Novel endoscopic approaches using the endocytoscopy for the target biopsy in esophageal eosinophilia

Background and aims Multiple biopsies are recommended for the diagnosis of eosinophilic esophagitis (EoE) because inflammatory changes are frequently patchy. Reports on EoE using endocytoscopy (ECS) are limited. This present study aimed to assess if diagnostic yield improves by adding ECS on conventional white light imaging (WLI) in patients with esophageal eosinophilia (EE). Methods A total of 284 biopsy specimens from 71 patients with a known diagnosis of EE were enrolled and divided into the WLI group (156 specimens) or the ECS group (128 specimens). Four biopsies from 5 and 10 cm proximal to the esophagogastric junction were taken from each patient. In the ECS group, the biopsy was performed where bilobed nuclei were observed. The biopsy sensitivity for EE, eosinophil count of a single specimen and the biopsy sensitivity of each endoscopic finding were evaluated between both groups. Results The sensitivity of a single biopsy specimen was higher in the ECS group than that of the WLI group (62.5 vs. 41.7%, P < 0.001). In addition, the median eosinophil count in the ECS group was significantly higher [19 vs. 6.5/high-power field (HPF), P < 0.001]. For each endoscopic finding, ECS-based biopsy had higher sensitivity than that of WLI in the diagnosis of edema (33.1 vs. 11.3%, P = 0.007) and linear furrows (75.8 vs. 52%, P = 0.005). Conclusion This study showed that adding ECS to WLI improved the biopsy sensitivity and eosinophil detection in patients with EE.