Retroview™ Colonoscope and Lesion Detection Rate

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 optic is not high definition and finally, the endoscopist has to get used to visualizing and processing two simultaneous video streams from the colonoscope and from the retroscope device.

Sex

All

Minimum age

18 Years

Maximum age

80 Years

Inclusion Criteria:

* Patients that agree to participate in the study.
* Able to understand and provide written informed consent.
* Colonoscopy indication for colorectal neoplasia screening or polyp surveillance.
* Colonoscopy indication for polypectomy.
* Colonoscopy indication for diagnostic workup including anemia, abdominal pain, constipation, abnormal imaging.

Exclusion Criteria:

* Age under 18 and over 80 years' old.
* Pregnancy
* Patients with heart disease, kidney, liver or severe metabolic disorder, who cannot tolerate sedation.
* Severe uncontrolled coagulopathy.
* Patients with difficulty understanding instructions of bowel preparation.
* Prior history of colon resection.
* Patients with an ileostomy or a colostomy.
* Abdomen or pelvis radiation therapy.
* Known inflammatory bowel disease, polyposis syndrome or acute diverticulitis.
* Suspected colonic obstruction or history of previous obstruction.
* Gastrointestinal bleeding.
* Lack of acceptance by the patient.
* Bowel preparation will be evaluated using the Boston Bowel Preparation Scale. Patients with \< 2 points in at least one of the three segments of the colon (rectum plus left-side colon, transverse colon plus left and right flexure, right-side colon) will be excluded from statistical analysis as well as those who after the beginning of the colonoscopy, had to be aborted because of an inability to reach the cecum by unfavorable anatomy or impassable tumors / stenosis.

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