Preface| Volume 33, ISSUE 1, Pxv-xvi, January 2023

Navigating a Path in Submucosal Endoscopy: Learning from the Past and Forging Ahead

Published:October 23, 2022DOI:
      In this issue of Gastrointestinal Endoscopy Clinics of North America, we explore the field of submucosal endoscopy. Work in this space first started in Asia with descriptions of endoscopic submucosal dissection (ESD). The value of working in the submucosal space and the recognition that there can be controlled and safe access beyond not only the mucosal layer but also the entire gastrointestinal (GI) wall inspired the field of Third Space Endoscopy (TSE) and endoscopic full-thickness resection (EFTR). As the introduction, training, and adoption of this field moves from Eastern to Western countries, there is a need to reconsider classical training patterns that require lengthy apprenticeship and focused indications, and adopt changes more rapidly as advances are being made in device and technique innovation. Given the differences in disease prevalence (ie, gastric cancer), training models, and the structure of practice settings, there is a need to reframe and even redefine the way in which we consider this field and make it more accessible to Western endoscopists. In addition, there is a recognition that these techniques are not limited to one disease entity, such as GI cancers, but have applications throughout many GI disorders and sometimes even outside of the discipline.
      In this issue, we are reminded of the origins of ESD as well as the considerations that must be made as we integrate the field into Western practice. We learn of indications and techniques of submucosal endoscopy for early neoplasms and submucosal lesions, in the esophagus, stomach, duodenum, colon, and rectum. Furthermore, we discuss resection of lesions not traditionally considered GI in nature but made possible by such techniques as TSE and EFTR. The expansive reach of the access created by the submucosal tunneling techniques in treating disorders that target muscular layers, such as achalasia, is thoroughly explored, including indications, outcomes, and techniques. For innovation to proceed, we must understand all aspects of submucosal endoscopy, including electrocautery principles, the tools currently available to perform these techniques, ways in which to manage adverse events, and how to consider training and measuring competency. It is equally important to see modifications and developing technology (ie, robotics) that will help guide growth in the field.
      Given the rapid pace at which the field of ESD and TSE is moving, it is important to not only maintain perspectives from the pioneers in the field but also appreciate how emerging endoscopists are adopting and innovating techniques to make these procedures safe and more effective and develop novel indications. I am grateful to the authors for providing their excellent guidance to help navigate the path ahead. And, on behalf of myself and all of the authors, I thank the editor, Dr Lightdale, for this opportunity to share our passion for this field.