Impaired Proximal Esophageal Contractility Predicts Pharyngeal Reflux in Patients With Laryngopharyngeal Reflux Symptoms

Abstract

Objectives: The pathophysiology of laryngopharyngeal reflux (LPR) remains incompletely understood. Proximal esophageal motor dysfunction may impair bolus clearance, increasing the risk of pharyngeal refluxate exposure. We aimed to evaluate the association of proximal esophageal contractility with objective reflux metrics.

Methods: We evaluated adults with LPR symptoms undergoing high-resolution manometry (HRM) and combined hypopharyngeal-esophageal multichannel intraluminal impedance-pH testing at a tertiary center between March 2018 and August 2019. Routine parameters per Chicago classification were obtained on HRM. Proximal esophageal contractility was evaluated using proximal contractile integral (PCI), which quantifies contractile pressure >20 mm Hg for the region spanning the distal margin of the upper esophageal sphincter and transition zone. Univariate (Kendall correlation and Student t test) and multivariable (general linear regression and logistic regression) analyses were performed.

Results: We enrolled 138 patients (66.7% women, mean age 57.1 years) in this study. Lower PCI was associated with an elevated risk of increased pharyngeal reflux (adjusted odds ratio 0.83 per 100 mm Hg-s-cm change in PCI, 95% confidence interval: 0.69-0.98), with a trend toward increased bolus exposure time and total reflux events, after multivariable adjustment. The relationship between PCI and pharyngeal reflux was strongest among participants without a primary motility disorder on HRM (adjusted odds ratio 0.63, 95% confidence interval: 0.42-0.85, P interaction = 0.04). Among continuously expressed reflux parameters, lower PCI was significantly associated with more distal acid reflux events (β = -0.0094, P = 0.03) and total reflux events (β = -0.0172, P = 0.05), after adjusting for confounders.

Discussion: Reduced proximal esophageal contractility as assessed by decreased PCI on HRM independently predicted increased pharyngeal reflux in patients with LPR symptoms, particularly among those without a coexisting motility disorder.

Figure 1.

(a) Measurement of the PCI on HRM. (b) The HEMII-pH catheter contains 2 pH sensors located within/above the upper esophageal sphincter and in the esophageal body and 6 impedance electrodes pairs, divided into pharyngeal (3 and 1 cm above UES and 1 cm below UES), proximal esophageal (1, 3 and 5 cm below UES), and distal esophageal (9, 11, and 13 cm below UES). (c) A full-column, pharyngeal reflux event on HEMII-pH, characterized by a ≥50% decrease in impedance, propagating from the distal esophageal to the pharyngeal electrode pairs in a retrograde fashion. HEMII-pH, hypopharyngeal-esophageal multichannel intraluminal impedance; HRM, high-resolution manometry; PCI, proximal contractile integral; UES, upper esophageal sphincter.

Figure 2.

Association between PCI and dichotomized reflux parameters (normal vs increased). Overall, PCI was significantly lower among patients with increased pharyngeal reflux, acid exposure time, and bolus exposure time on HEMII-pH. *P < 0.05, **P < 0.01. AET, acid exposure; BET, bolus exposure time; HEMII-pH, hypopharyngeal-esophageal multichannel intraluminal impedance; PCI, proximal contractile integral.

Figure 3.

Association of PCI and increased pharyngeal reflux by various subgroups. All models controlled for age, sex, BMI, smoking status, and percentage of ineffective swallows, with the exception of the given stratification variable. †ORs are expressed per 100 mm Hg-s-cm change in PCI. aOR, adjusted OR; BMI, body mass index; CI, confidence interval; OR, odds ratio; PCI, proximal contractile integral; UESP, upper esophageal sphincter pressure.