Length Normalisation for Pharyngeal and Distal Contractile Integrals: Is It Necessary?

Abstract

Introduction: High-resolution pharyngeal manometry (HRPM) is instrumental in evaluation of the intraluminal pressure in the pharynx, thus can be utilized in guiding therapy. The pharyngeal contractile integral (PhCI) is a HRPM metric assessing “vigor” of the pharyngeal contraction, and is analogous to the distal contractile integral (DCI) of the esophagus. Pharyngeal and esophageal length can vary from person to person and may confound PhCI and DCI measurements, so we decided to investigate this further. Methods: To compare normalized (nPhCI) and (nDCI) versus non-normalized PhCI and DCI using pharyngeal and esophageal length measurementsRetrospective study including 100 people underwent HRM excluding those with total absence of peristalsis. nDCI was calculated by dividing average DCI to their esophageal length which was defined by HRM as the distance between inferior border of UES to the upper of the LES. nPhCI was calculated by dividing average PhCI to its pharyngeal length. Pharyngeal length was measured radiographically from anterior superior edge of C1 vertebra to the anterior inferior edge of C5. Results: Results are summarized in table 1 and 2. nPhCI was tightly correlated with the original average PhCI, suggesting that pharyngeal length is fairly constant over the range of observed PhCI (r=0.95, p<0.001) (figure 1A). nDCI was also tightly correlated with the original average DCI value (r=0.99, p<0.001) (figure 1B). Conclusion: Data suggests that “normalization” for pharyngeal and esophageal lengths are not necessary when completing HRM. PhCI may a useful indicator of the severity of pharyngeal swallowing impairment. HRPM has the potential to be a valuable adjunct testing procedure in the evaluation and treatment of dysphagic individuals. 384_A Figure 1 No Caption available.384_B Figure 2 No Caption available.384_C Figure 3 No Caption available.