Effect of educational lecture on the diagnostic accuracy of Japan NBI Expert Team classification for colorectal lesions.

Background: An educational and training program is required for generalization of Japan NBI Expert Team (JNET) classification. However, there is no detailed report on the learning curve of the diagnostic accuracy of endoscopists using JNET classification. We examined the effect of an educational lecture on beginners and less experienced endoscopists for improving their diagnostic accuracy of colorectal lesions by JNET classification.

The utility of a novel colonoscope with retroflexion for colorectal endoscopic submucosal dissection.

The PCF-H290TI/L produced by Olympus is a novel colonoscope equipped with some advantageous features for endoscopic treatment. It is expected to improve the potential for retroflexion and overall endoscope operability, which can reduce the difficulty of performing colorectal ESD. The aim of this study was to evaluate the utility of the novel colonoscope in colorectal ESD.

Dual Red Imaging Maintains Clear Visibility During Colorectal Endoscopic Submucosal Dissection.

Background: The endoscopic lens becomes clouded and its visibility reduces during colorectal endoscopic submucosal dissection (ESD), especially in cases with submucosal fatty tissue. Dual red imaging (DRI) is a novel image-enhanced endoscopic technique that improves endoscopic visibility.

Aims: This study aimed to evaluate the predictive factors of submucosal fatty tissue and the clinical usefulness of DRI in maintaining clear visibility during colorectal ESD.

Use of anticoagulants increases risk of bleeding after colorectal endoscopic submucosal dissection.

Background And Study Aims: Japanese guidelines for gastroenterological endoscopy have recommended temporary withdrawal of anticoagulants (warfarin, direct oral anticoagulants [DOAC], or heparin) to prevent hemorrhagic complications during endoscopic submucosal dissection (ESD) for colorectal neoplasias (CRNs). However, serious thrombosis might occur during temporary withdrawal of anticoagulants. The current study aimed to evaluate outcomes with anticoagulants in patients undergoing ESD for CRNs.

Short-term outcomes of endoscopic submucosal dissection for superficial cecal tumors: a comparison between extension and nonextension into the appendiceal orifice.

Background: Few studies have investigated the use of endoscopic submucosal dissection (ESD) for cecal tumors extending into the appendiceal orifice. Herein, we assessed the feasibility and safety of ESD for cecal tumors extending into the appendiceal orifice.

Methods: We retrospectively examined the outcomes of ESD for 78 patients with 78 cecal tumors (male/female ratio, 40/38; mean [standard deviation, SD] age, 67 [9] years; mean [SD] tumor size, 32 [15] mm), who underwent ESD at the Hiroshima University Hospital between October 2008 and March 2016.

Validation study for development of the Japan NBI Expert Team classification of colorectal lesions.

Background And Aim: The Japan narrow-band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions.

Clinicopathologic and endoscopic features of early-stage colorectal serrated adenocarcinoma.

Background: Serrated adenocarcinoma (SAC) is a distinct colorectal carcinoma variant that accounts for approximately 7.5% of all advanced colorectal carcinomas. While its prognosis is worse than conventional carcinoma, its early-stage clinicopathologic features are unclear.

Clinical impact of surveillance colonoscopy using magnification without diminutive polyp removal.

Background And Aim: In Western countries, endoscopic removal of all adenomas during colonoscopy is recommended. The present study evaluates the usefulness of magnifying colonoscopy without removal of diminutive (≤5 mm) colorectal polyps.

Methods: Patients with diminutive polyps who were observed for over 5 years using magnification at Hiroshima University Hospital were selected retrospectively.

Clinical impact of dual red imaging in colorectal endoscopic submucosal dissection: a pilot study.

Background: Dual red imaging (DRI), a novel image-enhanced endoscopic technique, is expected to improve visibility of thin vessels, but no reports of the clinical use of DRI in colorectal endoscopic submucosal dissection (ESD) have been published. We aimed to compare the visibility of vessels, demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine, and fibrosis on DRI with that on white light imaging (WLI). We applied the principle of DRI to the image of the submucosal layer during colorectal ESD as a pilot study.

Clinical usefulness of a single-use splinting tube for poor endoscope operability in deep colonic endoscopic submucosal dissection.

Background And Study Aims: Poor endoscope operability remains a significant challenge during colorectal endoscopic submucosal dissection (ESD). We retrospectively evaluated the experience and clinical usefulness of a new single-use splinting tube in deep colonic ESD in the setting of poor scope operability.

Patients And Methods: Among 691 patients with colorectal tumors treated with ESD at Hiroshima University Hospital between November 2009 and July 2015, we analyzed 20 consecutive patients who underwent deep colonic ESD using a single-use splinting tube because of poor scope operability.

Long-term outcomes after endoscopic submucosal dissection for superficial colorectal tumors.

Background And Aims: Endoscopic submucosal dissection (ESD) is an effective procedure for en bloc resection of superficial colorectal tumors regardless of tumor size or location. However, there are few reports on long-term outcomes for patients with superficial colorectal tumors after ESD. We therefore aimed to evaluate the long-term outcomes after ESD for superficial colorectal tumors.

Clinical impact and characteristics of the narrow-band imaging magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

Background And Aims: The Japan NBI Expert Team (JNET) was established in 2011 and has proposed a universal narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors. The aim of this study was to evaluate the clinical usefulness of the JNET classification for colorectal lesions.

Methods: We analyzed 2933 colorectal lesions, which were diagnosed by NBI magnifying observation before endoscopic treatment or surgery.

Pedunculated-type T1 colorectal carcinoma with lung carcinoma metastasis at the deepest invasive portion.

We present a rare case of colorectal T1 carcinoma with metastasis of previous lung carcinoma found at the deepest invasive portion. A 61-year-old man presented with cervical lymphadenopathy 18 years after undergoing surgery for right lung carcinoma [poorly differentiated adenocarcinoma stage IIb (T3N0M0)]. Contrast-enhanced computed tomography showed enlarged lymph nodes (LNs) in the neck and mediastinal regions.

Narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

Many clinical studies on narrow-band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011.

Endoscopic submucosal dissection for anorectal tumor with hemorrhoids close to the dentate line: a multicenter study of Hiroshima GI Endoscopy Study Group.

Background: The lower rectum close to the dentate line has distinct characteristics, making endoscopic submucosal dissection (ESD) of tumors challenging. We assessed clinical outcomes of ESD for such patients with hemorrhoids.

Methods: Sixty-four patients (mean age, 68 years) underwent ESD for anorectal tumors close to the dentate line.

Long-term outcomes after treatment for T1 colorectal carcinoma.

Purpose: Long-term outcomes of patients with T1 colorectal carcinoma (CRC) treated by endoscopic resection (ER) or surgical resection are unclear in relation to the curative criteria in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines. The aim of this study was to retrospectively compare the long-term outcomes among patients with T1 CRC in relation to the treatment methods.

Methods: We examined 322 T1 CRC cases treated between January 1992 and August 2008 at Hiroshima University Hospital.

Clinical significance and validity of the subclassification for colorectal laterally spreading tumor granular type.

Background And Aim: Colorectal laterally spreading tumor granular type (LST-G) is generally divided into two subtypes based on morphology. Here, we retrospectively investigated the clinical significance of a concrete, objective LST-G subclassification.

Methods: This study examined 636 consecutive cases that were resected endoscopically or surgically.

Early squamous cell carcinoma of the anal canal resected by endoscopic submucosal dissection.

The standard treatment approach for squamous cell carcinoma (SCC) of the anal canal includes abdominoperineal resection and chemoradiotherapy. However, there are currently very few reports of early SCC of the anal canal resected by endoscopic submucosal dissection (ESD). We report 2 rare cases of SCC of the anal canal resected by ESD.

Risk of bleeding after endoscopic submucosal dissection for colorectal tumors in patients with continued use of low-dose aspirin.

Background: Although Japanese guidelines proposed by the Japan Gastroenterological Endoscopy Society for endoscopic submucosal dissection (ESD) for colorectal tumors recommend continued use of low-dose aspirin (LDA), this strategy is controversial. It was our practice to interrupt LDA therapy 5-7 days before ESD until December 2010, when we instituted the new guidelines and performed ESD without interrupting LDA therapy. The aim of the present study was to confirm the validity of the noninterrupted use of LDA inpatients undergoing ESD for colorectal tumors.

Endoscopic submucosal dissection as total excisional biopsy for clinical T1 colorectal carcinoma.

Background/aims: Only the depth of submucosal invasion can be estimated prior to determining the indications for endoscopic submucosal dissection (ESD) as a curative treatment for colorectal carcinoma (CRC). Here we evaluated the outcomes of ESD for clinical T1 CRCs.

Methods: Of 660 patients who underwent ESD for CRC at the Hiroshima University Hospital between June 2003 and December 2013, we examined the outcomes of 37 (6%; 26 men, 11 women; mean age ± SD, 68 ± 12 years) who underwent ESD as total excisional biopsy for various reasons, in spite of an endoscopic diagnosis of T1 CRC.

Towards safer and appropriate application of endoscopic submucosal dissection for T1 colorectal carcinoma as total excisional biopsy: future perspectives.

According to the Japanese Society for Cancer of the Colon and Rectum Guidelines 2014 for the Treatment of Colorectal Cancer, cases with T1 colorectal carcinoma should be considered for additional colectomy with lymph node dissection when histologically complete en bloc resection is endoscopically carried out and when one of the four risk factors listed below is present. These four risk factors are: (i) submucosal (SM) invasion depth ≥1000 μm; (ii) positive vascular invasion; (iii) poorly differentiated adenocarcinoma, signet ring cell carcinoma, or mucinous carcinoma; and (iv) grade 2/3 budding at the deepest part of SM invasion. However, the probability of lymph node metastasis is extremely low if none of these risk factors are present, with the exception of SM invasion depth ≥1000 μm.

Risk factors for delayed bleeding after endoscopic submucosal dissection for colorectal neoplasms.

Purpose: Although delayed bleeding is a major complication of endoscopic submucosal dissection (ESD) for colorectal neoplasms, few reports have assessed the risk factors for delayed bleeding after colorectal ESD.

Methods: This study included 363 consecutive patients in whom 377 colorectal neoplasms were resected using ESD between April 2006 and August 2012. We classified patients and lesions into two groups on the basis of presence or absence of delayed bleeding and retrospectively compared the clinicopathological characteristics and clinical outcomes of ESD between the two groups.

Is it possible to discriminate between neoplastic and nonneoplastic lesions in ulcerative colitis by magnifying colonoscopy?

Background: Colitis-associated cancer/dysplasia is an intestinal tract condition that can affect the life expectancy of patients with ulcerative colitis. It is often difficult to detect neoplastic lesions. This study evaluated whether any endoscopic features are effective for distinguishing colitis-associated cancer/dysplasia from nonneoplastic lesions in patients with ulcerative colitis.

Condition of muscularis mucosae is a risk factor for lymph node metastasis in T1 colorectal carcinoma.

Background: The Japanese Society for Cancer of the Colon and Rectum Guidelines for the Treatment of Colorectal Cancer 2010 state that curable T1 colorectal carcinoma (CRC) after endoscopic resection shows favorable histologic grade, absence of vessel involvement, submucosal invasion depth of <1,000 μm, and low-grade tumor budding.

Methods: We evaluated 322 consecutive T1 CRCs with LN dissection between January 1993 and March 2012. According to the muscularis mucosae condition, CRCs were classified into three groups: type A, clearly identified; type B, incompletely disrupted with deformity; or type C, completely disrupted.