Clinical Trial: Retroview™ Colonoscope and Lesion Detection Rate

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Retroview™ vs. Conventional Colonoscopy: it is Time to Change?

Brief Summary: Colonoscopy is considered the gold standard for colorectal polyp and cancer detection. However, even meticulous colonoscopy substantial numbers of colorectal polyps may be missed and carcinomas may not be prevented. Previous studies have found a 12-28% of miss rate for all polyps, a 31% for hyperplastic polyps and 6-27% for adenomas, with the higher miss rates noted for smaller polyps. The lesions missing rate depends on several factors as the location on difficult areas to be evaluated with conventional colonoscopes (the proximal side of the ileocecal valve, haustral folds, flexures or rectal valves), a flat shape, a poor bowel preparation and inadequate endoscopy technique, particularly rapid colonoscope withdrawal. Using the commonly available 140º angle of view colonoscope, approximately 13% of the colonic surface is unseen. The incorporation of colonoscopes with a 170-degree wide angled could not improve adenoma detection rate. The introduction of high definition (HD) colonoscopes and visual image enhancement technologies as narrow band imaging (NBI, Olympus America, Center Valley, PA), i-SCAN™ (PENTAX of America, Montvale, NJ) and Fuji Intelligent Chromo-Endoscopy (FICE™, Fujinon Endoscopy, Wayne, NJ) have improved the lesion characterization, but several studies proved no increase in adenoma detection rates. The Third Eye Retroscope (Avantis Medical Systems, Sunnyvale, CA) is a disposable retrograde viewing device advanced via the accessory channel of a standard colonoscope. Allows retrograde views behind colonic folds and flexures simultaneously with the forward view of the colon. Although it was shown an increase in adenoma detection rate by 11%-25%, it has many disadvantages. It requires a separate processor and the device is disposable making the cost bigger. Occupies the working channel of the colonoscope which limits the ability to suction. If a polyp is seen the viewing device has to be removed in order to perform the polypectomy. The

Detailed Summary:

The Retroview™ (PENTAX Medical, HOYA Co.) colonoscope has a short turning radius at the colonoscope tip, that allows a retroflexed view of the colon during withdrawal. This may allow for detection of polyps hidden behind flexures, folds and valves, from the cecum to the rectum. It offers many advantages like the ability to provide high definition views of the proximal aspects of colonic folds, flexures and valves with no additional equipment or device costs. The image is high definition and the colonoscope also incorporates i-SCAN technology. The suction/work channel of the colonoscope is available for therapeutic procedures. Polypectomy can be performed with the colonoscope in retroflexion, without losing views of the polyp. The only disadvantages are the higher consumed withdrawal time because the additional retroflexed withdrawal to the standard withdrawal and that a small portion of the colon is obscured by the shaft of the colonoscope in retroflexion that may be the reason why combined standard withdrawal with retroflexed withdrawal has proved to be better than retroflexed withdrawal alone.

The aim of this study is to determinate and compare the polyp / adenoma detection rate and lesion miss rate by performing a colonoscopy using conventional scopes vs PENTAX RetroView™ scope. As a secondary outcome, size of lesions will be measure in order to determinate if there is a difference between both technics.

MATERIALS AND METHODS

Setting: Instituto Ecuatoriano de Enfermedades Digestivas (IECED), Omni Hospital Academic Tertiary Center. We will include patients from December 2016 to July 2017. The study protocol and consent form has been approved by the Institutional Review Board and will be conducted according to the declaration of Helsinki. Patients will sign an
Sponsor: Instituto Ecuatoriano de Enfermedades Digestivas

Current Primary Outcome:

  • Polyp detection rate with the standard colonoscope and Retroview™ scope. [ Time Frame: 8 month ]
    Polyps found with standard colonoscope / total of polys found X 100; polyps found with Retroview™ scope / total of polys found X 100; The total of polyps found will be determinated by the combination of both technics (standard colonoscope and Retroview™ scope)
  • Adenoma detection rate with the standard colonoscope and Retroview™ scope. [ Time Frame: 8 month ]
    Adenomas found with standard colonoscope / total of adenomas found X 100; adenomas found with Retroview™ scope / total of adenomas found X 100. The total of adenomas found will be determinated by the combination of both technics (standard colonoscope and Retroview™ scope)


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Lesion miss rate with the standard colonoscope and Retroview™ scope. [ Time Frame: 8 month ]
    Lesion miss rate: lesions missed / total of lesions (polyps and adenomas) X 100
  • Number and size of lesions (adenomas and polyps) detected with the standard colonoscope and Retroview ™ scope. [ Time Frame: 8 month ]
    The number and size of lesions will be described in each patient with both procedures. The size will be measure using a standard biopsy catheter as comparison method.


Original Secondary Outcome: Same as current

Information By: Instituto Ecuatoriano de Enfermedades Digestivas

Dates:
Date Received: December 19, 2016
Date Started: May 1, 2017
Date Completion: August 2017
Last Updated: May 13, 2017
Last Verified: May 2017