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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., (© 2021. The Author(s).)

We aimed to develop a computer-aided diagnostic system (CAD) for predicting colorectal polyp histology using deep-learning technology and to validate its performance. Near-focus narrow-band imaging (NBI) pictures of colorectal polyps were retrieved from the database of our institution. Of these, 12480 image patches of 624 polyps were used as a training set to develop the CAD. The CAD performance was validated with two test datasets of 545 polyps. Polyps were classified into three histological groups: serrated polyp (SP), benign adenoma (BA)/mucosal or superficial submucosal cancer (MSMC), and deep submucosal cancer (DSMC). The overall kappa value measuring the agreement between the true polyp histology and the expected histology by the CAD was 0.614-0.642, which was higher than that of trainees (n = 6, endoscopists with experience of 100 NBI colonoscopies in <6 months; 0.368-0.401) and almost comparable with that of the experts (n = 3, endoscopists with experience of 2,500 NBI colonoscopies in ≥5 years) (0.649-0.735). The areas under the receiver operating curves for CAD were 0.93-0.95, 0.86-0.89, and 0.89-0.91 for SP, BA/MSMC, and DSMC, respectively. The overall diagnostic accuracy of the CAD was 81.3-82.4%, which was significantly higher than that of the trainees (63.8-71.8%, P < 0.01) and comparable with that of experts (82.4-87.3%). The kappa value and diagnostic accuracies of the trainees improved with CAD assistance: that is, the kappa value increased from 0.368 to 0.655, and the overall diagnostic accuracy increased from 63.8-71.8% to 82.7-84.2%. CAD using a deep-learning model can accurately assess polyp histology and may facilitate the diagnosis of colorectal polyps by endoscopists.

Objectives: Although chromoendoscopy is currently the recommended mode of surveillance in patients with long-standing ulcerative colitis, it is technically challenging and requires a long procedure time. The aim of this study was to compare the dysplasia detection rate of high-definition white light endoscopy with random biopsy (HDWL-R) vs high-definition chromoendoscopy with targeted biopsy (HDCE-T)., Methods: This was a multicenter, prospective randomized controlled trial involving 9 tertiary teaching hospitals in South Korea. A total of 210 patients with long-standing ulcerative colitis were randomized to undergo either the HDWL-R group (n = 102) or HDCE-T group (n = 108). The detection rates of colitis-associated dysplasia (CAD) or all colorectal neoplasia from each trial arm were compared., Results: There was no significant difference in the CAD detection rate between HDCE-T and HDWL-R groups (4/102, 3.9% vs 6/108, 5.6%, P = 0.749). However, HDCE-T showed a trend toward improved colorectal neoplasia detection compared with HDWL-R (21/102, 20.6% vs 13/108, 12.0%, P = 0.093). The median (range) time for colonoscopy withdrawal between the 2 groups was similar (17.6 [7.0-43.3] minutes vs 16.5 [6.3-38.1] minutes; P=0.212; for HDWL-R and HDCE-T, respectively). The total number of biopsies was significantly larger in the HDWL-R group (34 [12-72]) compared with the HDCE-T group (9 [1-20]; P < 0.001)., Discussion: On the basis of our prospective randomized controlled trial, HDCE-T was not superior to HDWL-R for detecting CADs.

Background and Aim: The feasibility of endoscopic submucosal dissection (ESD) as a treatment option for dysplasia in ulcerative colitis (UC) has been reported, but the associated therapeutic decision-making and clinical outcomes have not been extensively investigated., Methods: We retrospectively reviewed 25 UC patients who were referred for potential ESD of non-polypoid or sessile dysplasia. We analyzed the treatment decisions and the ESD and colectomy outcomes for this patient group., Results: All lesions were located at the colitic segments. The median UC duration was 13.4 years. A colectomy was recommended for 10 patients because of ulceration with indistinct borders (one patient), non-ulceration with indistinct borders (two patients), and non-lifting signs (seven patients). The remaining 15 patients underwent ESD. The en bloc and R0 resection rates were 93.3% and 80%, respectively. The median hospitalization periods were 1 (range, 1-2) day after ESD and 7 (range, 5-30) days after colectomy. No procedure-related complications occurred after ESD, but early and late postoperative complications occurred in two (22.2%) and six (66.7%) of the colectomized patients, respectively. Fourteen ESD cases were followed endoscopically for a median period of 24.7 (range, 5.2-64.8) months. Local recurrence occurred in 2 (14.3%) patients, and metachronous recurrence was identified in two separate patients (14.3%)., Conclusions: Endoscopic submucosal dissection is a feasible endoscopic treatment option for UC-associated dysplasia showing noninvasive pit or vascular patterns, no surface ulceration, distinct borders, and appropriate lifting after submucosal injection. Meticulous endoscopic surveillance is essential to monitor for local or metachronous recurrence of dysplasia after ESD., (© 2019 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background/aims: Multiple large colorectal lesions requiring endoscopic submucosal dissection (ESD) are sometimes diagnosed during colonoscopy. We evaluated the feasibility and safety of ESD of two colorectal lesions in one session., Materials and Methods: The lesions of 16 patients who underwent two ESD procedures in a single session (double ESD group) from November 2009 to July 2014 were matched with those of 64 patients who underwent a single ESD procedure (single ESD group) based on the size and location of the lesion and presence of submucosal fibrosis., Results: The net ESD time per patient was longer in double ESD group than in single ESD group (104.0±36.2 vs. 59.1±39.2 min, p<0.001). The net ESD time per lesion tended to be shorter in double ESD group than in single ESD group (49.6±30.0 vs. 59.1±39.2 min, p=0.077). The en bloc resection and curative resection rates did not differ between double ESD and single ESD groups (93.8 % vs. 98.4%, p=0.262; 90.6 % vs. 84.4 %, p=0.534, respectively). The intra- and postprocedural bleeding rates were 12.5% and 0% in double ESD group and 15.6% and 3.1% in single ESD group, respectively. Perforation occurred in two (6.3%) in double ESD group and in six (9.4%) in single ESD group (p=0.715)., Conclusion: Compared with the single ESD, two simultaneous colorectal ESD procedures in a patient did not increase complications; the en bloc and curative resection rates were similar when performed a single ESD procedure and two simultaneous ESD procedures.

Background: Although colonoscopy is useful for differentiating between Crohn's disease (CD) and intestinal tuberculosis (ITB), the technique has limitations. We developed a practical prediction model for differentiating between CD and ITB using laboratory and radiologic parameters and colonoscopic characteristics., Methods: We prospectively enrolled 80 patients newly diagnosed with CD (n = 40) and ITB (n = 40). We developed a new prediction score by integrating colonoscopic, laboratory, and radiologic parameters. The score's predictive ability was validated on an additional 37 patients., Results: The accuracy of colonoscopic scoring for differentiation was 81.2% (65/80), with 65.0% sensitivity for CD and 97.5% for ITB. In multivariate analysis, positive IgA and/or IgG anti-Saccharomyces cerevisiae antibody and involvement of the proximal intestine were the independent laboratory and radiologic parameters for CD, and positive QuantiFERON-TB Gold In-Tube Test and typical pulmonary TB findings were the parameters for ITB. A new prediction scoring combining colonoscopic, laboratory, and radiologic factors increased the accuracy of diagnosis from 81.2% to 96.3% (77/80). The CD prediction score (from -2 to 2) estimated the likelihood of CD, from 0.3% for patients scoring -2 to 100% for patients scoring 2. The area under the receiver operating characteristic curve of the score was 0.990 in the development group and 0.981 in the validation group., Conclusions: The new prediction model using a CD prediction score can be useful for calculating the probability of either CD or ITB at initial evaluation (NCT01392365).

Background and Aim: Although metabolic factors such as obesity and hyperlipidemia were reported to be associated with high prevalence of colorectal neoplasm (CRN), their influence on the occurrence of CRN at surveillance colonoscopy has not been clarified. The purpose of this study was to analyze the association between metabolic factors and the risk of CRN at the time of surveillance colonoscopy., Methods: We reviewed the medical records of 1792 asymptomatic subjects (average 52.1 years, 1233 male) who underwent screening and follow-up surveillance colonoscopies. Fasting glucose level, fasting insulin level, hemoglobin A1c (HbA1c), lipid profile, high sensitivity C-reactive protein, and colonoscopic findings at the time of baseline screening were analyzed to find any associations with the occurrence of CRN at the time of surveillance colonoscopy., Results: The median interval between screening and surveillance colonoscopies was 3.34 years. The 3- and 5-year cumulative CRN incidences were 22.3% and 54.8%, respectively. Several metabolic factors such as hypertension, waist circumference, fasting insulin, fasting glucose, HbA1c, and triglyceride were associated with the occurrence of CRN in univariate analysis. Age, current alcohol drinker status, and high-risk colonoscopy findings at baseline remained independent risk factors for CRN occurrence in multivariate analysis. High waist circumference was also an independent risk factor (hazard ratio 1.03, 95% CI 1.02-1.04; P < 0.001)., Conclusions: Metabolic factors, especially waist circumference, affect CRN occurrence at the time of surveillance colonoscopy. The surveillance colonoscopy interval may be optimized based on metabolic factors and screening colonoscopy findings., (© 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background and Aims: Colorectal endoscopic submucosal dissection (ESD) is difficult and time consuming. Optimization of ESD with snaring (optimized hybrid ESD) may shorten the procedure time. The purpose of this study was to prospectively compare ESD and optimized hybrid ESD in the colorectum., Methods: We prospectively enrolled 70 patients with colorectal neoplasia ≥20 mm. The patients were randomized to receive either ESD (36 patients) or optimized hybrid ESD (34 patients). In the optimized hybrid ESD group, snare resection was performed after an adequate amount of submucosal dissection. The primary outcome was procedure time. Secondary outcomes were en bloc and complete resection rates and adverse event rates., Results: ESD could not be completed in 5 patients (13.9%) in the ESD group because of technical difficulties. We tried hybrid ESD to finish the resection, and en bloc resection was achieved in 4 patients (80%). The mean procedure time was shorter in the optimized hybrid ESD group compared with the ESD group (27.4 vs 40.6 minutes; P = .005). The en bloc resection rates were similar (94.1% vs 100%; P = .493), as were the complete resection rates (91.2% vs 93.5%; P > .999) and perforation rates (3 patients [8.8%] vs 2 patients [6.5%]; P > .999)., Conclusions: Optimized hybrid ESD achieves shorter procedure times than ESD, with similar en bloc resection rates and adverse event rates. Optimized hybrid ESD in the colorectum may offer an easy alternative to colorectal ESD and a rescue method for failed ESD cases. (, Clinical Trial Registration Number: NCT01944540.)., (Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Experience in gastric endoscopic submucosal dissection (ESD) has been suggested as a prerequisite for performing colorectal ESD by some experts., Aims: To evaluate the feasibility of performing colorectal ESD without experience in gastric ESD., Methods: Between November 2009 and December 2013, ESD was attempted for 250 colorectal lesions by an endoscopist having extensive colonoscopy experience but no prior experience of gastric ESD. All attempts were categorized according to the chronological order of procedures: group 1, attempts 1-50; group 2, attempts 51-100; group 3, attempts 101-150; group 4, attempts 151-200; and group 5, attempts 201-250. Procedure-related outcomes were analyzed., Results: En bloc resection rate ≥80% was achieved after initial ten ESD attempts. The ESD success rate (72, 80, 90, 90, and 94% in group 1-5, respectively; p for trend = 0.001), perforation rate (14, 14, 6, 6, and 0% in group 1-5, respectively; p for trend = 0.003), and macroperforation rate (6, 6, 2, 2, and 0% in group 1-5, respectively; p for trend = 0.042) improved as experience accumulated. Performing >100 ESDs, rectal location, and absence of submucosal fibrosis were independent predictors of successful procedure., Conclusion: Colorectal ESD can be safely and effectively performed by an endoscopist having extensive experience in colonoscopy-related procedures even without previous experience of gastric ESD. Meticulous case selection for ESD novice and active supervision by expert endoscopists during the initial learning period may minimize the risk of perforation.

Objectives: To investigate the optimal cut-off of the maximum standard uptake value (SUVmax) for the detection of colorectal neoplasms and to suggest those for whom further colonoscopy is recommended among patients with incidental colonic uptake on positron emission tomography-computed tomography (PET-CT)., Materials and Methods: In 306 patients who underwent colonoscopy within 3 months of receiving PET-CT between January and December 2009, measurements of the per-patient and per-lesion diagnostic performance of PET-CT for the detection of colonic neoplasms were obtained. Receiver operating characteristic (ROC) analysis was used to identify the SUVmax that provided a high probability of diagnosing malignancy and high-grade dysplasia., Results: The per-patient and per-lesion PET-CT detection sensitivities for malignancies were 93.3% (28/30; 95% confidence interval (CI) 76.5% to 98.9%) and 93.5% (29/31, 95% CI 77.2% to 98.9%), respectively; the sensitivities for high-grade dysplasia were both 90.0% (9/10; 95% CI 54.1% to 99.5%). As a criterion to specifically detect both malignancy and high-grade dysplasia on focal uptake, a SUVmax greater than 2.5 yielded a 92.3% per-lesion sensitivity and a 42.9% per-lesion positive predictive value (PPV). In the ROC curve analysis, a cut-off value of SUVmax = 5.8 was established, at which the sensitivity, PPV and positive likelihood ratio for diagnosing malignancy and high-grade dysplasia were 71.8% (28/39; 95% CI 54.9% to 84.5%), 84.8% (28/33; 95% CI 67.3% to 94.3%) and 6.9, respectively., Conclusion: The optimal cut-off value to identify a malignancy or high-grade dysplasia was SUVmax = 5.8. However, to avoid missing a malignancy or high-grade dysplasia, a colonoscopy should be performed above a SUVmax = 2.5.

Goals: The purpose of this study is to investigate the learning curve for colonoscopic polypectomy (CP) by trainee endoscopists., Background: The amount of training required to achieve technical competence for CP is uncertain., Study: The CP times and en bloc resection rates of three experienced colonoscopists were obtained from 240 procedures. These data were compared to those of three gastroenterology trainees who performed 750 CP procedures. A trainee procedure was deemed to be a success if en bloc resection was obtained and the CP time was within twice the median CP time of the experienced colonoscopists. Trainees were deemed to be technically competent when they achieved a CP success rate of greater than or equal to 80%., Results: The median CP times and en bloc resection rates for the experienced colonoscopists and trainees were 79 s (range, 20-301 s) and 99.6% (239/240), and 118 s (range, 36-1051 s) and 95.6% (717/750), respectively. The trainee success rate of CP was 72% (540/750). The success rate of the procedure was associated with increased trainee experience (p = 0.003) and reached 80% after 250 procedures. The CP time significantly decreased (p < 0.001) and en bloc resection rate significantly increased (p = 0.011) as trainee experience accumulated. The level of experience was an independent predictor for successful CP., Conclusions: The achievement of technical competence with CP was associated with an accumulation of approximately 250 procedures. These findings suggest that dedicated education and training programs for CP are warranted.

Background: Diffusion-weighted imaging (DWI) is a novel technique to evaluate bowel inflammation in Crohn's disease (CD). It is unknown whether and how DWI adds to the accuracy of conventional magnetic resonance enterography (MRE)., Methods: Fifty consecutive adults suspected of CD prospectively underwent clinical assessment, conventional MRE and DWI at b = 900 sec/mm without water enema, and ileocolonoscopy within 1 week. MRE images were interpreted with proper blinding. Forty-four patients finally diagnosed with CD (male:female, 34:10; 26.9 ± 6.1 yr) were analyzed. The per-segment accuracy of MRE for diagnosing active CD was assessed in the terminal ileum, right colon, and rectum using location-by-location matching with endoscopy as the reference standard., Results: The study evaluated 58 bowel segments with deep or superficial ulcers, 34 with aphthae, erythema, or edema only, and 35 without inflammation. Conventional MRE + DWI was more sensitive for bowel inflammation than conventional MRE alone (83% [76/92] versus 62% [57/92]; P = 0.001) largely because of additional detection of aphthae, erythema, or edema. The sensitivities for deep and overt ulcers were similar regardless of DWI, ranging from 88% to 97%. Conventional MRE + DWI was less specific than conventional MRE alone (60% [21/35] versus 94% [33/35]; P < 0.001), mostly because of many false positives in the colorectum. Positive DWI findings in the bowel showing active inflammation on conventional MRE were associated with higher Crohn's disease endoscopic index of severity score (P = 0.021) and deep ulcers (P = 0.01; diagnostic odds ratio, 12)., Conclusions: DWI performed without water enema is not useful for incremental detection of bowel inflammation. DWI may help identify more severe inflammation among bowel segments showing active inflammation on conventional MRE.

Background: Current guidelines for the surveillance colonoscopy interval are largely based on the most recent colonoscopy findings., Aim: We aimed to evaluate differences in the probability of high-risk neoplasm recurrence according to the two previous colonoscopy findings., Methods: This was a retrospective cohort study from a tertiary-care center. A total of 4,143 subjects who underwent three or more colonoscopies for screening or surveillance purposes from January 2001 to December 2011 were enrolled. We compared the probability of high-risk neoplasm detection on follow-up colonoscopies after the second colonoscopy based on risk categories in both the second and first colonoscopies., Results: At the final colonoscopy, 370 participants (8.9 %) had high-risk neoplasms. In patients with a normal second colonoscopy, the probability of high-risk neoplasm recurrence was different between those with normal, low-risk, and high-risk findings at the first colonoscopy (3.8, 6.8, and 17.7 %, respectively). The hazard ratio of a high-risk neoplasm at the final colonoscopy for patients with a normal second and low-risk first colonoscopy over a normal second and normal first colonoscopy was 3.07 (95 % CI 2.04-4.64, P < 0.001). The hazard ratio of high-risk neoplasm at the final colonoscopy for patients with a normal second and high-risk first colonoscopy over a normal second with normal first colonoscopy was 7.88 (95 % CI 4.90-12.67, P < 0.001)., Conclusions: The rate of high-risk colorectal neoplasm recurrence differs according to the two previous colonoscopy findings. Therefore, surveillance intervals could be adjusted not just only by the most recent colonoscopy findings but also by considering two previous colonoscopy findings.

Background: The optimal colon-cleansing method after failure of bowel preparation (BP) for colonoscopy has not been established., Aims: We aimed to compare BP rescue methods after failed initial BP and to identify risk factors for rescue BP failure., Methods: Eighty-five patients with BP failure after 4 L polyethylene glycol (PEG) ingestion were prospectively enrolled from March 2008 to March 2012. A second colonoscopy was performed either on the same day after ingestion of another 2 L PEG (group A) or 1 week later after ingestion of 4 L PEG plus 20 mg oral bisacodyl (group B). Differences between groups in terms of BP quality and risk factors for a poor BP on the second colonoscopy were investigated., Results: Median patient age was 59 years, 45 were male (52.9 %), and 17 (20 %) had poor BP on the second colonoscopy. For group B, the multivariable-adjusted odds ratio (OR) for poor BP on the second colonoscopy relative to group A was 0.68 (95 % confidence interval [CI], 0.16-2.95). Adequately ingested PEG during the initial colonoscopy was associated with poor BP on the second colonoscopy (OR 4.05; 95 % CI 1.04-15.75). The two groups had similar patient discomfort rates during the second BP., Conclusions: The two groups did not differ in rescue BP failure rate. Initial BP failure after adequate consumption of 4 L PEG may be a risk factor for rescue BP failure. A stricter BP regimen should be considered for these patients.

Background: The epidemiology of colorectal neoplasm in liver transplantation recipients has not been fully determined., Objective: The aim of this study was to evaluate the prevalence of colorectal neoplasm in liver transplantation recipients and to compare it with that in the average-risk population., Design: This study was retrospective and observational., Setting: This study was conducted at a tertiary care center., Patients: From January 2000 to December 2011, 257 liver transplantation recipients who had undergone posttransplant colonoscopy were enrolled. A total of 1028 control subjects matched for age, sex, and calendar year of the index colonoscopy were recruited from those who had undergone screening colonoscopy at our institution., Main Outcome Measures: Colonoscopy findings were compared between the 2 groups. The prevalence of overall and advanced colorectal neoplasms and their risk factors were investigated., Results: The median age was 54 years, and each group consisted of approximately 75.5% men. The prevalence of overall and advanced colorectal neoplasm was 35.4% and 5.8% in liver transplantation recipients and 41.7% and 3.5% in controls (p = 0.07 and p = 0.11). The prevalence of invasive colorectal cancer was higher in liver transplantation recipients than in controls (0.8% versus 0.0%, p = 0.04). The prevalence of overall and advanced colorectal neoplasms in liver transplantation recipients younger than 40 years was higher than age-matched controls (p = 0.003 and p = 0.04)., Limitations: The retrospective design was a limitation of this study., Conclusions: The prevalence of colorectal neoplasms may not increase in liver transplantation recipients compared with the general population. However, the prevalence of invasive colorectal cancer may be higher in liver transplantation recipients. A prospective study is warranted to determine an appropriate colorectal cancer screening strategy for liver transplantation recipients.

Objective: Few data are available on the influence of a colonoscope length for trainees, which could affect both the duration of training and colonoscopy quality. We conducted this study to validate which scope needs more duration for training to reach technical competence and to shows better quality indicators during diagnostic colonoscopy., Materials and Methods: We conducted a prospective randomly assigned study from April 2010 to February 2011 at Asan Medical Center. Among the 1329 patients enrolled, 1200 colonoscopies were analyzed. We compared cecal intubation rate, adenoma detection rate, cecal intubation time (<20 min), and withdrawal time between the trainees using the intermediate-length colonoscope and those using long-length colonoscope., Results: Trainees who used the long-length colonoscope showed a higher overall cecal intubation rate (88.2% vs. 81.0%, p = 0.001) and adenoma detection rate (49.7% vs. 34.2%, p < 0.001) than those using the intermediate-length colonoscope. The successful cecal intubation rate improved significantly and reached the requisite standard of competence (>90%) after 90 procedures in the long-length colonoscope group. However, the trainees using the intermediate-length colonoscope reached the requisite standard of competence after 150 procedures. Logistic regression analysis revealed that prolonged cecal intubation was associated with the use of the intermediate-length colonoscope, poor colon preparation, a small number of esophagastroduodenoscopy or sigmoidoscopy procedures conducted, and pain during procedures., Conclusions: During the same training period, use of the long-length colonoscope in trainee was better in terms of reaching competency and quality indicators, and was less painful for the patients during colonoscopic procedures.

Background: The impact of one-stage polypectomy (removal of all neoplasms during diagnostic colonoscopy) versus two-stage polypectomy (removal of all neoplasms during therapeutic colonoscopy following the initial diagnostic colonoscopy) on the development of metachronous neoplasms is poorly understood. Our aim was to compare the effects of one- versus two-stage polypectomy on the development of metachronous neoplasms, Methods: We retrospectively reviewed the medical records of 249 patients in a tertiary center who underwent one-stage polypectomy, which was followed by one or more surveillance colonoscopy. The development of metachronous neoplasm in this group was compared with that of an age- and sex-matched two-stage polypectomy group consisting of 498 patients, Results: In total, 346 (46.3 %) patients developed any metachronous neoplasm and 29 (3.9 %) patients developed advanced metachronous neoplasm. The 5 years cumulative incidences of any and advanced metachronous neoplasm were 46.2 and 5.0 %, respectively, in the one-stage group, which are not significantly different from the rates of 50.7 and 3.3 % in the two-stage group (p = 0.94 and 0.30, respectively). The only significant risk factor for developing any metachronous neoplasm was ≥ 3 neoplasms at the baseline polypectomy [hazard ratio (HR) 1.75; 95 % confidence interval (CI) 1.41-2.17; p < 0.001]. The only significant risk factor for developing advanced metachronous neoplasm was advanced neoplasm at the baseline polypectomy (HR 2.37; 95 % CI 1.16-4.84; p = 0.01). One- and two-stage polypectomy did not affect the development rates of metachronous neoplasm, Conclusions: The risks of developing metachronous neoplasm may be similar following one- and two-stage polypectomy.

Background/aims: Although incomplete endoscopic resection of colonic neoplasms can lead to the development of interval invasive cancer, few studies have assessed clinical outcomes after histologically incomplete resection of colonic mucosal cancer. We aimed to evaluate the clinical outcomes of patients with histologically positive or uncertain resection margins after endoscopically complete resection of colonic mucosal cancer., Methodology: We analyzed the clinical course of 38 patients (median 62 years, male:female = 27:11) who underwent endoscopically complete resection of colonic mucosal cancer, but who showed histologically positive or uncertain resection margins., Results: The median size of the 38 colonic mucosal cancers was 14 mm (range, 5-50 mm). Of these, 20 were resected by a piecemeal resection, and had uncertain histological resection margins. The remaining 18 patients underwent en-bloc resection; of these, 16 had uncertain resection margins and 2 had positive margins. Patients underwent a median of 2.3 follow-up endoscopies (range, 1-7) during a median follow-up time of 18.3 months (range, 3-75 months). No local or distant recurrence was detected., Conclusions: Cautious followup without immediate additional treatment can be considered for patients who undergo endoscopically complete resection of colonic mucosal cancers, even when histological examination shows uncertain or positive resection margins.

Background: Only 30% to 40% of patients with advanced proximal neoplasms (APN) have distal colon neoplasms., Objective: To develop a risk score model for APN and propose an individualized screening protocol for colorectal cancer., Design: Retrospective cohort study., Setting: Tertiary-care center., Patients: Derivation cohort (6200 adults) and validation cohort (1389 adults)., Intervention: Screening colonoscopy., Main Outcome Measurements: An APN risk score model was developed from the derivation cohort (6200 adults) and was tested in the validation cohort (1389 adults), who underwent screening colonoscopy., Results: Age, male sex, and smoking were clinical risk factors for APN. The presence of a distal neoplasm was a sigmoidoscopic risk factor for APN. We calculated APN risk scores (0-8) based on these variables and classified patients as low risk (0-2) or high risk (3-8). In the validation cohort, the relative risk of APN was 3.5-fold higher in the high-risk group than in the low-risk group. Our model suggests that colonoscopy should be performed as an initial screening test in patients with a high clinical risk for APN. Sigmoidoscopy should be performed initially in patients with low clinical risk for APN followed by supplementary colonoscopy in those with high APN risk scores based on both clinical and sigmoidoscopic risk factors. This protocol detected APN in 22 of 34 APN+ patients (64.7%) with little increase in the endoscopy burden, whereas only 16 of 34 APN+ patients (47.1%) would be identified by initial sigmoidoscopy followed by colonoscopy only in cases with distal neoplasms., Limitations: Retrospective design., Conclusion: Our APN risk score model provides an algorithm for efficient screening of colorectal cancer by sigmoidoscopy and colonoscopy., (Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Post-polypectomy surveillance has become a major indication for colonoscopy as a result of increased use of screening colonoscopy in Korea. However, because the medical resource is limited, and the first screening colonoscopy produces the greatest effect on reducing the incidence and mortality of colorectal cancer, there is a need to increase the efficiency of postpolypectomy surveillance. In the present report, a careful analytic approach was used to address all available evidences to delineate the predictors for advanced neoplasia at surveillance colonoscopy. Based on the results of review of the evidences, we elucidated the high risk findings of the index colonoscopy as follows: 1) 3 or more adenomas, 2) any adenoma larger than 10 mm, 3) any tubulovillous or villous adenoma, 4) any adenoma with high-grade dysplasia, and 5) any serrated polyps larger than 10 mm. In patients without any high-risk findings at the index colonoscopy, surveillance colonoscopy should be performed five years after index colonoscopy. In patients with one or more high risk findings, surveillance colonoscopy should be performed three years after polypectomy. However, the surveillance interval can be shortened considering the quality of the index colonoscopy, the completeness of polyp removal, the patient's general condition, and family and medical history. This practical guideline cannot totally take the place of clinical judgments made by practitioners and should be revised and supplemented in the future as new evidence becomes available.

Background: Despite a high en bloc resection rate, its technical difficulty and risk of complications limit the widespread use of colorectal endoscopic submucosal dissection (ESD)., Objective: To analyze outcomes after colorectal ESD and ESD with snaring (ESD-S), a simplified modification of ESD., Design: A retrospective observational study., Setting: A single, tertiary-care, referral center., Patients and Intervention: ESD was performed on 163 lesions in 162 patients and ESD-S on 74 lesions in 71 patients. All lesions were nonpedunculated colorectal neoplasms of 15 mm or larger., Main Outcome Measurements: We analyzed procedure-related variables such as en bloc resection rate, procedure time, and complications. Histopathologic results were reviewed. Follow-up data were analyzed., Results: The en bloc resection rate was higher for ESD than for ESD-S (87% vs 64%, P < .01). The histologically complete resection rate was also higher for ESD. However, both rates for resection of lesions of <20 mm were not different between ESD and ESD-S groups. The rates of perforation and bleeding were similar for both groups. Submucosal cancers were present in 21% and 31% of the ESD and ESD-S groups, respectively. One patient from each group developed a local adenoma recurrence., Limitations: Retrospective design., Conclusion: Both ESD and ESD-S were safe and effective for resection of colorectal neoplasms. The higher en bloc resection rate for ESD suggests that it should be the first option for resection of suspected superficial submucosal cancers in the colorectum. ESD-S can be a good alternative to ESD for en bloc resection of colorectal lesions of <20 mm., (Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: No study has systematically investigated the colonoscopic findings and histologic diagnostic yield in the diagnosis of colorectal endometriosis., Objectives: We classified the colonoscopic features of colorectal endometriosis and determined the diagnostic yield of endoscopic biopsy in relation to endoscopic subtypes of colorectal endometriosis., Methods: A total of 17 patients with colorectal endometriosis were assessed. The data from the colonoscopic and histologic assessments made between November 1994 and October 2009 were retrospectively analyzed in single tertiary referral teaching hospital., Results: Colonoscopy showed eccentric wall thickening in 14 patients (82%) and polypoid lesions in 3 patients (18%). Surface nodularities were noted in 11 of the 14 patients (79%) with eccentric wall thickening, and in 1 of the 3 patients (33%) with polypoid lesions. The overall histologic diagnostic yield was 47% (8 of the 17 patients). The rate of histologic confirmation was higher in patients with surface nodularities (8 of the 12 patients, 67%) versus those without (0 of the 5 patients, 0%) surface nodularities (P=0.02)., Conclusions: Eccentric wall thickening is the most common colonoscopic finding of colorectal endometriosis, and the histologic diagnostic yield of endoscopic biopsy is high when lesions are accompanied by surface nodularities.

Background: Colonic perforation is an uncommon but serious colonoscopy-associated complication. This study assessed the effectiveness of conservative management with endoscopic clipping for colonoscopy-associated perforations., Methods: Clinical manifestations and management outcomes were assessed for 38 patients with colonoscopy-associated colonic perforations that occurred between January 2001 and April 2008 at the Asan Medical Center, Seoul, Korea. These perforations were classified as endoscopically evident, endoscopically suspected, and radiologically proven., Results: Of the 38 perforations, 19 were endoscopically evident, 9 were endoscopically suspected, and 10 were radiologically proven but without endoscopic evidence. Of the 19 patients with endoscopically evident perforations, 13 (68.4%) underwent endoscopic closure with clips, and all improved without surgery. All nine patients with endoscopically suspected perforations underwent endoscopic closure, and eight (88.9%) improved without surgery. Of the 10 radiologically proven perforations, 7 were detected within 1 day after colonoscopy. All the patients improved without surgery. However, two of the three patients with delayed perforations required emergency laparotomy. Consequently, of the 38 patients with perforations, 29 (76.3%) improved without surgery. Of the 28 patients with endoscopically evident or suspected perforations, conservative management was successful for 21 (95.5%) of the 22 patients with effective clipping, but for none (0%) of the 6 patients without clipping., Conclusions: Conservative management by immediate endoscopic closure with clips can be effective for the treatment of colonic perforations detected during colonoscopy. Conservative management also may be tried cautiously for stable patients who have radiologically proven colonoscopy-associated perforations without endoscopic evidence.

Objectives: It is difficult to diagnose intestinal Behçet's disease (BD) due to various extraintestinal manifestations emerging at different time points in the disease course and a lack of reliable diagnostic criteria. We conducted this study to develop and validate novel diagnostic criteria for intestinal BD., Methods: Experts from three universities generated the preliminary diagnostic criteria for intestinal BD, and a consensus was reached using a modified Delphi method with 13 gastroenterologists participating. To validate the criteria, we recruited 12,850 consecutive patients who underwent colonoscopic examinations between January 2000 and December 2006 at Severance Hospital, Yonsei University, Seoul, Korea., Results: The novel diagnostic criteria were developed on the basis of two aspects: colonoscopic findings and extraintestinal manifestations. Of the 12,850 patients, 280 with ileocolonic ulcers were enrolled for validation. At the time of initial colonoscopic examinations, patients were categorized for BD status into 4 groups: definite (84 patients), probable (67), suspected (15), and nondiagnostic (114). At the end of the follow-up period (mean, 50.9+/-25.7 months), intestinal BD was confirmed in 145 patients (51.8%)-84 (100%) from the definite group, 49 (73.1%) from the probable group, 10 (66.7%) from the suspected group, and 2 (1.8%) from the nondiagnostic group. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the diagnosis probability of these criteria were 98.6, 83.0, 86.1, 98.2, and 91.1%, respectively., Conclusions: These newly proposed, simple criteria might be useful in diagnosing intestinal BD, especially in patients with ileocolonic ulcers who do not fully satisfy the diagnostic criteria of systemic BD.

Background and Study Aims: A prepackaged low residue one-day diet (breakfast, lunch and dinner) has been recently developed to improve patient tolerance for bowel preparation prior to colonoscopy. The aims of this study were to evaluate the efficacy and tolerability of bowel preparation protocols based on a low residue diet and 4L polyethylene glycol (PEG) solution, and to compare these new options with the traditional liquid diet and the PEG 4L lavage., Methods: A total of 214 patients (mean age: 54.1 years; 120 male, 94 female) from four university hospitals were included in the analysis. Patients were randomized to receive a clear liquid diet and the PEG 4L regimen (106 patients) or the low residue test meals and the PEG 4L regimen (TM-PEG 4L, 108 patients). The colon cleansing efficacy of the different preparations was rated using the Ottawa bowel preparation scale., Results: No significant differences were observed between the treatment groups according to the Ottawa cleansing scale findings (PEG 4L: 2.97 vs TM-PEG 4L: 2.46, P = 0.063). The overall tolerability was higher in the TM-PEG 4L group than in the PEG 4L group (P = 0.036). No difference was found when the two groups were compared with regard to adverse events (P = 0.599)., Conclusions: A prepackaged low residue one-day diet provided cleansing efficacy similar to that of a clear liquid diet and offered the benefit of improved tolerability compared to the conventional PEG 4L regimen.

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 cm(2) relative to those with VAT under 67.23 cm(2). 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.

Background/aims: The possibility of proximal lesion without distal polyps is a weak point of sigmoidoscopic colon cancer screening, but the clinical significance of distal findings for advanced proximal neoplasm (APN) is uncertain. The aim of this study was to assess the significance of a distal finding as a predictor of APN., Materials and Methods: Asymptomatic patients > or =50 years old were enrolled from among patients who underwent polypectomy at 11 tertiary medical centers during the Korean Association for the Study of Intestinal Disease prospective study conducted between July 2003 and March 2004. Polyps located distal to the splenic flexure were defined as distal polyps. An advanced neoplasm was defined as a polyp of > or =10 mm in size, and/or with villous features, and/or with high-grade dysplasia, or invasive cancer. Age, gender, and distal polyp size, appearance, and histology were analyzed as risk factors of APN. The sensitivity and positive predictive value of distal polyps for APN were calculated., Results: Data from 826 patients were analyzed. Mean patient age was 60.1 years (range 50-86), and 71.3% were men. APN was found in 98 patients, and 45 (45.9%) patients had no distal polyps. Risk factors of APN were a male gender, distal polyp size, and an advanced distal neoplasm. Sensitivities of a distal polyp of > or =10 mm and of an advanced distal neoplasm for APN were both 38.8% with positive predictive values of 13.3 and 14.4%, respectively., Conclusions: Although distal colon findings were found to be helpful for predicting APN in asymptomatic patients aged > or =50 years, APN without distal polyps requires careful consideration.

Background and Aims: Although the incidence of colorectal cancer is rising in Asian countries, there are no guidelines for its screening in this region due in part to the lack of epidemiological data regarding colorectal neoplasms. This study aimed to evaluate the prevalence of colorectal neoplasms in average-risk Koreans and to assess the effectiveness of screening colonoscopy in Korea., Methods: The prevalence of colorectal neoplasms was assessed by primary screening colonoscopy in 5,086 consecutive asymptomatic adults (males 70.5%; age 20-84 years) with no risk factors for colorectal cancer., Results: The overall prevalence of colorectal neoplasms in the 5,086 subjects was 21.9% and this increased linearly with age. Among the 2,435 subjects aged >or=50 years (males 66.7%; mean age 57.7 years), the prevalence of all colorectal neoplasms was 30.2% (males 35.9% vs females 18.7%; P < 0.001), while advanced neoplasms accounted for only 4.1% (males 5.1% vs females 2.0%; P < 0.001). The prevalence of advanced neoplasms in Korean men of a specific age group was similar to that of Korean women in the 10-years older age group. Also, Koreans in a specific age group showed a prevalence of advanced neoplasms similar to that of Westerners in the 10-years younger age group., Conclusions: Colonoscopy is a useful modality for colorectal cancer screening in Korea, as established in Western countries. However, the screening colonoscopy may begin at an older age for Koreans than for Westerners. Similarly, the optimal starting age for screening in Korean women may be higher than that in men by 10 years.

Aim: To evaluate and compare the clinical outcomes of prophylactic submucosal saline-epinephrine injection and saline injection alone for large colon polyps by conventional polypectomy., Methods: A prospective study was conducted from July 2003 to July 2004 at 11 tertiary endoscopic centers. Large colon polyps (> 10 mm in diameter) were randomized to undergo endoscopic polypectomy with submucosal saline-epinephrine injection (epinephrine group) or normal saline injection (saline group). Endoscopic polypectomy was performed by the conventional snare method, and early (< 12 h) and late bleeding complications (12 h-30 d) were observed., Results: A total of 561 polyps in 486 patients were resected by endoscopic polypectomy. Overall, bleeding complications occurred in 7.6% (37/486) of the patients, including 4.9% (12/244) in the epinephrine group, and 10.3% (25/242) in the saline group. Early and late postpolypectomy bleeding (PPB) occurred in 6.6% (32/486) and 1% (5/486) of the patients, respectively, including 4.5% (11/244), 0.4% (1/244) in the epinephrine group, and 8.7% (21/242), 1.7% (4/242) in the saline group. No significant differences in the rates of overall, early and late PPB were observed between the 2 groups. Multivariate stepwise logistic regression analysis revealed that large size (> 2 cm) and neoplastic polyps were independently and significantly associated with the presence of PPB., Conclusion: The prophylactic submucosal injection of diluted epinephrine does not appear to provide an additional advantage over the saline injection alone for the prevention of PPB.

Background: Colorectal neoplasm is rapidly increasing in Asia, but a guideline for screening is not available., Objective: To evaluate the characteristics of colorectal neoplasm in asymptomatic Asian subjects., Design: Prospective cohort study., Setting: Multinational multicenters, including both primary and referral centers in Asia., Patients: A total of 860 consecutive asymptomatic adults undergoing screening colonoscopy in 11 Asian cities from July 2004 to December 2004. Patients under 16 years old; those patients with a colorectal resection history, colonoscopies, or barium enema within 5 years; symptoms suggestive of colorectal diseases; and those who had undergone surveillance colonoscopy were excluded., Main Outcome Measurements: The incidence and distribution of colorectal neoplasm and advanced neoplasm., Results: The mean age (+/-SD) was 54.4+/-11.6 years; 471 were men (54.8%). The prevalence of colorectal neoplasm and advanced neoplasm was 18.5% and 4.5%, respectively. Male sex, advancing age, and a family history of colorectal cancer were risk factors for advanced neoplasm. Of the 168 patients with colorectal neoplasm, 76 had distal neoplasm only (45.2%), 66 had proximal neoplasm only (39.3%), and 26 had both proximal and distal neoplasms (15.5%). Although the presence of distal advanced neoplasm was a significant risk factor for proximal advanced neoplasm, 14 of the 758 subjects without distal neoplasm had proximal advanced neoplasm (1.8%)., Limitations: The small number of enrolled subjects, especially from certain ethnic groups., Conclusions: The overall prevalence of advanced colorectal neoplasm in asymptomatic Asians is comparable with the West. Male sex, advancing age, and a family history of colorectal cancer were associated with a higher risk of advanced neoplasm.

Objectives: The aims of this prospective study were to document the incidence of colon immediate postpolypectomy bleeding (IPPB) according to grade, and to identify potential risk factors of IPPB in patients who have received complete colonoscopy and polypectomy because of a colorectal polyp., Methods: This was a prospective, cross-sectional study of 5,152 patients treated at 11 tertiary medical centers between July 2003 and July 2004. Patient-related, polyp-related, and procedure-related variables were evaluated as potential risk factors for IPPB. IPPB was defined as a bleeding occurring during the procedure and was graded as G1-G4. Risk factors associated with IPPB were analyzed by univariate and multivariate logistic regression analysis., Results: A total of 9,336 colonic polyps were removed in 5,152 patients, and 262 (2.8%) colorectal polyps in 215 patients presented with IPPB. Polyp-based multivariate analysis revealed that old age (>or=65 yr), comorbid cardiovascular or chronic renal disease, anticoagulant use, polyp size greater than 1 cm, gross morphology of polyps such as pedunculated polyp or laterally spreading tumor, poorer bowel preparation, cutting mode of the electrosurgical current, and the inadvertent cutting of a polyp before current application were significant risk factors for IPPB., Conclusion: Nine factors have been found to be associated with IPPB and polypectomy should be undertaken with caution under these conditions.

Background/aims: Intestinal tuberculosis can be difficult to diagnose because it may mimic many other intestinal diseases. The aim of this study was to evaluate the diagnostic yield of colonoscopic biopsy and frequency of concomittent extra-intestinal tuberculosis in intestinal tuberculosis., Methods: The medical records of 225 consecutive patients with intestinal tuberculosis (81 men, 144 women; mean age 40.6 yrs) were analyzed retrospectively., Results: Histological examination of colonoscopic biopsy specimens revealed granulomas in 163 (72.4%) of the 225 patients. However, caseous necrosis was found in only 25 (11.1%) patients, and acid-fast bacilli (AFB) were noted in 39 (17.3%) of the 225 patients. Mycobacterium tuberculosis was isolated from the culture of biopsy specimens in 52 (29.3%) of 177 patients. Eighty-four patients (37.3%) had concomitant extra-intestinal tuberculosis and 67 (29.8%) showed active pulmonary tuberculosis. Histological examination of the biopsy specimens enabled the diagnosis of intestinal tuberculosis by the presence of either caseating granulomas or AFB in 52 (23.1%) patients. Combination of histological examination and Mycobacterium culture established the diagnosis in 87 (38.7%) patients. Before getting the result of Mycobacterium culture, the diagnosis could be made, by either histological examination or the presence of extra-intestinal tuberculosis in 107 (47.6%) patients. Combination of caseating granulomas, AFB staining, Mycobacterium culture, and the presence of extra-intestinal tuberculosis resulted in the diagnosis in 126 (56.0%) patients., Conclusions: To increase the diagnostic yield, AFB staining and Mycobacterium culture should be routinely performed on biopsy specimens in addition to routine histological examination for caseating granulomas.

Background: The aims of this study were to classify primary ileocolonic lymphomas according to colonoscopic findings and to determine the clinicopathologic relationship according to classes., Methods: Thirty-two patients (22 men, 10 women; age range 29 to 75 years) with primary malignant lymphoma of the terminal ileum and/or colorectum were studied. The clinicopathologic features were evaluated according to colonoscopic findings., Results: Thirty-six lesions in 32 patients were endoscopically classified as follows: fungating (14, 39%), ulcerofungating (11, 31%), infiltrative (5, 14%), ulceroinfiltrative (4, 11%), and ulcerative (2, 6%). Location of the lesions was as follows: terminal ileum, 15 (42%); colorectum, 14 (39%); both regions, 7 (19%). The most common histopathologic types were diffuse large cell (22, 69%) and large cell immunoblastic (5, 16%). There was no relationship between the endoscopic findings and histologic types. In 9 patients (28%), the clinical manifestation was intussusception, and all were found endoscopically to have the fungating type lesion., Conclusions: Primary ileocolonic lymphomas can be classified endoscopically into fungating, ulcerative, infiltrative, ulcerofungating, and ulceroinfiltrative types. Among these, fungating and ulcerofungating are the most frequent. Intussusception is a common clinical finding in ileocolonic lymphomas, occurring mainly in patients with the fungating type of lesion.

Background: Acute appendicitis is one of the most common causes of acute abdomen. Despite recent advances in radiologic imaging, the diagnosis of acute appendicitis may be difficult on occasion. The aims of this study were to describe the colonoscopic features of appendicitis and to determine whether colonoscopy can be used as an adjunct for the diagnosis of appendicitis in patients with atypical presentations., Methods: The colonoscopic findings in 21 patients (14 men, 7 women; average age 55 years) with a colonoscopic or histopathologic diagnosis of appendicitis were analyzed retrospectively. Colonoscopy was performed because diagnoses suggested by CT were other than acute appendicitis (11 patients), and/or the presenting clinical features were atypical for acute appendicitis with the duration of symptoms being 10 days or longer (17 patients)., Results: The colonoscopic diagnosis was acute appendicitis for all 21 patients. Seventeen underwent appendectomy, the diagnosis being verified in all cases. Of the 4 patients whose symptoms improved without appendectomy, 3 were considered to have acute appendicitis because pus was seen to drain from the appendiceal orifice at colonoscopy. A definite diagnosis could not be made in the remaining 1 patient. Therefore, the diagnosis of appendicitis was considered confirmed in 20 of 21 patients. Colonoscopic findings in these 20 patients included hyperemia (15) and bulging (18) at the appendiceal orifice area with surrounding mucosal edema (19), and drainage of pus from the appendiceal orifice (7)., Conclusion: Colonoscopy may be useful in the diagnosis of appendicitis when the clinical presentation is atypical for appendicitis and/or imaging studies are nondiagnostic.

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]

Objectives: To prospectively investigate how Buscopan affects the diagnosis of bowel inflammation by diffusion-weighted imaging MR enterography (DWI-MRE) in Crohn's disease (CD).Methods: Thirty CD patients without previous bowel surgery underwent DWI-MRE (b = 900 sec/mm2) before and after intravenous Buscopan. The 30 patients were randomly divided into two groups; using a crossover design, interpretations were made regarding the presence of restricted mural diffusion (i.e., bowel inflammation) in nine bowel segments in two separate reading sessions by two readers. The readers also judged restricted mural diffusion extent in each bowel segment on two side-by-side DWI-MRE images with a random right-to-left order. Ileocolonoscopy and conventional MRE interpreted by an expert panel were reference standards.Results: We analyzed 262 bowel segments. DWI-MRE without Buscopan significantly decreased sensitivity for both readers (58.8 % vs. 72.9 %, P = 0.046; 57.6 % vs. 85.9 %, P = 0.001) and did not significantly increase specificity (P = 0.085 and 0.396). Two readers noted that 28.6 % and 23.3 % of 262 bowel segments had greater diffusion restriction extent on DWI-MRE with Buscopan compared with DWI-MRE without Buscopan (P < 0.001) and 68.7 % and 74 %, respectively, had similar extent between them.Conclusion: Omitting Buscopan caused a greater loss in sensitivity of DWI-MRE than false-positive reduction for diagnosing bowel inflammation in CD.Key Points: • Omitting Buscopan significantly decreases DWI-MRE sensitivity for diagnosing bowel inflammation in CD. • Increase in the corresponding DWI-MRE specificity by omitting Buscopan is less apparent. • DWI-MRE without Buscopan underestimates the extent of bowel inflammation in CD. [ABSTRACT FROM AUTHOR]

In recent decades, the appearance of inflammation near the appendix in patients with distal ulcerative colitis (UC) has been highlighted. Many epidemiological studies have confirmed the link between appendectomy and decreased incidence of UC. However, the clinical significance of appendiceal orifice inflammation (AOI) or peri-appendiceal red patch (PARP) as a 'skip lesion' in UC has not been well elucidated. In this review, we summarized the literature regarding AOI/PARP and the role of this lesion in relation to UC. Since the appendiceal 'skip area' in UC was first described in 1958, several reports using histologic examination of colectomy specimens and colonoscopy have been published. AOI/PARP has been more frequently associated with distal, mild UC than extensive, severe disease. Although it is still controversial, AOI/PARP seems to have little prognostic implication in the disease course of UC, including remission, relapse and proximal disease extension. However, some case reports have raised the possibility of a relationship between AOI/PARP and appendiceal neoplasms such as appendiceal cystadenoma and appendiceal adenocarcinoma. In addition, some investigators have treated UC patients who were resistant to conventional medical therapy with appendectomy and have reported inconsistent therapeutic effect. Further research may lead to the discovery of etiologic and pathogenic roles of appendiceal inflammation in UC. [ABSTRACT FROM AUTHOR]

Background: Although the diagnostic and therapeutic values of double balloon endoscopy (DBE) have been investigated, the subjective tolerability to DBE has not been assessed. We aimed to evaluate patients' tolerability to DBE.Methods: We prospectively enrolled patients who underwent DBE. For the comparison of tolerability to DBE with that to esophagogastroduodenoscopy (EGD) and colonoscopy, those who had not undergone EGD nor colonoscopy were excluded. A total of 52 patients were included. All procedures were performed under conscious sedation with midazolam with or without pethidine. Patients' tolerability to DBE, EGD, and colonoscopy was assessed through an interview with a questionnaire using a 10-point Likert scale.Results: A total of 36 patients underwent both antegrade DBE and EGD under conscious sedation. The level of abdominal pain during procedures, the level of post-procedural abdominal discomfort, and the proportion of patients with persistent abdominal discomfort until the next morning were higher in antegrade DBE. However, when analyzed in 16 patients who had good quality of sedation, the differences in the level of abdominal pain during procedures and the persistent abdominal discomfort until the next morning disappeared. A total of 23 patients underwent both retrograde DBE and colonoscopy under conscious sedation. Tolerability parameters were not different between retrograde DBE and colonoscopy. Serious complications, including hemodynamic instability, did not occur during all procedures.Conclusion: Patients tolerated DBE well. DBE may be performed as comfortably as EGD and colonoscopy if the quality of sedation is good enough. [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.