Detection and Classification of Colon Polyps: A Comparison of High Definition White Light and Narrow Band Imaging (Endoscopic Trimodal Imaging; ETMI)
1. The use of NBI colonoscopy will reduce the miss rate for colon polyps compared to
standard white light imaging.
2. HDWl and HDNBI are more accurate than standard colonoscopy for the classification of
adenomatous polyps in comparison to other non-premalignant polyps.
III. Specific Aims:
1. Compare the miss rate of standard white light imaging compared to NBI for detection of
colon polyps with NBI
2. Estimate the accuracy of standard white light, HDWL and HDNBI imaging modes for the
classification of adenomatous (premalignant) versus non-adenomatous (hyperplastic,
inflammatory, normal) polyps.
3. Examine the inter-observer agreement for classification of adenomatous versus
non-adenomatous polyps based on standard, NBI and HDWL imaging.
IV. Research Design and Methods:
4.1 Study Design: A prospective phase II cross-over trial. Patients will undergo both
procedures (standard, NBI) back to back under conscious sedation. The order of the
procedure will be randomized.
4.2 Setting: The study will take place at Mayo Clinic Jacksonville, Division of
Gastroenterology, an expert center in the diagnosis and treatment of colon polyps.
4.3 Study Subjects All patients scheduled for colonoscopy at Mayo Clinic Jacksonville will
be screened for eligibility using inclusion and exclusion criteria. The patients that are
deemed eligible will be offered participation in the study. Informed consent will be
obtained and the participant will be registered in our database. Prior to consent the
participant will be made aware of the investigative nature of the study, alternatives,
risks, and benefits.
4.4 Eligibility Criteria
1. Age 18 years or older.
2. Informed written consent.
1. History of inflammatory bowel disease.
2. Patients with severe cardiopulmonary disease precluding colonoscopy.
3. Presence of conditions not allowing for polypectomy or biopsy (e.g. coagulation
4. Known familial polyposis syndrome (FAP, HNPCC, Juvenile polyposis, etc)
5. Sub-optimal preparation for the procedure, which will be determined by patient history
or based on the initial colonoscopy.
4.5 Procedure and Data Collections
All patients will be prepared for colonoscopy with the standard preparation and will be
scheduled to have the procedure at Mayo Clinic Jacksonville. The principal investigator
(PI) will screen eligible patients based on medical history, physical exam and laboratory
data on day of procedure.
Patients typically arrive at the registration area at least 60 minutes before start of
scheduled procedure. A GI endoscopy nurse will prepare patients in the standard manner and
intravenous access will be placed. Eligible patients will be offered informed consent by
the study PI or designee. Patients who agree to participate in the study will sign informed
consent and will be registered in the database. A log with only non-identifiable (e.g.
patients # 1) will also be maintained of eligible patients who decline to participate. The
GI endoscopy nurse will monitor patient's vitals before, during and after procedure as per
The exams will be performed back to back with a standard colonoscope and an ETMI colonoscope
provided by Olympus. The order of the first and second procedure will be randomized
according to a list prepared by the statistician using randomly permuted blocks to ensure
equal numbers of patients are randomized to the two groups. All patients will be sedated
with meperidine or fentanyl and midazolam to achieve conscious sedation. Each procedure
will be preformed by a different endoscopist. The endoscopist will be either the P.I.
supervised by a GI staff physician or solely by one of the five GI staff physicians. During
the initial colonoscopy all visualized polyps will be noted, photographed, and removed.
When the ETMI colonoscope is used, all polyps will be photographed using these modes (HDWL,
HDNBI). The NBI portion of the exam will be performed using the MB-046 cap to further
enhance stabilization of the focal length of the colonoscope.
The second procedure will be done with the same level of careful inspection as the first
although we not specifically regiment the time of withdrawal beyond what the endoscopist
feels is necessary for a careful examination. During the second colonoscopy all visualized
polyps will be noted, photographed and removed. During the first procedure, the time will
be evaluated with a stopwatch. The stopwatch will start when the endoscopist begins
pull-back at the cecum and end when the scope is removed from the anal verge. The clock will
be stopped during washing of the bowel, polypectomy, biopsy or any other therapeutic
maneuver. At the end of the first procedure, the endoscopist will be informed of the
withdrawal and inspection time and every effort will be made to match this to the second
procedure. Time will be recorded similarly for the second procedure. Polyps will be
classified as pedunculated, raised-sessile (rounded) or flat. Flat polyps will be further
classified according to the Paris endoscopic classification 14.
After the procedure all patients will be brought to the recovery and monitored as per
standard protocol. Participants will be given discharge instructions as per protocol and
also be provided with information to contact the P.I. if any problems should occur. Any
post procedure complication will be reviewed on weekly intervals.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Diagnostic
1. Compare the miss rate of standard white light imaging compared to NBI for detection of colon polyps with NBI
Seth A. Gross, M.D.
United States: Institutional Review Board
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