Does Cap Assisted Colonoscopy Improve Detection of Adenomatous Polyps? (CAP Trial)
| Status: | Completed |
|---|---|
| Conditions: | Gastrointestinal |
| Therapuetic Areas: | Gastroenterology |
| Healthy: | No |
| Age Range: | 50 - 85 |
| Updated: | 9/27/2018 |
| Start Date: | December 2010 |
| End Date: | May 2012 |
Effectiveness of screening colonoscopy in cancer prevention relies on the detection and
removal of adenomatous polyps. However, a substantial rate of adenomas is missed during a
colonoscopy. It has been estimated that two thirds of missed adenomas are located on the
proximal aspect of colonic folds. Attaching a transparent cap to the tip of a colonoscope may
allow examination of the proximal aspect of colonic folds, and some early studies have
suggested an increased polyp and adenoma detection using this technology. However, the
studies have in part substantial methodological limitations (e.g. missing polyp histology,
single endoscopist study, polyps not removed at the time of detection). Therefore, at this
point it is unclear whether cap assisted colonoscopy may improve adenoma detection. The
objective of this study is to evaluate whether cap assisted colonoscopy improves adenoma
detection.
The investigators propose a two-center multiple endoscopists randomized controlled trial.
Patients will be randomized to cap assisted colonoscopy or standard high definition white
light colonoscopy. The cap is a 4mm commercially available transparent cap that is attached
to the tip of the colonoscopy. Primary outcome measure is the adenoma detection rate (mean
number of adenoma per patient). The investigators will assess and adjust for possible
variables that can affect adenoma detection, including withdrawal time and quality of colon
preparation. As a secondary outcome of interest the investigators will evaluate a possible
learning curve effect among all endoscopists (a minimum of six) new to this method. In
addition the investigators will evaluate whether cap assisted endoscopy improves real time
prediction of polyp histology.
removal of adenomatous polyps. However, a substantial rate of adenomas is missed during a
colonoscopy. It has been estimated that two thirds of missed adenomas are located on the
proximal aspect of colonic folds. Attaching a transparent cap to the tip of a colonoscope may
allow examination of the proximal aspect of colonic folds, and some early studies have
suggested an increased polyp and adenoma detection using this technology. However, the
studies have in part substantial methodological limitations (e.g. missing polyp histology,
single endoscopist study, polyps not removed at the time of detection). Therefore, at this
point it is unclear whether cap assisted colonoscopy may improve adenoma detection. The
objective of this study is to evaluate whether cap assisted colonoscopy improves adenoma
detection.
The investigators propose a two-center multiple endoscopists randomized controlled trial.
Patients will be randomized to cap assisted colonoscopy or standard high definition white
light colonoscopy. The cap is a 4mm commercially available transparent cap that is attached
to the tip of the colonoscopy. Primary outcome measure is the adenoma detection rate (mean
number of adenoma per patient). The investigators will assess and adjust for possible
variables that can affect adenoma detection, including withdrawal time and quality of colon
preparation. As a secondary outcome of interest the investigators will evaluate a possible
learning curve effect among all endoscopists (a minimum of six) new to this method. In
addition the investigators will evaluate whether cap assisted endoscopy improves real time
prediction of polyp histology.
All patients who present for a colonoscopy and meet inclusion and exclusion criteria will be
asked to participate (see inclusion and exclusion criteria). All patients will undergo a
regular bowel preparation with polyethylene glycol lavage (based on current standard of care)
until clear rectal fluid is evacuated. Patients will be randomized to one of two groups:
1. Standard colonoscopy, or
2. Cap assisted colonoscopy. All colonoscopies will be performed using state of the art
high-definition wide angle colonoscopy. The transparent cap, which is attached to the
tip of the colonoscope, has a 4mm margin extending beyond the tip of the colonoscope.
All patients will undergo a careful endoscopic examination. A timer will provide
feedback on the time of insertion and the withdrawal time. Detected polyps will be
assessed with standard white light and narrow band imaging to predict polyp histology
(adenoma versus no adenoma), then resected and sent for histological evaluation
according to standard of care. At least 8 experienced endoscopists at the participating
centers will participate. Each endoscopist will perform at least 50 cap assisted
colonoscopies as part of the study. Each endoscopist will be asked to complete a survey
after 10 and after 50 cap assisted colonoscopies.
Patients will be randomized in blocks of four allocated to each examiner. The order of
randomization will be computer generated. Information on randomization will be contained in
sealed envelopes assigned to each examiner and individually opened immediately before the
procedure after a patient's All participating endoscopist will fill out a questionnaire
regarding the use of cap assistance colonoscopy after the initial 10 cap assisted
colonoscopies and after at least 50 cap assisted cap colonoscopies. Endoscopists will also
undergo a training session with respect to real time polyp diagnosis before study
commencement and after each 20 colonoscopies enrollment.
asked to participate (see inclusion and exclusion criteria). All patients will undergo a
regular bowel preparation with polyethylene glycol lavage (based on current standard of care)
until clear rectal fluid is evacuated. Patients will be randomized to one of two groups:
1. Standard colonoscopy, or
2. Cap assisted colonoscopy. All colonoscopies will be performed using state of the art
high-definition wide angle colonoscopy. The transparent cap, which is attached to the
tip of the colonoscope, has a 4mm margin extending beyond the tip of the colonoscope.
All patients will undergo a careful endoscopic examination. A timer will provide
feedback on the time of insertion and the withdrawal time. Detected polyps will be
assessed with standard white light and narrow band imaging to predict polyp histology
(adenoma versus no adenoma), then resected and sent for histological evaluation
according to standard of care. At least 8 experienced endoscopists at the participating
centers will participate. Each endoscopist will perform at least 50 cap assisted
colonoscopies as part of the study. Each endoscopist will be asked to complete a survey
after 10 and after 50 cap assisted colonoscopies.
Patients will be randomized in blocks of four allocated to each examiner. The order of
randomization will be computer generated. Information on randomization will be contained in
sealed envelopes assigned to each examiner and individually opened immediately before the
procedure after a patient's All participating endoscopist will fill out a questionnaire
regarding the use of cap assistance colonoscopy after the initial 10 cap assisted
colonoscopies and after at least 50 cap assisted cap colonoscopies. Endoscopists will also
undergo a training session with respect to real time polyp diagnosis before study
commencement and after each 20 colonoscopies enrollment.
Inclusion Criteria:
• Any patient ≥ 50 years old and < 85 years old who presents for a colonoscopy with a
potential for polyp resection and who does not meet any of the exclusion criteria mentioned
below will be asked to participate
Exclusion criteria:
- Patients with known inflammatory bowel disease or active colitis
- Patients with familial adenomatous polyposis or other genetic syndromes that are
associated with a high number of colonic polyps
- Patients who are receiving an emergency colonoscopy
- Poor general health (ASA class > 3)
- Patients on coumadin at the time of the procedure or with a coagulopathy and an
elevated INR ≥ 1.5, or platelets < 50
- Patients who do not consent
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