Tu1994 Increased Frequency of Transient Lower Esophageal Sphincter (LES) Relaxation in Cascade Stomach

Background: In the Chicago Classification (CC) peristaltic integrity is determined by the size of the largest break in the isobaric contour. However, bolus clearance might be affected by the occurrence of non-continuous breaks. The aim of the study was to assess the effect of peristaltic integrity on bolus clearance by using pressure-flow analysis. Methods: 22 solidstate high-resolution impedance manometry (HRIM) tracings of 10 liquid swallows of healthy asymptomatic adults (6M; mean age 36.1 SD 11.7 years) were retrospectively analysed using MMS analysis software (version 9.1). Measures of peristaltic integrity (largest break and total break size in cm of the 20mmHg isobar) were derived. Pressure-flow analysis was performed using purpose designed MATLAB-based software (AIMplot, T. Omari) which derived peak pressure (PeakP), intra-bolus pressure (IBP), bolus flow relative to peak pressure (PNadImp) and its timing to peak pressure (TNadImp-PeakP). In addition the pressure-flow index (PFI), a composite measure of bolus pressurisation relative to flow and the impedance ratio (IR) a measure of the extent of bolus clearance failure were calculated. Results: Out of 220 swallows, 214 were suitable for analysis. A strong correlation between total break size and the largest break in the isobaric contour was found (r=0.846,p=0.000). There was a trend towards larger break size and higher IR, with a stronger correlation for the largest break (table 1). Both largest break and total break size correlated with lower PeakP, lower PNadImp, lower IBP and longer TNadImp-PeakP. However, no correlation was found between larger break size and PFI. Conclusion: Largest break and total break size seem to characterize peristaltic integrity equally. Larger break size is associated with lower peristaltic pressurization and impaired bolus movement. There seems to be little quantifiable difference between the largest break and total breaksize in relation to bolus pressurization. Esophageal break size and AIM-derived pressure-flow metrics