Endoscopic submucosal dissection (ESD): still a matter for debate or a gold standard technique in both Western and Eastern countries?

Endoscopic submucosal dissection (ESD) was developed to make possible the en bloc removal of large, flat, superficial lesions of the gastrointestinal tract, and reports on its efficiency were first published more than 25 years ago [1,2]. In Eastern countries, this technique became the gold standard for the treatment of early gastric cancer. Since then, indications for the method have been expanded to include other structures, such as the esophagus and colon, and other types of lesions, such as submucosal tumors. In well-validated indications, assessments of both the shortand long-term efficacy of ESD, along with safety and recurrence rates, have proved its superiority to all other therapeutic modalities, including ablation techniques, endoscopic mucosal resection (EMR), and surgery. Recent studies have confirmed that ESD is superior to EMR in terms of higher rates of en bloc resection and histologically proven complete resection of early gastrointestinal neoplasia, along with resultant lower rates of recurrence [3,4]. In theWesternworld, the role of ESD is still a subject of debate, and most editorials and reviews emphasize the associated difficulties, concerns, and caveats [5]. At many conferences, the “pros and cons” of the use of ESD continue to be debated [6]. Evidence of its clinical value is still limited and based primarily on data from Japan. Such data may not be directly applicable to Europe, where the outcome of ESD may be innately less favorable because of limited Western expertise in this challenging technique. I personally find this continuing debate, and the obstacles that still prevent ESD from being adopted as a “gold standard,” quite surprising. From the early beginnings of ESD, I have felt that it would revolutionize endoscopy in the same way that both endoscopic ultrasonography (EUS) and natural orifice transluminal endoscopic surgery (NOTES) have modified our vision of current and future endoscopic therapy. EUS enables us to look in and through the digestive wall, and NOTES has increased our confidence in accessing the peritoneal and mediastinal spaces. The ESD technique has created another bridge between endoscopy and surgery, providing interventional endoscopists with access to “surgical” and “oncologic” values, such as R0 resection and complete remission of cancer. Furthermore, ESD has improved our technical skills in hemorrhage control and enabled the development of new tools and techniques, such as the tunneling methods of peroral endoscopic myotomy (POEM) in achalasia. TheWestern ESD debate centers primarily on two issues: concern regarding training and the “wellvalidated” appropriateness of piecemeal EMR. Although piecemeal resection is no longer considered suitable for early gastric cancer (including carcinomas of the esophagogastric junction) or esophageal squamous carcinoma, it is still considered appropriate in other contexts, such as Barrett’s and colorectal neoplasias. Used in these conditions, en bloc and histologically proven complete resection of early gastrointestinal neoplasia has exerted only a minor effect on clinical outcome. The typical issues associated with EMR – incomplete resection in these locations, along with higher recurrence rates – have been shown to be “easily” managed by early follow-up endoscopies and endoscopic re-treatment [7,8]. Evidence of the clinical value of ESD is indeed still limited and based primarily on Japanese data, which cannot be directly extrapolated to our countries [9]. The level of evidence demonstrating the superiority of ESD over EMR in terms of clinical outcome is even weaker in the context of Barrett’s neoplasia. In addition, the contribution offered by Komeda and colleagues to this debate [10] further illustrates that the superiority of ESD in this location will be difficult to prove. Their literature review included a total of 16 studies: 10 EMR studies originating from Western countries and 6 ESD studies from Japan, published be-