An experimental manometric study simulating upper esophageal sphincter narrowing

RATIONALE AND OBJECTIVES. Elevated intrabolus pressure above a pharyngeal narrowing has been postulated as an important finding in patients with cricopharyngeal bars. To elucidate the significance of intrabolus pressure around lumen narrowings in the pharynx, intraluminal pressure characteristics were evaluated in a laboratory model simulating upper esophageal sphincter narrowing. METHODS. Intraluminal solid-state manometry was performed in an experimental model in which variable narrowing was created in an expandable balloon simulating the pharyngeal walls. RESULTS. Intrabolus pressure was dependent on the position of the manometric sensor, degree of lumen narrowing, bolus volume, flow rate, and fluid viscosity. CONCLUSIONS. Elevated intrabolus pressure is an important finding. Intrabolus pressure is dependent on many parameters, and hence, is difficult to evaluate. If results found with this model hold true in patients, manometric sensor positioning is crucial, and concurrent fluoroscopy is highly recommended to achieve a standardized manometric technique in pharyngeal manometry.