Chicago Classification for the interpretation of esophageal manometry: Evaluating for disorders of EGJ outflow obstruction

EGJ: esophagogastric junction; IRP: integrated relaxation pressure; LES lower esophageal sphincter; PEP: panesophageal pressurization.
* For further assessment of EGJ obstruction, additional maneuvers may include rapid drink challenge, liquid swallows in a secondary position (eg, upright), and/or multiple rapid sequence swallows. These maneuvers may be performed if abnormal IRP is suspected or as part of a center's protocol.
¶ The diagnosis of achalasia is based on clinical, endoscopic, radiographic and manometric findings. Patients with achalasia typically have an elevated median IRP based on 10 liquid swallows. When additional maneuvers (eg, rapid drink challenge) are performed in patients with achalasia, the IRP of the LES is similarly elevated. However, a manometric pattern consisting of absent peristalsis and elevated IRP based on an additional maneuver only is regarded as inconclusive for type I or II achalasia. In such cases, other testing such as timed barium esophagram or functional luminal probe imaging may help to establish that LES relaxation is impaired.
Δ Patients with EGJ outlet obstruction and presence of peristaltic swallows fulfill criteria for EGJ outlet obstruction. However, such patients may also have features suggestive of achalasia or other patterns of abnormal peristalsis defined by criteria for disorders of peristalsis: EGJ outlet obstruction with spastic features, EGJ outlet obstruction with hypercontractile esophagus, EGJ outlet obstruction with ineffective motility, or EGJ outlet obstruction with no evidence of disordered peristalsis.
◊ Manometry findings suggest a likely diagnosis, but it needs to be confirmed by symptoms and supportive testing.