Effects of Bolus Consistencies on Different Esophageal Variables Using High Resolution Esophageal Pressure Topography (HREPT)

Abstract

Purpose: Esophageal manometry is used in evaluating patients with esophageal motility disorders. The standard protocol involves placing the patient in the supine position with head turned to left (SHL) while evaluating liquid bolus swallows. There is scarce data evaluating the effect different kind of bolus consistencies on the measured variables. We hypothesized that different bolus consistencies could affect esophageal variables measured by HREPT compared to the standard liquid bolus. Aim: To compare esophageal pressure morphologies and function during swallowing different bolus consistencies in three different positions compared to water in traditional SHL position. Methods: Healthy adult volunteers were screened using a GERD symptom assessment scale (GSAS) questionnaire. Those eligible underwent an HREPT. The probe (36 sensors, 2.75 mm in diameter, 1 cm apart) was positioned from the nasopharynx to stomach. The volunteers were placed in the following positions: supine head left (SHL), seated at a 90° angle with head facing forward, and standing with head facing forward. Each patient was given 10 standard liquid boluses in the SHL position (traditional way), 3 boluses each of applesauce (AS), crackers (CR), and marshmallow (MM). All boluses were given in the aforementioned positions. We evaluated resting upper and lower esophageal sphincter (UES and LES) pressures, integrated relaxation pressure (IRP), contractile front velocity (CFV), distal contractile integral (DCI), intrabolus pressure (IBP), and IBP-LES. Data was compared using repeated test ANOVA corrected for multiple comparison using Tukey. Results: 44 healthy volunteers (M/F: 25/19, mean age=27 years, mean BMI= 25) were evaluated. The UES pressure was significantly different while subjects swallowed solids in most positions compared to liquid SHL (p<0.05). The IRP and IBP-LES were significantly different while subjects swallowed CR compared to liquid (p<0.05). The LES, CFV, DCI, and IBP were not significantly different while the subjects swallowed solids compared to liquids in all positions (Table 1).Table: [19] Table 1. Comparison between water and solid bolus on esophageal variablesConclusion: The resting UES pressure was significantly different while subjects swallowed solid bolus in most positions compared to standard liquid SHL. The IRP was significantly different while subjects swallowed CR compared to liquid SHL, but IBP-LES was only different in the SHL compared to liquid. The LES resting pressure, CFV, DCI, and IBP were not significantly different while the subjects were swallowing solids, compared to standard liquid SHL. Different bolus consistencies and different positions can affect HRM parameters, and could have a diagnostic implication on HREPT protocols, and treatment in patients suffering from GERD and dysphagia.