Esophageal Disorders Not Yet Addressed by High-resolution Manometry

TO THE EDITOR: We greatly appreciate the insight provided by Wang et al 1 regarding their recent review of the esophageal disorders not assessed by the Chicago classification of motility disorders of the esophagus. This is an important issue as many people still fail to understand that the Chicago classification was designed to describe and categorize distal esophageal motor disorders focused on dysphagia and was not meant to be a global classification across the entire spectrum of esophageal disorders. All patients undergoing manometry will have a Chicago classification diagnosis, however, there may be other motor abnormalities of the upper esophageal sphincter, proximal esophagus or esophagogastric junction and proximal stomach that may be important in the patients presenting complaints and these need to be described separately from the Chicago classification diagnosis. To utilize the Chicago classification, one has to follow specific rules and calculate specific metrics in a predefined order and the analysis is confined to an assessment during 10 supine 5 mL water swallows. 2 We experienced that changing position elicited a change in diagnosis in about 10% of studies, and that provocative bolus challenges modified the diagnoses by increasing the number of patients classified with an esophagogastric junction outflow obstruction. 3 However, this did require utilization of different standard values and thresholds to allow for a refined characterization and represents one aspect where the Chicago classification diagnosis can be complemented. Similarly, the Chicago classification is also restricted to assessing patients before definitive treatment and although the Chicago classification can be modified to assess patients after antireflux procedures, bariatric surgery or treatments focused on disrupting the lower esophageal sphincter in achalasia; there are no reference ranges to define what is normal in the post-operative state. Nevertheless, the Chicago classification metrics, such as the integrated relaxation pressure and intrabolus pressure pattern, can help one discern whether there is an outflow obstruction after intervention and continued abnormal peristalsis. 4,5 Thus, it is likely that the met-rics described in the Chicago classification can be utilized, or modified, to help define disorders outside of those that are fo-cused on distal esophageal motor function. Moving forward, the next steps in the evolution of high resolution manometry and esophageal pressure topography should focus on describing specific disease related processes highlighted in the review published by Wang et al, 1 such as disorders related to gastroesophageal reflux, upper esophageal sphincter and prox-imal esophageal dysfunction in dysphagia, post-prandial …