Clinical Esophagology: alive and kicking!

Clinical Esophagology in the field of Neurogastroenterology and Motility underwent a major impulse in the last several years. A fear for a scientific winter, caused by the retreat of PPI producing sponsors was reversed by new enthusiasm generated by three important newcomers: a new diagnostic technique, a new treatment, and a new disease. These factors have helped to drive research to new levels. And the best thing is a lot of the new research comes from international collaborations, with authors from several continents working together. This issue of Neurogastroenterology and Motility is entirely dedicated to Clinical Esophagology, in this editorial paper some of the most important advances in the field are summarized and the scientific challenges are identified. Although high-resolution manometry (HRM) is considered a new technique, the first studies with micromanometry were performed more than 15 years ago and these studies were first published in Neurogastroenterology and Motility.1, 2 At that time, investigators were struggling with the large numbers of lines in the tracings. It was only after the visually attractive pressure topography and color plots were advocated that the technique really became popular.3, 4 Pioneering work has been performed by the Chicago group, resulting in the formation of the International HRM Working Group publication of the Chicago Classification of Esophageal Motor Disorders version 1 and 2 in the past and now version 3 in this issue of the journal.5-7 The formation of the working group and classification has resulted in a universal language for esophagologists. There are many indications that the Chicago Classification has been picked up globally, meaning that, after following the diagnostic algorithm, a gastroenterologist in Japan would come to the same final diagnosis as a gastroenterologist in the USA or Europe. Normal values for each system have been produced, as also described in this issue.8 Besides the visual attractiveness of HRM color plot tracings, the improved presentation of data also resulted in the recognition that there are several clinically important subtypes of achalasia.9 Data are suggesting that the HRM profile of patients in part determines the most appropriate treatment.10 It is also likely that HRM has reduced the number of achalasia diagnoses missed. The significance of deviations of normality in HRM parameters will be hopefully be clarified in the future, undoubtedly resulting in more exciting papers such as the work by Mello et al. in this issue.11 In the 1990s, it was observed that a specific group of GERD patients were very different from other GERD patients.12 These patients had much more mucosal eosinophils, did not respond to acid suppression and their main symptom was dysphagia and not heartburn or regurgitation. The atopic nature of many of these patients in combination with the spectacular effect of elementary diets prompted the hypothesis that these patients suffered from an allergic disease. Eosinophilic esophagitis (EoE) or allergic esophagitis was born. Now, 15 years later, we have learned a lot about the disease, but many aspects remain unclear. Much more is now known about the pathophysiology of EoE, but many gaps in our knowledge are still to be filled. It is not clear why this disease suddenly emerged and why its prevalence increases so rapidly and little is known about natural course.13-15 All treatments are prescribed off-label, as there are still no drugs registered for EoE. Dietary treatments for EoE are either very extensive, such as the six food group elimination diet, or have a variable efficacy, such as the skin prick test- and patch test-based diets. The field thus seems open and there is much to study. The first description of endoscopic myotomy for achalasia has been followed by many descriptions of open label treatment results.16 With excellent short-term efficacy data from international studies, per-oral endoscopic myotomy (POEM) has the potential to become a real competitor for the current routinely performed treatments for achalasia such as pneumodilation and laparoscopic Heller myotomy.17 However, long-term follow-up data are required, including comparisons with the current standard treatments. Because POEM is a complex procedure and is only performed by endoscopy experts, collaboration between esophageal motility expert and endoscopist has intensified in many centers. Patient selection indeed seems pivotal, and high quality care and cutting edge science can only be guaranteed by collaboration of both disciplines. Although better and more often detected now with HRM, achalasia is still a rare disease and this is why the large consortia performing the randomized controlled trials are all multinational. The results of these trials will determine the place of POEM in the treatment of achalasia.18 Although progress has been made on several fronts, there is still much to do. Except for the three above-mentioned topics, there are many unresolved issues in other fields of esophagology. For example, for the most prevalent esophageal disorder, GERD, it is still largely unknown how reflux causes symptoms. Central and peripheral sensitization play a role here, some more light is shed on this in a paper by Siwiec et al. in this issue, but many issues are unresolved.19 We even do not know which receptor is triggered by reflux and what the role is of longitudinal muscle contractions. What exactly is the role of mucosal integrity changes in GERD and is baseline impedance a good reflection of this? How best to manage refractory GERD and how do we treat symptomatic non-acid reflux? These are exciting times to work as an esophagologist. Research with new diagnostics, new treatments and even a new disease deliver new insights every month and make the field so dynamic. Clinical Esophagology is indeed alive and kicking! None declared. No funding declared. AJB received research funding from Endostim, Medical Measurement Systems, Danone and Given and received speaker and/or consulting fees from MMS, Astellas, AstraZeneca and Almirall.