Digestive Diseases and Sciences | 2019
Do Vigorous Esophageal Contractions Contribute to Rigorous Phenotyping of Gastroesophageal Reflux Disease?
Abstract
Nearly one third of the adult US population experiences troublesome symptoms such as heartburn or regurgitation suggestive of gastroesophageal reflux disease (GERD). Historically, empirical management strategies for GERD have resulted in suboptimal patient outcomes and a substantial healthcare burden [1]. With the increased recognition that patients with GERD are heterogeneous, the management of GERD is now shifting toward phenotype-guided treatment. Conceptual frameworks to phenotype GERD take into consideration the integrity of the anti-reflux barrier, the pattern of reflux burden, the mechanism of gastroesophageal reflux events, visceral sensitivity, and effectors of esophageal clearance [2, 3]. The latter, effectors of esophageal clearance, is primarily measured by the vigor of esophageal contractility as assessed by high-resolution esophageal manometry. When the vigor of at least half of test swallows on manometry is weak (distal contractile integral less than 450 mmHg s cm), ineffective esophageal motility (IEM) is diagnosed according to the Chicago classification version 3.0 [4]. Although IEM is the most commonly encountered motility disorder diagnosed with manometry, frequently found in asymptomatic patients and in patients with GERD, the clinical relevance of identifying IEM in order to phenotype and manage GERD remains unclear. In this issue of Digestive Diseases and Sciences, Reddy and colleagues aim to characterize gastroesophageal reflux patterns among patients with IEM [5]. This retrospective cross-sectional study of esophageal manometry studies comparing up to 239 patients with IEM and 100 patients with normal esophageal motor function reports that patients with IEM have a higher number of reflux events as measured with impedance-pH monitoring (on or off acid suppression) and a greater acid exposure time as measured with pH monitoring performed off acid suppressive therapy. Furthermore, patients with IEM have a lower esophagogastric junction contractile integral, a surrogate measure of anti-reflux barrier integrity [6]. The authors further sub-group patients with IEM according to esophagogastric junction morphology type (I, II, and III), and note that patients with IEM and esophagogastric junction morphology type III (> 2 cm separation between the crural diaphragm and lower esophageal sphincter) have a higher body mass index, greater acid exposure, higher number of reflux events, and higher bolus exposure time. The findings by Reddy and colleagues corroborate the notion that IEM is associated with GERD-associated pathologies such as increased reflux burden, a disrupted anti-reflux barrier, and obesity. An issue that remains unresolved in this observational study is the directionality of association. Does reduced esophageal contractility impair clearance of refluxate, increasing gastroesophageal reflux burden, or does chronic gastroesophageal reflux lead to esophageal injury and dysfunctional esophageal peristalsis? Regardless of the underlying pathophysiology, esophageal contractility seems to be a physiologically relevant component of GERD. As the authors mention, the clinical significance of IEM in GERD is unknown. Thus, inclusion of patient-reported * Rena Yadlapati [email protected]