Search

Background: The fatty acid profile of the fecal metabolome and its association with colorectal cancer (CRC) has not been fully evaluated.Aims: We aimed to compare the fecal fatty acid profiles of CRC patients and healthy controls.Methods: We enrolled 26 newly diagnosed CRC patients and 28 healthy individuals between July 2014 and August 2014 from our institute. Long- and short-chain fatty acids were extracted from fecal samples and analyzed using gas chromatography-mass spectrometry.Results: Regarding fecal long-chain fatty acids, the levels of total ω-6 polyunsaturated fatty acids and, particularly, of linoleic acid (C18:2ω-6) were significantly higher in male CRC patients than in healthy men (2.750 ± 2.583 vs. 1.254 ± 0.966 µg/mg feces, P = 0.040; 2.670 ± 2.507 vs. 1.226 ± 0.940 µg/mg feces, P = 0.034, respectively). In addition, the levels of total monounsaturated fatty acid and, particularly, of oleic acid (C18:1ω-9) were significantly higher in male CRC patients than in healthy men (1.802 ± 1.331 vs. 0.977 ± 0.625 µg/mg feces, P = 0.027; 1.749 ± 1.320 vs. 0.932 ± 0.626 µg/mg feces, P = 0.011, respectively). However, those differences were not shown in female gender. The level of fecal short-chain fatty acids was not different between CRC patients and healthy controls.Conclusions: There were changes in the profiles of fecal fatty acid metabolomes in CRC patients compared to healthy controls, implying that fecal fatty acids could be used as a novel screening tool for CRC. [ABSTRACT FROM AUTHOR]

Background and Aims Angioectasias are the most common sources of bleeding in the small bowel. They can be treated using balloon-assisted enteroscopy (BAE). This study aimed to identify the rebleeding rate and associated factors after BAE in patients with small bowel angioectasia bleeding. Methods We retrospectively analyzed the records of patients with bleeding due to small bowel vascular lesion in a multicenter enteroscopy database including 1108 BAEs. Finally, in rebleeding analysis, we analyzed 66 patients with angioectasia on the basis of the Yano-Yamamoto classification. Patients who had undergone endotherapy (ET) were divided into ET ( n = 45) and non-ET ( n = 21) groups. Rebleeding was defined as evidence of bleeding at least 30 days after BAE. Results Fifty-three patients (80.4%) underwent only one-side enteroscopy. The most common ET was argon plasma coagulation (87.2%). During a mean follow-up duration of 24.5 months, ET and non-ET groups had rebleeding rates of 15.6% and 38.1% ( P = 0.059), respectively. Median rebleeding time of ET and non-ET groups was 32.5 and 62 months, respectively. Liver cirrhosis (LC), low platelet count (< 105/μL), and transfusions were the rebleeding-associated factors in the univariate analysis. In the multivariate analysis, the presence of LC (HR 4.064, 95% CI 1.098-15.045; P = 0.036) was the only independent rebleeding-associated risk factor. Conclusions ET using BAE did not significantly affect the rebleeding rate in patients with small bowel angioectasia bleeding. An independent rebleeding risk factor was the presence of LC. Regardless of ET, careful long-term follow-up may be needed, especially in LC patients with small bowel angioectasia bleeding. [ABSTRACT FROM AUTHOR]

In recent years, the incidence of colorectal cancer (CRC) has been increasing, and CRC has been becoming the major cause of cancer deaths in Asian countries. Therefore, an organized screening program to reduce CRC incidence and mortality is currently implemented in each country. In the present review, we summarize the current status and future perspectives of CRC screening of the general population in East Asian and South-East Asian countries. The fecal occult blood test is widely used for CRC screening in these countries, and its effectiveness in reducing CRC incidence and mortality has been demonstrated; however, the low participation rate in CRC screening programs is a problem to be solved in every country. Improvement in the public awareness of CRC and promotion of CRC screening by physicians will help to raise the participation rate and reduce the number of deaths caused by CRC. Regarding screening colonoscopy, several studies have recently demonstrated its effectiveness in reducing CRC incidence and mortality. However, at present, CRC screening colonoscopy is not adopted as a primary population-based screening tool because of staffing constraints in relation to large population sizes, increased medical costs, and potential adverse events (e.g. perforation and drug-induced anaphylaxis). Further study is required to consider colonoscopy as CRC screening that is established in Western countries. [ABSTRACT FROM AUTHOR]

Background and Aim Performance of double balloon enteroscopy ( DBE) on older patients with comorbidities is a matter of safety. We aimed to investigate the utility and safety of DBE in older patients. Methods We retrospectively reviewed the medical records of patients 75 years or older who underwent DBE in our open-access endoscopy unit in a tertiary center. We analyzed the diagnostic yield, therapeutic intervention, and safety including complications of DBE. Results Four scheduled DBEs were canceled because of poor conditions. Two hundred and fourteen DBEs were performed in 167 elderly patients. All DBEs were performed under monitored anesthesia care using intravenous propofol administered by anesthesiologists. One half of the patients were male (female : male = 80:87). The mean age of patients was 80.1 ± 3.7 years. Co-morbidity of significant chronic diseases was noted in 208 (97.2%) DBEs. Fifty-one (23.8%) DBEs were performed in patients with American Society of Anesthesiologists ( ASA) physical status II, 151 (70.6%) DBEs with ASA class III, and 12 (5.6%) DBEs with ASA class IV. The most common indication was obscure gastrointestinal bleeding. The mean DBE procedure time was 131 ± 51 min. Abnormalities were detected in 129 (60.3%) DBEs with therapeutic interventions performed in 83 (38.8%) cases. Pancreatitis, hypoxia, and aspiration pneumonia developed after three (1.4%), three (1.4%), and two (0.9%) DBEs, respectively, all of which resolved with conservative care. Conclusions Double balloon enteroscopy can be done with acceptable safety in the elderly with high ASA class. DBE shows a high diagnostic yield and can deliver many therapeutic applications. [ABSTRACT FROM AUTHOR]

Objective. Few studies have assessed the diagnostic efficacy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and/or trucut biopsy (TCB) in patients with rectal and perirectal lesions. We aimed to evaluate the diagnostic utility of EUS-FNA and/or TCB in patients with rectal and perirectal lesions. We also assessed their influence on the management and clinical course of these patients. Material and methods. We performed EUS-FNA and/or TCB in 11 consecutive patients (4 men and 7 women, 33-69 years) with rectal and perirectal lesions for whom conventional diagnostic tools could not provide definitive diagnoses. Patients with definite intraluminal cancer were excluded. Results. The 11 patients underwent 12 procedures, with 9 being EUS-FNA alone and 3 being EUS-FNA and TCB. Seven patients had rectal lesions and four had perirectal lesions. Initial EUS-FNA and/or TCB established a diagnosis of malignancy in five patients and of benign lesions in four. EUS-FNA plus TCB confirmed malignant lymphoma after diagnostic failure of initial EUS-FNA in one patient. In one other patient with suspicious secondary linitis plastica, EUS-FNA could not establish a definitive diagnosis. Correct diagnoses were obtained in 10 out of 11 patients who underwent EUS-FNA and/or TCB. EUS-FNA and/or TCB changed clinical courses, which included avoidance of unnecessary surgeries, having a chance of anal sphincter-saving surgeries, and timely administration of chemotherapy. No serious complications related to the use of EUS-FNA or TCB were evident. Conclusion. EUS-FNA and/or TCB are useful in the diagnostic evaluation of and appropriate therapeutic plan in patients with rectal and perirectal lesions. [ABSTRACT FROM AUTHOR]

Background and Aim: Obesity as a risk factor for colorectal neoplasm (CRN) is controversial. In the present study, we evaluated visceral obesity as a risk factor for CRN. Methods: We prospectively enrolled 200 consecutive, asymptomatic adults (male : female = 133:67, mean age, 50.9 ± 8.5 years) undergoing both colonoscopy and abdominopelvic computed tomography (CT) scan for routine health evaluations. The presence or absence and the characteristics of CRN were determined during colonoscopy. The amount of visceral adipose tissue (VAT) and subcutaneous adipose tissue was measured by an abdominopelvic CT scan. Body mass index, waist circumference, and percentage of body fat were measured. Blood pressure and other blood markers for assessing the metabolic syndrome were also investigated. Results: Of the 200 patients, 53 (26.5%) had CRN. Old age, smoking, metabolic syndrome, and a high fasting plasma glucose level were associated with an increased risk of CRN. VAT ( P < 0.01) and waist circumference ( P = 0.01) were significantly higher in those with CRN. A multivariate analysis of the risks of CRN showed an odds ratio of 4.07 (95% confidence interval: 1.01–16.43, P = 0.03) for those with VAT over 136.61 cm2 relative to those with VAT under 67.23 cm2. Waist circumference, metabolic syndrome, and fasting plasma glucose levels were not independent risk factors for CRN in the multivariate analysis. Conclusion: Increased VAT is an independent risk factor for CRN. Further large scale studies are needed to clarify the causal relationship between VAT and CRN. [ABSTRACT FROM AUTHOR]

Vascular endothelial growth factor-C (VEGF-C) is a specific growth factor of lymphatics, which is known to play some role in tumor growth and metastasis to lymph nodes and distant organs in various malignancies.The purpose of the present study was to investigate the expression of VEGF-C in human esophageal squamous cell carcinomas (ESCC) to elucidate its role in tumor progression and lymph node metastasis. Another aim of the study was to investigate the relation between VEGF-C and cyclooxygenase-2 (COX-2) in ESCC. The degree of VEGF-C expression increased as the depth of primary tumor progressed (r = 0.521, P = 0.002), the stage progressed (r = 0.572, P < 0.001), and the degree of COX-2 expression increased (r = 0.387, P = 0.024).TheVEGF-C positive rate was different between early cancers in which regional lymph node metastasis was thought to be absent and advanced cancers in which regional lymph node metastases were confirmed after surgery (20.0% vs 100.0%; P < 0.001). The VEGF-C expression in ESCC is related to COX-2 expression, and VEGF-C is also associated with the depth of primary tumor, the stage, and probably lymph node metastasis. Thus the investigation of VEGF-C expression in ESCC may assist in management planning. © 2004 Blackwell Publishing Asia Pty Ltd [ABSTRACT FROM AUTHOR]

Objectives Methods Results Conclusions There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices.Two experts in interventional endoscopy spearheaded an evidence‐based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three‐round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5‐point Likert scale.Forty‐two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision‐making; seven statements on postresection evaluation; and eight statements on postresection care.An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow‐up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices. [ABSTRACT FROM AUTHOR]

Summary Background Aims Methods Results Conclusions The impact of continuing or stopping 5‐aminosalicylates (5‐ASA) after commencing anti‐tumour necrosis factor (anti‐TNF) therapy in patients with inflammatory bowel disease (IBD) remains unclear.To compare the outcomes of patients with IBD who stopped or continued 5‐ASA after starting anti‐TNF therapy.We analysed data from the Korean National Health Insurance claims database between 2007 and 2020. We compared the clinical outcomes of patients who stopped or continued 5‐ASA within 90 days of anti‐TNF initiation. The primary outcome was any adverse clinical event defined as a composite of new corticosteroid use, IBD‐related hospitalisation, or intestinal surgery.Among 7442 patients included for analysis (4479 [60.2%] with Crohn's disease [CD] and 2963 [39.8%] with ulcerative colitis [UC]), 1037 (13.9%) discontinued 5‐ASA within 90 days of starting anti‐TNF therapy. During a median 4.3‐year follow‐up, discontinuation of 5‐ASA was not associated with an increased risk of adverse clinical events (adjusted hazard ratio 1.01, 95% confidence interval 0.93–1.10). The cumulative incidence of each adverse clinical event and the composite outcome were not significantly different between groups (all, p > 0.05). Additionally, separate analyses in CD and UC cohorts revealed no differences in adverse clinical outcomes between the 5‐ASA continuation and discontinuation groups. Subgroup analyses by presumed risk factors for disease relapse showed no significant differences in the risk of adverse events between groups.In this nationwide population‐based study, discontinuing 5‐ASA after starting anti‐TNF therapy was not associated with an increased risk of adverse events in patients with IBD. [ABSTRACT FROM AUTHOR]

Background and Aim Methods Results Conclusions Reliable bowel preparation assessment is important in colonoscopy. However, current scoring systems are limited by laborious and time‐consuming tasks and interobserver variability. We aimed to develop an artificial intelligence (AI) model to assess bowel cleanliness and evaluate its clinical applicability.A still image‐driven AI model to assess the Boston Bowel Preparation Scale (BBPS) was developed and validated using 2361 colonoscopy images. For evaluating real‐world applicability, the model was validated using 113 10‐s colonoscopy video clips and 30 full colonoscopy videos to identify “adequate (BBPS 2–3)” or “inadequate (BBPS 0–1)” preparation. The model was tested with an external dataset of 29 colonoscopy videos. The clinical applicability of the model was evaluated using 225 consecutive colonoscopies. Inter‐rater variability was analyzed between the AI model and endoscopists.The AI model achieved an accuracy of 94.0% and an area under the receiver operating characteristic curve of 0.939 with the still images. Model testing with an external dataset showed an accuracy of 95.3%, an area under the receiver operating characteristic curve of 0.976, and a sensitivity of 100% for the detection of inadequate preparations. The clinical applicability study showed an overall agreement rate of 85.3% between endoscopists and the AI model, with Fleiss' kappa of 0.686. The agreement rate was lower for the right colon compared with the transverse and left colon, with Fleiss' kappa of 0.563, 0.575, and 0.789, respectively.The AI model demonstrated accurate bowel preparation assessment and substantial agreement with endoscopists. Further refinement of the AI model is warranted for effective monitoring of qualified colonoscopy in large‐scale screening programs. [ABSTRACT FROM AUTHOR]

Fecal calprotectin (FC) is commonly used to assess Crohn's disease (CD) activity. However, standardized cut-off values accounting for bowel resection history and disease location are lacking. In this study, we analyzed data from patients with CD who underwent magnetic resonance enterography, ileocolonoscopy, and FC measurements from January 2017 to December 2018. In 267 cases from 254 patients, the FC levels in the 'operated' patients were higher when the disease was active compared with those who were in the remission group (178 vs. 54.7 μg/g; p < 0.001), and similar findings were obtained for the 'non-operated' patients (449.5 vs. 40.95 μg/g; p < 0.001). The FC levels differed significantly according to the location of inflammation, with lower levels in the small bowel compared to those in the colon. The FC cut-off levels of 70.8 μg/g and 142.0 μg/g were considered optimal for predicting active disease for operated and non-operated patients, respectively. The corresponding FC cut-off levels of 70.8 μg/g and 65.0 μg/g were observed for patients with disease only in the small bowel. In conclusion, different FC cut-off values would be applicable to patients with CD based on their bowel resection history and disease location. Tight control with a lower FC target may benefit those with a history of bowel resection or small-bowel-only disease. [ABSTRACT FROM AUTHOR]

Background and Aim: Although obesity is a known risk factor for colorectal neoplasms, the correlation between weight change and colorectal neoplasm is unclear. Thus, we aim to evaluate the association between weight change and advanced colorectal neoplasm (ACRN) recurrence during post‐polypectomy surveillance colonoscopy. Methods: This retrospective cohort study included 7473 participants diagnosed with colorectal neoplasms between 2003 and 2010 who subsequently underwent surveillance colonoscopies until 2020. We analyzed the association between the risk of metachronous ACRN and weight change, defining stable weight as a weight change of <3% and weight gain as a weight increase of ≥3% from baseline during the follow‐up period. Results: During a median 8.5 years of follow‐up, 619 participants (8.3%) developed ACRN. Weight gain was reported as an independent risk factor for metachronous ACRN in a time‐dependent Cox analysis. A weight gain of 3–6% and ≥6% had adjusted hazard ratios (AHRs) of 1.48 (95% confidence interval [CI]: 1.19–1.84) and 2.14 (95% CI: 1.71–2.69), respectively. Participants aged 30–49 and 50–75 years with weight gain of ≥6% showed AHRs of 2.88 (95% CI: 1.96–4.21) and 1.90 (95% CI: 1.43–2.51), respectively. In men and women, weight gain of ≥3% was significantly correlated with metachronous ACRN. Conclusions: Weight gain is associated with an increased risk of metachronous ACRN. Furthermore, weight gain is associated with the recurrence of ACRN in both men and women regardless of age. [ABSTRACT FROM AUTHOR]

Background and Aim: Low‐volume bowel preparation solutions, including 1‐L polyethylene glycol plus ascorbate (PEG‐A), have been developed to improve tolerability. The oral sodium sulfate tablet (OST) is a new agent with simethicone as a preloaded component. We investigated the efficacy, safety, and tolerability of OST compared to 1‐L PEG‐A. Methods: A single‐center, prospective, controlled study was performed with randomization into the OST (group A) and 1‐L PEG‐A (group B) groups. Bowel preparation efficacy was assessed on the Boston Bowel Preparation Scale (BBPS) and Bubble Scale. Safety and tolerability were evaluated using a questionnaire and laboratory examination. Results: Final analysis was performed on 171 patients (group A: 87, group B: 84). The proportion of bowel preparation success (BBPS ≥ 2 for each colonic segment) in group A was not inferior compared to group B (95.4% vs 96.4%, P = 0.736, 1‐sided 97.5% lower confidence limit −7.0%). The adenoma detection rate was not different (59.6% vs 41.9%; P = 0.087). The bubble scale was better in group A (0.2 ± 0.9 vs 1.9 ± 1.7, P < 0.001). All adverse events were mild in both groups. Nausea was less frequent in group A (14.9% vs 38.1%, P = 0.001). Overall satisfaction was better in group A (8.1 ± 2.1 vs 6.4 ± 2.8, P < 0.001). No clinically significant laboratory abnormality developed in both groups. These findings were similarly shown in old patients ≥65 years. Conclusions: Both OST and 1‐L PEG‐A were efficacious, safe, and tolerable for bowel preparation of colonoscopy. The OST showed fewer bubbles and slightly better tolerability. [ABSTRACT FROM AUTHOR]

Background and Aim: This study aimed to investigate the effect of stenting‐related factors, including endoscopists' expertise, on clinical outcomes after bridge‐to‐surgery (BTS) stenting for obstructive colorectal cancer (CRC). Methods: We analyzed BTS stenting‐related factors, including stenting expertise and the interval between stenting and surgery, in 233 patients (63 [13] years, 137 male) who underwent BTS stenting for obstructive CRC. We evaluated the influence of these factors on post‐BTS stenting clinical outcomes such as stent‐related complications and cancer recurrence. Results: The interval between stenting and surgery was ≤ 7 days in 79 patients (33.9%) and > 7 days in 154 patients (66.1%). BTS stenting was performed by endoscopists with ≤ 50, 51–100, and > 100 prior stenting experiences in 94, 43, and, 96 patients, respectively. The clinical success rate of BTS stenting was 93.1%. Stent‐related and postoperative complications developed in 19 (8.2%) and 20 (8.6%) patients, respectively. Cancer recurrence occurred in 76 patients (32.6%). Short BTS interval of ≤ 7 days increased the risk of postoperative complications (odds ratio [OR], 2.61 [1.03–6.75]; P = 0.043). Endoscopists' stenting experience > 100 showed greater clinical success of stenting (OR, 5.50 [1.45–28.39]; P = 0.021) and fewer stent‐related complications (OR, 0.26 [0.07–0.80]; P = 0.028) compared with stenting experience ≤ 50. BTS stenting‐related factors did not affect long‐term oncological outcomes. Conclusion: Greater expertise of endoscopists was associated with better short‐term outcomes, including high stenting success rate and low rate of stent‐related complications after BTS stenting for obstructive CRC. An interval of > 7 days between BTS stenting and surgery was required to decrease postoperative complications. [ABSTRACT FROM AUTHOR]

Background: In this prospective cohort study, we evaluated features of "adult‐onset megacolon with focal hypoganglionosis." Methods: We assessed the radiologic, endoscopic, and histopathologic phenotyping and treatment outcomes of 29 patients between 2017 and 2020. Data from community controls, consisting of 19,948 adults undergoing health screenings, were analyzed to identify risk factors. Experts reviewed clinical features and pathological specimens according to the London Classification for gastrointestinal neuromuscular pathology. Key results: The median age of the patients with adult‐onset megacolon with focal hypoganglionosis at symptom onset was 59 years (range, 32.0–74.9 years), with mean symptom onset only 1 year before diagnosis. All patients had focal stenotic regions with proximal bowel dilatation (mean diameter, 78.8 mm; 95% confidence interval [CI], 72–86). The comparison with community controls showed no obvious risk factors. Ten patients underwent surgery, and all exhibited significant hypoganglionosis: 5.4 myenteric ganglion cells/cm (interquartile range [IQR], 3.7–16.4) in the stenotic regions compared to 278 cells/cm (IQR, 190–338) in the proximal and 95 cells/cm (IQR, 45–213) in the distal colon. Hypoganglionosis was associated with CD3+ T cells along the myenteric plexus. Colectomy was associated with significant symptom improvement compared to medical treatment [change in the Global Bowel Satisfaction score, −5.4 points (surgery) vs. ‐0.3 points (medical treatment); p < 0.001]. Conclusions and inferences: Adult‐onset megacolon with focal hypoganglionosis has distinct features characterized by hypoganglionosis due to inflammation. Bowel resection appears to benefit these patients. [ABSTRACT FROM AUTHOR]

Background: Endoscopic submucosal dissection (ESD) with snaring (hybrid ESD) bridges the gap between ESD and endoscopic mucosal resection. We evaluated factors predictive of en bloc and complete resection of large colorectal neoplasms using hybrid ESD.Methods: This was a prospective clinical study of 78 patients who underwent hybrid ESD for excision of colorectal neoplasms (≥ 2 cm) between May 2015 and September 2016 at six university hospitals. We evaluated lesion and patient characteristics, endoscopist experience level (< 50 or ≥ 50 cases with colorectal ESD), and technical factors such as concurrent fibrosis, completion of a circumferential incision, degree of submucosal dissection (< 50 or ≥ 50%), and visualization during snaring (< 50 or ≥ 50%).Results: Multivariate analyses showed that the en bloc resection rate was significantly related to the degree of visualization during snaring (odds ratio (OR) 7.811, 95% confidence interval [CI] 1.722-35.426; p = 0.008) and the presence of fibrosis (OR 0.258, 95% CI 0.68-0.993; p = 0.049). The complete resection rate was significantly related to the colorectal ESD endoscopist skill level (OR 5.626, 95% CI 1.485-21.313; p = 0.011) and gross lesion type (OR 0.145, 95% CI 0.022-0.936; p = 0.042). When all three technical factors, i.e., completion of circumferential incision, ≥ 50% submucosal dissection, and ≥ 50% visualization during snaring, were satisfied performing hybrid ESD, the en bloc resection rate (87.5%) was similar to that of ESD.Conclusions: Visualization during snaring, presence of fibrosis, gross lesion type, and endoscopist colorectal ESD experience level affect en bloc or complete resection of large colorectal neoplasia using hybrid ESD. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG) has been used in clinical practice for more than 40 years and its safety and preferential accumulation in tumors has been reported for various tumor types, including colon cancer. However, reports on clinical assessments of ICG-based molecular endoscopy imaging for precancerous lesions are scarce. We determined visualization ability of ICG fluorescence endoscopy in colitis-associated colon cancer using 30 lesions from an azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model and 16 colon cancer patient tissue-samples. With a total of 60 images (optical, fluorescence) obtained during endoscopy observation of mouse colon cancer, we used deep learning network to predict four classes (Normal, Dysplasia, Adenoma, and Carcinoma) of colorectal cancer development. ICG could detect 100% of carcinoma, 90% of adenoma, and 57% of dysplasia, with little background signal at 30 min after injection via real-time fluorescence endoscopy. Correlation analysis with immunohistochemistry revealed a positive correlation of ICG with inducible nitric oxide synthase (iNOS; r > 0.5). Increased expression of iNOS resulted in increased levels of cellular nitric oxide in cancer cells compared to that in normal cells, which was related to the inhibition of drug efflux via the ABCB1 transporter down-regulation resulting in delayed retention of intracellular ICG. With artificial intelligence training, the accuracy of image classification into four classes using data sets, such as fluorescence, optical, and fluorescence/optical images was assessed. Fluorescence images obtained the highest accuracy (AUC of 0.8125) than optical and fluorescence/optical images (AUC of 0.75 and 0.6667, respectively). These findings highlight the clinical feasibility of ICG as a detector of precancerous lesions in real-time fluorescence endoscopy with artificial intelligence training and suggest that the mechanism of ICG retention in cancer cells is related to intracellular nitric oxide concentration. [ABSTRACT FROM AUTHOR]

The clinical usefulness of repeat colonoscopic polypectomy in patients with numerous polyps has not been sufficiently determined. We aimed to analyze the clinical outcomes of colonoscopic polypectomy with surveillance colonoscopies in patients with ≥ 10 polyps. We reviewed the medical records of 152 patients who underwent polypectomy of ≥ 10 polyps at the baseline colonoscopy. We investigated polyp number, polyp size, polypectomy method, procedure time, and adverse events of the baseline colonoscopy. We also investigated the frequency and interval of surveillance colonoscopies and their findings. The mean number of polyps detected at the baseline colonoscopy was 20.0, of which 16.0 polyps were endoscopically resected. The mean size of the largest polyp was 13.4 mm. The mean procedure time was 54.9 min. Post-polypectomy bleeding occurred in 6 (3.9%) patients, all of whom were treated conservatively. No patients developed perforation. With an increasing number of surveillance colonoscopies, the number of detected polyps and the procedure time decreased. Surveillance colonoscopies identified colorectal cancer only in three patients (2.0%), all of which were mucosal cancers that could be curatively treated by polypectomy. Colonoscopic polypectomy with repeat surveillance colonoscopies is a clinically effective, efficient, and safe management option in patients with ≥ 10 polyps. [ABSTRACT FROM AUTHOR]

A correction to the article "Is Endoscopic Closure With Clips Effective for Both Diagnostic and Therapeutic Colonoscopy-Associated Bowel Perforation?" that was published in the April 17, 2010 issue is presented.

Objectives: Three subcategories of high‐risk flat and depressed lesions (FDLs), laterally spreading tumors non‐granular type (LST‐NG), depressed lesions, and large sessile serrated lesions (SSLs), are highly attributable to post‐colonoscopy colorectal cancer (CRC). Efficient and organized educational programs on detecting high‐risk FDLs are lacking. We aimed to explore whether a web‐based educational intervention with training on FIND clues (fold deformation, intensive stool/mucus attachment, no vessel visibility, and demarcated reddish area) may improve the ability to detect high‐risk FDLs. Methods: This was an international web‐based randomized control trial that enrolled non‐expert endoscopists in 13 Asian countries. The participants were randomized into either education or non‐education group. All participants took the pre‐test and post‐test to read 60 endoscopic images (40 high‐risk FDLs, five polypoid, 15 no lesions) and answered whether there was a lesion. Only the education group received a self‐education program (video and training questions and answers) between the tests. The primary outcome was a detection rate of high‐risk FDLs. Results: In total, 284 participants were randomized. After excluding non‐responders, the final data analyses were based on 139 participants in the education group and 130 in the non‐education group. The detection rate of high‐risk FDLs in the education group significantly improved by 14.7% (66.6–81.3%) compared with −0.8% (70.8–70.0%) in the non‐education group. Similarly, the detection rate of LST‐NG, depressed lesions, and large SSLs significantly increased only in the education group by 12.7%, 12.0%, and 21.6%, respectively. Conclusion: Short self‐education focusing on detecting high‐risk FDLs was effective for Asian non‐expert endoscopists. (UMIN000042348). [ABSTRACT FROM AUTHOR]

The original version of the article unfortunately contained errors in author affiliation. Affiliation of third and ninth author was incorrectly assigned. [ABSTRACT FROM AUTHOR]

Objectives: Post‐polypectomy surveillance intervals should be determined based on index colonoscopy findings. However, the risk of metachronous lesions, resulting from the coexistence of adenoma and sessile serrated lesions (SSLs), has rarely been addressed. We evaluated the impact of synchronous SSL on the risk of metachronous lesions within similar adenoma risk groups. Methods: We retrieved individuals with one or more adenomas on index colonoscopy in a single‐center retrospective cohort and stratified them into four groups depending on the presence of SSL and low‐risk/high‐risk adenoma (LRA/HRA). Participants who underwent surveillance colonoscopies at least 12 months apart were included. We compared the risks of metachronous lesions including HRA, advanced adenoma (AA), or SSL within similar adenoma risk groups according to the presence of SSL. Results: Overall 4493 individuals were included in the analysis. The risk of metachronous HRA/AA was not significantly higher in the adenoma with SSL group compared with the adenoma without SSL group, irrespective of LRA (HRA, 6/86 vs. 231/3297, P = 1.00; AA, 0/86 vs. 52/3297, P = 0.64) or HRA (HRA, 11/64 vs. 240/1046, P = 0.36; AA, 3/64 vs. 51/1046, P = 1.00). However, the risk of metachronous SSL in individuals with synchronous SSL was higher than that in those without SSL for both LRA (15/86 vs. 161/3297, P < 0.001) and HRA groups (11/64 vs. 61/1046, P = 0.002). Conclusion: The presence of synchronous SSL did not increase the risk of metachronous HRA/AA, compared with isolated adenoma, but increased the risk of metachronous SSL. [ABSTRACT FROM AUTHOR]

INTRODUCTION: This systematic review and meta-analysis evaluated the available evidence on the risk of metachronous advanced neoplasia (AN) and colorectal cancer (CRC) in patients with 3-4 nonadvanced adenomas (NAAs). METHODS: We searched MEDLINE, EMBASE, and Cochrane Library databases up to January 2021 for studies evaluating metachronous AN and CRC risk by comparing 3 groups (1-2 vs 3-4 vs >=5 NAAs) at index colonoscopy. The estimates for risk of metachronous AN and CRC were evaluated using random-effects models. RESULTS: Fifteen studies (n = 36,375) were included. The risk of metachronous AN was significantly higher in the 3-4 NAAs group than in the 1-2 NAAs group (relative risk [RR] 1.264, 95% confidence interval [CI] 1.053-1.518, P = 0.012; I2 = 0%); there was no difference between the >= 5 NAAs and 3-4 NAAs groups (RR 1.962, 95% CI 0.972-3.958, P = 0.060; I2 = 68%). The risks of metachronous CRC between the 1-2 NAAs and 3-4 NAAs groups (RR 2.663, 95% CI 0.391-18.128, P = 0.317; I2 = 0%) or the 3-4 NAAs and >= 5 NAAs groups (RR 1.148, 95% CI 0.142-9.290, P = 0.897; I2 = 0%) were not significantly different. DISCUSSION: Although the risk of metachronous AN was greater in the 3-4 NAAs group than in the 1-2 NAAs group, the risk of metachronous AN and CRC between the 3-4 NAAs and >= 5 NAAs groups was not different. This suggests that further studies on metachronous AN and CRC risk in the 3-4 NAAs group are warranted to confirm a firm >=5-year interval surveillance colonoscopy. [ABSTRACT FROM AUTHOR]

Background: Owing to an increased number of colonoscopy screenings, the incidence of diagnosed rectal neuroendocrine tumors (NETs) has also increased. Tumor size is one of the most frequently regarded factors when selecting treatment; however, it may not be the determinant prognostic variable. We aimed to evaluate oncological outcomes according to the treatment modality based on the size of rectal NETs. Methods: A retrospective analysis was performed on patients who were treated for rectal NETs between March 2000 and January 2016 at the Asan Medical Center, Seoul, Korea. Patients who underwent endoscopic removal, local surgical excision, and radical resection were included. The primary outcome was recurrence-free survival (RFS). Data were specified and analyzed following the 2019 World Health Organization classification (WHO). Results: A total of 644 patients were categorized under three groups according to the treatment modality used: endoscopic removal (n = 567), surgical local excision (n = 56), and radical resection (n = 21). Of a total of 35 recurrences, 27 were local, whereas eight were distant. The RFS rate did not differ significantly between the treatment groups in the same tumor-size group (≤ 1 cm group: P =.636, 1–2 cm group: P =.160). For T1 tumors, RFS rate was not different between local excision and radical resection (≤ 1 cm group: P =.452, 1–2 cm group: P =.700). Depth of invasion, a high Ki-67 index, and margin involvement were confirmed as independent risk factors for recurrence. Among patients treated with endoscopic removal, endoscopic biopsy was a significant factor for worse RFS (P <.001), while tumor size did not affect the RFS. Conclusion: The current guideline recommends treatment options according to tumor size. However, more oncologically important prognostic factors include muscularis propria invasion and a higher Ki-67 index. [ABSTRACT FROM AUTHOR]

Background and Aim: Evidence has emerged that a pretreatment immune profile in rectal cancer is associated with response to chemoradiotherapy (CRT) and recurrence after CRT. However, few studies have evaluated the immune profile differences after CRT regarding recurrence and nonrecurrence. Methods: We included patients with advanced rectal cancer treated with CRT and surgery with recurrence within 1 year in a recurrence group. After sex and age matching with the recurrence group, patients with no recurrence for 3 years after CRT were included in a nonrecurrence group. We extracted the immune profile, including CD3 and CD8, from the surgical specimen after CRT using multispectral fluorescence immunohistochemistry and compared the two groups. Results: The immune profiles of 65 patients with rectal cancer were assessed; 30 were included in the recurrence group and 35 were included in the nonrecurrence group. CD3+ and CD8+ T lymphocyte densities were significantly higher in the nonrecurrence group than in the recurrence group (CD3+; P < 0.001, CD8+; P = 0.003) in the primary tumor. Consistent results were found in epithelial and stromal cells. Compared with the recurrence group, the distinct profiles of co‐expressed immune markers in the nonrecurrence group were revealed (CD3+CD8+, P = 0.001; CD3+CD8+PD‐L1−, P = 0.001; CD3+CD8+ FOXP3− PD‐L1−, P = 0.001). Conclusions: Vigorous CD3+ and CD8+ T cell priming post‐CRT was prominent in the nonrecurrence group compared with that of the recurrence group. This finding suggests that differences in immune profiles may have clinical significance even after CRT. [ABSTRACT FROM AUTHOR]

Background: Chronic viral hepatitis is associated with a wide range of extrahepatic diseases; however, evidence on a link between chronic viral hepatitis and colorectal neoplasia is still lacking. Aims: To analyze the association between chronic viral hepatitis and prevalence of colorectal neoplasia. Methods: A systematic review of articles published in the MEDLINE, EMBASE, and Cochrane Library between 2000 and 2020 was performed. Subgroup analyses based on the types of colorectal neoplasia and the etiology of chronic viral hepatitis were conducted. Results: Twelve eligible studies with 48,428 hepatitis B virus (HBV) patients and 46,561 hepatitis C virus (HCV) patients were included. Chronic viral hepatitis was significantly associated with an increased risk of both colorectal adenoma (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.16–2.02; I2 = 83%) and colorectal cancer (CRC) (OR, 1.32; 95% CI, 1.08–1.61; I2 = 94%). The etiology of chronic viral hepatitis was an independent factor related to heterogeneity for CRC subgroup analysis revealed an increased risk of CRC in both HBV (OR, 1.18; 95% CI, 1.09–1.27; I2 = 37%) and HCV (OR, 1.88; 95% CI, 1.78–1.97; I2 = 0%). HCV was associated with an increased risk of colorectal adenoma (OR, 1.48; 95% CI, 1.22–1.79; I2 = 0%); however, HBV was not associated with an increased risk of colorectal adenoma and had considerable heterogeneity (OR, 1.65; 95% CI, 0.88–3.09; I2 = 90%). Conclusion: Our meta-analysis showed that chronic viral hepatitis is associated with an increased risk of colorectal neoplasia. The strategy of stricter screening colonoscopy may benefit from patients with chronic viral hepatitis. [ABSTRACT FROM AUTHOR]

Background: Anti-tumor necrosis factor (TNF) treatment for inflammatory bowel disease (IBD) increases the risk of tuberculosis (TB) infection. In the present study, we analyzed the clinical characteristics and risks of TB in Korean patients with IBD who received anti-TNF treatment.Methods: The study included patients with IBD who were treated using anti-TNF agents between January 2001 and June 2018 at the Asan Medical Center. Overall, 1434 patients with ulcerative colitis or Crohn's disease were enrolled. We calculated the incidence of active TB infection after anti-TNF treatment and compared the clinical characteristics of the TB group with those of the non-TB group.Results: Twenty-one patients (1.46%) developed active TB infection, and the incidence rate of active TB was 366.73 per 100,000 person-years. In total, 198 patients (14.9%) were positive for latent tuberculosis infection (LTBI), of whom only eight (4%) did not complete LTBI treatment. The age at which the anti-TNF therapy was started was significantly higher in the TB group than in the non-TB group (HR 1.041, 95% CI 1.014-1.069, p = 0.002), and as age increased, so did the incidence rate of active TB infection (linearity p < 0.001). There was no significant difference in the incidence rate of LTBI between the TB and non-TB groups (HR 0.896, 95% CI 0.262-3.066, p = 0.862).Conclusions: In patients with IBD, the incidence rate of TB increased with age at anti-TNF therapy initiation. Active treatment of LTBI may lower the incidence of TB in patients with IBD who are to undergo anti-TNF therapy. [ABSTRACT FROM AUTHOR]

Introduction: Immunomodulators remain fundamental for the medical treatment of Crohn's disease (CD). Methotrexate (MTX) is widely used as a second-line immunomodulator; however, there is a lack of recent data on MTX monotherapy among the Asian population with CD. Therefore, in this study, we aimed to investigate the tolerability and clinical outcomes of MTX in Korean patients with CD. Methods: A retrospective chart review was performed for CD patients treated with MTX monotherapy or in combination with 5-aminosalicylic acid (5-ASA), at the Asan Medical Center, Seoul, South Korea. The tolerability of MTX monotherapy within 6 months was assessed and the clinical effectiveness of MTX was evaluated based on the Crohn's disease activity index (CDAI). Results: In total, 85 patients were included, of which 29 (34.1%) discontinued MTX due to intolerability during the follow-up. Adverse events (AEs) were reported in 41 (48.2%) patients. The most common AE was gastrointestinal disorders (17/41) and only one patient experienced a serious AE, a systemic infection that required hospitalization. Among the 56 patients who tolerated MTX within 6 months, 44 (65.9%) showed a clinical response. Moreover, no factor was significantly associated with intolerability. The administration method was the only factor significantly associated with a response to MTX (p = 0.041). The adjusted odds ratio of parenteral injection compared to oral administration was 5.68 (95% confidence interval (CI), 1.07–30.08). Conclusion: In this study, one-third of patients were intolerant to MTX; nonetheless, the response rate was as high as 65.9% among tolerant patients. In addition, no significant factors affected intolerability. In terms of the clinical response, parenteral injection could be better than oral administration. [ABSTRACT FROM AUTHOR]

Background: The Rutgeerts score is used to predict postoperative recurrence in CD patients after ileocolic resection and is primarily based on endoscopic findings at the neoterminal ileum. However, the optimal assessment of anastomotic ulcers (AUs) remains subject to debate. Aims: We aimed to investigate the association between anastomotic ulcers (AUs) and endoscopic recurrence in postoperative Crohn's disease (CD) patients. Methods: This single-center retrospective study, conducted between 2000 and 2016, evaluated postoperative CD patients with endoscopic remission at the first ileocolonoscopy within 1 year after ileocolic resection and those who underwent subsequent ileocolonoscopic follow-up. The study outcome was the clinical significance of AUs in predicting endoscopic recurrence. Results: Among 116 patients who were in endoscopic remission defined as the RS of i0 to i1 at the index postoperative ileocolonoscopy, 84.5% (98/116) underwent subsequent ileocolonoscopies. During the median 30.0 months (interquartile range, 21.3–53.3) of follow-up after the first ileocolonoscopy, 56.1% (55/98) of patients showed endoscopic recurrence. Furthermore, 65.8% (48/73) with AUs and 75.5% (40/53) with major AUs, defined as either an ulcer occupying ≥ 1/4 of the circumference, ≥ 3 ulcers confined to anastomotic ring, or any ulcers extending to the ileocolonic mucosa, showed endoscopic recurrence. On multivariable analysis, AUs (adjusted hazard ratio [aHR], 4.33; 95% confidence interval [CI], 1.87–10.0; P < 0.001) and major AUs (aHR, 3.64; 95% CI, 1.95–79; P < 0.001) were associated with endoscopic recurrence. Conclusions: AUs are associated with a significantly high risk of endoscopic recurrence in postoperative CD patients who are in endoscopic remission. [ABSTRACT FROM AUTHOR]

Background and Aim: Data comparing the outcomes of cyclosporin A (CsA) and infliximab (IFX) as rescue therapy for steroid‐refractory acute severe ulcerative colitis (SR‐ASUC) among Asians are scarce. Methods: In this single‐center study, we retrospectively reviewed 121 patients with SR‐ASUC according to the Truelove and Witts' criteria who received CsA or IFX as rescue therapy between 1995 and 2015. The cumulative rates of treatment failure and colectomy at 3 months were compared. Treatment failure was defined as colectomy, switch to other medications, acute flare‐up events requiring steroid treatment, or adverse events leading to drug interruption. Results: Among 121 patients with SR‐ASUC (male, 55.6%; median disease duration, 47.1 months; extensive colitis, 61.2%), 23 received CsA as rescue therapy. Baseline characteristics (e.g. age at diagnosis, sex, disease duration, disease extent at rescue therapy, and Mayo score at treatment initiation) were comparable between the two groups. During follow‐up (median, 45 months; interquartile range 29.3–61.8), 84 patients (69.4%) experienced treatment failure, and 25 patients (20.7%) underwent colectomy. The CsA group and the IFX group did not show significant differences in the cumulative rates of treatment failure (39.1% vs 34.7%, P = 0.714) and colectomy (26.1% vs 13.3%, P = 0.198) at 3 months. Previous use of azathioprine (odds ratio [OR] = 2.309, 95% confidence interval [CI] = 1.076–4.951, P = 0.032) was associated with treatment failure at 3 months. Mayo score > 10 at the time of rescue therapy was significantly associated with colectomy at 3 months (OR = 8.444, 95% CI = 2.592–27.506, P < 0.001). Conclusion: Among Korean patients with SR‐ASUC, the rates of treatment failure and colectomy at 3 months were not significantly different between the CSA and the IFX treatment groups. [ABSTRACT FROM AUTHOR]

Background and Aim: Acute severe lower gastrointestinal bleeding (LGIB) in patients with Crohn's disease (CD) is uncommon; however, it is a potentially life‐threatening complication, and its recurrence is common. We thus aimed to identify the predictors for rebleeding in CD patients with acute severe LGIB and particularly focused on whether anti‐tumor necrosis factor (TNF) therapy lowers the risk of rebleeding compared with conventional medical therapy (CMT) or surgery. Methods: The risk of rebleeding was analyzed in 131 CD patients with acute severe LGIB. Patients were classified into the CMT group (n = 99), anti‐TNF therapy group (n = 22), and surgery group (n = 10). No patients in the surgery group received anti‐TNF therapy. Results: During the median follow‐up of 98 months after the first episode of acute severe LGIB, rebleeding occurred in 50.5%, 18.2%, and 30.0% of the CMT group, anti‐TNF therapy group, and surgery group, respectively (P = 0.015). The cumulative risks of rebleeding at 1 and 10 years were 20.0% and 64.7% in the CMT group, 13.6% and 18.4% in the anti‐TNF therapy group, and 0% and 40.7% in the surgery group, respectively (P = 0.020). Multivariable Cox regression analysis showed that anti‐TNF therapy was associated with a lower risk of rebleeding compared with CMT (hazard ratio, 0.303; 95% confidence interval, 0.108–0.849; P = 0.023). Conclusions: In CD patients with acute severe LGIB, anti‐TNF therapy may reduce the risk of rebleeding compared with CMT. Although surgery is considered effective in preventing early rebleeding, concomitant anti‐TNF therapy may be helpful in further lowering the long‐term risk of rebleeding. [ABSTRACT FROM AUTHOR]

Background: A sessile-serrated adenoma (SSA) has a high risk for incomplete resection. Little is known regarding how to immediately detect remnant SSA tissue after endoscopic resection. We investigated the usefulness of narrow-band imaging (NBI) to detect remnant SSA tissue after endoscopic mucosal resection (EMR). Methods: We performed a prospective randomized study on 138 patients who had suspicious SSA on colonoscopy at five centers. After EMR on the suspected SSA determined on the endoscopic morphology, all lesions were randomized into two inspection methods, NBI and white light endoscopy (WLE), to detect remnant tissue on the resected margin. If remnant tissue was detected, an additional resection was performed. Finally, we obtained quadrant biopsies on the resection margin to evaluate the incomplete resection. The proportion of incomplete resection was calculated by combining the detection of remnant tissue and the positivity of SSA cells on the final quadrant biopsies. The primary outcome was the proportion of remnant tissue detection, and the secondary outcome was the proportion of incomplete resection of SSA. Results: In all, 145 lesions from 138 patients were removed. The diagnostic rate of SSA was 87.6% (127/145). After randomization, NBI inspection was performed on 69 lesions, and WLE inspection was performed on 76 lesions. The histologic diagnostic rate of SSA was 89.9% (62/69) in the NBI group and 85.5% (65/76) in the WLE group (p > 0.05). There were no significant differences in the detection of remnant tissue (12.9% (8/62) vs. 15.4% (10/65), p > 0.05), the proportion of SSA in remnant tissue (11.3% (7/62) vs. 12.3% (8/65), p > 0.05), or the proportion of incomplete resection (6.5 (4/62) vs. 10.8 (7/65), p > 0.05) between the NBI and WLE inspection groups, respectively. Conclusion: NBI was not superior to WLE for detecting remnant SSA tissue after EMR and could not decrease the proportion of incomplete resection of SSA. [ABSTRACT FROM AUTHOR]

For the sensitive diagnosis of colorectal cancer lesions, advanced molecular imaging techniques using cancer-specific targets have emerged. However, issues regarding the clearance of unbound probes and immunogenicity remain unresolved. To overcome these limitations, we developed a small-sized scFv antibody fragment conjugated with FITC for the real-time detection of colorectal cancer by in vivo molecular endoscopy imaging. A small-sized scFv fragment can target colon cancer secreted protein-2 (CCSP-2), highly expressed in colorectal adenocarcinoma tissues; moreover, its full-length IgG probe has been used for molecular imaging previously. To assess the efficacy of anti-CCSP-2 scFv-FITC, surgical specimens were obtained from 21 patients with colorectal cancer for ex vivo molecular fluorescence analysis, histology, and immunohistochemistry. Orthotopic mice were administered with anti-CCSP-2 scFv-FITC topically and intravenously, and distinct tumor lesions were observed by real-time fluorescence colonoscopy. The fluorescence imaging of human colon cancer specimens allowed the differentiation of malignant tissues from non-malignant tissues (p < 0.05), and the CCSP-2 expression level was found to be correlated with the fluorescence intensity. Here, we demonstrated the feasibility and safety of anti-CCSP-2 scFv-FITC for molecular imaging as well as its potential in real-time fluorescence colonoscopy for the differential diagnosis of tumor lesions. [ABSTRACT FROM AUTHOR]

Small rectal neuroendocrine tumors (NETs) can be treated using cap-assisted endoscopic mucosal resection (EMR-C), which requires additional effort to apply a dedicated cap and snare. We aimed to evaluate the feasibility of a simpler modified endoscopic mucosal resection (EMR) technique, so-called anchored snare-tip EMR (ASEMR), for the treatment of small rectal NETs, comparing it with EMR-C. We retrospectively evaluated 45 ASEMR and 41 EMR-C procedures attempted on small suspected or established rectal NETs between July 2015 and May 2020. The mean (SD) lesion size was 5.4 (2.2) mm and 5.2 (1.7) mm in the ASEMR and EMR-C groups, respectively (p = 0.558). The en bloc resection rates of suspected or established rectal NETs were 95.6% (43/45) and 100%, respectively (p = 0.271). The rates of histologic complete resection of rectal NETs were 94.1% (32/34) and 88.2% (30/34), respectively (p = 0.673). The mean procedure time was significantly shorter in the ASEMR group than in the EMR-C group (3.12 [1.97] vs. 4.13 [1.59] min, p = 0.024). Delayed bleeding occurred in 6.7% (3/45) and 2.4% (1/41) of patients, respectively (p = 0.618). In conclusion, ASEMR was less time-consuming than EMR-C, and showed similar efficacy and safety profiles. ASEMR is a feasible treatment option for small rectal NETs. [ABSTRACT FROM AUTHOR]

Background and Aim: The clinical impact of perianal Crohn's disease (CD) (pCD), a well‐known poor prognostic factor of CD, has not been fully evaluated in Asian patients. We investigated the outcomes of CD in Korean patients according to the presence of pCD at CD diagnosis. Methods: Using 2010–2014 data from the national health insurance claims database, we evaluated the disease course of CD according to the presence of pCD at CD diagnosis. The results were verified in a hospital‐based cohort of 2923 patients. Results: The cumulative risk of intestinal resection was lower in patients with pCD at diagnosis than in those without, in the population‐based cohort (9.1% vs 14.7% at 5 years after diagnosis, P < 0.001), but it was similar between the two groups in the hospital‐based cohort (36.8% vs 36.8% at 10 years after diagnosis, P = 0.950). Moreover, the cumulative risk of behavioral progression was not significantly different between the two groups in the hospital‐based cohort (43.4% vs 41.6% at 10 years after diagnosis, P = 0.366). On multivariable analysis, pCD at CD diagnosis was not a predictor of intestinal resection, behavioral progression, CD‐related hospital admission, or diverting surgery; however, it was an independent predictor of proctectomy (hazard ratio [HR] 3.210, P < 0.001) and anorectal cancer (HR 3.104, P = 0.047). Conclusions: Although the presence of pCD increased the risk of proctectomy and anorectal cancer in Asian patients, the clinical impact of pCD on the overall outcomes of patients with CD may be less significant in Asian patients compared with Western patients. [ABSTRACT FROM AUTHOR]

We aimed to investigate the endoscopic features and clinical course of CMV gastroenterocolitis in immunocompetent patients. We reviewed the medical records and endoscopic images of 86 immunocompetent patients with CMV gastroenterocolitis. Immunocompetent patients were defined as those without congenital or acquired immunodeficiency syndrome, use of anti-cancer chemotherapeutic and immunosuppressive agents, and inflammatory bowel diseases. The mean age was 65.5 ± 11.8 years and 53 (61.6%) were male. Sixty-eight (79.1%) patients had comorbidities. Upper gastrointestinal-dominant, small bowel-dominant, and colon-dominant types were observed in 19, 7, and 60 patients, respectively. Endoscopic features could be classified into discrete ulcerative type with/without exudate and diffuse erythematous type with/without exudate. Antiviral treatment with ganciclovir was initiated in 51 patients (59.3%), 40 of whom improved and 1 improved after changing ganciclovir to foscarnet. Thirty-three patients (38.4%) improved without antiviral treatment. Surgery was necessary in two patients because of colon perforation before antiviral treatment. Another two patients underwent surgery because of sigmoid stricture and cecal perforation during antiviral treatment. Endoscopic type was not associated with clinical outcomes, such as surgery and death. CMV gastroenterocolitis in immunocompetent patients mostly occur in older patients with comorbidities, and the endoscopic features vary with no association with clinical outcomes. [ABSTRACT FROM AUTHOR]

The endoscopic features between herpes simplex virus (HSV) and cytomegalovirus (CMV) esophagitis overlap significantly, and hence the differential diagnosis between HSV and CMV esophagitis is sometimes difficult. Therefore, we developed a machine-learning-based classifier to discriminate between CMV and HSV esophagitis. We analyzed 87 patients with HSV esophagitis and 63 patients with CMV esophagitis and developed a machine-learning-based artificial intelligence (AI) system using a total of 666 endoscopic images with HSV esophagitis and 416 endoscopic images with CMV esophagitis. In the five repeated five-fold cross-validations based on the hue–saturation–brightness color model, logistic regression with a least absolute shrinkage and selection operation showed the best performance (sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the receiver operating characteristic curve: 100%, 100%, 100%, 100%, 100%, and 1.0, respectively). Previous history of transplantation was included in classifiers as a clinical factor; the lower the performance of these classifiers, the greater the effect of including this clinical factor. Our machine-learning-based AI system for differential diagnosis between HSV and CMV esophagitis showed high accuracy, which could help clinicians with diagnoses. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown vitamin D status to be associated with disease activity in patients with inflammatory bowel disease (IBD), but its influence on the clinical course of IBD has not been established. Aims: We aimed to analyze whether the serum 25-hydroxyvitamin D3 [25(OH)D] status is associated with clinical characteristics and affects the risk of surgery in patients with IBD. Methods: From the IBD registry of the Asan Medical Center, we identified all patients who had at least one 25(OH)D measurement; we then analyzed the association between clinical factors and 25(OH)D status. 25(OH)D was considered borderline deficient, deficient, and severely deficient at levels of < 30, < 20, and < 10 ng/mL, respectively. Results: We included 711 Crohn's disease (CD) and 764 ulcerative colitis (UC) patients who had not undergone surgery before 25(OH)D was measured. Both in CD and in UC patients, reduced 25(OH)D was associated with higher disease activity scores and CRP levels (p < 0.001). Severe 25(OH)D deficiency was associated with ileocolonic disease and complicated behavior in CD (p < 0.05) and was relevant to the disease extent in UC (p < 0.001). Additionally, severe 25(OH)D deficiency was associated with CMV colitis in patients with UC (p < 0.001). In multivariable analysis, severe deficiency of 25(OH)D was an independent risk factor for surgery in both CD (HR 1.93, 95% confidence interval [CI] 1.38–2.70) and UC (HR 2.77, 95% CI 1.14–6.74). Conclusion: Severe 25(OH)D deficiency may be a marker of a more aggressive clinical course of IBD. [ABSTRACT FROM AUTHOR]

The usage of direct oral anticoagulants (DOACs) to prevent and treat thromboembolic events is gradually increasing. We aimed to evaluate the outcomes of patients taking DOACs after polypectomy. We retrospectively reviewed 131 patients taking DOACs and 270 taking clopidogrel who underwent polypectomy between November 2010 and December 2017. The risk of delayed postpolypectomy bleeding (PPB) was evaluated and compared. A total of 989 polyps were removed (320 polyps in the DOAC and 669 polyps in the clopidogrel group). DOACs and clopidogrel were discontinued for 2.8 ± 1.7 days and 5.8 ± 2.5 days before polypectomy, respectively. DOACs and clopidogrel were restarted on 1.6 ± 2.9 days and 1.7 ± 1.1 days after polypectomy, respectively. According to per polyp analysis, delayed PPB rate was 1.6% in both groups (p = 0.924). Logistic regression analysis was performed after propensity score matching and revealed that DOACs did not increase the delayed PPB risk compared to clopidogrel (OR 0.929, 95% CI 0.436–1.975, p = 0.847). With the majority following the antithrombotic discontinuation guidelines, the incidence of delayed PPB was 3.1% in the patients taking DOACs. The delayed PPB risk was not greater in those taking DOACs than in those taking clopidogrel. [ABSTRACT FROM AUTHOR]

Background: Many patients with ulcerative colitis (UC) in clinical remission frequently complain of bowel symptoms such as increased stool frequency (SF) and rectal bleeding (RB). However, studies on these patient-reported outcomes in patients with inactive UC are limited, especially in Korea. Therefore, we investigated the prevalence and risk factors of bowel symptoms in Korean patients with inactive UC.Methods: We investigated the prevalence of bowel symptoms in patients with endoscopically quiescent UC between June 1989 and December 2016 using a well-characterized referral center-based cohort. The Mayo clinic score (MCS) was used to evaluate bowel symptoms at the most recent visit near the date of endoscopy. Clinical characteristics of the patients were compared based on the presence or absence of bowel symptoms.Results: Overall, 741 patients with endoscopically quiescent UC were identified, of whom 222 (30%) and 48 (6.5%) had an SF and RB subscore of ≥ 1, respectively. Patients with bowel symptoms (SF + RB ≥ 1; n = 244 [32.9%]) had higher rates of left-sided colitis (E2) or extensive colitis (E3) than patients without bowel symptoms (SF + RB = 0; n = 497 [67.1%]; P = 0.002). Multivariate analysis revealed that female sex (odds ratio [OR]: 1.568; 95% confidence interval [CI]: 1.023-2.402; P = 0.039) and E2 or E3 (OR 1.411; 95% CI 1.020-1.951; P = 0.038) were the significant risk factors for increased SF.Conclusions: This study revealed that one-third of patients with endoscopically quiescent UC reported increased SF. Female sex and disease extent may be associated with bowel symptoms. [ABSTRACT FROM AUTHOR]

Introduction: Immunomodulators remain fundamental for the medical treatment of Crohn's disease (CD). Methotrexate (MTX) is widely used as a second-line immunomodulator; however, there is a lack of recent data on MTX monotherapy among the Asian population with CD. Therefore, in this study, we aimed to investigate the tolerability and clinical outcomes of MTX in Korean patients with CD. Methods: A retrospective chart review was performed for CD patients treated with MTX monotherapy or in combination with 5-aminosalicylic acid (5-ASA), at the Asan Medical Center, Seoul, South Korea. The tolerability of MTX monotherapy within 6 months was assessed and the clinical effectiveness of MTX was evaluated based on the Crohn's disease activity index (CDAI). Results: In total, 85 patients were included, of which 29 (34.1%) discontinued MTX due to intolerability during the follow-up. Adverse events (AEs) were reported in 41 (48.2%) patients. The most common AE was gastrointestinal disorders (17/41) and only one patient experienced a serious AE, a systemic infection that required hospitalization. Among the 56 patients who tolerated MTX within 6 months, 44 (65.9%) showed a clinical response. Moreover, no factor was significantly associated with intolerability. The administration method was the only factor significantly associated with a response to MTX (p = 0.041). The adjusted odds ratio of parenteral injection compared to oral administration was 5.68 (95% confidence interval (CI), 1.07–30.08). Conclusion: In this study, one-third of patients were intolerant to MTX; nonetheless, the response rate was as high as 65.9% among tolerant patients. In addition, no significant factors affected intolerability. In terms of the clinical response, parenteral injection could be better than oral administration. [ABSTRACT FROM AUTHOR]

Background: Biopsies with conventional forceps beyond the operating range are difficult and cumbersome. Thus, we developed a new bendable forceps for improved access to gastrointestinal lesions and evaluated its technical feasibility. Methods: A bendable forceps was constructed with two channels and a two-stage knob. The bending motion-related structures were designed to improve the range of motion. For the evaluation of the forceps, we used 2 gastrointestinal simulators: an ex vivo porcine model, and an in vivo porcine model with some difficult endoscopic biopsy cases. All evaluations were performed by 5 expert endoscopists and an expert pathologist. Results: Compared with the conventional forceps, the bendable forceps had greater efficacy in the simulator (6.2 ± 0.4 vs. 1.96 ± 0.2, p < 0.001), ex vivo porcine model (6.33 ± 0.52 vs. 4.25 ± 0.89, p < 0.001), and in vivo porcine model (6.33 ± 0.52 vs. 4.25 ± 0.89, p < 0.001); greater safety in the simulator (1.92 ± 0.13 s vs. 4.88 ± 0.50 s, p < 0.001), ex vivo porcine model (2.02 ± 0.15 s vs 4.66 ± 0.27 s, p < 0.001), and in vivo porcine model (2.02 ± 0.15 s vs. 4.08 ± 0.70 s, p = 0.002); and larger specimens in the ex vivo porcine model (3.92 ± 0.03 mm vs. 3.85 ± 0.07 mm, p = 0.020). Conclusions: This study showed that compared with the conventional forceps, the bendable forceps was effective and safe to use for accessing difficult lesions in the three models. We believe that the bendable forceps serves as a useful supplementary diagnostic tool for accessing difficult lesions. However, further validation of its usefulness in the human body is needed. [ABSTRACT FROM AUTHOR]

Purpose: A modified endoscopic mucosal resection (EMR) technique, Tip-in EMR, was recently introduced to enhance the complete resection of colorectal neoplasia (CRN). We aimed to evaluate the feasibility of Tip-in EMR for flat CRNs. Methods: From January to September 2018, conventional or Tip-in EMR was consecutively performed for 112 flat CRNs ≥ 10 mm in diameter. Tip-in EMR was performed when en bloc snaring was impossible with conventional EMR or when a lesion was inadequately lifted owing to a previous forceps biopsy. We retrospectively collected the clinical, procedural, and histologic data of the conventional and Tip-in EMR groups and compared the en bloc resection rate, complete resection rate, and complications between the two groups. Results: Among 112 flat CRNs of 80 patients, conventional EMR and Tip-in EMR were performed for 74 and 38 lesions, respectively. The median lesion size was 12 (10–27) mm. Tip-in EMR was superior to conventional EMR in terms of en bloc resection (94.7% vs. 77.0%, p = 0.018) and histologic complete resection (76.3% vs. 54.1%, p = 0.022). There was no difference in postprocedural bleeding between the two groups; however, overall adverse events, including bleeding and postpolypectomy electrocoagulation syndrome, were more frequent in the Tip-in EMR group. Conclusions: Tip-in EMR is a feasible technique for flat colorectal lesions ≥ 10 mm and is superior to conventional EMR with respect to en bloc and complete resection rates. The safety profiles of Tip-in EMR and conventional EMR should be compared via large-scale prospective studies. [ABSTRACT FROM AUTHOR]

Background: Coexistence of colorectal neoplasia and atherosclerotic cardiovascular disease has been reported. Subclinical atherosclerosis can be evaluated noninvasively and easily by assessing carotid intima-media thickness (CIMT) and carotid plaque using ultrasonography.Aims: We aimed to evaluate the association between carotid ultrasonography findings and colorectal conventional adenoma (AD) in health checkup examinees.Methods: We retrospectively reviewed the medical records of health checkup examinees ≥ 40 years old who had undergone both carotid ultrasonography and colonoscopies at a single hospital between January 2012 and December 2016.Results: The median age of 4871 eligible participants was 54 years (range, 40-89). AD was found in 2009 individuals (41.2%), with a mean number of 1.9 ± 1.7 lesions. Abnormal CIMT (≥ 1 mm) and carotid plaque were found in 1366 (28.0%) and 1255 (25.8%) individuals, respectively. AD and high-risk adenoma (HRA) were observed more frequently in those with abnormal CIMT or plaque. Moreover, abnormal CIMT and plaque were independent risk factors for the presence of AD (odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.06-1.39, P = 0.006; OR: 1.24, 95% CI: 1.08-1.43, P = 0.002) and HRA (OR: 1.24, 95% CI: 1.05-1.52, P = 0.034; OR: 1.35, 95% CI: 1.10-1.65, P = 0.004), respectively.Conclusions: Abnormal CIMT and the presence of carotid plaque were significantly associated with AD and HRA, and each was an independent risk factor for AD and HRA. More careful observation might be needed during colonoscopies in individuals with abnormal carotid ultrasonographic findings. [ABSTRACT FROM AUTHOR]

Background and Aims: The phenotypic concordance among familial cases of inflammatory bowel disease (IBD) has been rarely reported. Thus, the present study aimed to evaluate the concordance regarding disease type and phenotypic features in a large cohort of Korean patients with IBD. Methods: A total of 6647 patients with IBD who visited the Asan Medical Center between June 1989 and September 2016 were enrolled in the study. When at least two familial cases existed in our cohort, they were included in the concordance analysis (κ index). The concordance between younger and older members for IBD type [Crohn's disease (CD) and ulcerative colitis (UC)] and phenotypic characteristics such as disease extent and location, disease behavior, the use of medication, and need for surgery were evaluated. Results: A positive family history of IBD was noted in 216 patients with CD (7.0%) and in 238 patients with UC (6.7%). Of all patients, 167 consanguineous pairs in 146 families were identified. The crude concordance rate for IBD type was 82.6% with a κ index of 0.656 [95% confidence interval (CI): 0.545–0.768, good concordance]. There was mild concordance for disease location in CD (κ = 0.256; 95% CI: 0.007–0.505) and for the use of antitumor necrosis factor agents in UC (κ = 0.354; 95% CI: −0.049–0.757). The concordance for IBD type and several phenotypes in first‐degree relative pairs was better than that in the entire pairs. Conclusions: Disease type and phenotypic characteristics of patients with familial IBD may be anticipated. [ABSTRACT FROM AUTHOR]

Background and Aims. Balloon-assisted enteroscopy (BAE) can be used to retrieve small intestinal foreign bodies (FBs). Here, we aimed at exploring the clinical usefulness of BAE for the retrieval of small intestinal FBs. Methods. We retrospectively reviewed the medical records of 34 patients who underwent BAE to retrieve small intestinal FBs at 3 tertiary referral centers between April 2005 and June 2017. Results. The retained materials included capsule endoscopes (CEs; n = 18 [52.9%]), self-expandable metal stents (SEMSs; n = 5 [14.7%]), biliary drainage catheters (n = 4 [11.8%]), gallstones (n = 3 [8.8%]), an embolization coil (2.9%), a needle, an intragastric bariatric balloon, and a razor blade. FBs were located or stuck in the ileum (n = 17 [50%]), jejunum (n = 16 [47.1%]), and an undetermined small intestinal segment (n = 1). Seventeen cases of FBs (50%; 7 CEs, 3 biliary drainage catheters, 3 SEMSs, 2 gallstones, 1 intragastric balloon, and 1 needle) were successfully retrieved enteroscopically. FBs of 4 asymptomatic patients (3 CEs and 1 razor blade) passed spontaneously. The remaining 13 patients underwent surgery for persistent or symptomatic FBs: 12 were successfully removed and 1 CE removal procedure failed due to severe peritoneal adhesions. The presence of symptoms was the only independent predictor of successful retrieval using BAE (odds ratio 13.40, 95% confidence interval 1.10–162.56, P = 0.042). BAE-related complications such as bowel perforation and acute pancreatitis occurred in 2 patients (5.9%). Conclusions. BAE can be the first option for FB removal in the small intestine. The presence of symptoms was associated with successful enteroscopic retrieval. [ABSTRACT FROM AUTHOR]

We developed and validated a deep-learning algorithm for polyp detection. We used a YOLOv2 to develop the algorithm for automatic polyp detection on 8,075 images (503 polyps). We validated the algorithm using three datasets: A: 1,338 images with 1,349 polyps; B: an open, public CVC-clinic database with 612 polyp images; and C: 7 colonoscopy videos with 26 polyps. To reduce the number of false positives in the video analysis, median filtering was applied. We tested the algorithm performance using 15 unaltered colonoscopy videos (dataset D). For datasets A and B, the per-image polyp detection sensitivity was 96.7% and 90.2%, respectively. For video study (dataset C), the per-image polyp detection sensitivity was 87.7%. False positive rates were 12.5% without a median filter and 6.3% with a median filter with a window size of 13. For dataset D, the sensitivity and false positive rate were 89.3% and 8.3%, respectively. The algorithm detected all 38 polyps that the endoscopists detected and 7 additional polyps. The operation speed was 67.16 frames per second. The automatic polyp detection algorithm exhibited good performance, as evidenced by the high detection sensitivity and rapid processing. Our algorithm may help endoscopists improve polyp detection. [ABSTRACT FROM AUTHOR]

Background: Although endoscopic submucosal dissection (ESD) is widely used, the current status and trend in its training have yet to be fully evaluated. We aimed to investigate how ESD endoscopists have been trained in actual clinical practice. Methods: Endoscopists aged <45 years who have completed a gastroenterology fellowship or were currently in a fellowship for ≥2 years were included. We conducted a nationwide survey on the ESD training experiences of these endoscopists. Results: Among 79 young Korean endoscopists invited to participate in the survey, 68 (86.1%) trained in 24 major hospitals responded to the questionnaire. Twenty, 25, and 23 participants belonged to the second-year fellow, <5 years after training, and ≥5 years after training groups, respectively. Sixty-nine percent of the participants observed ≥50 ESD cases before starting ESD under supervision by an expert endoscopist. Additionally, 22% experienced ≥20 supervised ESDs during the training period. The proportion of the participants who underwent a hands-on course differed among the groups (≥5 years after training, 13.0%; <5 years after training, 40.0%; and second-year fellow, 50.0%; P = 0.027). ESD under supervision, observation, and hands-on course were the preferred methods for learning ESD (91.1%, 80.9%, and 35.3%, respectively). Overall, 42.6% of the participants were satisfied with their training program. More experience in supervised ESD (≥20 cases) was associated with an increased satisfaction (odds ratio, 6.65; 95% confidence interval, 1.62–36.31). Conclusions: Observation and performance of ESD under the supervision of an expert endoscopist are the primary methods for learning ESD. Hands-on course program has been used more frequently in recent years. [ABSTRACT FROM AUTHOR]

Background: Few studies have compared the costs of colorectal endoscopic submucosal dissection (ESD) and endoscopic piecemeal mucosal resection (EPMR).Aims: Here, we aimed to investigate the cost-effectiveness of these approaches by analyzing clinical outcomes and costs.Methods: Data from patients undergoing colorectal ESD and EPMR were retrospectively reviewed. Clinical outcomes (procedure time, complete resection, and recurrence) were compared, and total direct costs (procedural and follow-up) were assessed.Results: Data from 429 ESD and 115 EPMR patients were included in the analysis. The complete resection rate was significantly higher (83.9% vs. 32.2%, p < 0.001), recurrence rate was lower (0.5% vs. 7.1%, p < 0.001), procedure time was longer (55.4 ± 47.0 vs. 25.6 ± 32.7 min, p < 0.001), and total direct procedural costs at the initial resection were higher (1480.0 ± 728.0 vs. 729.8 ± 299.7 USD, p < 0.001) in the ESD group than in the EPMR group. The total number of surveillance endoscopies was higher in the EPMR group (1.7 ± 1.5 vs. 1.3 ± 1.1, p = 0.003). The cumulative total costs of ESD and EPMR were comparable at 3 and 2 years' follow-up in the adenoma and mucosal/superficial submucosal cancer subgroups, respectively.Conclusions: Colorectal ESD was associated with higher complete resection and lower recurrence rates. EPMR showed shorter procedure times and similar cumulative total direct costs. ESD or EPMR should be chosen based on both clinical outcomes and cost-effectiveness. [ABSTRACT FROM AUTHOR]

Background: Little is known about the natural history of perianal fistulas in Asian populations with Crohn's disease (CD).Aims: We investigated the incidence and outcomes of perianal CD (pCD) in Korean CD patients.Methods: A nationwide population-based cohort of 6265 CD patients diagnosed in 2010-2014 was analyzed to investigate the incidence and outcomes of pCD. The results were validated in a hospital-based cohort of 2923 CD patients diagnosed in 1981-2015. Factors associated with pCD development were analyzed. The incidence and outcomes of pCD were compared between the prebiologic and biologic eras.Results: pCD occurred in 39.2% of the population-based cohort and 56.1% of the hospital-based cohort during the median follow-up of 4.2 and 8.5 years, respectively. The cumulative incidence of pCD was 40.0% at 5 years after CD diagnosis in the population-based cohort and 62.5% at 20 years in the hospital-based cohort. In multivariate analysis, pCD development was positively associated with male sex, younger age and colonic involvement at diagnosis, early diagnosis, and CD diagnosis in the prebiologic era. The cumulative probability of proctectomy at 10, 20, and 30 years after pCD diagnosis was 2.9%, 12.2%, and 16.2%, respectively. The cumulative incidence of pCD occurring after CD diagnosis and the cumulative probability of proctectomy were significantly lower in the biologic era than in the prebiologic era (p < 0.001 and p = 0.03, respectively).Conclusions: Compared with Western patients with CD, Korean patients show a high incidence of pCD but have a low probability of proctectomy, suggesting the favorable course of pCD. [ABSTRACT FROM AUTHOR]