View clinical trials related to Polyps.
Filter by:Interpretation of endoscopic characteristics of colorectal polyps with Blue Light Imaging A study of BLI images and videos of colorectal polyps will be presented initially as a training set followed by with explanation and teaching in a didactic session to two separate groups. A post-test will be conducted to look at the quality of the learning experience. To evaluate the teaching tool regarding the criteria for BLI images of colorectal polyps by the following measures - Inter-observer agreement between same and different groups - Accuracy in describing the morphology of colorectal polyps • This new teaching tool will improve - Inter-observer agreement by at least 5%- 10% (depending on the group) - Accuracy by at least 5%- 10% (depending on the group)• To determine the improvement of inter-observer agreement in identifying/ describing colorectal polyps after the didactic session in both the groups - Overall Accuracy, Sensitivity, Specificity, Positive predictive value and negative predictive value pre-and post-test in both the groups
The aim of the study is to develop a computer program which is able to classify different entities of colorectal polyps on the basis of optical polyp features. In the end, the computer program shall differentiate between (i) hypeplastic polyps, (ii) adenomas and (iii) serrated adenomas . In the first phase of the study a computer program will be established which aims to distinguish between the above mentions entities on the basis of optical features derived from still images. A machine learning apporach will be used for creating the program. Afterwards, in a second phase of the study, still images of 100 polyps (not used in the first phase) will be presented to the computer program. Quality of the computer program will be tested by calculating the accuracy for differentiating the three different polyp types. The gold standard for true polyp diagnoses will be based on histopathological diagnoses of the polyps. The same pictures of 100 polyps will also be presented to human experts. Experts will also predict histopathological diagnoses on the basis of optical polyps featurs. Accuracy of computer-decisions and human expert predictions will be compared. 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.
The device is intended to endoscopically transect polyps in the gastrointestinal tract (sessile or pedunculated) using electrocautery. During the same maneuver the polyp is captured, retrieved and submitted for pathological analysis. The Tandem Snare is an intervention tool inserted through the colonoscope for the resection and removal of polyps sized 6 to 25 mm. The Tandem snare utilizes a technology that has the potential to hold the polyp, lift it up, resect and remove it without losing it. This is a feasibility study aiming to demonstrate the safety of the Tandem Snare used for 6-25mm polyps' polypectomy in screening, diagnostic or surveillance colonoscopy.
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.