Modern diagnosis of GERD: the Lyon Consensus

Abstract

Clinical history, questionnaire data and response to antisecretory therapy are insufficient to make a conclusive diagnosis of GERD in isolation, but are of value in determining need for further investigation. Conclusive evidence for reflux on oesophageal testing include advanced grade 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 pH-impedance monitoring. A normal endoscopy does not exclude GERD, but provides supportive evidence refuting GERD in conjunction with distal AET <4% and <40 reflux episodes on pH-impedance monitoring off proton pump inhibitors. Reflux-symptom association on ambulatory reflux monitoring provides supportive evidence for reflux triggered symptoms, and may predict a better treatment outcome when present. When endoscopy and pH or pH-impedance monitoring are inconclusive, adjunctive evidence from biopsy findings (histopathology scores, dilated intercellular spaces), motor evaluation (hypotensive lower oesophageal sphincter, hiatus hernia and oesophageal body hypomotility on high-resolution manometry) and novel impedance metrics (baseline impedance, postreflux swallow-induced peristaltic wave index) can add confidence for a GERD diagnosis; however, diagnosis cannot be based on these findings alone. An assessment of anatomy, motor function, reflux burden and symptomatic phenotype will therefore help direct management. Future GERD management strategies should focus on defining individual patient phenotypes based on the level of refluxate exposure, mechanism of reflux, efficacy of clearance, underlying anatomy of the oesophagogastric junction and psychometrics defining symptomatic presentations.

Keywords: PH monitoring; endoscopy; gastroesophageal reflux disease; manometry.

Figure 1

Oesophagogastric junction morphology as depicted in HRM. With type 1 morphology the crural diaphragm (CD) component, evident during inspiration (I), is completely superimposed of the lower oesophageal sphincter (LES) component such that the magnitude of the actual LES pressure is not discernible. With type 2 morphology, there is partial separation of the LES and CD constituents, but the respiratory inversion point (RIP) remains at the level of the CD, evident by the decrease observed in the LES pressure band during inspiration. Other characteristics of type 2 morphology are that the LES-CD separation is <3 cm and that the pressure trough between the LES and CD is greater than intragastric pressure. With type 3 morphology, there is ≥3 cm separation between the LES and CD and the pressure trough between the two is equal to intragastric pressure during expiration (E). However, the RIP remains at the level of the CD in type 3a and elevated to the level of the LES pressure band with type 3b. This is evident by the decreases in LES pressure during inspiration in type 3a and increases in LES pressure during inspiration in type 3b.

Figure 2

High-resolution manometry metrics used in the motor classification of GERD. The oesophagogastric junction contractile integral (EGJ-CI) measures vigour of the EGJ barrier using a software tool that encompasses length and vigour of the EGJ above the gastric baseline. The measurement is made over three respiratory cycles during quiet rest, and corrected for duration of respiration. The distal contractile integral (DCI) measures vigour of smooth muscle contraction taking length, duration and amplitude of contraction into consideration. Following a series of repetitive swallows (multiple rapid swallows (MRS)), DCI augments higher than mean DCI from single swallows when there is contraction reserve.

Figure 3

Interpretation of oesophageal test results in the context of GERD. Any one conclusive finding provides strong evidence for the presence of GERD. While a normal EGD does not exclude GERD on its own, this provides strong evidence against GERD when combined with AET <4% and <40 reflux episodes on pH-impedance monitoring off proton pump inhibitor therapy. When evidence is inconclusive or borderline, adjunctive or supportive findings can add confidence to the presence or absence of GERD. Histopathology as an adjunctive measure requires a dedicated scoring system (incorporating papillary elongation, basal cell hyperplasia, DIS, intraepithelial inflammatory cells, necrosis and erosions) or evidence of DIS on electron microscopy. However, adjunctive findings, particularly histopathology and motor findings in isolation, are not enough to diagnose GERD. AET, acid exposure time; DIS, dilated intercellular spaces; MNBI, mean nocturnal baseline impedance; HRM, high-resolution manometry; PSPWI index, postreflux swallow-induced peristaltic wave index; EGJ, oesophagogastric junction. *Factors that increase confidence for presence of pathological reflux when evidence is otherwise borderline or inconclusive.