View clinical trials related to Colonic Polyps.
Filter by:The aim of the study is to develop a computer program which is able to automatically detect colorectal polyps in endoscopic video sequences. Furthermore, the program shall be able to automatically distinguish between adenomas, serrated adenomas and hyperplastic polyps on the basis of optical features of the polyps. Video sequences of polyps will be collected during routine colonoscopy procedures. All polyps will be resected endoscopically so that histopathological diagnoses (gold standard) can be notified. In the validation phase of the study a computer program will be established which aims to distinguish between adenomas, serrated adenomas and hyperplastic polyps on the basis of optical features derived from the videos. A deep learning approach will be used for programming. Afterwards, in the testing phase of the study, videos of 100 polyps (not used in the validation phase) will be presented to the computer program. The establishment of a well- functioning computer program is the primary aim of the study.
Adenomas are polyps of the colorectum that have the potential to develop into colon cancer. However, some adenomas never become malignant tumors, or if so, progression from adenoma into cancer takes a long time. As a result, screening colonoscopy programs were established in order to detect and resect adenomas at an early stage. After resection, polyps should be sent to pathology in order to make a histological diagnosis. Approximately 40-50% of all polyps have adenomatous histology whereas others contain benign histology (e.g. hyperplastic or inflammatory polyps). The latter polyps do not bear the risk to develop colon cancer. The bigger a polyp is the greater the chance is of it being malignant. During colonoscopy polyp size can be estimated visually by comparing the polyp with an opened biopsy forceps. The span of an opened forceps is 7 mm. Prior to using this technique, the forceps has to be inserted into the colon through a small working channel of the endoscope. Information on the actual adenoma size is crucial as surveillance recommendations depend on the size of the resected polyps. Moreover current guidelines contain the possibilities to disregard hyperplastic polyps in the sigmoid colon if the polyp size is below 5 mm. This means that diminutive hyperplastic polyps (< 5mm) do not necessarily require resection due to their benign dignity. However, there is increasing evidence that large human bias effects exist in estimating the size of polypoid lesions. For example, it has been shown that endoscopists exhibit terminal digit preferences leading to an exaggeration of estimated polyp size. In consequence the human bias problem might lead to wrong adenoma surveillance decisions. There is no doubt that technical devices are needed which can support endoscopists in finding the right declaration of polyp sizes. The aim of the current project is to create a computer program that is able to automatically measure polyp sizes during colonoscopy.
Optical Enhancement Technology might be superior to the conventional HD-WL in detecting colorectal adenomas
The purpose of this study is to determine the effects of the plant hormones strigolactones, on cell cultures of colonic polyps and colorectal cancer.
Individualized colonoscopy withdrawal time is determined based on the different grade of physician experience and quality of bowel preparation.
The investigators want to verify in a randomised trial, the effectiveness of EndoClotTM in preventing post-procedural bleeding after EMR (Endoscopic Mucosal Resection) or ESD (Endoscopic Submucosal Dissection) for sessile lesions >20 mm in the right colon
Bowel cancer is a common disorder in the UK. Most cancers happen when a type of polyp, called an adenoma, becomes cancerous. Polyps are growths in the large bowel that can be cancerous, non-cancerous, or pre-cancerous (adenoma). Polyps are most commonly detected during colonoscopy (camera test of the lower bowel). The removal of adenomas has been shown to reduce the subsequent risk of bowel cancer. Current practice is that all polyps are removed or biopsied to allow a laboratory diagnosis (histology). This is important as it influences if and when patients require follow-up colonoscopies, known as the surveillance interval. Patients with only non-cancerous polyps do not need surveillance. A new blue light technology, called narrow band imaging (NBI), used during colonoscopy can help colonoscopists (doctor or nurse performing the procedure)differentiate between polyp types during colonoscopy. NBI is currently available in a large number of UK endoscopy units however is variably used. Studies from 'expert' centres have demonstrated that NBI allows accurate optical diagnosis of colonic polyps. Benefits of optical diagnosis include avoiding removal of non-cancerous polyps and an immediate (on the day) diagnosis for the patient including the surveillance interval. The primary aim of this study is to evaluate the accuracy with which colonoscopists assess the required surveillance interval using optical diagnosis when compared with histology in non-expert centres. The investigators will invite 2500 patients, who have been referred for colonoscopy, to participate. Patients will undergo a routine colonoscopy the only addition being the use of NBI during the procedure. Colonoscopists will provide an optical diagnosis at the time of colonoscopy in addition to polyp removal or biopsy. The investigators will compare surveillance intervals provided using optical diagnosis with the diagnosis from histology and thereby the accuracy with which colonoscopists can use the technology. The investigators will also calculate the cost savings to the NHS.
Chromoendoscopy (that involves spraying of dyes over the colonic mucosa) combined with magnification has been utilized for polyp histology identification. Pit patterns on the surface of polyps described by Kudo et al have been shown to have a high diagnostic accuracy in differentiating the polyp types (18, 19). NBI, that is also referred to as "electronic chromoendoscopy" is another technique that has been evaluated for polyp histology identification by highlighting the superficial mucosal and vascular architecture (15, 20, 21). pCLE is another novel addition to the technologies aiming to accomplish in vivo histologic diagnosis with a high degree of accuracy. The pCLE system has three major components (Mauna Kea Technologies, Paris, France). The first is the confocal miniprobe made of approximately thirty thousand optical fibers bundled together and terminated by a distal microsystem. The images obtained have a lateral resolution of 1µm, an axial resolution of 10 µm and a maximum field of view of 240 µm. The depth of observation is from 55 to 65 µm. The miniprobe tip diameter is 2.5 mm and can be passed through the accessory channel of any standard endoscope. The second is the laser scanning unit (excitation wavelength - 488 nm) that combines the functions of laser light illumination and rapid laser scanning, enabling a frame rate up to 12 images per second and signal detection. The third is the control and acquisition software for real time image reconstruction, immediate sequences display and post-procedure analysis and editing tools. Once an area of interest (e.g. a polyp) is identified, 5 ml of 10% fluorescein sodium is injected intravenously; the confocal probe is passed through the accessory channel of the endoscope and placed against the lesion to obtain several high-quality images and video sequences. In a study by Buchner et al from the Mayo Clinic, Jacksonville, (22) this system was used to evaluate confocal images of 37 polyps from 25 patients in a blinded fashion without the knowledge of their histologic diagnosis or endoscopic appearance. The investigators developed the following criteria that were suggestive of neoplastic polyps: villiform pattern, nuclear characteristics - oval/irregular nuclear shape and increased number of nuclei. These features had a sensitivity of 82.6%, specificity of 92.9% and accuracy of 86.5% for the characterization of neoplastic polyps. Similarly, Meining et al (23) have also evaluated criteria for differentiating neoplastic from benign lesions in the colon with encouraging results. The investigators hypothesize that pCLE will have a high rate for accurate characterization of polyp histology real time during colonoscopy
Lesions, polyps and other abnormalities in the gastrointestinal (GI) tract have a different composition compared to the normal mucose. The investigators plan to gather spectroscopic information from these features. Characterizing their unique spectrums, may help to enhance the detection and identification of these objects during endoscopy.