Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0©

Abstract

Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). Fifty-two diverse international experts separated into seven working subgroups utilized formal validated methodologies over two-years to develop CCv4.0. Key updates in CCv.4.0 consist of a more rigorous and expansive HRM protocol that incorporates supine and upright test positions as well as provocative testing, a refined definition of esophagogastric junction (EGJ) outflow obstruction (EGJOO), more stringent diagnostic criteria for ineffective esophageal motility and description of baseline EGJ metrics. Further, the CCv4.0 sought to define motility disorder diagnoses as conclusive and inconclusive based on associated symptoms, and findings on provocative testing as well as supportive testing with barium esophagram with tablet and/or functional lumen imaging probe. These changes attempt to minimize ambiguity in prior iterations of Chicago Classification and provide more standardized and rigorous criteria for patterns of disorders of peristalsis and obstruction at the EGJ.

Keywords: achalasia; esophageal spasm; integrated relaxation pressure; lower esophageal sphincter; peroral endoscopic myotomy.

Figure 1.

Standard high-resolution esophageal manometry protocol per CCv4.0

Figure 2.

High-resolution manometry images depicted the standard protocol. 2A) The supine position includes a 60 second adaptation period, 3 deep breaths, 30 second baseline period, 10 five ml wet swallows and at least one multiple rapid swallow. 2B) Position is changed to the upright position followed by a 60 second adaptation, 3 deep breaths, 30 second baseline period, 5 five ml wet swallows and a rapid drink challenge.

Figure 2.

High-resolution manometry images depicted the standard protocol. 2A) The supine position includes a 60 second adaptation period, 3 deep breaths, 30 second baseline period, 10 five ml wet swallows and at least one multiple rapid swallow. 2B) Position is changed to the upright position followed by a 60 second adaptation, 3 deep breaths, 30 second baseline period, 5 five ml wet swallows and a rapid drink challenge.

Figure 3.

Chicago Classification 4.0 Hierarchical Classification Scheme. This flow diagram represents a conceptual model of a state of the art algorithm that defines the flow process of how the CCv4.0 diagnosis is generated within the constructs of the various phases of the protocol. In this conceptual model, the current protocol allows for some flexibility if the diagnosis is conclusive with 10 swallows in either the primary supine or upright position and allows for a sequenced progression of the protocol to help confirm or rule out the diagnosis. This flow diagram represents the optimal flow process, however exceptions will exist based on the fact that some cutoffs are arbitrary and that the model assumes that a motility expert or a highly qualified motility technician or nurse is performing the protocol and analysis. *Denote manometric patterns of unclear clinical relevance. A clinically relevant conclusive diagnosis requires additional information which may include clinically relevant symptoms and/or supportive testing (as detailed in the document). †Patients with EGJ obstruction and presence of peristaltic swallows would fulfill strict criteria for EGJOO and may have features suggestive of achalasia or other patterns of peristalsis defined by criteria for disorders of peristalsis: EGJOO with spastic features, EGJOO with hypercontractile esophagus, EGJOO with ineffective motility, or EGJOO with no evidence of disordered peristalsis. ‡ RDC, solid test swallows, and/or pharmacologic provocation with amyl nitrite or cholecystokinin (if available) can be instituted here to assess for obstruction. ◊Patients previously defined absent contractility based on 10 swallows in the primary position may have achalasia if the IRP is elevated in the alternate position, with the RDC, and/or with MRS. These cases should be considered inconclusive for type I or II achalasia as appropriate and evaluated further with TBE/FLIP. ¥ If no evidence of a disorder of peristalsis or EGJ outflow in a patient with high probability of a missed EGJOO, a solid test meal can be added to rule out an obstructive pattern; if abnormal then possibility of a mechanical obstruction should be readdressed. In a patient with regurgitation or belching post-prandial high-resolution impedance monitoring to assess for rumination/belching disorder. Integrated relaxation pressure (IRP); Multiple rapid swallow (MRS); Rapid drink challenge (RDC); Lower esophageal sphincter (LES); Intrabolus pressurization (IBP); Panesophageal pressurization (PEP); Esophagogastric junction (EGJ): EGJ outflow obstruction (EGJOO); Timed barium esophagram (TBE); Functional lumen imaging probe (FLIP)

Figure 4.

Achalasia Subtypes. Type I Achalasia: integrated relaxation pressure (IRP) is elevated with failed peristalsis (distal contractile integral (DCI) < 100 mmHg-s-cm), and without panesophageal pressurization. Type II Achalasia: IRP is elevated with failed peristalsis and panesophageal pressurization. Type III Achalasia: IRP is elevated with a normal DCI, and a reduced distal latency. Not applicable (NA)

Figure 5.

Inconclusive Diagnosis for Achalasia or Absent Contractility Requires Supportive Testing. Findings are inconclusive for type I achalasia or absent contractility as there is 100% failed peristalsis but the median integrated relaxation pressure (IRP) is at the upper limit of normal with 5ml wet swallows. With the rapid drink challenge there is absence of deglutitive inhibition across the lower esophageal sphincter (LES). Supportive testing is required in the setting of inconclusive findings with timed barium esophagram and/or functional lumen imaging probe (FLIP). Here the timed barium esophagram demonstrates a dilated distal esophagus with barium retention. On FLIP the esophago-gastric junction (EGJ) distensibility index (EGJ-DI) is reduced, maximal EGJ diameter is reduced and there is absent contractile response to distension.

Figure 6.

EGJOO sub-types: EGJOO with hypercontractile features: IRP is elevated with intrabolus pressurization and hypercontractile swallow. EGJOO with no evidence of disordered peristalsis peristalsis. IRP is elevated with normal contractile vigor. Manometric EGJOO related to artifactual rise in IRP: IRP is elevated in the absence of intrabolus pressurization, and is likely associated with artifact. Esophago-gastric junction (EGJ); EGJ outflow obstruction (EGJOO); integrated relaxation pressure (IRP); distal contractile integral (DCI)

Figure 7.

Disorders of Peristalsis with Reduced Contractile Vigor or Contiguity of Peristalsis. These include absent contractility or ineffective esophageal motility (either related to reduced contractile vigor or fragmented peristalsis). In this example of Absent Contractility there is failed peristalsis with a normal IRP. In the first example of IEM the DCI is reduced with a normal IRP. In the second example of IEM the DCI is normal with a fragmentation in peristalsis of > 5cm in the setting of a normal IRP. During the multiple rapid swallows (MRS) there is absence of contractile activity and there is deglutitive inhibition of lower esophageal sphincter followed by DCI which is greater than the single swallow DCI, signifying an intact contractile augmentation.

Figure 8.

Disorders of Peristalsis with Esophageal Spasticity or Hypercontractility. These include distal esophageal spasm or hypercontractile esophagus. In this example of Distal Esophageal Spasm the DCI is normal with a reduced distal latency and normal IRP. Hypercontractile esophagus includes sub-groups: Single peak hypercontractile swallow, hypercontractile with jackhammer esophagus, and hypercontractile with LES after-contraction. integrated relaxation pressure (IRP); distal contractile integral (DCI); lower esophageal sphincter (LES)