Esophageal sonography: a review of the utility of ultrasound in clinical esophagology

The utility and availability of ultrasound (US) are increasing. While US has traditionally not been performed on the esophagus, as the entire length of the esophagus cannot be optimally viewed, it does allow for visualization of the cervical and intraabdominal esophagus. There is growing evidence that esophageal US can be useful in clinical esophagology. This review summarizes the current knowledge concerning esophageal US in various esophageal disorders. Studies of achalasia patients have shown that US can distinguish patients with achalasia from health controls and esophagogastric cancer patients. US may be helpful as a screening test for esophageal varices in cirrhotic patients as esophageal wall thickness has been shown to correlate with the presence of varices. US has also been shown to identify the presence of esophageal foreign bodies in case reports in both the adult and pediatric population. In infants, numerous studies have shown its utility in diagnosing GERD and its correlation with pH study results, although the data in adults is less convincing. Taken together, these results suggest that there is a role for US—a non-invasive, cost-effective, and widely-available test—in evaluating esophageal disorders. Despite these promising results, it does not appear that esophageal US is frequently used in clinical practice. Barriers to its implementation, including the availability of US and the training required, are discussed, along with the lack of standardized US protocols, equipment, and normal values. Future high-quality studies on the utility of US in esophageal disorders are warranted and will accelerate the implementation of this promising technology.