Evaluation of Upper Esophageal Sphincter Function

Under normal circumstances, the upper esophageal sphincter (UES) serves as an important gatekeeper, regulating antegrade and retrograde bolus movement through the upper aerodigestive tract. Dysfunction of the UES can result in multiple distressing symptoms and serious complications; accurate diagnosis is critical to appropriate management. The complex anatomy and physiology of the UES precludes any single available testing modality from completely assessing all aspects of UES dysfunction. This article provides an overview of the basic anatomy and physiology of the UES and reviews the advantages and shortcomings of the current techniques for evaluating its function.