Discordance Between Functional Lumen Imaging Probe and Timed Barium Esophagram in Patients With a Chicago Classification v4.0 Manometric Diagnosis of Esophagogastric Junction Outflow Obstruction.

BACKGROUND: A conclusive diagnosis of esophagogastric junction outflow obstruction (EGJOO) requires confirmation of the manometric diagnosis either by timed barium esophagram (TBE) or functional lumen imaging probe (FLIP). However, the comparative performance of these tests for confirming EGJOO is not well defined. We aimed to assess the rate of agreement between FLIP and TBE in confirming a Chicago Classification version 4.0 (CCv4.0) manometric EGJOO diagnosis. METHODS: We included symptomatic patients with a CCv4.0 EGJOO manometric diagnosis who had confirmatory testing with both FLIP and TBE. FLIP metrics, TBE findings, tablet retention on esophagram, and Rapid Drink Challenge (RDC) results were recorded. KEY RESULTS: Among 101 total patients with manometric EGJOO, 30 had EGJOO confirmed by FLIP alone, 4 by TBE alone, and 11 by both FLIP and TBE; 56 had both negative FLIP and TBE. The FLIP and TBE positive concordance rate was 73.3%, and negative concordance rate was 65.1%. FLIP and TBE were both positive or both negative in 67/101 patients (overall concordance rate 66.3%) with a κ value of 0.22 (95% CI 0.01-0.44). Addition of barium tablet to TBE improved the κ value to 0.43 (95% CI 0.25-0.61). RDC agreed with FLIP in 45.7% and with TBE in 44.7% of patients, with RDC results frequently being indeterminant (39.4%). CONCLUSIONS: Discrepancies between FLIP and TBE for confirming EGJOO occur in one third of cases, and RDC results are often inconclusive. Additional testing may be needed to confirm manometric EGJOO despite a negative confirmatory test if clinical suspicion remains high.