The Lyon Consensus: Does It Differ From the Previous Ones?

Abstract

Gastroesophageal reflux disease (GERD) is a complex disorder with heterogeneous symptoms and a multifaceted pathogenetic basis, which prevent a simple diagnostic algorithm or any categorical classification. Clinical history, questionnaires and response to proton pump inhibitor (PPI) therapy are insufficient tools to make a conclusive diagnosis of GERD and further investigations are frequently required. The Lyon Consensus goes beyond the previous classifications and defines endoscopic and functional parameters able to establish the presence of GERD. Evidences for reflux include high-grade erosive esophagitis, Barrett's esophagus, and peptic strictures at endoscopy as well as esophageal acid exposure time > 6% on pH-metry or combined pH-impedance monitoring. Even if a normal endoscopy does not exclude GERD, its combination with distal acid exposure time < 4% on off-PPI pH-impedance monitoring provides sufficient evidence refuting this diagnosis. Reflux-symptom association on pH-monitoring provides supportive evidence for reflux-triggered symptoms and may predict a better treatment outcome, when present. Also recommendations to perform pH-impedance "on" or "off" PPI are well depicted. When endoscopy and pH-metry or combined pH-impedance monitoring are inconclusive, adjunctive evidence from biopsy findings (eg, microscopic esophagitis), high-resolution manometry (ie, ineffective esophagogastric barrier and esophageal body hypomotility), and novel impedance metrics, such as mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index, can contribute to better identify patients with GERD. Definition of individual patient phenotype, based on the level of refluxate exposure, mechanism of reflux, efficacy of clearance, underlying anatomy of the esophagogastric junction, and clinical presentation, will lead to manage GERD patients with a tailored approach chosen among different types of therapy.

Novel impedance‐pH parameters are associated with proton pump inhibitor response in patients with inconclusive diagnosis of gastro‐oesophageal reflux disease according to Lyon Consensus

“… 3 The recent Lyon Consensus delineates parameters on ambulatory reflux monitoring that categorically establish and rule out the presence of GERD. 4 , 5 In particular, conclusive evidence for reflux on oesophageal testing include severe erosive oesophagitis (LA grades C and D), long‐segment Barrett's mucosa or peptic strictures on endoscopy or distal oesophageal acid exposure time (AET) >6% on ambulatory pH or multichannel intraluminal impedance‐pH monitoring. On the other hand, AET between 4% and 6% is regarded as inconclusive for GERD.…”

The Role of Salivary Pepsin in the Diagnosis of Gastroesophageal Reflux Disease (GERD) Evaluated Using High-Resolution Manometry and 24-Hour Multichannel Intraluminal Impedance-pH Monitoring

“…Patients were classified into 3 groups on the basis of upper endoscopic findings, 24-h pH-MII monitoring, and HRM results based on the Lyon Consensus as follows: (1) conclusive evidence for GERD (conclusive GERD): presence of erosive esophagitis LA grade C&D, long-segment Barrett’s esophagus or peptic strictures and/or AET >6%; (2) evidence against pathologic reflux (evidence against GERD): without erosive esophagitis, AET <4%, and <40 reflux episodes while the patients were off PPIs; (3) inconclusive evidence for GERD (inconclusive GERD): LA grade A&B erosive esophagitis, and/or AET between 4% and 6%, and/or 40 to 80 reflux episodes. Factors such as positive reflux-symptom association, which was defined as the symptom index > 50%, the symptom association probability >95%, reflux episode >80, MNBI <2292 ohms, PSPWI <61%, hiatus hernia, esophageal hypomotility, or increased confidence for presence of pathological reflux when evidence was otherwise borderline or inconclusive [ 9 , 28 ].…”

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

“…Two novel impedance parameters, including baseline impedance and post-reflux swallow-induced peristaltic wave (PSPW), have been suggested as additional diagnostic tests in GERD diagnosis. 6,84,[124][125][126] Baseline impedance reflects the esophageal mucosa's permeability, even in the absence of macroscopic damage. 127 The PSPW index assesses the competence of esophageal refluxate clearance.…”