A pictorial presentation of 3.0 Chicago Classification for esophageal motility disorders

ABSTRACT High resolution manometry changed several esophageal motility paradigms. The 3.0 Chicago Classification defined manometric criteria for named esophageal motility disorders. We present a pictorial atlas of motility disorders. Achalasia types, esophagogastric junction obstruction, absent contractility, distal esophageal spasm, hypercontractile esophagus (jackhammer), ineffective esophageal motility, and fragmented peristalsis are depicted with high-resolution manometry plots.


INTRODUCTION
High resolution manometry ( Figure 1) has clear and inherent advantages over conventional manometry, despite its higher cost. (1) High resolution manometry detailed analysis of esophageal peristalsis changed several esophageal motility paradigms, including new manometric parameters and different classification for named "motility disorders based on pressure topography", the Chicago classification, (2) which was recently revised. (3) We present a pictorial atlas of the motility disorders according to the 3.0 Chicago Classification with highresolution plots.

Achalasia
Chicago Classification divided achalasia into three subtypes according to esophageal pressurization (4) (Figure 2). Type I is characterized by 100% failed contractions and no esophageal pressurization; type II has panesophageal pressurization in at least 20% of swallows; and type III is defined by the presence of preserved fragments of distal peristalsis or premature contractions for at least 20% of the swallows. (3) This classification may be applied to Chagas' disease esophagopathy as well, although type III is rarely, if ever, seem. (5)

Esophagogastric junction obstruction
Esophagogastric junction obstruction ( Figure 3) is characterized by an elevated residual pressure of the lower esophageal sphincter (LES) measured by a new and more sophisticated tool, the integrated relaxation pressure (6) in the absence of criteria for achalasia (absence of peristalsis). (3) This parameter measures the mean pressure of the 4 seconds of maximal deglutitive relaxation in the 10-second window beginning at the beginning of the swallow (upper sphincter relaxation). It is a rare finding usually present in patients with dysphagia after operations at the esophagogastric junction. (7) be noticed in patients with connective tissue diseases, end-stage gastroesophageal reflux disease etc.

Absent contractility
Absent contractility is characterized by aperistalsis in the setting of normal LES relaxation and absence of esophageal pressurization (3) (Figure 4). This finding may

Hypercontractile esophagus
Hypercontractile esophagus (Jackhammer esophagus) is characterized by at least two swallows with hypercontractility as measured by the distal contractile integral (DCI) (3) (Figure 6). The DCI measures the contractile vigor combining the amplitude versus duration versus length of the distal esophageal contraction exceeding 20mmHg from the transition zone to the proximal margin of the LES. (9) Hypercontractility is defined by DCI >8,000mmHg.s.cm. (3) It may occur with esophagogastric junction obstruction, gastroesophageal reflux disease and eosinophilic esophagitis. (10)

DISCUSSION
Motility patterns to define named disorders have been motive of controversy since the era of conventional manometry. Different definitions exist although the classification by Richter was the most used by experts. (12) High resolution manometry seems to bring a more intuitive and reproducible interpretation compared with conventional manometry, (13) and more sophisticated tools to define old and new manometric parameters. Despite all improvements, and similarity with conventional manometry, some cases are still unclassified, and the real clinical significance of some Chicago Classification disorders is still under investigation.