843 Association of Novel High-Resolution Impedance Manometry Parameters (HRIM) With Timed Barium Esophagram Measures and Dysphagia Symptoms in Achalasia Patients

Abstract

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.