The role of endoscopic ultrasound for the evaluation and treatment of esophageal motility disorders

Esophageal motor disorders constitute a heterogeneous group of diseases that result in symptoms of dysphagia and chest pain. The primary diagnostic tool in the evaluation of patients with esophageal motor disorders is high resolution esophageal manometry. While manometric findings provide the sine qua non for the diagnosis of achalasia, they are limited in that they cannot provide meaningful anatomic correlates. Endoscopic ultrasound (EUS) has a key role in the evaluation of patients with esophageal motor disorders. Both probe-based ultrasound systems and echoendoscopes can provide high resolution imaging of the esophageal wall and surrounding structures. Due to a variety of factors, EUS has demonstrated clear variability in esophageal and muscle thickness. This may also reflect further anatomic heterogeneity among esophageal motor disorders. The benefit of EUS in the evaluation of alternative causes for outflow obstruction and pseudoachalasia is clear and should be considered in patients with atypical presentations. Novel indications for EUS include advanced imaging techniques and EUS directed treatments to the lower esophageal sphincter. EUS alone is not a replacement for standard diagnostic tests, it remains a helpful tool in the overall management of patients with esophageal motor disorders.