Prediction of Pharyngeal 3D Volume Using 2D Lateral Area Measurements During Swallowing.

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3 years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10 mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R2 = 0.816). Adding height and sex to the model increased R2 to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R2 = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior-posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

Accuracy of High-Resolution Pharyngeal Manometry Metrics for Predicting Aspiration and Residue in Oropharyngeal Dysphagia Patients with Poor Pharyngeal Contractility.

Several physiological metrics can be derived from pharyngeal high-resolution impedance manometry (HRPM), but their clinical relevance has not been well established. We investigated the diagnostic performance of these metrics in relation to videofluoroscopic (VFS) assessment of aspiration and residue in patients with oropharyngeal dysphagia. We analyzed 263 swallows from 72 adult patients (22-91 years) with diverse medical conditions. Metrics of contractility, upper esophageal sphincter (UES) opening and relaxation, flow timing, intrabolus distension pressure, and a global Swallow Risk Index (SRI) were derived from pressure-impedance recordings using pressure-flow analysis. VFS data were independently scored for airway invasion and pharyngeal residue using the Penetration-Aspiration Scale and the Normalized Residue Ratio Scale, respectively. We performed multivariate logistic regression analyses to determine the relationship of HRPM metrics with radiological outcomes and receiver-operating characteristic (ROC) analysis to evaluate their diagnostic accuracy. We identified aspiration in 25% and pharyngeal residue in 84% of the swallows. Aspiration was independently associated with hypopharyngeal peak pressure < 65 mmHg (HypoPeakP) [adjusted odds ratio (OR) 5.27; 95% Confidence Interval (CI) (0.99-28.1); p = 0.051], SRI > 15 [OR 4.37; 95% CI (1.87-10.2); p < 0.001] and proximal esophageal contractile integral (PCI) < 55 mmHg·cm·s [OR 2.30; 95% CI (1.07-4.96); p = 0.034]. Pyriform sinus residue was independently predicted by HypoPeakP < 65 mmHg [OR 7.32; 95% CI (1.93-27.7); p = 0.003], UES integrated relaxation pressure (UES-IRP) > 3 mmHg [OR 2.96; 95% CI (1.49-5.88); p = 0.002], and SRI > 15 [OR 2.17; 95% CI (1.04-4.51); p = 0.039]. Area under ROC curve (AUC) values for individual HRPM metrics ranged from 0.59 to 0.74. Optimal cut-off values were identified. This study demonstrates the diagnostic value of certain proposed and adjunct HRPM metrics for identifying signs of unsafe and inefficient bolus transport in patients with oropharyngeal dysphagia.