View clinical trials related to Polyps.
Filter by:The investigators hypothesize that high definition colonoscopy with close focus narrow band imaging features has a high diagnostic accuracy for colorectal polyp histology, and can replace formal pathologic assessment in cases of high diagnostic confidence.
Recent studies have shown that narrow-band imaging (NBI) is a powerful diagnostic tool for the differentiation between neoplastic and non-neoplastic colorectal polyps. The aim of the present study is to develop and evaluate a computer-based method for automated classification of small colorectal polyps on the basis of vascularization features.In a prospective study 207 polyps with a size of 10mm or smaller should be detected by a zoom NBI colonoscopy. These polyps were imaged and subsequently removed for histological analysis. the polyp images were analyzed by a computer algorithm. The proposed computer-based method consists of several steps: preprocessing, vessel segmentation, feature extraction and classification. The results of the automatic classification (sensitivity, specificity, negative predictive value, positive predictive value and accuracy)were compared to those of human observers, who were blinded to the histological gold standard.
Colorectal cancer is the second most common cause of cancer death in the US. Colonoscopy is considered the best test colorectal cancer screening. It allows resection of adenomatous polyps (a known cancer precursor) and thus, interrupt the adenoma-carcinoma sequence. Despite the potential benefit of screening colonoscopy recent studies have reported cases of colorectal cancers in a short interval after prior screening or surveillance colonoscopies. One possible cause of such interval cancers may be incomplete resection of adenomatous polyps and hence ongoing growth and cancer development in such lesions. Complete resection may be particularly important for polyps of at least 5mm in size as up 10% of such polyps higher risk lesions as villous adenoma, tubulovillous adenoma, high grade dysplasia, or early carcinoma. Although adenoma resection of sessile and flat adenomatous polyps between 5 and 20mm is believed to be well standardized data on complete resection of adenomatous tissue are sparse. This may be related to the assumption that using a snare with electro-cautery will successfully remove the polyp and cauterize remaining marginal adenomatous tissue and hence completely remove and or destroy the lesion. The investigators are interested in examining how often sessile adenomatous polyps between 5 and 20mm are completely removed using standard polypectomy snare. The investigation was also directed at a comparison between complete resection of polyps between 5 and 9mm and 10 and 20mm.
The purpose of this study is to evaluate the performance of a non-cathartic, computer-assisted form of CT Colonography (Virtual Colonoscopy) for detection of pre-cancerous colon polyps in a group of asymptomatic screening patients.
The aim of the study is to perform a prospective, multicenter research comparing capsule endoscopy with the video colonoscopy in the detection of the adenomatous polyps and cancer specifically in a high risk population (sensibility, specificity, NPV, PPV and diagnostic accuracy). The investigators will used the Pillcam II™ colon capsule (second generation) and a high resolution colonoscope (with high definition). Both procedures will be perform in the same day with an adapted bowel preparation.
It is current practice to remove any polyps found during colonoscopy. This is because adenomatous polyps have the potential to turn into cancer. However, a proportion of polyps <10mm in size are hyperplastic, which cannot turn into cancer. Current practice requires these to be removed, as it is traditionally felt that they cannot be separated clinically from adenomas. This increases the risk of perforation and results in a significant cost in processing the samples. However, it has been suggested that it is possible to differentiate neoplastic from non neoplastic lesions using skills in polyp surface pattern recognition. If this is the case the investigators may be able to reduce the need for polypectomy The investigators believe that it is possible to tell the difference between polyps with cancerous potential and those that are harmless by assessment of surface patterns. This may enable us to improve the investigators clinical decisions when assessing polyps during colonoscopy, and reduce the number of unnecessary polypectomys being performed.
Several novel imaging technologies are currently used for detection and differentiation of colonic polyps during colonoscopy, such as NBI (Olympus), FICE (Fujinon), and i-Scan (Pentax). Several previous studies have indicated that NBI without magnification can be useful for real-time differentiation of diminutive colonic neoplasias. To date, however, there are no studies comparing NBI with other imaging systems (FICE or i-Scan) for differentiation of diminutive colonic polyps. The study objectives are to compare the diagnostic efficacy of NBI with that of i-Scan in real-time prediction of diminutive colonic polyps. In this prospective pilot study, diminutive colonic polyps detected during colonoscopy will be observed with conventional colonoscopy, thereafter will be observed with new imaging systems. Sensitivity, specificity, and diagnostic accuracy of both NBI and i-Scan will be assessed by reference to histological results obtained by endoscopic biopsy or polypectomy.
Colorectal cancer (CRC) is the second most common cancer and the fourth leading cause of cancer death in Korea. Colonoscopy with polypectomy decreases the incidence and mortality from colorectal cancer. However, significant lesions can be missed during colonoscopy. Recent retrospective studies have shown that fellow involvement as a second observer may increase adenoma detection rate in colonoscopy. The aim of this prospective, multicenter, randomized study is to evaluate the impact when endoscopy nurse participate in adenoma detection during screening colonoscopy. The primary outcome measure is the adenoma detection rate (ADR).
The aim of this study is to develop a blood test to determine which patients are at risk for pre-cancerous colon polyps (ACPs: Advanced Colon Polyps). The telomere length of peripheral blood lymphocytes (PBLs) can be measured from a blood sample. Mechanistic pathways and the investigator's preliminary data support PBL telomere length as a biomarker for ACPs. The long-term goal of this project is to decrease deaths from colon cancer by using a blood test to target colonoscopy for those patients who are at high risk for pre-cancerous polyps.
High quality bowel cleaning preparation was most important prerequisites of a accurate colonoscopy, because even a small amount of residual fecal matter can obscure small polyps and increase unnecessary procedure time. Until now, several studies evaluated the impact of bowel preparation on the quality of colonoscopy using comparison of the polyp detection rate in patients with adequate bowel preparation status to that in patients with inadequate bowel preparation status during colonoscopy. However, there was no direct measurement the effect bowel preparation status on the polyp missing rate, the quality of colonoscopy, using tandem colonoscopic evaluation in prospective setting.