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A Trial of Segmental Stiffening Wires to Improve the Efficiency and Patient Tolerability of Colonoscopy

Phase 1/Phase 2
40 Years
80 Years
Open (Enrolling)
Colonoscopy, Looping, Prevent Looping, Colon Cancer Screening, Segmental Stiffening Wire

Thank you

Trial Information

A Trial of Segmental Stiffening Wires to Improve the Efficiency and Patient Tolerability of Colonoscopy

Colonoscopy can be challenging to perform and painful due to looping of the colonoscope.
Looping occurs when further insertion of the colonoscope results in a loop forming in the
shaft of the colonoscope instead of advancement of the tip. Attempts have been made to solve
this problem, but to date there is no perfect solution. Since colonoscopy is the gold
standard for colon cancer screening providing a device that could prevent looping would be
valuable. We have developed an experimental device that has not been approved outside of the
context of this study known as the Segmental Stiffening Wire (SSW). This wire will be
utilized by passing it through the biopsy channel of the endoscope. The wire has a 15-25
inch area of increased thickness and stiffness. The stiffened section can be advanced into
areas of looping in an effort to prevent re-looping. We will conduct a pilot study in two
phases. The first phase will include approximately 10 healthy volunteers who will undergo
colonoscopy using the SSW. Fluoroscopy will be used to determine if the device prevents
re-looping. If in phase 1 the device is successful in over 30% of episodes, the second phase
will be undertaken. In the second phase volunteers willing to undergo two colonoscopies on
consecutive days will be recruited. Volunteers who experience looping will be randomized as
to whether the SSW is available. These volunteers will then undergo an otherwise identical
colonoscopy on the following day except the SSW will be available if it was not on the first
colonoscopy or it will not be available if it was on the first colonoscopy. Volunteers who
undergo two colonoscopies will not need a second bowel preparation but will be maintained on
a clear liquid diet between the two procedures. Volunteers in which looping does not occur
will have their initial colonoscopy completed as normal and then will leave the study. If
unable to obtain sufficient volunteers willing to undergo dual colonoscopy, then volunteers
willing to undergo single colonoscopy will be included and their procedures will be done
with or without the SSW in random fashion. The endpoints will be cecal intubation time;
cecal intubation rate; quantity of sedation/analgesia; number of ancillary maneuvers;
pain/sedation as measured by the Visual Analog Pain Scale, the Ramsey Sedation Scale, and
clinical observations; vital sign changes; and the endoscopists' subjective assessment of
procedure difficulty and the usefulness of the SSW.

Inclusion Criteria


Colonoscopy is indicated based on well-established national guidelines. This includes
volunteers age 50 or greater who are at average risk for colon cancer, and volunteers age
40 or greater who are at increased risk based on a personal history of colon polyps or a
family history of colon polyps or cancer.

Volunteer meets the criteria of Anesthesia Level 1 or 2.

Volunteer agrees to undergo the study procedures.


Ongoing psychiatric history including volunteers who have been hospitalized for
psychiatric reasons, have missed significant number of days of work for psychiatric
reasons, or who admit to suicidal ideations.

Former or current history of alcohol or drug dependency.

History of colonic resection.


Age greater than 80 or less than 40.

Prior radiation to the abdomen or pelvis.

American Society of Anesthesiologists Grade 3, 4, or 5.

Allergy or other contraindications to midazolam or fentanyl.

Type of Study:


Study Design:

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Single Blind, Primary Purpose: Treatment

Outcome Measure:

The use of SSW will prevent re-looping of the colonoscope.

Outcome Time Frame:

approximately 1 year

Safety Issue:


Principal Investigator

Stephen A Wank, M.D.

Investigator Role:

Principal Investigator

Investigator Affiliation:

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)


United States: Federal Government

Study ID:




Start Date:

July 2008

Completion Date:

April 2015

Related Keywords:

  • Colonoscopy
  • Looping
  • Prevent Looping
  • Colon Cancer Screening
  • Segmental Stiffening Wire
  • Colonoscopy
  • Looping
  • Prevent Looping
  • Colon Cancer Screening
  • Segmental Stiffening Wire
  • Colonic Neoplasms



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