Onigiri esophagography as a screening test for esophageal motility disorders

Background/aims No screening test for esophageal motility disorder (EMD) has been established, the objective of this study is to examine the potential usefulness of our newly developed "Onigiri esophagography" combined with an obstruction level (OL) classification system in screening for EMD. Methods A total of 102 patients with suspected EMDs who underwent both high-resolution manometry (HRM) and Onigiri esophagography between April 2017 and January 2019 were examined. The EMD diagnosis was performed based on the Chicago classification version 3.0 by HRM. Onigiri esophagography was performed using a liquid medium (barium sulfate) followed by a solid medium, which consisted of an Onigiri (a Japanese rice ball) with barium powder. The extent of medium obstruction was assessed by the OL classification, which was defined in a stepwise fashion from OL0 (no obstruction) to OL4 (severe obstruction). Results Thirty-two percent of the patients with OL0 (32.3%), OL1 (50.0%), OL2 (88.0%), OL3 (100.0%), and OL4 (100.0%) were diagnosed EMDs by HRM. The area under the curve, as determined by a receiver operating characteristic analysis, for the OL classification was 0.86. Using the cutoff value of OL1, the sensitivity and specificity were 87.3% and 61.3%, respectively, while using a cutoff value of OL2, the sensitivity and specificity were 73.2% and 90.3%, respectively. Conclusion In conclusion, Onigiri esophagography combined with the OL classification system can be used as a screening test for EMDs with a cutoff value of OL1.