Delayed Cancer Registration and Estimation of Screening Colonoscopy Effects.

This cohort study assesses the magnitude of cancer registration delays and their estimated affects on the NordICC trial results assessing the long-term effects of screening colonoscopy in preventing colorectal cancer.

Magnetic navigation-assisted colonoscopic enteral tube placement in swine (with video): a preliminary study.

BACKGROUND: Colonoscopic enteral tube placement using current methods has some shortcomings, such as the complexity of the procedure and tube dislodgement. The magnetic navigation technique (MNT) has been proven effective for nasoenteral feeding tube placement, and is associated with reduced cost and time to initiation of nutrition. This study attempted to develop a novel method for enteral tube placement using MNT. METHODS: The MNT device consisted of an external magnet and a 12 Fr tube with a magnet at the end. Ten swine were used, and bowel cleansing was routinely performed before colonoscopy. Intravenous anesthesia with propofol and ketamine was administered. A colonoscopic enteral tube was placed using the MNT. The position of the end of the enteral tube was determined by radiography, and angiography was performed to check for colonic perforations. Colonoscopy was used to detect intestinal mucosal damage after tube removal. RESULTS: MNT-assisted colonoscopic enteral tube placement was successfully completed in all pigs. The median operating time was 30 (26-47) min. No colon perforation was detected on colonography after enteral tube placement, and no colonic mucosal bleeding or injury was detected after the removal of the enteral tube. CONCLUSIONS: MNT-assisted colonoscopic enteral tube placement is feasible and safe in swine and may represent a valuable method for microbial therapy, colonic drainage, and host-microbiota interaction research in the future.

Long-term outcomes for Advanced Colorectal Polyps in the BowelScreen Programme.

Aims: Colonoscopies performed as part of a colorectal cancer screening programmes regularly identify large non-pedunculated colorectal polyps (LNPCPs). Endoscopic Mucosal Resection (EMR) is a minimally invasive endoscopic resection strategy, for effective management of LNPCPs. There is limited published data on clinical outcomes for EMR carried out within screening programmes. Methods: A retrospective analysis of a prospectively-maintained EMR database of BowelScreen patients in a single centre over a 5 year period. Results: Fifty-two polyps in 50 patients underwent EMR in the study period. Median polyp size was 25mm (range 20-70mm). Adenocarcinoma was identified in 7.8% of resection specimens (n 4/51). Complications were recorded in 5.7% of EMRs (n 3/52). Surveillance was completed for 87.8% (n=36/41) of eligible patients with a site-check recurrence rate of 8.3% (n 3/36). Recurrence was successfully managed endoscopically through the surveillance programme with an 18 month recurrence rate of 2.7% (n 1/36). Surgery was avoided in 92% (n 46/50) of patients undergoing EMR. Discussion: Complex polyps identified in the colorectal cancer screening programme are effectively and definitively managed by minimally invasive endoscopic resection.. Low recurrence and complication rates underscore the value of EMR as part of a screening programme. Post-EMR surveillance identifies a small number of endoscopically manageable recurrences, with encouragingly high levels of compliance.

Adverse events after colonoscopy in a randomised colorectal cancer screening trial.

OBJECTIVE: Colonoscopy-related adverse events increase the burden of colorectal cancer (CRC) screening. This cross-sectional study evaluates adverse events during and after colonoscopy in a large, randomised CRC screening trial in Norway comparing sigmoidoscopy to immunochemical testing for faecal blood. METHODS: We included all individuals who underwent colonoscopy at two screening centres between 2012 and 2020. From medical records, we retrieved data on adverse events during and within 30 days after colonoscopy and classified them according to the American Society for Gastrointestinal Endoscopy lexicon for endoscopic adverse events. Multivariable logistic regression models were fitted to identify risk factors for adverse events. RESULTS: Of the 10 244 included individuals, 242 (2.4%) had at least one adverse event that was possibly, probably, or definitively related to the colonoscopy. 188 (1.8%) had mild adverse events, 50 (0.49%) had moderate, 3 (0.03%) had severe, and 1 had a fatal adverse event. The most frequent adverse events were lower gastrointestinal bleeding (0.86%), abdominal pain (0.48%), vasovagal reaction (0.39%), postpolypectomy syndrome (0.20%), and perforation (0.08%). 23 (0.22%) individuals had non-gastrointestinal adverse events. Risk factors associated with adverse events were older age, female sex, screening centre, anticoagulant therapy, number of polypectomies, size of lesion removed, presence of proximal lesion, and adenocarcinoma. Adverse event rates per endoscopist ranged from 0% to 4.9%. CONCLUSION: Adverse events after colonoscopy of screening positives occurred in about 2 out of 100 procedures. Three-quarters of events were mild. Awareness of risk factors may help endoscopists to mitigate the risk. TRIAL REGISTRATION NUMBER: NCT01538550.

Predicting mucosal inflammation in IBD patients using patient-reported symptom scores and a faecal calprotectin home test: protocol for a multicentre prospective validation study.

INTRODUCTION: Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases (IBD) with a relapsing-remitting nature. With adequate non-invasive prediction of mucosal inflammation, endoscopies can be prevented and treatment optimised earlier for better disease control. We aim to validate and recalibrate commonly used patient-reported symptom scores combined with a faecal calprotectin (FC) home test as non-invasive diagnostic tool for remote monitoring of IBD, both in daily practice and in a strict trial setting. Endoscopy will be used as the gold standard. METHODS AND ANALYSIS: In this multicentre prospective validation study, adult IBD patients are asked to fill out questionnaires regarding disease activity (Monitor IBD At Home, mobile Health Index, Manitoba IBD Index, IBD control and patient-HBI/patient-Simple Clinical Colitis Activity Index), perform a FC home test and collect a stool sample for routine laboratory FC measurement, before the start of the bowel preparation for the ileocolonoscopy. Endoscopic disease activity will be scored according to the simplified endoscopic score for Crohn's disease (CD) for CD patients or Ulcerative Colitis Endoscopic Index for Severity and Mayo Endoscopic Subscore for ulcerative colitis patients. The main study outcome is the diagnostic test accuracy of the various patient-reported scores to assess mucosal inflammation in combination with a FC home test. ETHICS AND DISSEMINATION: This study is approved by the Medical Research Ethics Committee of azM/UM in Maastricht dated 03 March 2021 (METC 20-085) and is monitored by the Clinical Trial Centre Maastricht according to Good Clinical Practice guidelines. Written informed consent will be obtained from all patients. Study results will be published in international peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: NCT05886322.

A lighter hybrid feature fusion framework for polyp segmentation.

Colonoscopy is widely recognized as the most effective method for the detection of colon polyps, which is crucial for early screening of colorectal cancer. Polyp identification and segmentation in colonoscopy images require specialized medical knowledge and are often labor-intensive and expensive. Deep learning provides an intelligent and efficient approach for polyp segmentation. However, the variability in polyp size and the heterogeneity of polyp boundaries and interiors pose challenges for accurate segmentation. Currently, Transformer-based methods have become a mainstream trend for polyp segmentation. However, these methods tend to overlook local details due to the inherent characteristics of Transformer, leading to inferior results. Moreover, the computational burden brought by self-attention mechanisms hinders the practical application of these models. To address these issues, we propose a novel CNN-Transformer hybrid model for polyp segmentation (CTHP). CTHP combines the strengths of CNN, which excels at modeling local information, and Transformer, which excels at modeling global semantics, to enhance segmentation accuracy. We transform the self-attention computation over the entire feature map into the width and height directions, significantly improving computational efficiency. Additionally, we design a new information propagation module and introduce additional positional bias coefficients during the attention computation process, which reduces the dispersal of information introduced by deep and mixed feature fusion in the Transformer. Extensive experimental results demonstrate that our proposed model achieves state-of-the-art performance on multiple benchmark datasets for polyp segmentation. Furthermore, cross-domain generalization experiments show that our model exhibits excellent generalization performance.

Colonoscopy polyp classification via enhanced scattering wavelet Convolutional Neural Network.

Among the most common cancers, colorectal cancer (CRC) has a high death rate. The best way to screen for colorectal cancer (CRC) is with a colonoscopy, which has been shown to lower the risk of the disease. As a result, Computer-aided polyp classification technique is applied to identify colorectal cancer. But visually categorizing polyps is difficult since different polyps have different lighting conditions. Different from previous works, this article presents Enhanced Scattering Wavelet Convolutional Neural Network (ESWCNN), a polyp classification technique that combines Convolutional Neural Network (CNN) and Scattering Wavelet Transform (SWT) to improve polyp classification performance. This method concatenates simultaneously learnable image filters and wavelet filters on each input channel. The scattering wavelet filters can extract common spectral features with various scales and orientations, while the learnable filters can capture image spatial features that wavelet filters may miss. A network architecture for ESWCNN is designed based on these principles and trained and tested using colonoscopy datasets (two public datasets and one private dataset). An n-fold cross-validation experiment was conducted for three classes (adenoma, hyperplastic, serrated) achieving a classification accuracy of 96.4%, and 94.8% accuracy in two-class polyp classification (positive and negative). In the three-class classification, correct classification rates of 96.2% for adenomas, 98.71% for hyperplastic polyps, and 97.9% for serrated polyps were achieved. The proposed method in the two-class experiment reached an average sensitivity of 96.7% with 93.1% specificity. Furthermore, we compare the performance of our model with the state-of-the-art general classification models and commonly used CNNs. Six end-to-end models based on CNNs were trained using 2 dataset of video sequences. The experimental results demonstrate that the proposed ESWCNN method can effectively classify polyps with higher accuracy and efficacy compared to the state-of-the-art CNN models. These findings can provide guidance for future research in polyp classification.

Safety and efficacy of autologous blood tattooing for preoperative colonic localization: a comparative study with conventional India ink tattooing.

BACKGROUND: India ink has been a popular choice for a tattooing agent in preoperative endoscopic localization but often results in unfavorable effects. Subsequently, autologous blood tattooing has arisen as an alternative option. Due to the limited availability of comparative studies on the matter, we conducted a study to compare the perioperative outcomes associated with India ink tattooing versus autologous blood tattooing. METHODS: A total of 96 patients who underwent minimally invasive surgical procedures for left-sided colonic neoplasm following preoperative endoscopic localization were included in the study. These patients were categorized into two groups: 36 patients who received India ink tattooing and 60 patients who underwent autologous blood tattooing. The perioperative outcomes including procedure-related outcomes and postoperative outcomes were compared between the two groups. RESULTS: There was no significant difference in visibility and spillage of tattooing agent between India ink group and autologous blood group. However, India ink group showed a higher incidence of post-tattooing fever, higher level of postoperative C-reactive protein level, longer time to first flatus, resumption of surgical soft diet, and duration of hospital stay, and a higher occurrence of postoperative complications including ileus and surgical site infection compared with the autologous blood group. In the multivariate analysis, India ink tattooing was significantly associated with the occurrence of postoperative complications. In the subgroup analysis involving patients with intraperitoneal spillage, the autologous blood group demonstrated significantly favorable perioperative outcomes compared with India ink group. CONCLUSIONS: Autologous blood tattooing demonstrated comparable visibility and enhanced safety, establishing it as a potential alternative to India ink for preoperative endoscopic localization.

11 cases of peritoneal dialysis catheter penetrating into the intestinal cavity: case series.

The penetration of a peritoneal dialysis catheter into the intestinal cavity is a clinically rare complication. In the present retrospective clinical case series, 11 patients with uraemia who received continuous ambulatory peritoneal dialysis and attended hospital between 2019 and 2023 are described. The median patient age was 61.91 ± 11.33 years. All patients had previously experienced peritoneal dialysis-related peritonitis and were clinically cured by infusing sensitive antibiotics into the abdominal cavity. Colonoscopy was utilised to locate the penetrating catheter and close the perforation with a titanium clip once the catheter had been removed via an external approach. Following a 2-4-week fast, the perforations healed in all 11 patients. The present authors' experience illustrates that directly removing the catheter and clamping the perforation opening under the guidance of colonoscopy is simple to operate with few complications compared with traditional open surgery.

A Pressure Sensing Device to Assist in Colonoscopic Procedures to Prevent Perforation-A Case Study.

Colonoscopy has a limited field of view because it relies solely on a small camera attached to the end of the scope and a screen displayed on a monitor. Consequently, the quality and safety of diagnosis and treatment depend on the experience and skills of the gastroenterologist. When a novice attempts to insert the colonoscope during the procedure, excessive pressure can sometimes be applied to the colon wall. This pressure can cause a medical accident known as colonic perforation, which the physician should prevent. We propose an assisting device that senses the pressure applied to the colon wall, analyzes the risk of perforation, and warns the physician in real time. Flexible pressure sensors are attached to the surface of the colonoscope shaft. These sensors measure pressure signals during a colonoscopy procedure. A simple signal processor is used to collect and process the pressure signals. In the experiment, a colonoscope equipped with the proposed device was inserted into a simulated colon made from a colon extracted from a pig. The processed data were visually communicated to the gastroenterologist via displays and light-emitting diodes (LEDs). The device helps the physician continuously monitor and prevent excessive pressure on the colon wall. In this experiment, the device appropriately generated and delivered warnings to help the physicians prevent colonic perforation. In the future, the device is to be improved, and more experiments will be performed in live swine models or humans to confirm its efficacy and safety.

DLGRAFE-Net: A double loss guided residual attention and feature enhancement network for polyp segmentation.

Colon polyps represent a common gastrointestinal form. In order to effectively treat and prevent complications arising from colon polyps, colon polypectomy has become a commonly used therapeutic approach. Accurately segmenting polyps from colonoscopy images can provide valuable information for early diagnosis and treatment. Due to challenges posed by illumination and contrast variations, noise and artifacts, as well as variations in polyp size and blurred boundaries in polyp images, the robustness of segmentation algorithms is a significant concern. To address these issues, this paper proposes a Double Loss Guided Residual Attention and Feature Enhancement Network (DLGRAFE-Net) for polyp segmentation. Firstly, a newly designed Semantic and Spatial Information Aggregation (SSIA) module is used to extract and fuse edge information from low-level feature graphs and semantic information from high-level feature graphs, generating local loss-guided training for the segmentation network. Secondly, newly designed Deep Supervision Feature Fusion (DSFF) modules are utilized to fuse local loss feature graphs with multi-level features from the encoder, addressing the negative impact of background imbalance caused by varying polyp sizes. Finally, Efficient Feature Extraction (EFE) decoding modules are used to extract spatial information at different scales, establishing longer-distance spatial channel dependencies to enhance the overall network performance. Extensive experiments conducted on the CVC-ClinicDB and Kvasir-SEG datasets demonstrate that the proposed network outperforms all mainstream networks and state-of-the-art networks, exhibiting superior performance and stronger generalization capabilities.

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.

Ultrasonic assessment of gastric solid contents in patients undergoing upper endoscope with sedation.

BACKGROUND: Perioperative reflux aspiration presents a grave concern during sedation or general anesthesia, particularly when solid gastric contents prompt acute upper respiratory obstruction, potentially resulting in fatal consequences for patients. Currently, there are limited means for promptly assessing solid gastric contents in clinical settings. Therefore, this study examined the efficacy of ultrasound assessment for solid gastric contents, offering a rapid and non-invasive approach for early detection and decision-making regarding interventions. METHODS: The study included 400 patients scheduled for upper endoscopy procedures, which encompassed both gastroscope and gastroscope combined colonoscopy examinations with sedation. Ultrasound scanning of the antrum was performed while patients were positioned semi-sitting or in the right lateral decubitus (RLD) posture. The evaluation of solid gastric contents relied on direct visual observation during endoscopy. Gastric volume measurement occurred subsequent to endoscopic suction of gastric contents. Receiver operating characteristic curves were utilized to assess the effectiveness of ultrasonography in discerning solid contents. RESULT: Seven patients undergoing gastroscope with sedation were found to have solid gastric contents. The sensitivity, specificity, positive predictive value, and negative predictive value of the ultrasound qualitative evaluation of solid contents were 85.7%, 99%, 60%, and 99.7%, respectively. CONCLUSION: Solid stomach contents can be evaluated qualitatively with reasonable accuracy using ultrasonography. Additionally, in patients undergoing upper endoscopy and assessed to have solid gastric contents with ultrasound, administration of mild sedation is recommended. TRIAL REGISTRATION: www.chictr.org.cn (ChiCTR2100048994); registered 19/07/2021.

NA-segformer: A multi-level transformer model based on neighborhood attention for colonoscopic polyp segmentation.

In various countries worldwide, the incidence of colon cancer-related deaths has been on the rise in recent years. Early detection of symptoms and identification of intestinal polyps are crucial for improving the cure rate of colon cancer patients. Automated computer-aided diagnosis (CAD) has emerged as a solution to the low efficiency of traditional methods relying on manual diagnosis by physicians. Deep learning is the latest direction of CAD development and has shown promise for colonoscopic polyp segmentation. In this paper, we present a multi-level encoder-decoder architecture for polyp segmentation based on the Transformer architecture, termed NA-SegFormer. To improve the performance of existing Transformer-based segmentation algorithms for edge segmentation on colon polyps, we propose a patch merging module with a neighbor attention mechanism based on overlap patch merging. Since colon tract polyps vary greatly in size and different datasets have different sample sizes, we used a unified focal loss to solve the problem of category imbalance in colon tract polyp data. To assess the effectiveness of our proposed method, we utilized video capsule endoscopy and typical colonoscopy polyp datasets, as well as a dataset containing surgical equipment. On the datasets Kvasir-SEG, Kvasir-Instrument and KvasirCapsule-SEG, the Dice score of our proposed model reached 94.30%, 94.59% and 82.73%, with an accuracy of 98.26%, 99.02% and 81.84% respectively. The proposed method achieved inference speed with an Frame-per-second (FPS) of 125.01. The results demonstrated that our suggested model effectively segmented polyps better than several well-known and latest models. In addition, the proposed method has advantages in trade-off between inference speed and accuracy, and it will be of great significance to real-time colonoscopic polyp segmentation. The code is available at https://github.com/promisedong/NAFormer .

Prediction of immediate bleeding after cold snare polypectomy: A prospective observational study.

The risk factors for immediate post-polypectomy bleeding (IPPB) after cold snare polypectomy (CSP) are not well-known. We sought to define such risk factors and develop a predictive risk-scoring model. This prospective observational study included 161 polyps (4-9 mm in diameter) that were removed via CSP from 118 patients during the period from June to September 2019 in 2 tertiary hospitals. IPPB was defined as post-polypectomy bleeding within 24 hours or grade 3 or 4 intraprocedural bleeding requiring endoscopic hemostasis. IPPB incidences according to grade were 13.0% (21/161) (grade 3) and 0% (grade 4). Univariate analysis showed that the polyp size and morphology, as well as iatrogenic ulcer size and shape, were significantly associated with IPPB. Multivariate analysis showed that polyp size [6-9 mm vs 4-5 mm, odds ratio (OR) 3.72, 95% confidence interval (CI) 1.28-10.79], polyp morphology (polypoid vs non-polypoid, OR: 3.93, 95% CI: 1.22-12.64), and iatrogenic ulcer size (≥10 vs ≤ 9 mm, OR: 3.12, 95% CI: 1.04-9.38) were significantly associated with IPPB. We created a four-marker risk-scoring model to predict IPPB after CSP; we summed the points assigned for the 4 factors. At a cutoff of 2, the sensitivity was 85.7% and the specificity was 65.0%; at a cutoff of 3, the sensitivity was 65% and the specificity was 90.0%. Polyp size and morphology, as well as iatrogenic ulcer size and shape, were associated with IPPB after CSP. The four-marker risk-scoring model appears to effectively predict IPPB after CSP (Clinical Research Information Service: KCT0004375).