Detecting pharyngeal post-swallow residue by ultrasound examination: a case series.

Abstract

Aims: Prevention of aspiration pneumonia is a great concern in the era of global aging. The assessment of pharyngeal post-swallow residue is important because remaining food and liquid in the pharyngeal area has a possibility of flowing into the lower airway which can cause aspiration pneumonia. Ultrasound examination has been recently used to assess swallowing disorders because of its noninvasiveness. The aim of this study was to investigate the performance for detecting pharyngeal post-swallow residue using an ultrasound examination by comparing with those using a fiberoptic endoscopic evaluation of a swallowing study as a reference. Material and methods: A linear array transducer attached to the thyroid cartilage to visualize the vocal folds in the sagittal plane. The pharyngeal post-swallow residue in the ultrasound movie was interpreted as a misty hyperechoic area above the vocal folds that remained after swallowing. Nineteen ultrasound images simultaneously obtained with fiberoptic endoscopic evaluation of swallowing study images from nine participants (eight men) with a median age of 70 years at a dysphagia outpatient clinic were analyzed by the montage of swallowing examinations. Results: Misty hyperechoic areas above the vocal folds that remained after swallowing were detected in 10 ultrasound images. Eight ultrasound images out of ten correctly detected pharyngeal post-swallow residue. The sensitivity for detecting pharyngeal post-swallow residue of 19 images from nine participants by ultrasound examination was 62%, and the specificity was 67%. Conclusions: The proposed detection method of pharyngeal post-swallow residue by ultrasound examination enabled the real-time assessment for swallowing of people with dysphagia. Ultrasound assessment-based daily swallowing care which detects pharyngeal residue will be useful for preventing aspiration pneumonia.

Establishing a Methodology for Ultrasound Evaluation of Pharyngeal Residue in the Pyriform Sinus and Epiglottic Vallecula

“…We have established a methodology for the ultrasound evaluation of the presence of pharyngeal residue. In a previous study, 15 we obtained images with longitudinal scans, but the attenuation of the ultrasound beam due to air in the trachea often occurred, resulting in a sensitivity and specificity of 62% and 67%, respectively, for detecting pharyngeal residue. The method described in this study, which is based on a transversal scan, allows the visualization of the pyriform sinus and epiglottic vallecula while bypassing the trachea and its problematic volume of air.…”

“…13,14 Few studies have focused on pharyngeal residue detection by ultrasound examination. A study showed a sensitivity of 62% and specificity was 67% for ultrasound examinations of pharyngeal residue 15 using ultrasound images that were originally intended to detect aspiration. 16 The scanning method to detect aspiration focuses on the tracheal area, but the method to detect pharyngeal residue should focus instead on the pyriform sinus and epiglottic vallecula.…”

A Randomized Controlled Trial to Investigate the Effectiveness of the Prevention of Aspiration Pneumonia Using Recommendations for Swallowing Care Guided by Ultrasound Examination

“…Aspiration during swallowing on a US image was interpreted as the passage of a hyperechoic object through the vocal folds along the tracheal wall, involving movement that differed from that of the surrounding tissue [ 9 ]. Pharyngeal post-swallow residue was defined as the remaining hyperechoic misty area above the vocal folds after swallowing [ 12 ]. Recommendations to health care providers regarding swallowing care using US images were provided by a US operator through a full-time dietitian.…”

“…As expected, this method assisted detection of the aspirated boluses from complex US images, improving the sensitivity and specificity to 91% and 94%, respectively [ 11 ]. Pharyngeal post-swallow residue was also visualized by US as a misty hyperechoic object above the vocal folds after swallowing [ 12 ]. The sensitivity and specificity of US examination for detecting pharyngeal post-swallow residue were 67% and 75%, respectively.…”

Non-invasive quantification of human swallowing using a simple motion tracking system

“…Several types of non-invasive methods for evaluating swallowing function, including sound sensors 1 – 4 , respiratory flow 4 , electromyograms (EMG) 5 , accelerometers 1 , 3 , electroglottographs (EGG) 1 , 6 , ultrasound 7 , 8 , and mechanomyography (MMG) 9 , have been reported. These methods provide on-sensor measurements that require the placement of sensors on participants’ skin, and for some patients who suffer from dysphagia, the placement of these sensors is cumbersome if not unfeasible.…”