Full Colonoscopy Research Articles

P0805 Sigmoidoscopy is sufficient as a surveillance tool in pediatric Ulcerative Colitis; full colonoscopy is not typically needed

Abstract Background Sigmoidoscopy is a less invasive procedure than full colonoscopy, demands simpler preparation, requires shorter procedure time, and may be conducted with lighter sedation. Despite these advantages and the continuous nature of inflammation in ulcerative colitis (UC), which typically decreases from distal to proximal colon, the FDA recently requests full colonoscopy to assess UC in clinical trials (i.e. 3 colonoscopies in 54 weeks). Data to support this requirement are scarce in children. We, thus, aimed to assess the necessity of full colonoscopy versus limited sigmoidoscopy in pediatric UC. Methods We included two prospectively enrolled cohorts of children (0-18 years) with UC, both with identical data collection relevant to this study: one from a single-center prospective registry, and the other from a prospective validation of the TUMMY-UC, a patient-reported signs and symptoms for pediatric UC. In addition to explicit clinical, disease activity, labs and demographic data, the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) was recorded prospectively for each colonic segment. The first colonoscopy available after the time of diagnosis was included to better mirror the scenario of post-treatment follow-up monitoring, since the diagnostic procedure should always be full colonoscopy. Results A total of 85 patients were included (mean age 14 ± 3.4, 11 [13%] with endoscopic healing, 45 [53%] with mild colitis and 29 [34%] with moderate-severe colitis). The median UCEIS scores decreased progressively from the rectum and sigmoid (2, IQR:0-4) to the more proximal colon (descending 1, IQR:0-3; transverse and ascending 0, IQR:0-2; p < 0.001). Only 3 patients (3.5%) had inflammation in proximal segments without having inflammation in the rectosigmoid region. Another 10 patients (12%) had higher inflammation scores in the proximal colon than in the rectosigmoid (i.e. reverse gradient), though inflammation was still present in the rectosigmoid region. Conclusion In 96.5% of cases, endoscopic healing in the rectosigmoid region reflected endoscopic healing in the entire colon in children with UC. When inflammation was present in the rectosigmoid, in 86% the degree of colitis reflected the maximal endoscopic severity of the entire colon. These findings suggest that sigmoidoscopy may be a suitable routine post-treatment surveillance tool for pediatric UC patients and in the research setting in order to maximize feasibility and ethical considerations of clinical trials.

P0347 Correlation between histologic disease activity in the distal and proximal colon in Ulcerative Colitis: A flexible sigmoidoscopy is insufficient to assess histology

Abstract Background Ulcerative Colitis (UC) is a chronic inflammatory bowel disease characterized by relapsing inflammation of the colon. Current therapeutic goals emphasize clinical and endoscopic remission; however, histological remission has emerged as an important target due to its association with reduced relapse rates and improved long-term outcomes. Despite this, limited data exist on the concordance of histological activity between colonic segments, especially in UC patients in clinical remission. This study investigates the correlation between histological disease activity in the rectosigmoid colon (RSC) and other colonic segments in patients with UC in clinical remission. Methods This prospective study analyzed data from 203 UC patients in clinical remission, defined as a partial Mayo score ≤2 and rectal bleeding score = 0 for at least three months. Colonoscopies with segmental biopsies were performed, and histological activity was assessed using the Geboes score. Histological remission was defined as a Geboes score <2A.0, while active disease was classified as ≥3.1. Correlation between histological activity in the RSC and other colonic segments was evaluated using Spearman’s correlation coefficients and logistic regression. Statistical significance was defined as p < 0.05. Results Among the 203 patients, the median age was 45 years, with 55.1% having pancolitis. Histological activity in the RSC showed poor correlation with other colonic segments. In patients with a RSC Geboes score of ≥3.1, the correlation coefficient between the RSC and descending colon was 0.05 (p = 0.62), between the RSC and transverse colon was -0.03 (p = 0.71), and between the RSC and right colon was 0.12 (p = 0.09). In patients with a RSC Geboes score of <2A.0, the correlation coefficient between the RSC and descending colon was 0.12 (p = 0.22), between the RSC and transverse colon was 0.05 (p = 0.59), and between the RSC and right colon was 0.18 (p = 0.01). Even among patients with pancolitis, histological concordance between segments remained low. These findings underscore substantial segmental variability in histological activity. Conclusion Flexible sigmoidoscopy (FS) is commonly used to monitor UC due to its practicality; however, our findings suggest FS may not reliably reflect proximal histological disease. The lack of concordance highlights the limitations of FS in accurately assessing histological remission, including in patients with pancolitis or extensive colitis. Full colonoscopy with segmental biopsies remains the gold standard for comprehensive disease evaluation and management. Further research is warranted to refine histologic assessment strategies in UC.

P0451 Using a machine learning model to assess agreement between inflammation in the rectosigmoid and entire colon in patients with ulcerative colitis

Abstract Background Limited endoscopy of the rectosigmoid colon is sometimes used to assess endpoints in clinical trials for ulcerative colitis (UC). However, there is inherent inter- and intra-rater variability in endoscopic assessment of inflammation, and regulatory agencies have suggested that full colonoscopy is preferred1,2,3. We used a machine learning (ML) model to compare the degree of inflammation of full-length endoscopy videos to that seen in the distal colon and rectum. Methods We used a previously developed ML model that predicts the endoscopy subscore4, a component of the modified Mayo Score, and applied it to 49 full-length endoscopy videos randomly selected and stratified by endoscopic severity from the Phase 3 induction trial for mirikizumab in UC (NCT03518086). Each video was preprocessed by a human reviewer to identify the point of maximal extent and the end of the procedure. The withdrawal portion of the videos were divided into 15, 30, or 60 second clips (a series of smaller segments of video), and the ML model generated an endoscopy subscore for each clip (clip-level endoscopy subscore) and for the entire video (video-level endoscopy subscore). We assigned the final two clips during withdrawal as an assessment of the sigmoid and rectum. Therefore, in this analysis, we compared the ML endoscopy subscore grade of the final two clips to the video-level endoscopy subscore. Kappa statistics of variability between scores were performed. Results There was substantial agreement between the video-level endoscopy subscore and that of the last 2 clips (Table 1). For 60-second clips, the agreement rate between the video-level endoscopy subscore and clip 1 was 0.67 and that with clip 2 was 0.76. When comparing the video-level endoscopy subscore to clip 1 or clip 2, the agreement rate was 0.86, and this was greater than the agreement rate when looking at the higher grade of clip 1 or clip 2 (0.73). The 60 second clips had greater agreement rates than 30 second or 15 second clips (Table 1 and 2). The endoscopy subscores of clip 1 or clip 2 had excellent agreement with video-level grades 0-3 (Table 2), and this was best observed with 60 second clips (Table 2A, kappa 0.944). Conclusion The ML model demonstrated excellent agreement between clip-level endoscopy subscore assessments of the distal most portion of the withdrawal videos compared to the video-level endoscopy subscore, and this was best observed with 60 second clips. These findings support the use of distal colon and rectum assessment to determine the grade degree of endoscopic inflammation of the full colonoscopy. We propose further prospective study of the use of this ML model in this setting. References Feagan, B. G., Khanna, R., Sandborn, W. J., Vermeire, S., Reinisch, W., Su, C., . . . & Sands, B. E. (2021). Agreement between local and central reading of endoscopic disease activity in ulcerative colitis: Results from the tofacitinib OCTAVE trials. Alimentary Pharmacology & Therapeutics, 54(11-12), 1442-1453. Hashash, J. G., Yu Ci Ng, F., Farraye, F. A., Wang, Y., Colucci, D. R., Baxi, S., . . . & Melmed, G. Y. (2024). Inter-and intraobserver variability on endoscopic scoring systems in crohn’s disease and ulcerative colitis: A systematic review and meta-analysis. Inflammatory Bowel Diseases, izae051. Food and Drug Administration. Ulcerative Colitis: Developing Drugs for Treatment [Internet]. 2022 [cited 2024 Oct 17]. Available from: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/ulcerative-colitis-developing-drugs-treatment Rubin, D. T., Gottlieb, K., Colombel, J. F., Schott, J. P., Erisson, L., Prucka, B., . . . & McGill, J. (2023). Development of a novel ulcerative colitis Endoscopic Mayo Score prediction model using machine learning. Gastro Hep Advances, 2(7), 935-942.

Is histopathological analysis necessary in patients undergoing sigmoidectomy for diverticular disease? A retrospective study.

The purpose of this study was to assess the utility of routine histopathological examination in patients undergoing elective sigmoidectomy for diverticular disease after full colonoscopy 1 year prior to surgery. We retrospectively analysed medical records of all patients undergoing sigmoidectomy for diverticular disease with a documented colonoscopy within 1 year before surgery from January 2013 to December 2023. We collected preoperative, intraoperative and postoperative data of all patients. The primary endpoint was the percentage of patients with an unexpectedly abnormal histopathological report compared to colonoscopy. During the study period, 207 patients undergoing sigmoidectomy for diverticular disease were included. Mean age was 62.7 ± 13.0 years and 97 (46.9%) patients were men. In eight (3.9%) cases an unexpected finding was noted on the histopathological examination: five (2.4%) of them were hyperplastic polyps with no dysplasia and no clinical relevance, two (1.0%) were polyps with low-grade dysplasia and in one case (0.5%) a diffuse large B-cell lymphoma was present in a patient with history of lymphoma treated in the past 10 years. The Goodman and Kruskal's G index was 0.953 (95% lower limit of 0.913), which indicated high concordance between the colonoscopy and the definitive histopathological examination. In our series, the preoperative colonoscopy reliably predicted the result of the histopathological specimen findings in patients undergoing sigmoidectomy for diverticular disease. Only one (0.5%) high-risk patient had an unexpected clinically significant finding. Therefore, routine histopathological examination may not be justified for all patients.

FP3.13 - Acute Complicated Diverticulitis: Colorectal Cancer in Disguise? Five Years of Follow-up Practice at a 600-bed Hospital

Abstract Aims Complicated diverticular disease is associated with colonic neoplasia rates of 7.8% to 10.9%. ACPGBI guidelines recommend optical or virtual colonoscopy six weeks following an attack of acute complicated diverticulitis unless performed within the preceding two years. It has been posited that flexible sigmoidoscopy may be sufficient to rule out malignancy given that diverticulitis predominantly affects the sigmoid colon. Five years of practice at a 600-bed hospital was audited to the ACPGBI standard and malignancy rates and locations investigated. Methods All emergency admissions coded for acute complicated diverticulitis from January 2017 to December 2022 were included. Patient electronic records were reviewed retrospectively for demographic data, operation notes, as well as radiology, endoscopy and histology reports. Results A total of 197 patients were included in the study period. 97 cases underwent emergency or semi-elective resection within one year. 8 patients had colonic visualisation in the two years prior to their attack, leaving 92 cases in whom colonic visualisation was indicated. 44 patients had colonoscopy, 22 had flexible sigmoidoscopy, 2 had CT colonography and 24 had no further imaging. 7 malignancies were identified, 5 from resection specimens and 2 from endoscopy. All tumours were in sigmoid colon. Conclusions The ACPGBI standard was met in 50% (46/92) of cases. If flexible sigmoidoscopy were deemed acceptable this would increase to 74% (68/92). Malignancy was identified in 4% (7/197) of cases. All malignancies were in the range of flexible sigmoidoscopy, suggesting full colonoscopy may be superfluous. Less extensive endoscopy may reduce procedure duration, bowel preparation and patient discomfort.

A Phase II Trial of Celecoxib with Neoadjuvant Concurrent Chemoradiation for Patients with Localized Rectal Adenocarcinoma Stage II and III

Abstract Background In recent years, neoadjuvant chemoradiation and subsequent surgical resection with total mesorectal excision has been shown to increase local control with decreased toxicity in comparison to upfront surgical resection followed by adjuvant chemoradiation. Neoadjuvant chemoradiotherapy is the standard treatment for locally advanced rectal cancer. In this study we evaluated the efficacy of adding a selective COX-2 inhibitor to standart neoadjuvant chemoradiation on pathologic response, sphincter preservation and acute toxicity. Materials and Methods Thirty patients with Adenocarcinoma of rectum (up to 15 cm of anal verge) were enrolled in this phase 2 study. Patients undergone full colonoscopy, MRI rectal protocol, abdomino-pelvic and chest CT scan for staging then received neoadjuvant concurrent chemoradiation (capecitabine 825 mg/m2 bid in combination with celecoxib 200 mg bid and radiotherapy (50-50.4Gy/25-28fraction). Surgery was done 5-12 weeks after chemoradiation. Acute complications were scored by common toxicity criteria 5.0 and tumor response was graded according to AJCC and CAP guidelines for rectal adenocarcinoma. Results Of 30 patients, total mesorectal excision was done in 22 patients. Tumor regression grade was reported as: 7 patients (31.8%) had grade 0 or complete response, 7 patients (31.8%) had grade 1 or moderate response, 6 patients (27%) had grade 2 or minimal response and 2 patients (9%) had grade 3 or poor response. Primary tumor down staging was 63% and nodal down staging was 73% with sphincteric preservation rate of 77% among the operated cohort. No patients had hematologic or cardio-vascular toxicity. Conclusion Results indicate celecoxib in combination with neoadjuvant chemoradiation is safe and associated with low toxicity. This combination can promote pathologic complete response, tumor regression grade, sphincteric preservation, T and N down staging in rectal adenocarcinoma.

Automatic assessment of bowel preparation by an artificial intelligence model and its clinical applicability.

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.

Differences Between the 2016 and 2022 Food and Drug Administration Guidance-Implications for Design and Interpretation of Clinical Trials in Ulcerative Colitis.

In 2022, the Food and Drug Administration (FDA) updated its draft guidance for drug development in ulcerative colitis, replacing the version from 2016. Several changes from the 2016 version merit further discussion as they impact clinical trial design and the interpretation of trial results. We compared both documents and critically appraised the changes and implications for future clinical trials. The 2022 guidance recommends full colonoscopy, rather than flexible sigmoidoscopy, to document disease activity in all involved segments of the colon. The concordance between the findings of the 2 procedures is very high and there is little evidence to support colonoscopy over sigmoidoscopy. The use of colonoscopy, rather than sigmoidoscopy, is also associated with a higher burden to trial participants who must undergo full bowel preparation, cost, and a potential for more adverse events. The definition of the Mayo endoscopic score of 0 was changed from the original publication to "normal appearance of mucosa," which suggests that endoscopic signs of prior disease, such as pseudopolyps and scarring, are incompatible with a score 0, even though they are not associated with active disease. The term "mucosal healing" has been abolished and histologic outcomes defined as exploratory. A welcome change is that shorter washout periods than 5 half-lives will be considered to reduce patient exposure to corticosteroids as bridging therapy. The 2022 FDA draft guidance includes changes which for the most part are not informed by empirical evidence, which may ultimately complicate interpretation of future trials and preclude comparisons with past trials.

Enfermedad diverticular

Diverticula are sac-like protrusions that appear in the weak points of the colon wall. They are usually asymptomatic. Diverticular disease develops when symptoms appear. Its etiopathogenesis is likely multifactorial, although it is not fully known. Complicated diverticulosis includes acute diverticulitis, which is the most frequent complication and one of the most common reasons for consultation in emergency departments, and diverticular hemorrhage, one of the most frequent causes of lower gastrointestinal bleeding in our setting. A diagnosis of acute diverticulitis is established through an abdominal computed tomography scan. A diagnosis of hemorrhage is established by performing a full colonoscopy, for which adequate prior preparation of the patient by means of taking an oral laxative solution is recommended. The treatment of acute diverticulitis has classically been based on the use of antibiotics, although current evidence supports a decrease in the use of antibiotic treatment in patients with uncomplicated acute diverticulitis. In this disease, antibiotics must target a polymicrobial etiology consisting mainly of gram-negative and anaerobic bacilli.

Screening for colorectal cancer by full colonoscopy in first-degree relatives of colorectal cancer patients: a multicentric study by the Italian League for the Fight against Cancer.

Colorectal cancer currently presents the third-highest incidence of cancers worldwide, making secondary prevention through screening programs for colorectal cancer, usually by Fecal Occult Blood Testing, an essential preventive medicine intervention. First-degree relatives of colorectal cancer patients are a particularly at-risk group, with indications to consider direct screening by full colonoscopy. Colonoscopy is considered the gold standard for diagnosing colorectal cancer, as it has high sensitivity and specificity, and is both a diagnostic and therapeutic tool. However, it requires significant organizational and financial resources, and has a small but relatively higher risk of complications as opposed to fecal occult blood testing. The present study aimed to assess the appropriateness of a screening program without age restrictions of CRC by full colonoscopy in asymptomatic, first-degree adult relatives of patients with colorectal cancer, aiming both to actively increase screening coverage and to determine the detection rate of precancerous lesions and colorectal cancer in this population. Uncontrolled interventional study - colorectal cancer screening by full colonoscopy for at-risk population. The Italian League for the Fight against Cancer started a colorectal cancer screening program by full colonoscopy for first-degree relatives of colorectal cancer patients in 1998 in the province of Latina, Lazio Region, Italy. The program was expanded to the provinces of Rieti, Lazio Region, and Sassari, Sardinia Region, in 2014 and 2016 respectively, and was concluded in 2018. Subjects were actively and voluntarily recruited by the study's working group. Subjects that had already been subjected to a full colonoscopy in the preceding 5 years were excluded from this study. Identified neoplastic lesions were treated either directly or referred to the Day Hospital setting, and histologically diagnosed following World Health Organization guidelines. In total, 2,288 subjects (age range 15-88, mean 52.3 yrs, M/F = 946/1,204) were screened by colonoscopy, of which 103 (4.5%) were incomplete and 2,173 (95.0%) complete, with data on colonoscopy performance missing for 12 participants. Out of 468 positive outcomes on colonoscopy, diagnosis for 422 (204M/173F), 19.4% of total subjects, was adenomatous polyps and 46 (20M/20F), 2.1% of total subjects, was colorectal cancer. Female sex was a protective factor against a positive test outcome, with a 35% reduction compared to male sex, with OR=0.64 95%CI (0.52-0.80). On the other hand, being over 50 years of age was found to be a risk factor, making a positive outcome more than twice as likely, with OR=2.3 95%CI (1.8-2.9). Subjects over 50 also had significantly more instances of multiple adenomas being found, however the size distribution of found adenomas was not significantly different between subjects under and over 50, despite size being a predictor of risk of neoplastic progression. Given the high detection rate of precancerous lesions and colorectal cancer in the studied population, it is our opinion that guidelines should continue to recommend earlier and more frequent screening in first-degree relatives of patients with colorectal cancer, and, barring the introduction of more cost-effective and/or lower risk procedures with a similar efficacy profile, maintain the use of colonoscopy as the main screening option.

P492 All intestinal ultrasound scores for ulcerative colitis (and IBUS-SAS) strongly correlate with endoscopic activity: a prospective study

Abstract Background Intestinal ultrasound (IUS) is gaining increasing acceptance as a reliable tool for tight monitoring of ulcerative colitis (UC). Although several IUS scores have been proposed, none has been formally implemented into official recommendations of international scientific societies. This study aims to compare the available IUS score for UC, in terms of correlation with endoscopic activity. Methods Patients with UC ≥ 18 years old undergoing partial or full colonoscopy between April and October 2023 were prospectively included. Endoscopic evaluation of at least the sigmoid colon was mandatory for inclusion, and patients with proctitis (Montreal E1) were excluded. Endoscopic activity was scored with both the Mayo Endoscopic Subscore (MES) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and defined by MES ≥ 1 and UCEIS ≥ 2. IUS was performed within 4 weeks of endoscopy. The Milan Ultrasound Criteria (MUC, Allocca et al.), the UC-IUS score (Bots et al.), the US Score from Parente et al., and the score from Hata et al. were included in the analysis. Applicability of the US Score from Civitelli et al, an IUS score developed for paediatric patients, and the IBUS-SAS, an IUS score validated for Crohn’s disease, was also evaluated. The Spearman’s rank coefficient (rho = ρ) was used to perform correlations, while receiver operating characteristic (ROC) curves were compared with the Hanley & McNeil method. Results Fifty-nine patients were included, of which 59.3% and 50.8% showed any endoscopic activity using the MES and the UCEIS, respectively. Detailed information about the population is reported in Table. All the evaluated IUS scores showed a significant positive correlation with endoscopic activity (p < 0.001), with the UC-IUS score and the US Score from Civitelli et al. outperforming the others both with MES (ρ = 0.745, ρ = 0.762) and UCEIS (ρ = 0.751, ρ = 0.769). The same scores showed the highest Areas Under the Curve (AUC) for detecting a MES ≥ 2 (UC-IUS: 0.841, 95%CI 0.722-0.923, p < 0.001; Civitelli et al.: 0.842, 95%CI 0.724-0.924, p < 0.001) [Figure]. The optimal cut-offs for detecting a MES ≥ 2 with both the MUC and the Civitelli score were similar to that proposed by the Authors (> 5.04 vs > 6.20 and > 2 vs > 1, respectively). Conclusion All the included IUS scores showed good correlation with endoscopic activity. The UC-IUS and the US Score from Civitelli et al. performed better than the others in detecting a MES ≥ 2 and might be suggested to monitor disease activity of UC and intervene early during disease relapse.

P658 Safety and efficacy of MH002, an optimized live biotherapeutic product, for the treatment of mild to moderate ulcerative colitis: a first-in-disease, double-blind, randomized clinical trial

Abstract Background Treatment options for patients with mild to moderate ulcerative colitis (UC) failing 5-ASA are limited. MH002 is an optimized consortium of 6 non-pathogenic, well-characterized commensal bacteria with immune modulating, wound healing and gut barrier protective effects. This study evaluated the safety, efficacy, and mechanistic effects of MH002 in mild to moderate UC. Methods In this 2:1-randomized, double-blind, placebo-controlled first-in-disease study (EudraCT 2020-001355-33), 45 patients with mild to moderate active UC (Modified Mayo Score [MMS] =4-8 but including Mayo Endoscopic Sub-score [MES] ≥2) received treatment with 400mg MH002 or placebo (PBO) once daily for 8 wks. Full colonoscopies with biopsies were performed at baseline and wk8, biopsies and endoscopy videos were scored by blinded central readers. The primary endpoint was the rate of treatment-emergent adverse events (TEAEs). Exploratory efficacy endpoints included clinical remission (MMS ≤2 with all sub-scores ≤1 and rectal bleeding sub-score =0), endoscopic improvement (MES ≤1), and UC-100 and biomarker normalisation (C-reactive protein [CRP] ≤5mg/L, faecal calprotectin [FCP] ≤250mg/kg). Changes from baseline (CFBL) in MES and stool consistency (Bristol Stool Form Scale) were also evaluated. Results MH002 was safe and well tolerated: a TEAE was reported in 11/31 (35%) patients with MH002 and in 8/14 (57%) with PBO. Most TEAEs were mild and unrelated to study treatment. Early discontinuations (7/45; 16%) occurred similarly in both groups. At wk8, patients achieved clinical remission, endoscopic improvement, and biomarker improvements at higher rates with MH002 vs PBO (Table 1). Clinical remission rates were 14% for MH002 vs 7% for PBO (Per-protocol Set [PPS]: 18% vs 0%). Significant differences in favour of MH002 over PBO were seen in the CFBL for MES at wk8 (P=0.05, 1-sided Wilcoxon) and for stool consistency at wk2 (P=0.0057, 1-sided Student t). In total, 14/45 (31%) and 36/42 (86%) patients had elevated CRP and FCP levels at baseline, resp. Of these, more patients treated with MH002 achieved normalisation at wk8 (CRP: 60% vs 25%; FCP: 36% vs 15%). Decreases in FCP and stool consistency with MH002 were observed as early as wk2 and were greater than with PBO through wk8 (Fig 1). Conclusion MH002 treatment was safe and well tolerated and resulted in clinically meaningful improvements in disease activity and inflammatory parameters. MH002 therefore represents a promising new treatment for mild to moderate UC patients insufficiently controlled with 5ASA. These results warrant further development in a phase 2/3 study.

P921 Maintenance of clinical, biochemical and transmural remission in inflammatory bowel disease patients switching from intravenous to subcutaneous infliximab

Abstract Background Subcutaneous (SC) infliximab (IFX) effectively maintains biochemical, clinical and endoscopic remission in inflammatory bowel disease (IBD) with a comparable safety profile to intravenous (IV) formulation. Transmural healing is considered a desirable long-term treatment endpoint in IBD, especially in Crohn’s disease (CD). Whether switching from intravenous to SC-IFX effectively maintains transmural remission in IBD is still unknown. Methods This is a preliminary report from a prospective multicentre cohort study on IBD patients in clinical and endoscopic remission on IV-IFX treatment switched to SC-IFX. Enrolled patients were followed-up for 12 months, with fecal calprotectin (FC), C-reactive protein (CRP), infliximab trough levels and anti-drug antibodies (ADAs) measured at baseline, at 3, 6 and 12 months. Intestinal ultrasound (IUS) was performed at baseline and every six months. At month 12 a full colonoscopy was performed for mucosal healing assessment. Remission rates and safety profile were subsequently recorded. T-Test and ANOVA for mean comparisons and Kaplan-Meier estimates were used for survival curves. Results 43 IBD patients (69% males) were enrolled, 58% with CD, of whom 52% reported a history of perianal disease. Median disease duration and IFX therapy were 6 (IQR 3-12) and 5 (IQR 2-9) years, respectively. During a median follow-up of 311 (range 122-489) days, clinical remission rate was 98% (Harvey-Bradshaw Index <5 and Mayo score <2). No reactivation of perianal disease was reported. FC and CRP remained stable at each time point (p> 0.05). The median baseline infliximab level was 10.02 ( range 0.1- 41.84) ug/ml. Undetectable infliximab levels (<1 ug/ml) and positive ADAs were found in 6 and 14 patients, respectively; at 3 months, a significant increase in infliximab levels (mean increase 27.5 ng/ml; ± 12.5 SD; p< 0.001) and a progressive decrease of ADAs titer were observed, despite unchanged SC-IFX dose. At baseline, all patients had normal bowel wall thickness (i.e. ileum ≤ 3mm, colon≤4 mm) and a Limberg score ≤1at IUS; reactive lymphadenopathies were reported in 5 patients and a mild abdominal effusion in 1. No significant changes were shown during follow-up. Mild endoscopic activity was found in 2 out 30 patients who performed follow-up endoscopy. Regarding safety profile 12 mild infectious events, 2 mild cutaneous injection site reaction and 1 non-IBD related hospital admission were observed. Conclusion Switching from IV to SC infliximab in a selected cohort of IBD patients confirmed to be safe and effective in maintaining clinical, biochemical, and transmural remission. IUS is a useful, non-invasive and low-cost tool for periodic disease assessment in this subset of patients.

Assessing Guidelines on the Need for Colonoscopy after Initial Flexible Sigmoidoscopy in Young Patients with Outlet-Type Rectal Bleeding.

While young age of onset colorectal cancer is increasing in incidence lack of screening leads to symptomatic presentation, often with rectal bleeding. Because most cancers in patients under 50 are left-sided, flexible sigmoidoscopy is a reasonable way of investigating bleeding in these patients. To predict which patients undergoing flexible sigmoidoscopy for outlet rectal bleeding need a full colonoscopy. Findings at colonoscopy were compared with published indications for colonoscopy after flexible sigmoidoscopy. These were: (1) Any number of advanced adenomas defined as a tubular adenoma >9 mm, a tubulovillous or villous adenoma of any size, or any adenoma with high grade dysplasia. (2) Three or more tubular adenomas of any size or histology. (3) Any sessile serrated lesion. (4) Twenty or more hyperplastic polyps. Charity Hospital with volunteer specialists. Under age 57, outlet type rectal bleeding, undergoing flexible sigmoidoscopy at least to the descending colon, followed by colonoscopy with biopsy of all resected lesions. Flexible sigmoidoscopy and colonoscopy with excision of all removable lesions. Findings at colonoscopy. 66 cases who had a colonoscopy between 5 and 811 days after sigmoidoscopy, who also had complete data. Forty-three male and 23 female with mean age of 39.5 years. Analysis of flexible sigmoidoscopy criteria for finding proximal high-risk lesions on colonoscopy showed a sensitivity of 76.9%, a specificity of 67.9%, a positive predictive value of 37%, a negative predictive value of 92.3%, and an accuracy of 69.7%. Large number of exclusions for inadequate colonoscopy or inadequate data causing reduced patient number in the study. Our criteria for follow-up colonoscopy based on the findings at initial flexible sigmoidoscopy in young patients with outlet rectal bleeding are reliable enough to be used in routine clinical practice, provided this is audited.

Safety of full bowel preparation and colonoscopy in elderly patients with ulcerative colitis: A real-world multicenter retrospective cohort study.

The number of elderly patients with ulcerative colitis (UC) has been increasing worldwide. Complications are common in elderly patients who undergo colonoscopy, raising doubts about whether colonoscopy should be performed in the same way in this age group as in younger patients. The aim of this study was to determine the safety of full bowel preparation and colonoscopy in elderly patients with UC. We retrospectively reviewed a cohort of patients with UC who had visited any of the 12 hospitals and were registered in our inflammatory bowel disease database. We compared complications associated with colonoscopy and bowel preparation and relapse of UC after colonoscopy in 133 patients aged ≥65 years with UC (the elderly group) and 116 randomly selected patients aged <65 years with UC (the non-elderly group). Nine elderly patients were not referred for colonoscopy by their physicians because of poor performance status or advanced age. There was no significant between-group difference in the complication rate (p = 0.57) or frequency of relapse of UC after colonoscopy (p = 0.67). The findings of this study indicate that colonoscopy can be performed as safely in elderly patients with UC as in their younger counterparts. However, our results also indicate that colonoscopy is often avoided in elderly patients, possibly because of concerns about safety.

SPATIAL CONCORDANCE OF LEFT AND RIGHT COLON FINDINGS IN PEDIATRIC PATIENTS WITH ULCERATIVE COLITIS AFTER TREAMTENT

Achieving endoscopic remission has become the preferred clinical endpoint in the care of inflammatory bowel disease (IBD) patients. This requires repeat colonoscopy in patients with ulcerative colitis (UC) after initiation of therapy. Recent adult data suggests findings in the left colon on flexible sigmoidoscopy can be highly predictive of the findings if a full colonoscopy was performed; however, pediatric data is lacking for this association. The primary aim our study to assess the accuracy of findings on the left colon with the right colon for repeat endoscopy in pediatric patients with UC.

SPATIAL CONCORDANCE OF LEFT AND RIGHT COLON FINDINGS IN PEDIATRIC PATIENTS WITH ULCERATIVE COLITIS AFTER TREAMTENT

Abstract OBJECTIVES Achieving endoscopic remission has become the preferred clinical endpoint in the care of inflammatory bowel disease (IBD) patients. This requires repeat colonoscopy in patients with ulcerative colitis (UC) after initiation of therapy. Recent adult data suggests findings in the left colon on flexible sigmoidoscopy can be highly predictive of the findings if a full colonoscopy was performed; however, pediatric data is lacking for this association. The primary aim our study to assess the accuracy of findings on the left colon with the right colon for repeat endoscopy in pediatric patients with UC. METHODS This was a retrospective chart review of pediatric patients with UC seen at a single, academic center between 2010-2021. Patient demographics, clinical disease activity, laboratory values and endoscopic findings were collected. The Mayo Endoscopy Score (MES) was used to assess the findings in the right and left colon by a single reader (JM). Histologic findings were assessed using the Geobes index by a pathology resident (AKA) and over-read by an attending pathologist (SS). Weighted kappa correlation was used to assess concordance between left and right colon endoscopic and histologic findings. Receiver operator curve (ROC) analysis was used to assess the accuracy of left-sided findings predicting right-sided findings. RESULTS We analyzed repeat endoscopies from 57 patients, of which 31 (54.4%) were male, mean age at UC diagnosis was 13.5 ± 4.1 years, 53 (93%) were Caucasian. Most common medication was oral mesalamine (67.2%) and most common distribution was pancolitis (53.4%). Mean time between index and repeat colonoscopy was 11.3 months. On repeat colonoscopy, endoscopic findings on the left colon moderately correlated with findings on the right colon [(κ = 0.53 (0.30-0.75)], similarly histologic findings for the left and right colon had a moderate correlation [(κ = 0.41 (0.17-0.64)]. Area under the ROC (AUC) was 0.89 for endoscopic remission anywhere in the colon and 0.98 for complete endoscopic healing anywhere in the colon. Longer interval between the index and follow-up colonoscopy did not affect odds of concordance. CONCLUSIONS We found that endoscopic and histologic severity correlated between the right and left colon for repeat assessment after initiation of biologic therapy. Left sided findings were highly accurate for endoscopic remission and complete endoscopic healing anywhere in the colon. This data suggest a flexible sigmoidoscopy could be feasible in lieu of full colonoscopy when assessing for endoscopic remission in pediatric patients with UC, to reduce the burden to the family and healthcare system. Further, prospective studies with a central reading component for histology and endoscopy are needed to validate these findings.

Факторы риска плохой подготовки к колоноскопии и сравнение способов очищения кишечника в педиатрии

Objective. To study the influence of constipation in the anamnesis, diet as risk factors for inadequate bowel preparation for colonoscopy in children, after bowel preparation with sodium picosulfate with magnesium citrate , cleansing enemas or with combination of both. Patients and methods. Children (1 year – 17 years 11 months) were referred for routine colonoscopy to two children's hospitals in Moscow and were randomly assigned three types of preparation for the research. Exclusion criteria were the need for an emergency colonoscopy, kidney disease, or colectomy. All patients were prescribed low-fiber diet during three days before the procedure. Endoscopists did not know about the method of preparation and evaluated the effectiveness of preparation according to the Boston Bowel Preparation Scale (BBPS ), noting the maximum depth of insertion of device (intubation of the cecum, ileum, etc.). Tolerability of methods and adherence of diet were assessed using the questionnaire for patients, as well as by the incidence of undesirable effects. The BBPS of ≥2 in 3 segments of the colon (left, transverse, right) was considered satisfactory, while BBPS &lt;2 in more than 1 segment was considered unsatisfactory. Results. 440 children (mean age 12 years) were randomly assigned to bowel preparation with sodium picosulfate with magnesium citrate (n = 135), cleansing enemas (n = 79) or combination (n = 226) . The satisfactory result of preparation was achieved in 127 (94.1%) patients in the bowel preparation with sodium picosulfate group, in 71 (90%) in the group with cleansing enemas and in 201 (89%) using the combined method (BBPC value for bowel preparation with sodium picosulfate 7.0 (6.0–8.0), Cleansing enemas 7.0 (5.0–8.0), Combination 6.5 (6.0–8.0), p = 0.009). Analysis of logistic regression showed that age, body mass index and the presence of a diagnosis of constipation in the anamnesis did not affect (p &gt; 0.05)to success of achieving the satisfactory result of bowel preparation in all groups (p &gt; 0.05). However, constipation was associated with depth of insertion and intubation of the cecum and/or terminal ileum, which was 6.8 times less likely in patients with constipation (OR = 0.146; 95% CI: 0.036–0.602, p = 0.014). In patients who followed the diet, inadequate bowel preparation was observed with a probability of 7.4 times less (OR = 0.135; 95% CI: 0.053–0.345, p &lt; 0.001). In children who followed the dosage, the probability of inadequate bowel preparation was also 7.393 times lower, regardless of the method of preparation (OR = 0.135; 95% CI: 0.053–0.345, p &lt; 0.001). Frequency of undesirable effects between the groups was almost the same, there was no statistically significant difference (sodium picosulfate 29%, cleansing enemas 27%, combination 39%, p = 0.03). Conclusion. The results of our study show that in children without constipation on diet and adequate doses of medicines makes it easier to tolerate preparation, qualitatively prepare the intestines and conduct full colonoscopy. We consider that these criteria are the most important for bowel cleansing and the quality of the colonoscopy performed in children, regardless of the methods of colon preparation. Key words: colonoscopy, children, pediatrics, preparation

SAFETY AND EFFECTIVENESS OF LEFT SIDE COLONOSCOPY OR SIGMOIDOSCOPY VERSUS TOTAL COLONOSCOPY IN PATIENTS LESS THAN 45 YEARS OLD AGE PRESENTED WITH THE PERIANAL DISEASE AT KURDISTAN CENTER FOR GASTROENTEROLOGY/SULAIMANIYAH

Background &#x0D; Colonoscopy and flexible sigmoidoscopy are recommended tools for diagnosing colorectal diseases, but their relative effectiveness needs to be clarified. Direct comparisons of colonoscopy and sigmoidoscopy in the same population would help inform patients, providers, and policymakers about patients presented with perianal features and colorectal cancer (CRC) screening options.&#x0D; Objectives &#x0D; To evaluate the ability of each of these two modalities (colonoscopy and sigmoidoscopy) to reach the diagnosis in patients presenting with features suggestive of perianal disease and to determine factors that predict safely performing left-sided colonoscopy in patients less than forty-five years old given with features suggestive of perianal disease. &#x0D; Materials and Methods&#x0D; This prospective cross-sectional study will be conducted between the 1st of January 2021 and the 1st of January 2022 in the department of KCGH (Kurdistan center for gastrointestinal and Hepatology) / Teaching- Hospital, Sulaymaniyah City, Iraq. One thousand patients presented with features (bright red bleeding per-rectum, blood on toilet tissue, pain and itching in anal region, anal soiling) of perianal disease were subjected to sigmoidoscopy and extended to full colonoscopy. The patients are divided into two groups, each group of 500 patients. The first group (basic group) includes patients younger than 45 years and the second group (comparison group) includes patients aged equally and more than 45 years.&#x0D; Results&#x0D; The mean age of the primary group is about 33 years. All patients underwent sigmoidoscopy and extended to total colonoscopy with terminal ileal intubation; in the basic group, we have 48 (4.8%) patients with left side polyps (10 large and 38 small polyps) and 16 (1.6%) right side polyps (2 large and 14 small polyps), in this group, we have only 6 (0.6%) patients with left side colonic mass and no cases of right side colonic mass, while in comparison group we have 115 (11.5%) cases with left side colonic polyp (27 large and 88 small polyps) and about 86 (8.6%) cases of right side colonic polyp, regarding detecting mass in this group we have 20 (2.0%) cases of left side colonic mass and 6 (0.6%) cases of right side colonic mass.. &#x0D; Conclusion&#x0D; Colonoscopy and sigmoidoscopy are important tools for investigating patients presenting with perianal features. While both are sensitive to detecting pathology in the left side of the colon, our study concluded that although colonoscopy is the ideal procedure for detecting lesions in the whole colon (proximal &amp; distal to splenic flexure), limited colonoscopy up to splenic flexure can be safely carried out in patients less than 45 years old presented with perianal diseases.

A video based benchmark data set (ENDOTEST) to evaluate computer-aided polyp detection systems

Background and aims Computer-aided polyp detection (CADe) may become a standard for polyp detection during colonoscopy. Several systems are already commercially available. We report on a video-based benchmark technique for the first preclinical assessment of such systems before comparative randomized trials are to be undertaken. Additionally, we compare a commercially available CADe system with our newly developed one. Methods ENDOTEST consisted in the combination of two datasets. The validation dataset contained 48 video-snippets with 22,856 manually annotated images of which 53.2% contained polyps. The performance dataset contained 10 full-length screening colonoscopies with 230,898 manually annotated images of which 15.8% contained a polyp. Assessment parameters were accuracy for polyp detection and time delay to first polyp detection after polyp appearance (FDT). Two CADe systems were assessed: a commercial CADe system (GI-Genius, Medtronic), and a self-developed new system (ENDOMIND). The latter being a convolutional neuronal network trained on 194,983 manually labeled images extracted from colonoscopy videos recorded in mainly six different gastroenterologic practices. Results On the ENDOTEST, both CADe systems detected all polyps in at least one image. The per-frame sensitivity and specificity in full colonoscopies was 48.1% and 93.7%, respectively for GI-Genius; and 54% and 92.7%, respectively for ENDOMIND. Median FDT of ENDOMIND with 217 ms (Inter-Quartile Range(IQR)8–1533) was significantly faster than GI-Genius with 1050 ms (IQR 358–2767, p = 0.003). Conclusions Our benchmark ENDOTEST may be helpful for preclinical testing of new CADe devices. There seems to be a correlation between a shorter FDT with a higher sensitivity and a lower specificity for polyp detection.