S0351 Characterizing Reflux on High Resolution Esophageal Manometry With Impedance

Abstract

INTRODUCTION: In some patients, reflux at esophagogastric junction (EGJ) can be seen on the impedance portion of the high-resolution esophageal manometry with impedance (HREMI) studies. How this might correlate with reflux seen on conventional esophageal reflux monitoring studies is unknown. We aimed to: 1) Determine prevalence of reflux seen on HREMI, and 2) Correlate reflux during HREMI studies with reflux on esophageal reflux monitoring studies. METHODS: Patients undergoing HREMI from 7/2019 to 2/2020 were studied. Results of ambulatory reflux monitoring were obtained if undergone. Patients rated the severity of symptoms. RESULTS: Of 354 patients (mean age 56.0 ± 1.0, 68% females) undergoing HREMI, 99 (28%) had reflux at EGJ on HREMI on 3.9 ± 0.3 swallows. Patients with reflux on HREMI had lower Distal Contractile Integral/DCI (1414 ± 137 vs 2049 ± 159), lower esophageal sphincter (LES) basal pressure (19.2 ± 1.3 vs. 32.4 ± 1.1), integrated relaxation pressure/IRP (7.2 ± 0.7 vs 13.8 ± 0.6), less likely to have EGJ outflow disorders (8.1% vs 29.4%) and major disorders of peristalsis (7.1% vs 21.2%), and more likely to have hiatal hernia/HH (71.7% vs 31.4%) than patients without reflux on HREMI (all P < 0.01, Table 1). Patients with reflux on HREMI had lower severities of regurgitation, dysphagia, and vomiting than patients without reflux (all P ≤ 0.01), likely due to lower prevalence of major esophageal motility disorders. Of the 273 patients with ambulatory pH monitoring (multichannel intraluminal impedance-pH = 257, Bravo = 16), 135 (49.5%) had GERD (Table 2). Patients with reflux on HREMI were more likely to have GERD on ambulatory pH monitoring (60.5%) than patients without reflux on HREMI (44.8%, P = 0.02). Patients with reflux on HREMI had a higher number of reflux events detected on MII-pH than patients without reflux on HREMI (56.0 ± 4.7 vs 42.6 ± 2.5, P = 0.01). Reflux on ≥1 swallow on HREMI had a specificity of 76.8% and sensitivity of 36.3% for GERD (Table 3). Reflux on ≥4 swallows on HREMI improved specificity to 90.6%, with sensitivity of 14.8% for GERD. CONCLUSION: Amongst patients undergoing HREMI, 28% had reflux at EGJ on HREMI. These patients had lower DCI, LES basal pressure, IRP and more frequent HH on HREMI than patients without reflux on HREMI. Patients with reflux on HREMI were more likely to meet criteria for GERD on ambulatory pH monitoring. Reflux on HREMI had good specificity but low sensitivity for GERD. Reflux seen on HREMI may be supportive evidence for GERD.Table 1Table 2Table 3