Clinical application of endoscopic ultrasonography for esophageal achalasia.

Endoscopic ultrasonography (EUS) has been widely used for evaluating the nature of diseases of various organs. The possibility of applying EUS for esophageal motility diseases has not been well discussed despite its versatility. At present, peroral endoscopic myotomy (POEM) for esophageal achalasia and related diseases has brought new attention to esophageal diseases because POEM provides a more direct approach to the inner structures of the esophageal wall. In the present study, we discuss the clinical utility of EUS in evaluating and treating esophageal motility diseases such as esophageal achalasia and related diseases.