Toshifumi Hibi, Tadakazu Hisamatsu and Taku Kobayashi (eds.)Advances in Endoscopy in Inflammatory Bowel Diseasehttps://doi.org/10.1007/978-4-431-56018-0_23

23. Endoscopy in Inflammatory Bowel Disease: Asian Perspectives with Respect to Japan

Mamoru Watanabe¹

(1)

Department of Gastroenterology and Hepatology, Advanced Clinical Center for Inflammatory Bowel Disease, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan

Mamoru Watanabe

Email: mamoru.gast@tmd.ac.jp

Abstract

Endoscopy has an important role in the management of gastrointestinal tract disease in Japan. Mucosal healing is a new goal of the management of inflammatory bowel disease (IBD). This has expanded the use of endoscopy. This chapter presents a review of the use of endoscopy for IBD in Japan. Surveillance colonoscopy with target biopsy for long-standing ulcerative colitis (UC) is advocated. A consensus statement has been developed for the diagnosis and management of intestinal Behçet’s disease (BD) in Japan, and adalimumab has been approved to treat BD based on the findings of a Japanese multicenter study. A patency capsule that does not have a radioactive tag has been developed for capsule endoscopy (CE). CE can also be used as an alternative to traditional endoscopy to identify small intestinal lesions in patients with UC. Balloon-assisted endoscopy (BAE) is the gold standard for small intestinal lesions, and is more sensitive than magnetic resonance (MR) imaging for detecting intestinal damage. Endoscopic balloon dilation for the removal of foreign bodies, including retained capsule endoscope, is also important. Endocytoscopy is a developing technology to assess inflammation, and endocytoscopic narrow band imaging is useful for evaluating the severity of UC.

Keywords

IleocolonoscopyCapsule endoscopyBalloon-assisted endoscopyEndocytoscopyNarrow band imaging

23.1 Introduction

Endoscopy is the most widely used procedure used to manage gastrointestinal tract disease in Japan. Gastroenterologists are also endoscopists, and endoscopic findings are directly incorporated into the therapeutic strategy.

In Japan, Crohn’s disease (CD) is diagnosed according to a single, well-established set of diagnostic criteria first established in 1976 and updated in 1995 [1]. These criteria consist of combinations of specific morphological findings. The diagnosis of CD is confirmed based on the presence of longitudinal ulcers, or a cobblestone-like appearance on colonoscopy or enteroscopy. Endoscopy is indispensable.

Recently, mucosal healing has been advocated as a new goal of inflammatory bowel disease (IBD) treatment [2]. Mucosal healing is identified on endoscopy, and as such, is endoscopic healing. Because most doctors involved in the management of IBD in Japan are also endoscopists, this new paradigm is familiar, and this paradigm shift has led to expanded roles of endoscopy in IBD. Advances in enteroscopy, particularly the advent of balloon-assisted endoscopy (BAE) developed by Yamamoto [3] and capsule endoscopy (CE) [4], have made possible a detailed investigation of the small intestine, the part of the bowel most affected in CD.

Here, recent reports from Japan are reviewed, and the application of endoscopy in daily practice is discussed.

23.2 Ileocolonoscopy (ICS)

Most cases of CD are diagnosed by ICS, and ICS is widely used to assess inflammation in ulcerative colitis (UC). In Japan, ICS is the most important endoscopy for the management of IBD.

Long-standing UC is associated with an increased risk of colorectal cancer. Surveillance colonoscopy is important for the early detection of UC-associated tumors. Biopsy is an important procedure to detect dysplasia as a sign of early-stage carcinoma. In the past, step biopsies at an interval of 10 cm were recommended for surveillance [5]. However, in many cases, more than 30 biopsies were required. Therefore, the procedure was expensive. Recent advances in high-resolution endoscopy have enabled a detailed observation of the mucosa. Biopsy specimens represent only a small part of mucosal lesions, and the lesions could be overlooked with conventional endoscopy. With the advent of high-resolution endoscopy, collecting tissue from selected areas of the mucosa (so-called target biopsy) has been proposed. This approach has advantages over step biopsy, not only with respect to cost but also for more effective early detection of tumors.

However, early stage UC-associated tumors can be cryptic and may be missed. Therefore, it is important to understand the typical endoscopic findings of early neoplastic changes. The Research Group for Intractable Inflammatory Bowel Disease of the Ministry of Health, Labour, and Welfare of Japan reviewed the typical endoscopic findings on conventional endoscopy and chromoendoscopy [6]. The group also conducted a randomized, controlled study to compare step biopsy and target biopsy, and showed that target biopsy detects dysplasia at a similar rate as step biopsy [7]. Therefore, surveillance endoscopy is changing from blind step biopsy to intentional target biopsy.

Another important target for ICS is Behçet’s disease (BD). In 2007, the Japan consensus statement for the diagnosis and management of intestinal BD was developed. Recently, renewed consensus-based practice guidelines for the diagnosis and treatment of intestinal BD have been released. These updated guidelines state that the diagnosis of intestinal BD can be made if there is a typical oval-shaped large ulcer in the terminal ileum, or ulceration or inflammation in the small or large intestine [8].

ICS is also used to monitor the treatment of gastrointestinal disease. In 2014, adalimumab was approved for the treatment of BD in Japan. This acceptance was based on a multicenter, open-label, uncontrolled study to evaluate the efficacy and safety of adalimumab in patients with intestinal BD who were refractory to corticosteroid and/or immunomodulatory therapies. In that study, a composite efficacy index including endoscopic assessments was developed, and this index was combined with gastrointestinal symptoms to evaluate efficacy. Previously, there was no widely accepted clinical index for assessing intestinal BD activity. In that study, endoscopy had an important role in the objective evaluation of intestinal BD because patient-reported symptoms may be influenced by the knowledge of the treatment allocation in unblinded trials [9].

23.3 Capsule Endoscopy (CE)

The advent of CE represents a major advance in endoscopy of the small bowel. Previously, enteroscopy could only effectively target the terminal ileum or proximal jejunum. CE enables the visualization of the whole gut, and is very sensitive for detecting mucosal lesions. The small intestine is the most commonly affected part of the bowel in CD. Therefore, CE is recommended in the World Organization of Digestive Endoscopy and the European Crohn’s and Colitis Organization (OMED–ECCO) consensus guidelines for use in patients with unexplained symptoms when other examinations have been negative [10].

However, there are some complications associated with CE, including capsule retention. Retention is defined as a capsule endoscope remaining in the digestive tract for more than 2 weeks [11]. In patients with CD, stenosis of the bowel lumen is not uncommon, and one study has reported capsule retention in 13% of patients with established CD [12]. Therefore, CE can be problematic in CD patients. To address the problem of capsule retention, the revised patency capsule was developed in 2011 [13]. This patency capsule does not have a radioactive tag and is therefore safer than the original patency capsule. Patency is established when the complete patency capsule is evacuated or is located in the colon within 30 h of administration. Since approval of the patency capsule, the indications for CE have expanded, and the use of the method has increased. However, sometimes it is difficult to judge whether the patency capsule has reached the colon or is still in the small intestine, particularly when the capsule is located in the pelvic area on plain X-ray.

Only gold members can continue reading. Log In or Register to continue