Fluoroscopic Surrogate for Pharyngeal Strength: The Pharyngeal Constriction Ratio (PCR)

Abstract

The pharyngeal constriction ratio (PCR), derived directly from videofluoroscopy without the need for manometry, requires validation as a surrogate for pharyngeal strength. A correlation of −0.70 was previously identified between PCR and pharyngeal clearing pressures (PP) on separate fluoroscopic and manometric studies. As PP increases, PCR decreases. The objective of the current study was to evaluate the correlation between PCR and PP in 25 patients undergoing simultaneous fluoroscopy and pharyngeal manometry. The effect of the manometric catheter on PCR was also investigated. The correlation between the PCR and averaged pharyngeal clearing pressures was −0.72 (p < 0.001). All patients with a PCR > 0.25 had a PP < 60 mmHg. PCR did not differ significantly as a consequence of the manometric catheter. Results suggest the utility of an objective fluoroscopic measure in assessing pharyngeal strength when manometry may not be available or possible.

Measurement of Hyoid and Laryngeal Displacement in Video Fluoroscopic Swallowing Studies: Variability, Reliability, and Measurement Error

“…Generalization of the current results to studies on healthy subjects should therefore be done with caution. In addition, the present results may not apply directly to other aspects of swallowing kinematics such as measurement of the pharyngeal constriction ratio [27], which involves an area measurement rather than a distance measurement.…”

Pharyngeal dilation in cricopharyngeus muscle dysfunction and Zenker diverticulum

“…All outcome measures were calculated by a speech language pathologist (SLP) with extensive experience in the objective assessment of videofluoroscopic swallow studies. 11,12,[18][19][20]24 The SLP was removed from the statistical analysis of the data and was blind to the patient diagnosis and cricopharyngeus muscle dysfunction grouping. Thus, any misclassification bias should be nondifferential and bias the investigation toward the null hypothesis of no association between CPD and pharyngeal dilation and weakness.…”

“…The PCR is a surrogate marker of pharyngeal strength determined on fluoroscopy. 18,19 Previous studies have determined that the PCR increases as pharyngeal strength decreases. 18,19 The secondary outcome measures for this experiment were pharyngeal area in the lateral fluoroscopic view and PES opening.…”

The Relationship Between Pharyngeal Constriction and Post-swallow Residue

“…The PCR has been validated with manometry and has therefore been suggested as a surrogate method for measuring pharyngeal strength [4]. Additionally, it has been shown that higher PCR measures, indicating poor constriction, are associated with aspiration [5].…”