaging probe (FLIP) during endoscopy, were evaluated in a cross-sectional study. The esophageal body DP and compliance were measured using a customized analysis program, with compliance calculated as (Δ esophageal body volume)/(Δ pressure) between two FLIP-filled volumes.

In controls, the median (5-95th percentile) DP was 19.8 mm (17.9-21) and esophageal body compliance was 0.37 ml/mmHg (0.18-1.1), which was greater than in EoE (DP 19 (11-21)), compliance 0.19 (0.02-0.71), p-values <0.001. Among EoE patients, 70 (41%) had normal compliance (>0.2 ml/mmHg) and normal DP (>17 mm); 11 (6%) had normal compliance and reduced DP; 34 (20%) had reduced compliance and normal DP; and 56 (33%) had reduced compliance and reduce DP. Patients with both reduced compliance and DP had the greatest proportion of severe rings (61% with EREFS score 2-3) and stricture (100%).

FLIP provides an objective evaluation of biomechanical properties of the esophageal wall that appears enhanced by complementary application of metrics of DP and esophageal body compliance.