371. ENDOFLIP: THE FUTURE OF DYSPHAGIA DIAGNOSIS AND MANAGEMENT

Abstract Background High-resolution manometry (HRM) is the gold standard for characterizing esophageal motility disorders, but it’s frequently associated with poor patient tolerance. A newer diagnostic tool, the Endoscopic Functional Lumen Imaging Probe (EndoFLIP), has emerged to assess esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis. Also, for motility disorders such as EGJ outflow obstruction (EGJOO), HRM-isolated features aren’t enough for the diagnosis. The diagnosis also requires symptom correlation and additional investigations like EndoFLIP. Methods We conducted a single-center prospective cohort study for patients with dysphagia and inconclusive or intolerant to HRM. The inclusion criteria were patients with an elevated median integrated relaxation pressure (IRP) on HRM and patients with an inconclusive or intolerant to HRM. Patients with isolated IRP on HRM were included, as this isolated finding does not allow for the definitive diagnosis of EGJOO. These patients underwent EndoFLIP testing from January 2022 to February 2024 at a tertiary center. Results We performed EndoFLIP on 42 patients (50% male; 50% female), 23,8% with EGJOO diagnosis on HRM, 21,4% with inconclusive HRM, and 54,8% patients intolerant to HRM. Twenty-three patients intolerant to HRM underwent EndoFLIP, enabling diagnosis in all cases. Four patients were diagnosed with EGJOO, 6 with achalasia, and 4 with ineffective esophageal motility (IEM). On 88% of patients, the EndoFLIP allowed a correct diagnosis and treatment, with 29% undergoing endoscopic treatment during the same procedure. 9 patients with inconclusive HRM were diagnosed after EndoFLIP: 3 were diagnosed with EGJOO, 4 with IEM, and 3 with achalasia. We report a significant discordance between EGJOO diagnosis on HRM and EndoFLIP results. 50% of patients diagnosed with EGJOO on HRM showed normal EndoFLIP results, with only 20% confirming the diagnosis, while 20% raised the possibility of the diagnosis being achalasia. 43,8% of patients diagnosed with EGJOO confirmed by EndoFLIP underwent endoscopic therapy with botulinum toxin or balloon dilation during the same procedure, resulting in clinical improvement for all patients. Discussion The discordance between HRM and EndoFLIP may arise from HRM's tendency to overdiagnose EJGOO, leading to unnecessary testing and treatments for EGJOO. Many EGJOO HRM diagnoses don't require therapy, as symptoms often resolve spontaneously or with dietary education, casting doubt on the isolated HRM finding's clinical significance. It's particularly beneficial for patients with inconclusive/intolerance to HRM, allowing correct diagnosis and treatment in cases of obstructive symptoms. These results support EndoFLIP as a screening tool for patients undergoing endoscopy, enabling better selection of those benefiting from subsequent HRM.