High-resolution manometry permitted the creation of the Chicago classification, that is the categorization for esophageal motility disorders most currently used. Despite its wide acceptance, there are few pitfalls for the correct interpretation of the tests. This technique review illustrates some difficult cases that may lead to misinterpretation of the results. Difficult cases are analyzed, such as the distinction of: (1) esophagogastric junction morphology and lower esophageal sphincter excursion, (2) intrabolus pressure pattern or common cavity, (3) hypercontractile esophagus (jackhammer) and achalasia type III, (4) absent contractility and severe ineffective esophageal motility or achalasia type I, and (5) simultaneous distal esophageal spasm and ineffective esophageal motility.

High-resolution manometry permitted the creation of the Chicago classification, that is the categorization for esophageal motility disorders most currently used. Despite its wide acceptance, there are few pitfalls for the correct interpretation of the tests. This technique review illustrates some difficult cases that may lead to misinterpretation of the results. Difficult cases are analyzed, such as the distinction of: (1) esophagogastric junction morphology and lower esophageal sphincter excursion, (2) intrabolus pressure pattern or common cavity, (3) hypercontractile esophagus (jackhammer) and achalasia type III, (4) absent contractility and severe ineffective esophageal motility or achalasia type I, and (5) simultaneous distal esophageal spasm and ineffective esophageal motility.

Current parameters of the Chicago classification include assessment of the esophageal body (contraction vigour and peristalsis), lower esophageal sphincter relaxation pressure, and intra-bolus pressure pattern. Esophageal disorders include achalasia, esophagogastric junction outflow obstruction, major disorders of peristalsis, and minor disorders of peristalsis. Sub-classification of achalasia in types I, II, and III seems to be useful to predict outcomes and choose the optimal treatment approach. The real clinical significance of other new parameters and disorders is still under investigation.
Classification* ; Esophageal Achalasia ; Esophageal Motility Disorders ; Esophageal Sphincter, Lower ; Esophagogastric Junction ; Humans ; Peristalsis ; Relaxation