Comparison of cold snare endoscopic mucosal resection and hot snare endoscopic mucosal resection for small colorectal polyps: a randomized controlled trial.

Incomplete resection rates vary among endoscopists performing cold snare polypectomy. Cold snare endoscopic mucosal resection (CS-EMR) is the technique of cold resection after submucosal injection to reduce incomplete resection. This study aimed to evaluate the efficacy and safety of CS-EMR for small colorectal polyps compared to hot snare endoscopic mucosal resection (HS-EMR). Preplanned sample size required 70 polyps to CS-EMR group or HS-EMR group, respectively. Patients with polyps sized 6-9 mm were randomly allocated to either the CS-EMR or the HS-EMR group. The primary outcome was residual or recurrent adenoma (RAA) rate. A total of 70 and 68 polyps were resected using CS-EMR and HS-EMR, respectively. In the intention-to-treat population, the RAA rate was 0% in the CS-EMR group and 1.5% in the HS-EMR group (risk difference [RD], - 1.47; 95% confidence interval [CI] - 4.34 to 1.39). En bloc resection rate was 98.6% and 98.5% (RD, - 0.04; 95% CI - 4.12 to 4.02); the R0 resection rate was 55.7% and 82.4% (RD, - 27.80; 95% CI - 42.50 to - 13.10). The total procedure time was 172 s (IQR, 158-189) in the CS-EMR group and 186 s (IQR, 147-216) in the HS-EMR group (median difference, - 14; 95% CI - 32 to 2). Delayed bleeding was 2.9% vs 1.5% (RD, 1.37; 95% CI - 3.47 to 6.21) in both groups, respectively. CS-EMR was non-inferior to HS-EMR for the treatment of small colorectal polyps. CS-EMR can be considered one of the standard methods for the removal of colorectal polyps sized 6-9 mm.

Clinical audit of endoscopic sub-mucosal dissection performed for complex lateral spreading colorectal tumors from a region non-endemic for colorectal cancer.

BACKGROUND: Endoscopic resection is currently the treatment of choice for laterally spreading tumors (LSTs). Endoscopic sub-mucosal dissection (ESD) can achieve higher enbloc resection and R0 resection, albeit at a slightly higher risk of complications. Given scarce data on ESD from India, we performed a retrospective analysis of our experience with colorectal ESD (CR-ESD) to know its clinical efficacy and complications as well as to assess the learning curve of CR-ESD in non-endemic-areas. METHODS: Retrospective analysis of prospectively maintained datasheet performed. All patients with large (>2cm), complex or recurrent colorectal LST who underwent ESD at our center between 2012 and 2021 were included in the study. Various baseline lesion-related parameters, procedure-related parameters, enbloc resection (ER) rates, R0 margins and adverse event rates were retrieved. CUSUM analysis was performed to calculate the minimum required procedures to achieve competency in CR-ESD. RESULTS: Total 149 patients were included in the study; mean patient age was 61.36±18.21 years. Most patients had lesions in rectum (n=102; 68.5%) followed by sigmoid colon (n=25; 16.8%). The mean lesion size was 46.62 ± 25.46 mm and the mean procedure duration for ESD was 219.30 ± 150.05 min. ER was achieved in 94.6% of lesions. R0 resection was achieved in 132 patients (88.6%). Overall, six (4%) adverse events were noted, of which one required surgical intervention. As many as 105 patients (70.5%) had adenomatous lesions on histology. Seventy-four patients underwent follow-up colonoscopy, of which three had a recurrence of adenomatous lesions and five had post-resection stricture requiring endoscopic dilation. CUSUM curve analysis calculated the learning curve for ESD was 47 resections for ER and 55 for the occurrence of AEs, with a composite CUSUM at 47 procedures. CONCLUSION: CR-ESD even in non-endemic area is associated with high en bloc resection rates, R0 resection rates and acceptable complication profile. Approximately 50 cases of CR-ESD are required to achieve competency.

Colorectal Post-polypectomy Bleeding in Outpatient versus Inpatient Treatment: Propensity Score Matching Analysis.

Objectives: Delayed bleeding is the most frequent adverse event associated with endoscopic mucosal resection (EMR) and hot snare polypectomy (HSP) of colorectal polyps. However, whether the incidence of delayed bleeding differs between outpatient and inpatient treatment is unknown. Therefore, in this study, we aimed to evaluate delayed bleeding rates between outpatient and inpatient endoscopic treatments and clarify the safety of outpatient treatment. Methods: We enrolled 469 patients (1077 polyps) and 420 patients (1080 polyps) in the outpatient and inpatient groups, respectively, who underwent EMR or HSP for colorectal polyps at our institution between April 2020 and May 2023. Using propensity score matching, we evaluated the delayed bleeding rates between the two groups. Delayed bleeding was defined as a hemorrhage requiring endoscopic hemostasis occurring within 14 days of the procedure. Results: Propensity score matching created 376 (954 polyps) matched patient pairs. The median maximum diameter of polyps removed was 10 mm in both groups. Delayed bleeding rates per patients were 1.3% (5/376) in the outpatient group and 2.9% (11/376) in the inpatient group (P=0.21). In term of per polyp, early delayed bleeding (occurring within 24 hours) rates were higher in the inpatient group than outpatient group (0.2% [2/954] vs. 1.1% [10/954], respectively; P=0.04). No severe bleeding requiring a transfusion occurred in either group. Conclusions: Outpatient endoscopic treatment did not increase delayed bleeding compared with inpatient treatment. Outpatient treatment would be safe and common for the removal of colorectal polyps.

Combined Endoscopy-Laparoscopy Surgery: When and How to Utilize This Tool.

Combined endoscopic and laparoscopic surgery (CELS) has been used to resect colon polyps since the 1990s. These colon-sparing techniques, however, have not yet been widely adopted. With the evolution of technology in both diagnosing and treating colon cancer, colorectal surgeons should strive for a diverse and complete armamentarium through which they can best serve their patients. In this article, we hope to provide clarity on CELS by discussing three topics: (1) the history and fruition of CELS; (2) the techniques involved in CELS; and (3) the utility of CELS within different clinical scenarios. Our goal is to educate readers and stimulate consideration of CELS in select patients who might benefit greatly from these techniques.

Risk factors and prediction model for delayed bleeding after cold snare polypectomy: a retrospective study.

BACKGROUND: Delayed bleeding (DB) is a serious complication after cold snare polypectomy (CSP) for polyps in the colon. The present study aimed to investigate the incidence and risk factors of DB after CSP and to develop a risk-scoring model for predicting DB. METHODS: A retrospective study was conducted in four Chinese medical institutions. 10650 patients underwent CSP from June 2019 to May 2023. The study analyzed the rate of DB and extracted the general clinical information and polyp-related information of patients with postoperative DB. As a control, non-DB patients who received CSP at the same 4 hospitals were analyzed. A multivariate Cox regression analysis was performed to develop the prediction model. The model was further validated using a Kaplan-Meier log-rank analysis, receiver operating characteristic curve (ROC) plot and risk plot. RESULTS: In our study, we found a 0.24% rate of DB and the risk factors were history of hypertension, hyperlipidemia, antithrombotics use, antiplatelet use, anticoagulant use, abdominal operation, sigmoid colon lesion, hematoma, cold snare defect protrusion, polyp size, wound size, the grade of wound bleeding, and morphology of Ip. These factors were incorporated into the prediction model for DB after CSP. For 1, 3, and 5 days of bleeding, the AUC of the ROC curve was 0.912, 0.939, and 0.923, respectively. The Kaplan-Meier analysis indicated that the high-risk group had a significantly higher risk of DB than the low-risk group. CONCLUSIONS: This study screened the risk factors and established a prediction model of DB after CSP. The results may help preventing and reducing the DB rate after CSP of colorectal polyps.

Tubular Adenoma Arising Within a Rectosigmoid Xanthoma: A Case Report.

Colonic xanthomas are a rare finding, particularly when combined with a tubular adenoma in a single polyp. While transformation to malignancy is not thought to be higher than that of a tubular adenoma alone, there is still concern as to the pathophysiology of xanthoma formation within the colon and what that may mean for patient outcomes. Here, we present a patient undergoing a routine screening colonoscopy with the removal of a rectosigmoid polyp consistent with xanthoma and tubular adenoma histopathology. Proper follow-up for identification of possible metabolic derangements and increased colonic surveillance is recommended to mitigate the risk of further xanthoma or adenocarcinoma formation.

CT colonography has advantages over colonoscopy for size measurement of colorectal polyps.

PURPOSE: The aim of this study was to compare the accuracy of colonoscopy (CS) and CT colonography (CTC) in the measurement of colorectal polyps using pathological size as a reference. MATERIALS AND METHODS: The analysis included 61 colorectal polyps in 28 patients who underwent preoperative CTC at our institution. All polyps were endoscopically resected. Polyp sizes were measured by CS and CTC. Endoscopic polyp size was extracted from endoscopy records written by one of two endoscopists (A with 11 and B with 6 years of endoscopic experience, respectively), who estimated the size visually/categorically without any measuring devices. After matching the location, the polyp size was measured on CTC using manual three-dimensional (3D) measurement on a workstation. The sizes of resected polyps were also measured after pathological inspection. Differences of the polyp size between CTC and histology, and between CS and histology were compared using paired t tests. Differences in measurement between the two endoscopists were also analyzed. RESULTS: The mean diameters of polyps measured using CS, CTC, and pathology were 10.5 mm, 9.2 mm, and 8.4 mm, respectively. There was a significant correlation between CS and pathology, as well as between CTC and pathology (both P < 0.0001). The correlation coefficient for CS (r = 0.86) was lower than that for CTC (r = 0.96). The correlations between CS and pathology for endoscopists A and B were 0.90 and 0.89, respectively. CONCLUSION: Measurements of polyp size using CTC were closer to the pathological measurements compared to those by CS, which exhibited greater variability. This suggests that CTC may be more suitable for polyp size measurements in the clinical setting if patients undergo CTC concurrently with colonoscopy.

Association of Helicobacter pylori infection with colorectal polyps/adenomas: A single-center cross-sectional study.

BACKGROUND: Helicobacter pylori (H. pylori) infection may be associated with colorectal polyps/adenomas, but the current evidence remains controversial. METHODS: We retrospectively screened the medical records of 655 participants who underwent both colonoscopy and H. pylori test from June 15, 2020 to April 30, 2023. The number, size, location, and pathological type of colorectal polyps/adenomas were compared between H. pylori positive and negative groups. Adjusting for age, gender, smoking, drinking, hypertension, diabetes, fatty liver, body mass index, and inflammatory and metabolic indicators, multivariate logistic regression analyses were performed to evaluate the association of H. pylori infection with the number, size, location, and pathological type of colorectal polyps/adenomas, where no polyp/adenoma was used as reference. RESULTS: Overall, 508 participants were included, of whom 154 and 354 were divided into H. pylori positive and negative groups, respectively. H. pylori positive group had significantly higher colorectal polyps/adenomas (74.7 % vs. 65.8 %, P=0.048), low-grade adenomas (55.7 % vs. 47.6 %, P=0.026), advanced adenomas (22.6 % vs. 13.3 %, P=0.008), and colorectal polyps/adenomas with sizes of ≥6 mm (61.7 % vs. 48.5 %, P=0.002) and ≥10 mm (25.2 % vs. 14.6 %, P=0.004) than H. pylori negative group. In multivariate logistic regression analyses, H. pylori infection was independently associated with low-grade adenomas (OR=2.677, 95 %CI=1.283-5.587, P=0.009), advanced adenomas (OR=3.017, 95 %CI=1.007-9.036, P=0.049), right-side colon polyps/adenomas (OR=5.553, 95 %CI=1.679-18.360, P=0.005), and colorectal polyps/adenomas with sizes of ≥10 mm (OR=4.436, 95 %CI=1.478-13.310, P=0.008), but not number of colorectal polyps/adenomas. CONCLUSION: H. pylori infection is associated with increased risk of colorectal polyps/adenomas, especially low-grade adenomas, advanced adenomas, right-side colon polyps/adenomas, and large colorectal polyps/adenomas.

Analysis of Immunohistochemical Expression of BRAF (V600E) Mutation in Serrated Colorectal Polyps: A Study from Tertiary Hospital in Oman.

BACKGROUND AND AIM: Colorectal cancer (CRC) is considered one of the most common cancers in the world. Serrated polyps were found to be precursor lesions for CRC. BRAF mutation (V600E) has been strongly linked to the development of these lesions. No previous study concerning BRAF immunohistochemical expression in serrated polyps- was done in Oman. The primary objective of our study was to assess the prevalence of BRAF (V600E) mutation in serrated colorectal polyps in the Omani population. The secondary objectives were to assess the prevalence of serrated polyps and their characteristic features: type, site and size as well as the relationship between BRAF (V600E) mutation and polyp type, site and size. MATERIALS AND METHODS: Ninety-one hyperplastic polyps (HP) (76.5%), 24 sessile serrated lesions (SSL) (20.2%) and 4 cases of tubular adenomas with low grade dysplasia (3.4%) were studied for BRAF (V600E) immunohistochemical expression. No case of traditional serrated adenoma (TSA) was present. Control cases of craniopharyngioma and papillary thyroid carcinoma were included. RESULTS: BRAF (V600E) IHC was positive in 63 of the HP polyps (69.2%), 13 SSLs (54.2%) and none of the adenomatous polyps. The majority of positive polyps (75.0%) were ≤5 mm in size, 17.9% were 5-10 mm and 7.1% were ≥10 mm in size.  The majority of BRAF (V600E) positive polyps (68.1 %) were in the distal colon and 31.9 % were in the proximal colon. The majority of positive cases for BRAF (V600E) were showing multiple polyps (61.8 %). None of the tubular adenomas showed any BRAF (V600E) positivity. CONCLUSION: Serrated polyps are now well known for their potential to develop CRC. Immunohistochemistry is an easy and reproducible way to detect BRAF (V600E) mutation. Our study showed there is high prevalence (64.3%) of BRAF mutation in serrated polyps in the Omani population. The majority of these polyps- were HP and SSL; and ≤5 mm in size and located in the distal colon.

A Case of Osseous Metaplasia in a Juvenile Rectal Polyp.

Rectal mucosal prolapse is uncommon in children. While most patients present with rectal bleeding and constipation, the occurrence of osseous metaplasia within the prolapsed mucosa is extremely rare. Overlapping clinical, gross, and histological features between rectal mucosal prolapse polyps and malignancy pose a challenge for diagnoses. We describe a case of a 16-year-old male who had a rectal mucosal prolapsed polyp with osseous metaplasia. He initially presented due to periumbilical pain with a sore throat and fever. Incidentally, during the workup of his periumbilical pain, he was found to have a soft tissue mass in his rectum on a CT scan, with a biopsy confirming the diagnosis. The case was complicated by the development of sepsis. The patient was treated with empiric antibiotics and was discharged without further complications.

Rationalizing polyp matching criteria in colon capsule endoscopy: an international expert consensus through RAND (modified DELPHI) process.

Background: Colon capsule endoscopy (CCE) has gained momentum as an alternative modality for the investigation of the lower gastrointestinal tract. Of the few challenges that remain, the comparison and - eventually - matching of polyps at different timestamps leads to the potential for double reporting and can contribute to false-positive findings and inaccuracies. With the impending artificial intelligence integration, the risk of double reporting the same polyp due to the lack of information on spatial orientation underscores the necessity for establishing criteria for polyp matching. Objectives: This RAND/University of California, Los Angeles (modified Delphi) process aims to identify the key factors or components used to match polyps within a CCE video. This involves exploring the attributes of each factor to create comprehensive polyp-matching criteria based on international expert consensus. Design: A systematic qualitative study using surveys. Methods: A panel of 11 international CCE experts convened to assess a survey comprised of 60 statements. Participants anonymously rated statement appropriateness on a 1-9 scale (1-3: inappropriate, 4-6: uncertain and 7-9: appropriate). Following a virtual group discussion of the Round 1 results, a Round 2 survey was developed and completed before the final analysis. Results: The factors that were agreed to be essential for polyp matching include (1) timestamp, (2) polyp localization, (3) polyp vascular pattern, (4) polyp size, (5) time interval of the polyp appearance between the green and yellow camera, (6) surrounding tissue, (7) polyp morphology and (8) polyp surface and contour. When five or more factors are satisfied, it was agreed that the comparing polyps are likely the same polyp. Conclusion: This study has established the first complete criteria for polyp matching in CCE. While it might not provide a definitive solution for matching difficult, small and common polyps, these criteria serve as a framework to guide and facilitate the process of polyp-matching.

Creating criteria and standards for matching polyps (abnormal growth in the bowels) on colon capsule video analysis: an international expert agreement using the RAND (modified Delphi process) process Background: Doctors often use colon capsule endoscopy (CCE), a high-tech capsule with two cameras, to record and check for diseases in the small and large bowels as the capsule travels through the intestines. One of the most common conditions in the large bowel is polyps, which are abnormal growths in the lining of the bowel. Comparing and matching polyps in the same video from the capsule can be tricky as they look very similar, leading to the possibility of incorrectly reporting the same polyp twice or more. This can lead to wrong results and inaccuracies. The literature did not have any criteria or standards for matching polyps in CCE before. Aim: Using the RAND/UCLA (modified Delphi) process, this study aims to identify the key factors or components used to match polyps within a CCE video. The goal is to explore each factor and create complete criteria for polyp matching based on the agreement from international experts. Method: A group of 11 international CCE experts came together to evaluate a survey with 60 statements. They anonymously rated each statement on a scale from 1 to 9 (1-3: inappropriate, 4-6: uncertain, and 7-9: appropriate). After discussing the Round 1 results virtually, a Round 2 survey with the same but revised questions was created and completed before the final analysis of their agreement. Results: The main factors for matching polyps are 1) the timing when the polyp was seen, 2) where it is in the bowel, 3) its blood vessel pattern, 4) size, 5) the timing of its appearance between cameras, 6) surrounding tissue features, 7) its shape, and 8) surface features. If five or more of these factors match, the compared polyps are likely the same. Conclusion: This study establishes the first complete criteria for matching polyps in CCE. While it may not provide a definitive solution for matching challenging and small polyps, these criteria serve as a guide to help and make the process of polyp matching easier.

APOE genotype, eicosapentaenoic acid (EPA) supplementation and n-3 highly unsaturated fatty acid (HUFA) levels in patients with multiple colorectal polyps: A secondary analysis of the seAFOod polyp prevention trial.

INTRODUCTION: We examined the relationship between Apolipoprotein E (APOE) genotype and n-3 highly unsaturated fatty acid (HUFA) levels in participants of the seAFOod trial, who were undergoing colonoscopy surveillance after removal of colorectal polyps. METHODS: Baseline and on-treatment (eicosapentaenoic acid [EPA] 2 g daily or placebo for 6 months) levels of n-3 HUFAs, and plasma 18-hydroxyeicosapentaenoic acid (HEPE), were analysed according to APOE genotype (based on polymorphisms rs429358 and rs7412) in 584 participants. RESULTS: Before treatment, APOE2/2 individuals had lower levels, and APOE4/4 participants had higher levels, of n-3 HUFAs, including EPA, than APOE3/3 counterparts (P < 0.01 for the APOE2/2 versus APOE4/4 comparison). After EPA supplementation, n-3 HUFA levels were not significantly different when stratified by APOE genotype, although APOE4 carriers displayed lower plasma 18-HEPE levels than individuals without an APOE4 allele (P = 0.002). CONCLUSIONS: APOE genotype is associated with differential n-3 HUFA and 18-HEPE levels in individuals with multiple colorectal polyps.

Relationship between Helicobacter pylori infection and colorectal polyp/colorectal cancer.

Helicobacter pylori (H. pylori) plays an important role in the development of gastric cancer, although its association to colorectal polyp (CP) or colorectal cancer (CRC) is unknown. In this issue of World Journal of Gastrointestinal Surgery, Zhang et al investigated the risk factors for H. pylori infection after colon polyp resection. Importantly, the researchers used R software to create a prediction model for H. pylori infection based on their findings. This editorial gives an overview of the association between H. pylori and CP/CRC, including the clinical significance of H. pylori as an independent risk factor for CP/CRC, the underlying processes of H. pylori-associated carcinogenesis, and the possible risk factors and identification of H. pylori.

Computer-aided diagnosis system for optical diagnosis of colorectal polyps under white light imaging.

OBJECTIVES: This study presents a novel computer-aided diagnosis (CADx) designed for optically diagnosing colorectal polyps using white light imaging (WLI).We aimed to evaluate the effectiveness of the CADx and its auxiliary role among endoscopists with different levels of expertise. METHODS: We collected 2,324 neoplastic and 3,735 nonneoplastic polyp WLI images for model training, and 838 colorectal polyp images from 740 patients for model validation. We compared the diagnostic accuracy of the CADx with that of 15 endoscopists under WLI and narrow band imaging (NBI). The auxiliary benefits of CADx for endoscopists of different experience levels and for identifying different types of colorectal polyps was also evaluated. RESULTS: The CADx demonstrated an optical diagnostic accuracy of 84.49%, showing considerable superiority over all endoscopists, irrespective of whether WLI or NBI was used (P < 0.001). Assistance from the CADx significantly improved the diagnostic accuracy of the endoscopists from 68.84% to 77.49% (P = 0.001), with the most significant impact observed among novice endoscopists. Notably, novices using CADx-assisted WLI outperform junior and expert endoscopists without such assistance. CONCLUSIONS: The CADx demonstrated a crucial role in substantially enhancing the precision of optical diagnosis for colorectal polyps under WLI and showed the greatest auxiliary benefits for novice endoscopists.

The Relationship Between Serum Lipids and the Formation of Colorectal Polyps.

BACKGROUND AND AIMS: Obesity, metabolic syndrome, and hyperlipidemia are known as risk factors for colorectal tumors. Colorectal polyps are accepted as potential precursors of colorectal cancer (CRC). This study was designed to clarify the association between the levels of serum lipids and the presence of colorectal polyps. METHODS: This study was conducted at Basaksehir Cam and Sakura City Hospital, Gastroenterological Surgery Clinic, Istanbul, Turkey. We retrospectively analyzed patients who underwent colonoscopy with serum lipid profile within one month for a one-year period. Groups were analyzed in terms of the correlation between hyperlipidemia and the formation of polyps. The study group was also evaluated in terms of the polyp type, localization, and number. RESULTS: Among 453 patients, females were 248 and males were 211, with a mean age of 56.7. The study and control groups involved 259 and 194 patients, respectively. The age and serum levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglyceride (TG) were found to be statistically significant in terms of polyp presence and number (p < 0.05). CONCLUSION: Colorectal polyps are well-known precursors of CRC. We found that the combination of elevated serum levels of low-density lipoprotein cholesterol, total cholesterol, and triglycerides may be a risk predictor for the presence of colorectal polyps, which can be advantageous in cancer screening.

Demographic and clinical profile of patients undergoing colonoscopy at a tertiary care center in Nepal: a retrospective cross-sectional study.

Background: Colonoscopy is widely used as a tool for diagnosis, screening and treatment of various pathologies in the rectum, colon, and terminal ileum. The aim of this study is to evaluate the demographic, clinical, and histological parameters of the records of patients undergoing colonoscopy at a tertiary care hospital in Nepal. Materials and methods: This retrospective cross-sectional study included the hospital records of all patients who underwent colonoscopy from 2015 to 2019 in a tertiary care centre in Nepal. Results: A total of 1255 records were included in the study. The mean and standard deviation of age were 43.8 and 19 years, respectively. Among the total study population, 61.9% were males and 38.1% were females. Common indications for colonoscopy included lower gastrointestinal bleeding (27.7%), altered bowel habit (26.9%) and persistent or recurrent abdominal pain (17.3%). Only 3% of the patients who underwent colonoscopy had inadequate bowel preparation. The overall diagnostic yield of colonoscopy was 57.5%. Findings during colonoscopy included colorectal polyp (19.4%), internal haemorrhoids (8.2%) and colitis (6.5%). Having an age of 50 or more years was significantly associated with the presence of colorectal adenocarcinoma (P=0.017, χ2 test) with an odds ratio of 2.35 (95% CI: 1.14, 4.89). Furthermore, having a female sex was found to be significantly associated with the presence of colorectal adenocarcinoma (P=0.012, χ2 test) with an odds ratio of 2.43 (95% CI: 1.19, 4.97). Conclusion: In the authors' study, a smaller proportion of the colonoscopies was aimed at screening for colorectal carcinoma (CRC), when compared to studies in developed countries. The sex predisposition of CRC in the authors' study is in contrast to the global trend. The authors recommend conducting studies to determine the risk factors and need for CRC screening in the Nepalese population.

Protocol for a prospective multicenter randomized controlled trial to evaluate the efficacy of texture and color enhancement imaging (TXI) observation in the detection of colorectal lesions (deTXIon study).

Colonoscopy is the gold standard for detecting and resecting adenomas or early stage cancers to reduce the incidence and mortality rates of colorectal cancer. In a recent observational study, texture and color enhancement imaging (TXI) was reported to improve polyp detection during colonoscopy. This randomized controlled trial involving six Japanese institutions aims to confirm the superiority of TXI over standard white-light imaging (WLI) in detecting colorectal lesions during colonoscopy. During the 1-year study period, 960 patients will be enrolled, with 480 patients in the TXI and WLI groups. The primary endpoint is the mean number of adenomas detected per procedure. The secondary endpoints include adenoma detection rate, advanced adenoma detection rate, polyp detection rate, flat polyp detection rate, depressed lesion detection rate, mean polyps detected per procedure, sessile serrated lesion (SSL) detection rate, mean SSLs detected per procedure and adverse events.

Implementing narrow banding imaging with dual focus magnification for histological prediction of small rectosigmoid polyps in Vietnamese setting.

Background and Aim: Small rectosigmoid colorectal polyps (<10 mm) are prevalent, with a low prevalence of advanced neoplastic lesions. The "diagnose-and-leave" strategy, employing narrow band imaging (NBI), is gaining popularity for its safety and cost-effectiveness by reducing polypectomy complications and minimizing histopathology expenses. This study assessed the diagnostic efficacy of NBI with dual focus (DF) magnification for real-time neoplastic prediction of rectosigmoid polyps and explored the feasibility of implementing this strategy in Vietnam. Methods: In a prospective single-center study, 307 rectosigmoid polyps from 245 patients were analyzed using three consecutive endoscopic modes: white light endoscopy (WLE), NBI, and NBI-DF. Endoscopists assessed polyps for size, location, macroscopic shape, optical diagnosis, and confidence levels before histopathological evaluation. High confidence was assigned when the polyp exhibited all features of a single histology type. Predictions were compared with final histopathology results. Results: Of the total, 237 (77.2%) were diminutive (≤5 mm) polyps, and 18 (5.8%) were advanced neoplastic lesions. WLE + NBI and WLE + NBI + NBI-DF exhibited significantly higher accuracy compared to WLE (88.6% and 90.2% vs 74.2%, P < 0.01). For diminutive polyps, the DF mode significantly increased the rate of high-confidence optical diagnoses (89.1% vs 94.9%, P < 0.001). WLE + NBI + NBI-DF demonstrated high sensitivity (90.1%), specificity (95.5%), and negative predictive value (93.4%) in high-confidence predictions, enabling the implementation of the "diagnose-and-leave" strategy. This approach would have reduced 58.2% of unnecessary polypectomies without missing any advanced neoplastic lesions. Conclusion: NBI and DF modes provide accurate neoplastic predictions for rectosigmoid polyps. For diminutive polyps, DF magnification improves the confidence level of the optical diagnosis, allowing the safe implementation of the "diagnose-and-leave" strategy.

Multi-scale nested UNet with transformer for colorectal polyp segmentation.

BACKGROUND: Polyp detection and localization are essential tasks for colonoscopy. U-shape network based convolutional neural networks have achieved remarkable segmentation performance for biomedical images, but lack of long-range dependencies modeling limits their receptive fields. PURPOSE: Our goal was to develop and test a novel architecture for polyp segmentation, which takes advantage of learning local information with long-range dependencies modeling. METHODS: A novel architecture combining with multi-scale nested UNet structure integrated transformer for polyp segmentation was developed. The proposed network takes advantage of both CNN and transformer to extract distinct feature information. The transformer layer is embedded between the encoder and decoder of a U-shape net to learn explicit global context and long-range semantic information. To address the challenging of variant polyp sizes, a MSFF unit was proposed to fuse features with multiple resolution. RESULTS: Four public datasets and one in-house dataset were used to train and test the model performance. Ablation study was also conducted to verify each component of the model. For dataset Kvasir-SEG and CVC-ClinicDB, the proposed model achieved mean dice score of 0.942 and 0.950 respectively, which were more accurate than the other methods. To show the generalization of different methods, we processed two cross dataset validations, the proposed model achieved the highest mean dice score. The results demonstrate that the proposed network has powerful learning and generalization capability, significantly improving segmentation accuracy and outperforming state-of-the-art methods. CONCLUSIONS: The proposed model produced more accurate polyp segmentation than current methods on four different public and one in-house datasets. Its capability of polyps segmentation in different sizes shows the potential clinical application.

Effectiveness of Dual-Focus Magnification on Confidence Levels in Optical Diagnosis of Small Colorectal Polyps.

Background and objectives Achieving accurate real-time optical diagnoses of colorectal polyps with high-confidence predictions is crucial for appropriate decision-making in daily practice. The dual-focus (DF) magnification mode helps endoscopists scrutinize subtle features of polyp surfaces and vessel patterns. This prospective study aimed to evaluate the impact of DF imaging on enhancing the rate of high-confidence narrow-band imaging (NBI)-based optical diagnosis. Methods Consecutive adult patients who underwent colonoscopy and had small colorectal polyps (<10 mm) were enrolled between September 2022 and May 2023. The optical diagnosis of each polyp was evaluated during colonoscopy in two stages by the same endoscopist, utilizing NBI with DF magnification (NDB-DF). A confidence level was assigned to each prediction. High confidence was indicated by clinical judgment when a polyp exhibited distinctive features associated solely with one histological subtype and lacked characteristics of any other subtype. All procedures were carried out with a prototype 190 series Exera III NBI system (Olympus Corporation, Tokyo, Japan) with DF magnification. Results The study included 413 patients with 623 polyps, comprising 483 ≤ 5 mm and 140 measuring 6-9 mm. The majority were low-grade adenomas (343 lesions), with 17 identified as high-grade adenomas, and none characterized as deep submucosal invasive carcinomas. NBI-DF significantly improved the rate of high-confidence optical diagnoses compared to NBI for both ≤ 5 mm polyps (93.1% vs. 87.5%, p < 0.0001) and 6-9 mm polyps (97.9% vs. 94.2%, p = 0.03). Furthermore, DF significantly facilitated the assessment of microvessel and surface pattern criteria (p < 0.01). Conclusion DF magnification markedly enhanced the rate of high-confidence NBI-based optical predictions for small colorectal polyps. This technique demonstrates the potential for improving the diagnostic yield in real-time optical diagnosis of colorectal polyps in the Vietnamese setting.