LAUSR

Endoscopy plays an important role in the clinical daily practice of diagnosis and treatment in gastrointestinal diseases. Aggressive endoscopists have been developing novel endoscopic procedures for various diseases that had been treated by surgery a few decades ago. However, bleeding associated with endoscopic procedures is still an inextricable complication and a major concern for endoscopists even though endoscopic procedures are less invasive compared to surgery. In contrast, as the number of patients receiving antithrombotics is increasing in clinical daily practice, endoscopists encounter more patients who require endoscopic procedures during antithrombotic therapy. Antithrombotics decrease the risk of thromboembolism although they also increase the risk of gastrointestinal bleeding at the same time. From that standpoint, cessation during periendoscopic periods seems preferable although careless cessation of antithrombotics causes the unfortunate event of thromboembolism. Thus, the management of antithrombotics in such patients during the periendoscopic period has remained a great dilemma for endoscopists. The present guidelines revised in 2012 by the Japan Gastroenterological Endoscopy Society offered a new direction concerning this dilemma. They permitted continuation of antithrombotics during endoscopic procedures considering the more severe outcome of thromboembolism than that of bleeding. These guidelines brought about a drastic paradigm shift in the clinical daily practice of gastrointestinal endoscopy. As a result of this revision of the guidelines, continuation of antithrombotics during endoscopic procedures has gradually become more popular. Thus, accumulation of evidence to validate the recommendations in the guidelines became easier than before. Nowadays, the acceptance of biopsy and high-bleeding-risk procedures without cessation of any antithrombotics and aspirin are growing, respectively. However, these guidelines have a major problem in that they lack a recommendation for novel antithrombotics. Direct oral anticoagulants (DOAC) have become major options for anticoagulant superseding warfarin as a conventional anticoagulant. They directly inhibit the coagulation system cascade and result in a shorter time to produce effects than warfarin. As a result, dabigatran, rivaroxaban, apixaban, and edoxaban are rapidly gaining a significant share of DOAC. However, three DOAC except for dabigatran are not mentioned in the present guidelines. Additionally, the necessity for heparin bridge therapy (HBT) for DOAC is still controversial because of their immediate effects and shorter duration of action. Moreover, it is reported that HBT itself does not reduce the risks of thromboembolism in spite of the higher bleeding risk. Thus, there are not negligible sceptical views that HBT for anticoagulants is not mandatory. However, there are enough data to make conclusions concerning this problem. In this issue of Digestive Endoscopy, Yoshio et al. reported the risk factors for postoperative bleeding after gastric endoscopic submucosal dissection (ESD) in patients receiving anticoagulants including DOAC. They revealed that HBT, multiple antithrombotic agents, and revaroxaban are risk factors for postoperative bleeding after gastric ESD. The former two factors are previously reported risk factors of bleeding, although this article also demonstrated the possibility that the risk of each DOAC might differ. In spite of its retrospective design and its small number of patients, its impact upon clinical daily practice of gastrointestinal endoscopy is not small because it also revealed the necessity for further accumulation of evidence concerning the management of DOAC. Meanwhile, the present environment surrounding antithrombotic therapy is quite different from that around the time when the present guidelines were published. Thienopyridine derivatives are one of a triad for antithrombotic therapy as mentioned in various guidelines for the treatment of ischemic heart disease, valve disease, and arrhythmia. They are commonly used in combination therapy with aspirin after coronary artery stent implantation (DAPT: dual antiplatelet therapy) or with anticoagulants, although the most popular thienopyridine derivatives are changing rapidly from ticlopidine to clopidogrel, or prasgrel. Additionally, ticagrelor, a novel ADP receptor antagonist, may supersede other thienopyridine derivatives in the near