Pitfalls in the Interpretation of Chicago Classification for Esophageal Motility Disorders.

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.