Water-aided Colonoscopy vs Air Insufflation Colonoscopy in Colorectal Cancer Screening

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02041507
Recruitment Status : Completed
First Posted : January 22, 2014
Last Update Posted : April 13, 2016
Information provided by (Responsible Party):
Sergio Cadoni, M.D., Presidio Ospedaliero Santa Barbara

Brief Summary:

The degree of protection afforded by colonoscopy against proximal colorectal cancer (CRC) appears to be related to the quality of the procedure, and the incomplete removal of lesions has been shown to increase the subsequent risk of developing a colon cancer.

Some studies suggest that small polyps with advanced histology are more common in the right than in the left colon (right colon proximal to splenic flexure, left colon distal to the splenic flexure). The average size of polyps in the right colon with advanced pathology or containing adenocarcinoma was ≤9 mm, whereas in the left colon their average size was >9 mm, P<0.001. Inadequate prevention of right-sided CRC incidence and mortality may be due to right-sided polyps with advanced histology or that harbor malignancy. These presumptive precursors of cancer are smaller and possibly more easily obscured by residual feces, and more likely to be missed at colonoscopy.

Water-aided colonoscopy (WAC) can be subdivided broadly into two major categories: water immersion (WI), characterized by suction removal of the infused water predominantly during the withdrawal phase of colonoscopy, and water exchange (WE), characterized by suction removal of infused water predominantly during the insertion phase of colonoscopy.

In some reports WE appeared to be superior to both WI and air insufflation colonoscopy (AI) in terms of pain reduction and adenoma detection, particularly for <10 mm adenomas in the proximal colon.

In this multicenter, double-blinded randomized controlled trial (RCT) we test the hypothesis that that WE, compared to AI and WI, will enhance overall Adenoma Detection Rate (ADR) in CRC screening patients. Confirmation of the primary hypothesis will provide evidence that WE enhances the quality of screening colonoscopy.

We also hypothesize that WE may be more effective in detecting proximal colon adenomas than WI and AI, particularly <10 mm adenomas, thus increasing proximal colon ADR and proximal colon ADR <10 mm. Confirmation of secondary hypotheses will provide justification for further testing that WE may provide a strategy to improve prevention of colorectal cancer by increasing detection of adenomas in screening colonoscopy.

Unlike previous reports of single colonoscopist studies, the insertion and withdrawal phases of colonoscopy will be done by different investigators. The second investigator will be blinded to the method used to insert the instrument, thus eliminating possible bias about procedure related issues.

Several secondary outcomes will also be analysed.

Condition or disease Intervention/treatment Phase
Colorectal Cancer Colorectal Adenomas Colorectal Polyps Pain Other: Air insufflation method. Other: Water Immersion method. Other: Water Exchange method. Not Applicable

Detailed Description:

Design: Prospective double-blinded multicenter randomized controlled trial. Methods: Colonoscopy with Air Insufflation, Water Immersion, Water Exchange to aid insertion of colonoscope; split dose bowel preparation. Sedation available at the start of the procedure or on-demand.

Control method: Air insufflation colonoscopy. Study methods: Water Immersion colonoscopy, Water Exchange colonoscopy.

Population: Consecutive 50 to 70 year-old screening patients. After informed consent, assignment to control or study arms based on computer generated randomization list with block allocation and stratification.

Primary outcome: overall Adenoma Detection Rate. Secondary outcomes: proximal colon ADR, Mean Adenomas resected per Procedure (MAP), cecal intubation rate and time, total procedure time (including biopsy and/or polypectomy), maximum pain during colonoscopy assessed during insertion and at discharge, the need for sedation/analgesia and its dosage. In addition loop reduction maneuvers, position changes, abdominal compression, the amount of infused and suctioned water during insertion and withdrawal, and patients willingness to repeat the examination will be evaluated.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 1224 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Official Title: A Randomized, Controlled Trial Comparing Air Insufflation, Water Immersion and Water Exchange for Adenoma Detection Rate in Screening Colonoscopy
Study Start Date : February 2014
Actual Primary Completion Date : March 2016
Actual Study Completion Date : April 2016

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Active Comparator: Air insufflation method.
Colonoscopy performed in the standard fashion, with the minimal air insufflation required to aid insertion and allowing for washing as needed. Considered to be standard procedure.
Other: Air insufflation method.
Air insufflation colonoscopy.
Experimental: Water Immersion method.
Infusion of water during the insertion phase of colonoscopy mainly to open the colonic lumen and progress to the cecum immersed in the water environment thus created, without attempting to clear the colon contents. Residual air in the colon will not be removed. Infused water and residual feces will be suctioned back predominantly during withdrawal. Insufflation not used until the cecum is reached. It will be allowed only 3 times and no more than 10 seconds each time (ITT failure if >3) if the lumen cannot be seen. Withdrawal phase done using air insufflation.
Other: Water Immersion method.
Water Immersion during insertion, air insufflation during withdrawal.
Experimental: Water Exchange method.
Insufflation not used until the cecum is reached. Infusion of a sufficient amount of water to render the lumen of the colon a slit to progress with the colonoscope. Part of the infused water will be constantly suctioned back exchanging clean for dirty or hazy water. Air pockets will be always aspirated to collapse the lumen. After cecal intubation as much residual water as possible will be aspirated before beginning the withdrawal phase. During withdrawal residual water and feces will be suctioned. Withdrawal phase done using air insufflation.
Other: Water Exchange method.
Water Exchange during insertion, air insufflation during withdrawal.

Primary Outcome Measures :
  1. Adenoma Detection Rate. [ Time Frame: 18 months. ]
    Proportion of subjects with at least one adenoma of any size.

Secondary Outcome Measures :
  1. Proximal colon Adenoma Detection Rate. [ Time Frame: 18 months. ]
    Proportion of subjects with at least one adenoma of any size in the proximal colon.

  2. Proximal colon <10 mm Adenoma Detection Rate. [ Time Frame: 18 months. ]
    Proportion of subjects with at least one adenoma <10 mm in the proximal colon.

  3. Mean adenomas resected per procedure. [ Time Frame: 18 months. ]
    Total number of adenomas resected per subject.

  4. Cecal intubation rate. [ Time Frame: 1 hour. ]
    Cecal intubation will be defined as passage of the tip of the colonoscope beyond the ileocecal valve so that the medial wall of the cecum proximal to the ileocecal valve will be observed.

  5. Cecal intubation time. [ Time Frame: 1 hour. ]
    Cecal intubation time will be defined as the time for passage of the colonoscope from the rectum to the cecum.

  6. Total procedure time. [ Time Frame: 1 hour. ]
    Total procedure time (including time required for polyp resection or biopsy).

  7. Maximum pain score recorded during insertion phase of colonoscopy. [ Time Frame: 1 hour. ]
    Pain will be measured on a visual analogue scale (VAS) with a score 0=absence of pain, 1-2=simply "discomfort", 10=the worst possible pain. Before the procedure, an endoscopic nurse will explain the VAS scoring system to the patient. Patient will be informed that the request for pain information is not to remind that the examination should be uncomfortable, but to let the colonoscopist be alerted to the need to use maneuvers to minimize discomfort (e.g. loop reduction, removal of colonic content, abdominal compression and/or change in patient position). At regular intervals during colonoscopy (e.g. every 60 seconds) patients will be asked about discomfort or pain. The responses will be recorded, and the maximum pain score noted.

  8. Pain score at discharge. [ Time Frame: 1 hour. ]
    After the procedure and at discharge from the Endoscopy Unit, an assistant nurse blinded to the procedure will ask patients about maximum pain during insertion phase of the procedure using the same VAS when neither the endoscopist nor the assistant nurse who performed the colonoscopy will be present. Patients will be asked to quantify the degree of pain experienced and to place a mark over the VAS accordingly.

  9. Need for sedation/analgesia and its dosage [ Time Frame: 1 hour. ]
    All patients will be offered sedation for the procedure. Patients can accept or decline the medication. If they accept, the procedure will be started with the administration of 2 mg of Midazolam intravenously (minimal sedation). If the patient will choose on-demand sedation, minimal sedation will be offered when pain score reaches ≥2 on the VAS. Patients can accept or decline the offered medication. If they accept, minimal sedation will be administered as described above. To avoid bias by the colonoscopist, sedation medication will be administered based on the patients' confirmation that the pain is no longer tolerable, and not at the discretion of the colonoscopist. The colon segment in which patients requests sedation will be recorded. If additional medication will be required despite the abovementioned maneuvers and/or minimal sedation, it will be provided according to local standards and it will be recorded.

Other Outcome Measures:
  1. Loop reduction maneuvers. [ Time Frame: 1 hour. ]
    Applied as needed if advancement of the colonoscope fails.

  2. Position changes. Position changes. Position changes. Position changes. Position changes. [ Time Frame: 1 hour. ]
    Change in patient position as needed if advancement of the colonoscope fails.

  3. Abdominal compression. [ Time Frame: 1 hour. ]
    Compression of abdomen if advancement of the colonoscope fails.

  4. Amount of water used during the procedure. [ Time Frame: 1 hour. ]
    Amount of water infused and aspirated during insertion and withdrawal.

  5. Patients willingness to repeat the examination. [ Time Frame: 1 hour. ]
    Patients willingness to repeat the examination based on overall satisfaction about procedure. Measured at discharge on a yes/no question.

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Ages Eligible for Study:   50 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • consecutive screening patients

Exclusion Criteria:

  • previous colonoscopy within 5 years
  • surveillance colonoscopy
  • previous colorectal surgery
  • indication for a proctosigmoidoscopy or bidirectional endoscopy
  • history of inflammatory bowel disease
  • patient refusal or inability to provide informed consent
  • inadequate consumption of bowel preparation

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02041507

United States, California
Sepulveda Ambulatory Care Center, VA Greater Los Angeles Healthcare System
Los Angeles, California, United States, 91343
Czech Republic
Digestive Diseases Center, Vìtkovice Hospital
Ostrava, Czech Republic, 703 84
Digestive Endoscopy Unit, Ospedale S. Barbara
Iglesias, CI, Italy, 09016
Division of Gastroenterology, Ospedale Valduce
Como, CO, Italy, 22100
Sponsors and Collaborators
Presidio Ospedaliero Santa Barbara
Principal Investigator: Sergio Cadoni, MD S. Barbara Hospital, Iglesias (CI), Italy

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Sergio Cadoni, M.D., Responsabile Servizio Endoscopia Digestiva, Presidio Ospedaliero Santa Barbara Identifier: NCT02041507     History of Changes
Other Study ID Numbers: PI.2013.2502
Delibera 1047.2013 ( Other Identifier: ASL 07 Carbonia, Italy )
First Posted: January 22, 2014    Key Record Dates
Last Update Posted: April 13, 2016
Last Verified: April 2016

Keywords provided by Sergio Cadoni, M.D., Presidio Ospedaliero Santa Barbara:
Water-aided colonoscopy
Water Immersion
Water Exchange
On-demand sedation
Unsedated colonoscopy
Adenoma detection rate
Mean adenomas per procedure

Additional relevant MeSH terms:
Colorectal Neoplasms
Intestinal Neoplasms
Gastrointestinal Neoplasms
Digestive System Neoplasms
Neoplasms by Site
Digestive System Diseases
Gastrointestinal Diseases
Colonic Diseases
Intestinal Diseases
Rectal Diseases
Neoplasms, Glandular and Epithelial
Neoplasms by Histologic Type