Frequent discrepancies among diagnostic tests for detecting lower esophageal sphincter-related obstruction

Background: There are frequent discrepancies among high-resolution manometry (HRM), functional lumen imaging probe (FLIP), and esophagram in identifying lower esophageal sphincter (LES)-related obstruction. We aimed to determine the frequency of those discrepancies and how they influenced clinical treatment/outcomes. Methods: We identified patients who had all three tests (HRM, FLIP, and esophagram) and endoscopy performed for evaluation of esophageal symptoms in our Center for Esophageal Diseases. Discrepancies among the tests for the presence of LES obstruction were noted, and the performance of individual tests was compared against a consensus opinion rendered by a panel of esophagologists. Binary logistical regression was performed, and ROC curves were generated for prediction of the consensus clinical diagnosis of LES obstruction. Key Results: A total of 126 patients (mean age 57.9 ± 17.0 years; 67% female) met inclusion criteria. All three tests agreed on the presence or absence of LES obstruction in only 72 (57%) patients [no LES obstruction in 57 (45%), LES obstruction in 15 (12%)]. Thirteen patients (10%) had a change in management based on additional findings on FLIP +/− esophagram not seen on HRM with 69% having symptomatic improvement after LES-directed intervention. FLIP was the strongest predictor of a consensus diagnosis of LES obstruction by logistic regression and ROC (OR 23.36, AUC 0.796), followed by HRM (OR 15.41, AUC 0.764). Conclusions & Inference: High-resolution manometry, functional lumen imaging probe, and esophagram each have considerable limitations for identifying LES obstruction, and discrepancies among these tests occur frequently. Multimodal testing is often required for adequate evaluation of LES-related obstruction.