Clinical Trial: Experience and Enhancement: Improving Colonoscopic Polyp Detection

Study Status: Recruiting
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Evaluation of Effect of Colonoscopist Experience and Addition of of Mucosal Enhancement Techniques on Detection of Colonic Polyps When Viewing Videotaped Colonoscopic With

Brief Summary:

The study looks at 2 hypotheses in 2 patient groups:

  1. Are more experienced endoscopists better at detecting subtle lesions (polyps) on the lining of the colon (large bowel) than less experienced endoscopists?
  2. Do existing and new techniques that can highlight lesions on the lining of the bowel improve endoscopists ability to spot them? This will be tested using video footage of endoscopies from 2 patient groups: those with a normal colon linig and those with colitis (bowel lining inflamation)

Detailed Summary:

Colorectal cancer is the second commonest cause of cancer death. In a majority of cases it is preceeded by a precancerous lesion called an adenoma (commonly known as polyp). Patients with colitis are at specially high risk of colorectal cancer which is estimated to be 18% at 30 years of disease. Detection and removal of adenomas at colonoscopy has been shown to reduce the death rate from colorectal cancer. However, despite meticulous examination there is a "miss rate" for adenomas at colonoscopy with ranges from 6-15% in back-to-back colonoscopy studies. The nature of the polyps which as well as being pedunculated (cherry like) can be flat or depressed making them difficult to see and may also contribute to the "miss rate".

The factors that affect whether an endoscopist sees a polyp are not well studied. Polyp detection rates vary widely, even amongst experts. Endoscopist experience is assumed to improve polyp detection rates; however in one study the least experienced endoscopists found the most polyps. Techniques that highlight lesions advanced in recent years. Chromoendoscopy, spraying dye on the bowel lining, has been shown to help pick up more pre-cancerous polyp in one of three studies in normal patients and seems definitely helpful in colitis. Autofluorescence endoscopy and narrow band imaging use light filters to produce a false colour image of the bowel lining where polyps stand out. These techniques have been used with some success in the oesophagus and stomach but little work is available for the colon. High definition endoscopy produces very clear images and may also help in polyp detection.

This study aims to collect videos of colonoscopy when the colonoscope is being removed. This is the main time when polyps are looked for. Some videos will have subtle polyps. The study will re-examine an
Sponsor: London North West Healthcare NHS Trust

Current Primary Outcome: The difference in adenoma detection rate on video between consultants endoscopist vs. trainee endoscopists who have performed more than 200 endoscopies vs. trainee endospopists who have performed less than 200 endoscopies

Original Primary Outcome: Same as current

Current Secondary Outcome:

  • For each technique:
  • differences in adenoma detection rate between endoscopist of varying abilities with and without techniques to highlight polyps. Differences in adenoma detection rate in terms of esperience.


Original Secondary Outcome:

  • For each technique:
  • 1.differences in adenoma detection rate between endoscopist of varying abilities with and without techniques to highlight polyps.
  • 2. differences in adenoma detection rate for more experienced endoscopists without techniques to highlight polyps are compared to detection rates for less experienced endoscopists with techniques to highlight polyps


Information By: London North West Healthcare NHS Trust

Dates:
Date Received: October 10, 2005
Date Started: October 2005
Date Completion:
Last Updated: September 21, 2007
Last Verified: September 2007