Kenjiro Shigita

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. Consequently, it is assumed that there will be an increasing number of cases where no additional surgery is done, or cases of moderate invasive carcinoma in which endoscopic treatment is carried out to achieve an excisional biopsy, for which complete resection is applicable. In these cases, the preoperative diagnosis, resection techniques such as endoscopic submucosal dissection, features of resected specimens, and the accuracy of pathological diagnosis are all extremely important.

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.

Effectiveness and safety of endoscopic radial incision and cutting for severe benign anastomotic stenosis after surgery for colorectal carcinoma: a three-case series

Benign colonic anastomotic stenosis sometimes occurs after surgical resection and usually requires surgical or endoscopic dilation. Limited data are available on the effectiveness and safety of the endoscopic radial incision and cutting (RIC) method at sites other than the esophagus. The aim of this retrospective study was to investigate the effectiveness and safety of RIC dilation for severe benign anastomotic colonic stenosis. Subjects were 3 men (median age 72 years, range 65 – 76 years) who developed severe benign anastomotic stenosis after surgical resection for colorectal carcinoma and were subsequently treated by RIC dilation at Hiroshima City Asa Citizens Hospital between May 2014 and December 2016. Severe anastomotic stenosis was defined as a narrowed anastomosis through which a standard colonoscope could not be passed. The median interval from surgery to RIC was 21 months (range 9 – 29 months). RIC was successful in all 3 patients and reduced the severity of dyschezia postoperatively; 2 patients experienced improvement after a single RIC session and the other after 6 RIC sessions. No treatment-related adverse events or re-stenosis requiring repeat dilation was noted during a median follow-up of 27 months (range 8 – 37 months). Our findings indicate that the RIC technique can be applied safely and effectively to various sites in the colon, avoiding the need for reoperation.

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.

Endoscopic transluminal water irrigation for duodenal diverticulitis

Duodenal diverticula are usually asymptomatic, but complications such as cholestasis, inflammation, abscess formation, and perforation may occur, with clinically significant effects [1, 2]. In certain cases, endoscopic intervention may be chosen over surgery [3, 4]. However, the former is a complicated procedure requiring careful manipulation of the endoscope. A 75-year-old man presented with a high temperature of 38.5 °C and pain in the right upper abdomen. Laboratory findings revealed notable inflammatory results, but with no elevation of liver enzymes or amylase level. A contrast-enhanced computed tomography (CT) scan showed a swollen juxtapapillary duodenal diverticulum containing air and fluid, and an increased concentration of surrounding fatty tissue (▶Fig. 1). There was however no evidence of abscess formation or perforation. In spite of 2 days of fasting and the administration of broad-spectrum antibiotics, there was no clinical improvement, and resistance to conservative treatment was indicated in a subsequent endoscopic examination. Side-viewing endoscopy revealed a juxtapapillary diverticulum impacted with food debris. Following disimpaction of the food debris using forceps, pus was discharged from the diverticulum (▶Fig. 2 a, b). Thereafter, an endoscopic cannula was inserted on the underside of the diverticulum and plenty of water was delivered. A large amount of cylindrical food debris was released from the diverticulum around the cannula (▶Fig. 2 c; ▶Video1). The endoscopic treatment was completed without placement of a drainage tube. A subsequent diverticulogram revealed no residual food debris or perforation (▶Fig. 2d). The patient’s clinical symptoms disappeared and laboratory findings returned to normal immediately after the procedure, which allowed early resumption of oral food intake. No furVideo 1 Disimpaction of food debris at the orifice of the diverticulum led to the discharge of pus. Thereafter, cannulation on the underside of the diverticulum and water irrigation released cylindrical food debris.

“Step-clipping” method: a technique for detecting previously bleeding diverticula

Bleeding of colonic diverticula is a common complaint, but it remains challenging to treat endoscopically because of the difficulty in determining the responsible diverticulum, particularly if the bleeding stops spontaneously. Additionally, endoscopic examinations lasting >60 minutes are, in some cases, also problematic [1]. Thus, an innovative diagnostic technique is eagerly anticipated. Extravasation, observed during contrast-enhanced computed tomography (CECT), is an important factor in the identification of a bleeding diverticulum. However, even when CECT shows extravasation, colonoscopy-based detection of the responsible diverticulum occurs in only 60%–68% of cases [2–4]. This is because colonoscopy does not provide the precise positioning provided by CT, particularly if active bleeding is absent. Here, we report a case of diverticular bleeding in which the “step-clipping” method was used to identify the responsible diverticulum (▶Video1). A 70-year-old woman was admitted with massive hematochezia. Upon admission, CECT was conducted and revealed numerous diverticula in the ascending colon and active bleeding from one of them (▶Fig. 1). Subsequently, colonoscopy identified a fresh pool of blood remaining in the ascending colon. However, the active bleeding had spontaneously stopped, making detection of the responsible diverticulum difficult. After minimal searching, we placed five marking clips, 2 inches apart, in the ascending colon (step-clipping method), and performed unenhanced CT (▶Fig. 2). The positional relationship between each clip and the responsible diverticulum, identified in the initial CECT study, was evaluated. The responsible diverticulum was found opposite the second clip, near the ileocecal bulb (▶Fig. 3). Based on this evaluation, colonoscopy successfully identified the responsible diverticulum within 1 minute. Endoscopic band ligation [1] was performed to provide endoscopic hemostasis. An exposed vessel on the ligated diverticulum provided evidence of the cause of this bleeding incident. After ligation, there was no recurrence of bleeding, demonstrating the clinical feasibility of the step-clipping method.