Transcutaneous cervical esophagus ultrasound in adults: Relation with ambulatory 24-h pH-monitoring and esophageal manometry

Noninvasive Bolus Transit Detection in Cervical Esophagus Utilizing Ultrasound Characteristics

This pilot study aims to identify characteristic A-mode ultrasound features relevant to noninvasive detection of esophageal bolus transit in the proximal esophagus. Ultrasound signals at a lateral neck site were obtained via a single-element ultrasonic transducer with synchronous videofluoroscopic swallowing studies images of swallows of differing viscosities in 21 adult dysphagia outpatients. Characteristic ultrasound features were extracted to differentiate a bolus-filled from a collapsed esophagus. From 21 subjects, 412 swallows exhibited 4 reproducible waveform patterns associated with bolus transit as displayed in a heatmap: (1) Strong Reflectors; (2) Echo Shifts; (3) Distal Acoustic Enhancement; and (4) Speckling: One or more of these features were observed in the swallow series for all 21 subjects. Distinct acoustic waveform features acquired by single-element ultrasonic transducers can identify bolus transit through the cervical esophagus.

Botulinum Toxin Injection for the Treatment of Upper Esophageal Sphincter Dysfunction

Dysphagia associated with upper esophageal sphincter (UES) dysfunction remarkably affects the quality of life of patients. UES injection of botulinum toxin is an effective treatment for dysphagia. In comparison with skeletal muscles of the limb and trunk, the UES is a special therapeutic target of botulinum toxin injection, owing to its several anatomical, physiological, and pathophysiological features. This review focuses on (1) the anatomy and function of the UES and the pathophysiology of UES dysfunction in dysphagia and why the entire UES rather than the cricopharyngeal muscle before/during botulinum toxin injection should be examined and targeted; (2) the therapeutic mechanisms of botulinum toxin for UES dysfunction, including the choice of injection sites, dose, and volume; (3) the strengths and weaknesses of guiding techniques, including electromyography, ultrasound, computed tomography, and balloon catheter dilation for botulinum toxin injection of the UES.

Bolus Detection in the Proximal Esophagus Using Pulse-Echo Ultrasound: A Feasibility Study

Here, the feasibility of using nonimaging pulse-echo ultrasound as a method of noninvasively detecting a bolus in the proximal esophagus was demonstrated. To accomplish this, patient swallows were recorded on a clinical ultrasound device with research interface that allowed for collection of the pulse-echo data. These ultrasound data of the proximal esophagus were processed with a series of signal processing techniques in both the temporal and spectral domains, which revealed characteristic signatures that were unique for both liquid and food boluses compared to the normal collapsed esophageal state. Since substantial amounts of laryngopharyngeal reflux are gaseous in nature, future work will revolve around expanding the data set to include boluses of gaseous refluxate, a standardized methodology for capturing bolus events; developing automated detection tools for identifying laryngopharyngeal reflux for an extended duration; and assessing technology limitations due to user error.

Lack of utility of transabdominal ultrasound in the detection of gastroesophageal reflux disease-induced esophagitis in comparison with endoscopy

BACKGROUND

Although upper gastrointestinal (GI) tract endoscopy is the investigation of choice for patients with suspected gastroesophageal reflux disease (GERD)-induced esophagitis, it is associated with complications and significant patient discomfort. The aim of the current study was to compare the accuracy of transabdominal ultrasonography with upper GI tract endoscopy in the detection of GERD-induced esophagitis.

MATERIALS AND METHODS

In this descriptive study, 350 patients (mean age, 41.41 ± 14.52 years) referred to a gastroenterologist with symptoms suggestive of GERD were enrolled. The esophageal wall thickness was measured with transabdominal ultrasonography, and patients were subsequently assessed by upper GI endoscopy, representing the criterion standard in the diagnostic evaluation for GERD-induced esophagitis.

RESULTS

Endoscopic evaluation identified 100 patients with esophagitis (case group), and 250 subjects were reported to have normal endoscopic findings (control group). The wall thickness was significantly higher in the case group compared with the control (P < 0.0001).In the receiver operating characteristic analysis, only 2 cutoff points had a positive predictive value (PPV) greater than 50%. The cutoff point of 2.7 mm had 38% sensitivity, 91% specificity, 63% PPV, and 79% negative predictive value in the detection of GERD. Its positive and negative likelihood ratios were 4.32 and 0.68, respectively.

CONCLUSIONS

According to the identified sensitivity/specificity, low PPV and positive likelihood ratio, and relatively high negative likelihood ratio, we failed to find the transabdominal ultrasound effective in the detection of GERD-induced esophagitis.