Trial Information

ScopeGuide-assisted Colonoscopy Versus Conventional Colonoscopy for Improved Endoscopic Performance and Enhanced Patient Experience

Summary of Research Proposal

Background:

Colon and rectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality
in Canada. Colonoscopy is the preferred screening modality for CRC and has been shown to
decrease the likelihood of developing CRC as well as CRC-related mortality, particularly
through the detection and removal of potentially pre-cancerous polyps, with the aim of
preventing colon cancer, and for the diagnosis of early stage CRC that is more likely to be
treatable and result in long-term survival. However, recent evidence suggests that
colonoscopy has not been as universally protective against CRC as had been previously hoped,
particularly for proximal cancers located in the right colon. Theories as to why this might
be the case include speculation about altered biology of cancers that develop in the
proximal colon and technical issues relating to the performance of colonoscopy itself. In
particular, one of the problems is incomplete colonoscopy that fails to examine the entire
colon to the cecum, which may occur in 10-20% of cases. Furthermore, from a public health
standpoint, a considerable proportion of the population remain averse to undergoing
colonoscopy, particularly because of fears of procedure discomfort, decreasing the potential
impact for overall CRC reduction. Thus, optimizing the technical performance of colonoscopy
and improving its acceptance among patients is important for maximizing the possible
benefits to society.

One of the most common reasons for incomplete colonoscopy is excessive internal looping of
the endoscope. This looping has also been shown to be the major cause of patient discomfort
during the procedure. Experts agree that colonoscopy is most successful at reaching the
cecum and most comfortable for patients when the endoscope is kept in a straight position by
minimizing loop formation and reducing loops once they have formed. Thus, identification and
reduction of endoscope loops is critically important for the successful and comfortable
completion of colonoscopy. Over the years, several techniques have emerged to overcome loop
formation, including withdrawal of the endoscope with torque, abdominal wall pressure and
patient position changes, yet these are all done in a "trial and error" fashion. Despite
this limitation, these maneuvers form the cornerstones of current colonoscopy technique.
Technological innovations such as smaller caliber "pediatric" colonoscopes and "variable
stiffness" colonoscopes with adjustable rigidity have been introduced that have had moderate
success in diminishing patient discomfort and increasing rates of colonoscopy completion.
Yet despite these efforts to improve colonoscopy practice, the reality is that many
procedures are still done poorly. An audit of all colonoscopies performed in Winnipeg from
2004 to 2006 demonstrated a dismal completion rate of only 65%. Thus, something more clearly
needs to be done. In an effort to help improve colonoscopy from both the technical
standpoint of the endoscopist and also the comfort level of patients, Olympus has redesigned
a previously developed real-time imaging system that enables visualization of the shape of
the entire endoscope while it is inside the patient's body. This technology, called
ScopeGuide (Olympus America, Center Valley, PA), consists of electromagnetic coils embedded
within the endoscope that are detected by an external receiver dish, generating a 3D
representation of the endoscope that is displayed on a monitor. It is anticipated that by
visualizing the entire scope as it moves through the body, endoscopists will gain useful
visual information about loop formation and scope position that will enable greater
technical success while creating a more comfortable patient experience.

Study Objectives:

The purpose of this project is to perform a randomized, non-blinded colonoscopy study to
determine if real time visualization of the colonoscope using the new Olympus ScopeGuide
system is superior to conventional colonoscopy for the achievement of endoscopic procedural
outcomes and for an improved patient experience in terms of reduced discomfort and decreased
sedation requirements.

Methods:

Consecutive patients referred for colonoscopy at the University of Alberta Hospital (UAH)
will be considered for study enrollment. Eligible patients who meet the inclusion and
exclusion criteria and who provide informed consent will be randomized to undergo
conventional colonoscopy or colonoscopy with the assistance of the ScopeGuide system. The
control group will use Olympus CF-H180AL variable-stiffness, high-definition colonoscopes
that do not differ from the usual procedure and the investigational group will use Olympus
CF-H180DL variable-stiffness, high-definition colonoscopes equipped with ScopeGuide
capabilities. ScopeGuide will provide the endoscopist with a 3-dimensional image on the
monitor depicting the shape of the colonoscope inside the patient's body as it moves through
the colon.

The colonoscopy will be performed as clinically indicated, either with or without the aid of
the ScopeGuide system. All patients will undergo a purgative bowel preparation followed by
an overnight fast prior to their colonoscopy according to standard clinical practice at UAH.
At the start of the colonoscopy, all patients will initially be given standardized doses of
conscious sedation medications consisting of midazolam 2 mg IV and fentanyl 25 mcg IV.
However, the procedure may be initiated without any sedation upon patient request.
Additional doses of sedative medications may be given at patient request or when the nurse
or physician believes that the patient is uncomfortable. In all cases, the endoscopist will
attempt to minimize the formation of loops within the colon and will straighten those loops
whenever possible. This will be achieved by conventional methods that rely on "feel" and
"instinct" in the control group and will be directed by the ScopeGuide visualization in the
investigational group. The endoscopist may use any technical maneuvers deemed necessary to
facilitate completion of the procedure, including the application of external abdominal
pressure by the nurse, the repositioning of the patient, or tightening of the
variable-stiffness setting of the colonoscope. Upon intubation of the cecum, the insertion
distance of the colonoscope from the anus to the cecal pole will be recorded as a marker of
the straightness of the endoscope. Any abnormalities detected during colonoscope insertion
will be more closely inspected, photographed and biopsied during subsequent colonoscope
withdrawal. Furthermore, polyps will also be preferentially removed during colonoscope
withdrawal, which is the existing standard-of-care. Any diagnostic or therapeutic
applications that are required during the colonoscopy are permitted as clinically indicated.

Relevant demographic and clinical information will be recorded prior to the procedure.
Additional data regarding procedural metrics, technical maneuvers, and sedation doses will
be recorded during the colonoscopy. At the conclusion of the colonoscopy, the endoscopist
will rate the procedural difficulty as "usual" or "difficult" and will also note the
procedural diagnosis.

After the procedure, the patient will be kept in the post-endoscopy recovery area in the
usual fashion. Prior to discharge home from the recovery area, participants will complete a
visual analogue scale reflecting their degree of discomfort experienced during the
procedure.