View clinical trials related to Colonic Polyps.
Filter by:Colonoscopy is the gold standard investigation in the screening of colorectal neoplasms. The investigators hypothesise that visualisation of the colonic mucosa on extubation may be improved by changing patient position as follows: left lateral position for the right colon, supine for the transverse colon and right lateral position for the left colon(fixed positioning). The investigators aim to validate our hypothesis by performing a randomised control study, comparing mucosal visualisation in patients placed in the 'routine' positions at the discretion of the endoscopist with visualisation in those placed in the above described positions. The hypothesis is that fixed positioning confers an advantage.
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
This simple technique of attaching a transparent cap to the tip of the colonoscope has been evaluated in Japan for improving the detection of polyps and cecal intubation but has not been formally evaluated in the US and other western countries. In one study (19), the polyp detection rate was higher with the transparent cap compared to no cap (49% vs. 39%, p=0.04). Also, the cecal intubation time was shorter with the cap (11.5 min vs 14 min, p=0.008). In a recently published study, a variation of the cap called the transparent retractable extension device was used (21). Overall, the number of adenomas detected were significantly higher with the device compared to without it (205 vs. 150, p=0.04). In an earlier study by Tada et al (22), use of a transparent cap improved the detection rate of lesions per patient (0.86 vs. 0.58) but did not increase the cecal intubation time. Finally, Lee et al (20) used cap assisted colonoscopy in patients with difficult colonoscopy procedure (defined as failure to pass through sigmoid colon after 20 minutes or failure to reach cecum). Using the cap, cecal intubation was achieved in 94% of patients and this proved to be an effective rescue method for failed or difficult colonoscopy. The major appeal of this technique is that it is inexpensive, very practical, and easy to use. Furthermore it is safe and there are no reported complications from this. If found to be effective in increasing the polyp yield it has the potential to being incorporated by busy gastroenterologists in their day to day clinical practice. These features and the preliminary data from Japan merit the evaluation of this promising technique in the US.
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.
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.
This study aims to compare the outcomes of patients who undergo single-port laparoscopic colectomy and conventional laparoscopic colectomy for colonic neoplasia (large polyp not amenable to endoscopic removal/ cancer) through a randomized controlled trial. After informed consent, patients will be randomized to have either conventional or single-port laparoscopic colectomy by a team of surgeons with good experience in laparoscopic colorectal surgery. Patients' demographic, operative detail and post-operative outcomes including operating time, blood loss, complications, pain score, analgesic requirement, resumption of gastrointestinal function and length of hospital stay will be recorded prospectively. The patients will be blinded to the type of treatment that they have received during the first three days after operation (post-operative pain and analgesic requirement will be recorded in these period). Patients will have long term up to record for cancer recurrence and survival. The results of two groups of patients will be compared scientifically to assess if single-incision laparoscopic colectomy results in any difference in outcomes when compared to conventional laparoscopic colectomy.
Hypotheses 1. Loading the sigmoid colon with warm water and warm water irrigation for dealing with spasm (Study Treatment) will significantly reduce the proportion of patients complaining of abdominal discomfort compared with no water loading and waiting for spasms to subside (Control Treatment). The median discomfort score reported by the patients will be significantly lower in the group receiving the Study Treatment than the group receiving Control Treatment. Hypothesis 2. Exploratory hypothesis: There are differences in secondary outcome variables when patients managed by the Study and Control Treatments are compared. Co-variables affect the primary and secondary outcome variables.
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.
The purpose of this study is to evaluate the sensitivity of computed tomographic colonography (CTC) in detecting colorectal polyps and cancers in 1,500 subjects at increased risk of colorectal cancer (CRC), using optical colonoscopy as the reference standard.