Endosonographic evaluation of the patient with achalasia.

Using endosonography, esophageal wall thickening is commonly observed in patients with achalasia. Imaging artifacts with the endosonographic appearance of an esophageal tumor in some patients with achalasia suggest that endosonographic images must be interpreted with caution. The endosonographer must be aware of anatomical peculiarities (dilated, tortuous, or "sigmoid" esophagus) and imaging techniques (tangential imaging) that may lead to artifactual imaging, and thereby avoid misinterpretation of results. Failure to recognize such imaging artifacts may lead to an erroneous diagnosis of pseudoachalasia, thereby subjecting patients to unnecessary surgery. Future applications of endoscopic ultrasonography for patients with achalasia may include endosonographically guided therapy. Prospective analyses of EUS-guided therapy are anticipated.