Yuzuru Tamaru

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. The colorectal lesions consisted of 136 hyperplastic polyps/sessile serrated polyps (HPs/SSPs), 1926 low-grade dysplasia (LGD), 571 high-grade dysplasia (HGD), 87 superficial submucosal invasive (SM-s) carcinomas, and 213 deep submucosal invasive (SM-d) carcinomas. We evaluated the relationship between the JNET classification and the histologic findings of these lesions. RESULTS The sensitivity, specificity, positive and negative predictive values, and accuracy of Type 1 lesions for the diagnosis of HP/SSP were, respectively, 87.5%, 99.9%, 97.5%, 99.4%, and 99.3%; of Type 2A lesions for the diagnosis of LGD were 74.3%, 92.7%, 98.3%, 38.7%, and 77.1%; of Type 2B lesions for the diagnosis of HGD/SM-s carcinoma were 61.9%, 82.8%, 50.9%, 88.2%, and 78.1%; for Type 3 lesions for the diagnosis of SM-d carcinoma were 55.4%, 99.8%, 95.2%, 96.6%, and 96.6%, respectively. CONCLUSIONS Types 1, 2A, and 3 of the JNET classification were very reliable indicators for HP/SSP, LGD, and SM-d carcinoma, respectively. However, the specificity and positive predictive value of Type 2B were relatively lower than those of others. Therefore, an additional examination such as pit pattern diagnosis using chromoagents is necessary for accurate diagnosis of Type 2B lesions.

Diagnostic performance of Japan NBI Expert Team classification for differentiation among noninvasive, superficially invasive, and deeply invasive colorectal neoplasia

BACKGROUNDS AND AIMS The Japan NBI Expert Team (JNET) classification is the first universal narrow-band imaging magnifying endoscopic classification of colorectal tumors. Considering each type in this classification, the diagnostic ability of Type 2B is the weakest. Generally, clinical behavior is believed to be different in each gross type of colorectal tumor. We evaluated the differences in the diagnostic performance of JNET classification for each gross type (polypoid and superficial) and examined whether the diagnostic performance of Type 2B could be improved by subtyping. METHODS We analyzed 2933 consecutive cases of colorectal lesions, including 136 hyperplastic polyps/sessile serrated polyps, 1926 low-grade dysplasias (LGDs), 571 high-grade dysplasias (HGDs), and 300 submucosal (SM) carcinomas. We classified lesions as polypoid and superficial type and compared the diagnostic performance of the classification system in each type. Additionally, we subtyped Type 2B into 2B-low and 2B-high based on the level of irregularity in surface and vessel patterns, and we evaluated the relationship between the subtypes and histology, as analyzed separately for polypoid and superficial types. We also estimated interobserver and intraobserver variability. RESULTS The diagnostic performance of JNET classification did not differ significantly between polypoid and superficial lesions. Ninety-nine percent of Type 2B-low lesions were LGDs, HGDs, or superficial submucosal invasive (SM-s) carcinomas. In contrast, 60% of Type 2B-high lesions were deep submucosal invasive (SM-d) carcinomas. The results were not different between each gross type. Interobserver and intraobserver agreements for Type 2B subtyping were good, with kappa values of .743 and .786, respectively. CONCLUSIONS Type 2B subtyping may be useful for identifying lesions that are appropriate for endoscopic resection. JNET classification and Type 2B sub classification are useful criteria, regardless of gross type.

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. Poor operability was defined as paradoxical movement of the endoscope, poor control with adhesions, and lesion motion with heartbeat or breathing. Technical and clinical success rates and adverse events were assessed. Results: Paradoxical movement and poor control with adhesions were improved in all cases using the single-use splinting tube. The en bloc resection rate was 95 % (19/20) and histological en bloc resection rate was 100 % (20/20). There were no complications related to use of the splinting tube. Conclusions: Use of a single-use splinting tube helped to overcome poor scope operability in deep colonic ESD.

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. In case 1, a 66-year-old woman underwent a colonoscopy due to blood in her stool, and an elevated lesion, 15 mm in size, was identified from the rectum to the dentate line of the anal canal on internal hemorrhoids. The lesion was diagnosed as an early SCC of the anal canal, and ESD was successfully performed. The histopathological diagnosis was SCC in situ. In case 2, a 71-year-old woman underwent a colonoscopy due to constipation, and an elevated lesion, 25 mm in size, was identified from the dentate line to the anal canal. The lesion was diagnosed as early-stage SCC of the anal canal, and ESD was successfully performed. The histopathological diagnosis was SCC in situ. No complications or recurrence after ESD occurred in either case.

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. Methods: A total of seven physicians compared 17 DRI images to the corresponding WLI images in colorectal ESD. The physicians compared the number of arteries identified on DRI with the actual number of arteries. The physicians rated the visibility of vessels, the demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine, and fibrosis. Inter-observer agreement was also examined using the kappa statistic. Results: Visibility of vessels and the demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine improved with the use of DRI compared with that using WLI. DRI can discriminate between arteries and veins clearly through the color of the vessels. Conclusions: DRI improves the visibility of vessels, especially that of arteries, as they appear orange, and the demarcation line of the muscle layer. DRI may help to make colorectal ESD safer and faster.

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. The indication for ESD in cecal tumors extending into the appendiceal orifice was recognition of the distal edge of the lesion in the appendix. They were classified into two groups: patients with cecal tumors extending (Group A: 29 patients, 29 tumors) and not extending (Group B: 49 patients, 49 tumors) into the appendiceal orifice. We compared the outcomes of ESD between both groups. Results: No significant differences in clinicopathological characteristics were observed between both groups. The rate of severe submucosal fibrosis in Group A (48%) was significantly higher than that in Group B (24%) (p < 0.05). The mean (SD) procedure speed in Group A (14 [10] mm2/min) was significantly slower than that in Group B (23 [16] mm2/min) (p < 0.01). The en bloc resection rates in Groups A and B were 90% and 96%, respectively. There were no significant differences in adverse events reported between both groups. Conclusions: ESD for cecal tumors with extension into the appendiceal orifice is effective and safe.

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. Patients and methods  This study was a single-institution retrospective cohort study based on clinical records. We assessed 650 consecutive patients with 698 CRNs who underwent ESD at Hiroshima University Hospital between December 2010 and June 2016. The patients were divided into three groups: the warfarin group (19 patients with 19 CRNs), DOAC group (7 patients with 9 CRNs), and no-antithrombotics group (624 patients with 670 CRNs). We replaced warfarin with heparin 3 to 5 days before endoscopy. Although DOAC was suspended on the morning of endoscopy, we did not replace heparin. Results  Bleeding after the procedure occurred in 26.3 % (5/19), 22.0 % (2/9), and 2.7 % (18/670) of patients in the warfarin, DOAC, and no-antithrombotics groups, respectively. In the warfarin group, four patients who bled after the procedure took not only warfarin but also other antiplatelets. En bloc resection rates were 94.7 % (18/19), 100 % (9/9), and 96.6 % (647/670) in the warfarin, DOAC, and no-antithrombotics groups, respectively. No patients experienced ischemic events in the perioperative period. Conclusions  Among patients undergoing ESD for CRNs, risk of bleeding was higher among patients who took anticoagulants than among those who did not. In particular, careful attention to patients who took antiplatelets in addition to warfarin before ESD for CRNs is warranted.

Prevention and management of spouting bleeding during endoscopic submucosal dissection for large subpedunculated-type colonic tumor

ENDOSCOPIC SUBMUCOSAL DISSECTION (ESD) is a reliable method for treating superficial colorectal tumors; however, it is technically more difficult and requires more experience than gastric ESD, because of difficulties associated with endoscope operability and the anatomical features of the colorectal region, including the presence of folds/flexures, bending of the intestinal tract, and the thinness of the intestinal wall. Main accidental complications during colorectal ESD are perforation and bleeding. With continued bleeding, visibility of the operative field deteriorates. In addition, with the recent rise in the number of elderly individuals, the rate of comorbidities, including cardiovascular and cerebral vascular diseases, has been increasing in Japan. This has resulted in an increase in the use of antithrombotic drugs for the treatment of comorbidities in elderly patients. For bleeding associated with ESD, clipping or coagulation with hemostatic forceps is appropriate. In cases of minor bleeding from a small vessel, contact coagulation with the tip of a knife or coagulation with hemostatic forceps is usually used for hemostasis. In cases of severe bleeding from a large vein or artery, hemostatic forceps are indispensable. During colorectal ESD, we use hemostatic forceps mainly for prevention or treatment of arterial bleeding, but use the tip of a knife for bleeding from a small vessel. Furthermore, we use clips together for prevention or treatment of thick arterial bleeding of pedunculated lesions. Epinephrine is a potent vasoconstrictor to reduce hemorrhage. In situations where there is a burst of bleeding from a large artery and we can’t recognize the bleeding point in the blood pool, it is useful to spray diluted epinephrine (1 mg per 20 mL physiological saline) into the field. A few seconds after spraying, vasoconstriction of the artery occurs and it becomes easy to recognize the bleeding point. Authors declare no conflicts of interest for this article.

Dual Red Imaging Maintains Clear Visibility During Colorectal Endoscopic Submucosal Dissection

BackgroundThe 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.AimsThis study aimed to evaluate the predictive factors of submucosal fatty tissue and the clinical usefulness of DRI in maintaining clear visibility during colorectal ESD.MethodsThe study participants included 586 consecutive patients with 645 colorectal tumors who underwent ESD between January 2014 and July 2017. First, the degree of submucosal fatty tissue was evaluated by reviewing recorded images, and the clinical characteristics of the patients and tumors related to severe submucosal fatty tissue were evaluated. Second, 34 tumors resected using DRI were propensity score-matched in a 1:1 ratio to other resected tumors using white light imaging (WLI), and the degree of endoscope lens cloudiness and clinical outcomes were evaluated.ResultsThe proportion of tumors located in the right side of the colon, body mass index (≥ 25, BMI), and hemoglobin A1c (≥ 6.5%, HbA1c) were significantly higher in patients with severe submucosal fatty tissue. The visibility in the DRI group was significantly better than in the WLI group. Treatment outcomes in the DRI group were as good as those in the WLI group.ConclusionsTumor location in the right side of the colon, BMI (≥ 25), and HbA1c (≥ 6.5%) are the predictive factors of severe submucosal fatty tissue. DRI is useful in maintaining clear visibility during colorectal ESD, especially with submucosal fatty tissue.

Clinical impact of surveillance colonoscopy using magnification without diminutive polyp removal

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.