Development of multi-class computer-aided diagnostic systems using the NICE/JNET classifications for colorectal lesions.

BACKGROUND AND AIM: Diagnostic support using artificial intelligence may contribute to the equalization of endoscopic diagnosis of colorectal lesions. We developed computer-aided diagnosis (CADx) support system for diagnosing colorectal lesions using the NBI International Colorectal Endoscopic (NICE) classification and the Japan NBI Expert Team (JNET) classification. METHODS: Using Residual Network as the classifier and NBI images as training images, we developed a CADx based on the NICE classification (CADx-N) and a CADx based on the JNET classification (CADx-J). For validation, 480 non-magnifying and magnifying NBI images were used for the CADx-N and 320 magnifying NBI images were used for the CADx-J. The diagnostic performance of the CADx-N was evaluated using the magnification rate. RESULTS: The accuracy of the CADx-N for Types 1, 2, and 3 was 97.5%, 91.2%, and 93.8%, respectively. The diagnostic performance for each magnification level was good (no statistically significant difference). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CADx-J were 100%, 96.3%, 82.8%, 100%, and 96.9% for Type 1; 80.3%, 93.7%, 94.1%, 79.2%, and 86.3% for Type 2A; 80.4%, 84.7%, 46.8%, 96.3%, and 84.1% for Type 2B; and 62.5%, 99.6%, 96.8%, 93.8%, and 94.1% for Type 3, respectively. CONCLUSIONS: The multi-class CADx systems had good diagnostic performance with both the NICE and JNET classifications and may aid in educating non-expert endoscopists and assist in diagnosing colorectal lesions.

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. METHODS: Seven beginners with no endoscopy experience (NEE group), 7 less experienced endoscopists (LEE group), and 3 highly experienced endoscopists (HEE group) performed diagnosis using JNET classification for randomized NBI images of colorectal lesions from 180 cases (Type 1: 22 cases, Type 2A: 105 cases, Type 2B: 33 cases, and Type 3: 20 cases). Next, the NEE and LEE groups received a lecture on JNET classification, and all 3 groups repeated the diagnostic process. We compared the correct diagnosis rate and interobserver agreement before and after the lecture comprehensively and for each JNET type. RESULTS: In the HEE group, the correct diagnosis rate was more than 90% with good interobserver agreements (kappa value: 0.78-0.85). In the NEE and LEE groups, the correct diagnosis rate (NEE: 60.2 → 68.0%, P < 0.01; LEE: 66.4 → 86.7%, P < 0.01), high-confidence correct diagnosis rate (NEE: 19.6 → 37.2%, P < 0.01; LEE: 43.6 → 61.1%, P < 0.01), and interobserver agreement (kappa value, NEE: 0.32 → 0.43; LEE: 0.39 → 0.75) improved after the lecture. In the examination by each JNET type, the specificity and positive predictive value in the NEE and LEE groups generally improved after the lecture. CONCLUSION: After conducting an appropriate lecture, the diagnostic ability using JNET classification was improved in beginners or endoscopists with less experience in NBI magnifying endoscopy.

Long-Term Outcomes after Endoscopic Submucosal Dissection for Ulcerative Colitis-Associated Dysplasia.

INTRODUCTION: The Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients: International Consensus Recommendations guidelines recommend surveillance colonoscopy instead of colectomy after the complete removal of "endoscopically resectable" dysplastic lesions in ulcerative colitis (UC). There are no studies on long-term outcomes of endoscopic submucosal dissection (ESD) for UC-associated neoplasia (UCAN). We aimed to evaluate the clinical outcomes of ESD for UC-associated dysplasia (UCAD) during long-term follow-up. METHODS: We retrospectively enrolled 17 consecutive UC patients with 22 UCADs, who underwent initial ESD or total proctocolectomy at the Hiroshima University Hospital. The clinicopathological features of the patients and neoplasias and clinical outcomes of ESD were evaluated and compared with those of total proctocolectomy. RESULTS: UCAD in the ESD and total proctocolectomy groups was mostly noted on the left side of the colon, and most lesions were superficial macroscopic lesions. In the ESD group, en bloc resection and histological complete resection rates were 83 and 67%, respectively. One patient died of malignant melanoma; however, none of the patients died of UC-associated carcinoma in both groups. Metachronous neoplasias developed in 5 of the 7 patients in the ESD group. Among the 5 patients with metachronous UCAN, 4 finally underwent total proctocolectomy and 1 underwent additional ESD. CONCLUSIONS: ESD for UCAD is a useful method for total excisional biopsy. UC patients with UCAD resected by ESD have a high risk of developing metachronous UCAN during the follow-up period.

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. METHODS: The 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. RESULTS: The 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. CONCLUSIONS: Tumor 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.

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.

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. METHODS: ESD was performed on 257 colorectal tumors in 255 consecutive patients at Hiroshima University Hospital between June 2003 and July 2010. We investigated the following variables: patient characteristics, the American Society of Anesthesiologists score, tumor location, tumor size, growth type, histology, en bloc resection rate, achievement of curative resection, procedure time, and adverse events. The 5-year overall survival (OS), 5-year disease-specific survival (DSS), local recurrence, and metachronous tumor occurrence were also analyzed. RESULTS: We identified 224 tumors in 222 patients who were confirmed dead or had follow-up data for more than 5 years. After a median follow-up of 79 months, 5-year OS and DSS rates were 94.6% and 100%, respectively. The local recurrence rate (1.5%) was significantly higher in patients undergoing piecemeal resection (9.1%) compared with en bloc resection (0.6%), in cases of histologic incomplete resection compared with complete resection, and in cases of non-R0 resection compared with R0 resection. The rates of total number of tumors (≥6 mm) and carcinoma metachronous tumors after ESD without additional surgical resection were 18.9% (38/201) and 4.0% (8/201), respectively. CONCLUSIONS: Long-term outcomes after ESD for superficial colorectal tumors are favorable. Patients should be surveyed for both local recurrence and metachronous tumors after ESD.

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.

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. We therefore aimed to clarify the clinicopathologic and endoscopic characteristics of early-stage SACs. METHODS: Forty consecutive early-stage SAC patients at Hiroshima University Hospital were enrolled; SACs were classified into epithelial serration (Group A, n = 17) and non-epithelial serration (Group B, n = 23) groups. Additionally, we classified serrated adenoma into 4 types: sessile serrated adenoma (SSA), traditional serrated adenoma (TSA), unclassified, and non-serrated adenoma type. RESULTS: There were significant differences between Groups A and B in terms of tumor size (27.6 vs. 43.1 mm), incidences of T1 carcinoma (71% vs. 13%), and having the same color as normal mucosa (47% vs. 17%), respectively (p <0.01). In SACs >20 mm, the incidence of T1 carcinoma in Group A (70%) was significantly greater than that in Group B (13%) (p <0.05). There were significant differences in 'Japan NBI Expert Team' type 3 and type V pit pattern classifications between the 2 groups. The average TSA-type tumor size (42.6 mm) was significantly larger than that of the SSA (17.2 mm) and non-serrated component types (18.3 mm). The incidences of submucosal invasion in SSA- (80%), unclassified- (100%), and non-serrated-type (100%) tumors were significantly higher than that in the TSA type (11%). CONCLUSIONS: Epithelial serration in the cancerous area and a non-TSA background indicated aggressive behavior in early-stage SACs.

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. Lesions ≥6 mm in size, depressed lesions, and lesions with type V pit pattern were indications for endoscopic resection. We investigated the characteristics of lesions indicated for endoscopic resection detected on surveillance colonoscopy and the risk factors for the incidence of lesions indicated for endoscopic resection. RESULTS: A total of 706 consecutive patients were enrolled. Sixty-eight lesions indicated for endoscopic resection were detected, averaging 9.0 ± 4.8 mm, and 33 (49%) lesions were located in the right colon. Pathological diagnoses were adenoma, Tis carcinoma, and T1 carcinoma in 58 (85%), eight (12%), and two (3%) lesions, respectively. Five lesions were considered to grow from previously detected diminutive polyps. Relative risks for the incidence of a lesion indicated for endoscopic resection were 1.76 (95% confidence interval [CI], 1.004-3.23) for males compared with females, 3.76 (95% CI, 2.03-7.50) for more than three polyps at initial colonoscopy compared with one polyp, and 2.84 (95% CI, 1.43-5.24) for patients with carcinoma at initial colonoscopy compared with patients with no lesion indicated for endoscopic resection. Nine carcinomas were resected endoscopically. CONCLUSION: Diminutive low-grade adenomas detected by using magnifying colonoscopy may not necessarily require removal.

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. LST-G was subclassified as follows: Type 1, a lesion with homogenous uniform granules with uniform (<5 mm) nodules; Type 2, a lesion with granules and small nodules (≥5 mm, <10 mm); or Type 3, a lesion accompanied by large nodules (≥10 mm). For the validation study, 194 images were compiled from 97 cases investigated using conventional colonoscopy and chromoendoscopy with indigo carmine dye spraying. Images were distributed in a randomized order to students without prior endoscopy experience, less-experienced endoscopists (LEE group), and highly experienced endoscopists (HEE group). Diagnostic accuracy and interobserver agreement were then evaluated. RESULTS: There was no submucosal invasion in Type 1 lesions. The incidence of deep submucosal invasive carcinoma was higher for Type 3 lesions than for Type 2 lesions. Interobserver agreement was good in each group. Diagnostic accuracy was higher in the HEE group than in the student and LEE groups. Chromoendoscopy had a higher accuracy rate than conventional colonoscopy in the LEE and HEE groups (LEE, 0.74 vs 0.69, P < 0.05; HEE, 0.84 vs 0.78, P < 0.05). CONCLUSIONS: This subclassification of LST-G according to the diameters of granules and nodules was both useful for choosing therapeutic strategies in the clinical setting and universally applicable.

Autopsy of anaplastic carcinoma of the pancreas producing granulocyte colony-stimulating factor.

A 50-year-old man presented to a nearby hospital with high fever and anorexia. An abdominal tumor was detected, and he was referred to our hospital. A pancreatic tumor was detected by computed tomography and abdominal ultrasonography. He had high fever, leukocytosis, and high serum granulocyte colony-stimulating factor (G-CSF). We performed a tumor biopsy and histological examination revealed anaplastic carcinoma of the pancreas. Based on the diagnosis, we initiated chemotherapy using gemcitabine plus S-1. However, the tumor rapidly progressed and he deteriorated and died 123 days after admission. As immunohistochemical study showed positive staining for G-CSF in the tumor cell, we diagnosed the tumor producing G-CSF during autopsy. Anaplastic carcinoma of the pancreas producing G-CSF is very rare, with 10 cases, including ours, reported in the literature.

Efficacy of single-balloon overtube for endoscopic submucosal dissection in the proximal colon: A propensity score-matched analysis.

Objectives: A single-balloon overtube (SBO) can improve poor scope operability during colonic endoscopic submucosal dissection (ESD). We aimed to evaluate the clinical usefulness of SBO for ESD in the proximal colon and the predictive factors for cases in which SBO is useful. Methods: A total of 88 tumors located in the proximal colon resected by balloon-assisted ESD (BA-ESD) using SBO and 461 tumors resected by conventional ESD (C-ESD) between June 2015 and November 2020 were considered. Seventy-eight tumors each in the BA-ESD and C-ESD groups were matched by propensity score matching. ESD outcomes were compared between the groups, and a decision tree analysis was performed to explore the predictive factors for cases in which SBO is useful. Results: There were no significant differences between the groups in the major outcomes such as en bloc resection rate (95% vs. 99%, p = 0.17), R0 resection rate (92% vs. 96%, p = 0.30), mean dissection speed (16 mm2/min vs. 16 mm2/min, p = 0.53), and intraoperative perforation rate (5% vs. 6%, p = 0.73). Even when considering cases with poor preoperative scope operability, there were no significant differences between the groups. Comparison of tumors ≥40 mm in diameter between the groups confirmed that the intraoperative perforation rate was significantly lower in the BA-ESD group than in the C-ESD group (0% vs. 24%, p = 0.0188). Conclusion: SBO is useful for ESD of tumors ≥40 mm in diameter in the proximal colon to prevent intraoperative perforation, which usually has a long procedure time.

Clinical Features and Genomic Characterization of Post-Colonoscopy Colorectal Cancer.

INTRODUCTION: Some colorectal cancers (CRCs) may be missed during colonoscopies. We aimed to determine the clinicopathological, biological, and genomic characteristics of post-colonoscopy CRCs (PCCRCs). METHODS: Of the 1,619 consecutive patients with 1,765 CRCs detected between 2008 and 2016, 63 patients with 67 PCCRCs, when colonoscopies were performed 6-60 months before diagnosis, were recruited. After excluding patients with inflammatory bowel disease, familial polyposis syndrome, CRCs that developed from diminutive adenomatous polyps, and recurrent CRCs after endoscopic resection, 32 patients with 34 PCCRCs were enrolled. The lesions' clinicopathological features, mismatch repair proteins (MMRs), and genomic alterations were investigated. RESULTS: The overall PCCRC-5y rate, rate of intramucosal (Tis) lesions, and rate of T1 or more deeply invasive cancers were 3.7% (66/1,764), 3.9% (32/820), and 3.6% (34/944), respectively. Thirty-three patients' MMRs were investigated; 7 (21%) exhibited deficient MMRs (dMMRs), comprising 4 with T2 or more deeply invasive cancers and 5 whose lesions were in the proximal colon. Twenty-three tumors' genomic mutations were investigated; PIK3CA had mutated in 5 of 6 T2 or more deeply invasive cancers, of which, 4 were located in the proximal colon. Two patients with dMMRs and BRAF mutations had poor prognoses. Sixty-one percent (17/28) of the macroscopic type 0 lesions were superficial. All superficial Tis and T1 PCCRCs were detected <24 months after the negative colonoscopies. They were distributed throughout the colon and rectum. DISCUSSION: PCCRCs may be invasive cancers in the proximal colon that exhibit dMMRs and/or PIK3CA mutations or missed early CRCs especially superficial lesions.

Clinical usefulness of the S-O clip during colorectal endoscopic submucosal dissection in difficult-to-access submucosal layer.

Background and study aims In colorectal endoscopic submucosal dissection (ESD), the S-O clip improves the accessibility to the submucosal layer of the colon. However, its safety and usefulness in difficult colorectal ESDs are unclear. Thus, in this study, we aimed to assess the effectiveness of the S-O clip in colorectal ESD in the difficult-to-access submucosal layer. Patients and methods From January 2016 to December 2016, 189 consecutive cases of colorectal ESD were performed at Hiroshima University Hospital before the S-O clip was introduced. Between January 2017 and June 2018, among 271 consecutive colorectal ESD cases, 41 cases were performed colorectal ESD using the S-O clip. We compared outcomes between the two groups (41 cases with S-O clip [use group] and 189 cases without S-O clip [non-use group]) using propensity score matching. Results Prior to propensity score matching, 41 cases with the S-O clip (use group) and 189 cases without the S-O clip (non-use group) were extracted. The degree of submucosal fibrosis was more severe and the procedure time was longer in the use group than in the non-use group. In the use and non-use groups, en bloc resection (100 % vs. 94.7 %) and complete en bloc resection (100 % vs. 92.6 %) rates were satisfactory. After propensity score matching, 33 cases in each group were extracted. As a result, complete en bloc resection rate was significantly higher in the use group than in the non-use group (100 % vs. 84.9 %). Conclusion The S-O clip is effective and can be used safely in colorectal ESD in the difficult-to-access submucosal layer.

Can surveillance colonoscopy be discontinued in an elderly population with diminutive polyps?

OBJECTIVES: Surveillance colonoscopy after endoscopic resection (ER) for adenomatous polyps reduces the incidence and mortality of colorectal cancer (CRC). However, its significance in the elderly population is uncertain. The study aimed to determine whether surveillance colonoscopy should be discontinued in the elderly population. METHODS: We enrolled 105 patients who underwent baseline colonoscopy between January 2004 and December 2009 and were subsequently followed-up over 5 years in our institution. All had diminutive colorectal polyps and were aged <80 years at baseline colonoscopy and ≥80 years at follow-up in May 2018. Patients who had undergone colectomy or who had inflammatory bowel disease, familial adenomatous polyposis, Lynch syndrome, and no diminutive polyps were excluded. The cumulative incidence of the target lesion was evaluated. Histopathological diagnoses included low-grade dysplasia (LGD), high-grade dysplasia (HGD), and carcinoma. RESULTS: The target lesion was detected in 15% (16/105) of the patients. There was no invasive carcinoma; however, two HGDs were detected. There were three lesions that had increased from previously detected diminutive lesions, all of which were LGDs. There were no target lesions detected after 84 years of age, and the cumulative incidence was 0.20. The cumulative incidence was significantly higher in the group with HGD than in the group with no target lesions at baseline colonoscopy. There was no HGD after age 79 years, and the cumulative incidence was 0.019. CONCLUSION: Surveillance colonoscopy for patients with diminutive polyps may be discontinued after age 79 years.

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

Background and study aims 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. Methods Three hundred and forty-eight consecutive colorectal lesions resected via ESD between June 2014 and January 2017 at Hiroshima University Hospital were included in the retroflexion ability analysis. We compared the retroflexion potential of PCF-H290TI to that of a conventional endoscope. Two hundred and twenty-seven colorectal lesions located in the left-sided colon and resected with ESD between April 2009 and February 2018 were enrolled in the treatment outcome analysis. Treatment outcomes using PCF-H290TI compared to those of the conventional colonoscope, and outcomes of the PCF-H290TI with retroflexion compared to those of the conventional colonoscope without retroflexion were evaluated by propensity score matching. Results The retroflexion rate with the PCF-H290TI was 76 %, which was significantly higher than the 44 % rate with the conventional scope. Endoscope operability was better and dissection speed was faster when using the PCF-H290TI with retroflexion compared to the conventional colonoscope without retroflexion. There were no significant differences between the groups in en bloc resection rate and adverse events. Conclusion Compared to the conventional colonoscope, the PCF-H290TI/L made it easier to perform ESD via a retrograde approach regardless of tumor location, and thus may be useful for performing 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. 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.

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.

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. Combined hybrid-F-fluorodeoxyglucose positron emission-computerized tomography showed increased radionuclide uptake in multiple cervical LNs and mediastinal LNs. LN biopsy revealed a poorly differentiated adenocarcinoma, suspected to be a metastatic tumor of the lung. Subsequent colonoscopy revealed a pedunculated-type lesion with a depressed area in the ascending colon. We performed polypectomy as total excisional biopsy; this tumor was composed mainly of moderately differentiated adenocarcinoma, partially mixed with mucinous adenocarcinoma. The pathological findings of the invasive front of the colorectal carcinoma showed poorly differentiated adenocarcinoma with a morphological pattern similar to that of the previous lung carcinoma. Furthermore, immunohistochemical results for the histological type of the deepest invasive portion of the tissue specimen were positive for thyroid transcription factor-1 but negative for Caudal-type homeobox 2. From these morphological and immunohistochemical findings, the final diagnosis was moderately differentiated lung carcinoma, pTX N3 M1b (LN, colon) Stage IV.

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.