Vela, Marcelo F.

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.

AbstractBackgroundAn international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro‐esophageal reflux disease (GERD).MethodsLiterature search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.Key ResultsReflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter‐based or wireless pH‐monitoring or pH‐impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH‐impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom‐reflux association in the absence of pathological AET defines hypersensitivity to reflux.Conclusions and InferencesThe consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.

Abstract Background Baseline impedance measured with ambulatory impedance pH monitoring ( MII ‐pH) and a mucosal impedance catheter detects gastroesophageal reflux disease ( GERD ). However, these tools are limited by cost or patient tolerance. We investigated whether baseline impedance measured during high‐resolution impedance manometry ( HRIM ) distinguishes GERD patients from controls. Methods Consecutive patients with clinical HRIM and MII ‐pH testing were identified. Gastroesophageal reflux disease was defined by esophageal pH <4 for ≥5% of both the supine and total study time, whereas controls had an esophageal pH <4 for ≤3% of the study performed off PPI . Baseline impedance was measured over 15 seconds during the landmark period of HRIM and over three 10 minute intervals during the overnight period of MII ‐pH. Key Results Among 29 GERD patients and 26 controls, GERD patients had a mean esophageal acid exposure time of 22.7% compared to 1.2% in controls ( P <.0001). Mean baseline impedance during HRIM was lower in GERD (1061 Ω) than controls (2814 Ω) ( P <.0001). Baseline mucosal impedance measured during HRIM and MII ‐pH correlated ( r =0.59, P <.0001). High‐resolution esophageal manometry baseline impedance had high diagnostic accuracy for GERD , with an area under the curve ( AUC ) of 0.931 on receiver operating characteristics ( ROC ) analysis. A HRIM baseline impedance threshold of 1582 Ω had a sensitivity of 86.2% and specificity of 88.5% for GERD , with a positive predictive value of 89.3% and negative predictive value of 85.2%. Conclusions & Inferences Baseline impedance measured during HRIM can reliably discriminate GERD patients with at least moderate esophageal acid exposure from controls. This diagnostic tool may represent an accurate, cost‐effective, and less invasive test for GERD .

SummaryBackgroundObesity is associated with increased oesophageal acid exposure time (AET) in patients with gastro‐oesophageal reflux (GER), and may decrease the effects of proton pump inhibitors (PPIs).AimTo evaluate the effects of increased body mass on the ability of PPI therapy to decrease AET in patients with reflux symptoms.MethodsAcid exposure time profiles collected from adult patients using wireless pH‐metry while on or off PPI therapy was retrospectively reviewed. Patients were separated into five body mass index (BMI) categories as defined by the World Health Organization. A multivariable logistic regression evaluated the association between abnormal AET and BMI groups while controlling for age, gender and pH capsule placement methods.ResultsThe study group comprised 968 patients with 336 (34.7%) studied on a PPI and 632 (65.3%) studied off PPI therapy. AET (total greater than 5.3%) was found more frequently in the overweight (67%) and obese classes (74–80%) compared to those who were normal weight (40%) while off acid‐suppressing medications (P < 0.001). No significant differences were found between these groups when studied on acid‐suppressing medications, and the proportion of patients with abnormal AET across BMI classes was similar regardless of taking a PPI either once or twice daily.ConclusionsThis is the largest study to report on the relationship between BMI and oesophageal acid exposure time in patients with GER on and off PPI therapy. We conclude that obesity is related to increased acid exposure time, but with no significant difference in acid exposure time among different weight‐based groups when taking a once or twice‐daily PPI.

AbstractTreatment options for achalasia include oral pharmacologic therapy, endoscopic injection of botulinum toxin, pneumatic dilation, and myotomy (conventionally by laparoscopy, but more recently by an endoscopic approach). Oral pharmacologic agents have fallen out of use because of insufficient efficacy and frequent side effects. Endoscopic injection of botulinum toxin is safe and has good short‐term effectiveness, but as the effect invariably wears off after a few months, this treatment is reserved for patients who are not candidates for more definitive treatments. Pneumatic dilation and surgical myotomy are currently considered the most effective treatments, with similar effectiveness in randomized controlled trials with follow‐up of up to 2 years. The risk/benefit ratio and choice of therapy depend on patient characteristics (age, comorbidities, disease stage, prior treatments), patient's preference, and locally available expertise. Treatment of patients who fail or relapse after initial therapy is challenging and the success rate of pneumatic dilation or myotomy in this group is lower compared with previously untreated patients. The recently developed peroral endoscopic approach to myotomy has achieved excellent results in early uncontrolled studies, but high‐quality randomized trials are needed to ensure widespread adoption is reasonable. Finally, retrospective data suggest that achalasia subtypes as defined by high‐resolution esophageal pressure topography may guide treatment choice, but confirmation in prospective outcome studies is awaited.