Bolus clearance in esophagogastric junction outflow obstruction is associated with strength of peristalsis

Abstract

Background: A manometric diagnosis of esophagogastric junction outflow obstruction (EGJOO) without a mechanical cause creates a therapeutic conundrum. The aim of this study was to assess esophageal bolus clearance in EGJOO and assess manometric factors associated with clearance in EGJOO. Methods: Bolus clearance was assessed using line-tracing method and contour method to determine Complete Bolus Transit (CBT) and Functional Clearance (FC), respectively, on combined High-Resolution Impedance Manometry (HRIM). HRIM studies of EGJOO patients, as well as a sample of achalasia types I-III and asymptomatic controls, were retrospectively analyzed. In EGJOO, associations between Integrated Relaxation Pressure (IRP) or Distal Contractile Integral (DCI) and clearance were assessed using receiver-operating-characteristic (ROC) curves. Key Results: Seventy-five EGJOO, 28 achalasia, and 11 normal subjects were included. Agreement between CBT and FC was good (Kappa=0.75). CBT across swallows in each group was as follows: type I achalasia: 14%, type II achalasia: 8%, type III achalasia: 61%, EGJOO: 86%, and normal: 98% (p values.023,.006, and 610 mmHg-s-cm (accuracy 87.7%, P=.004). Complete Bolus Transit(CBT) across individual swallows was 97.8% when DCI>884 mmHg-s-cm (accuracy 81.9%, P 900 mmHg-s-cm.