Neoplasms

All Conditions

Symptoms and General Pathology

Digestive System Diseases

Adenoma

Colonic Polyps

Polyps

Colorectal Neoplasms

Intestinal Neoplasms

Gastrointestinal Neoplasms

Digestive System Neoplasms

Gastrointestinal Diseases

Colonic Diseases

Intestinal Diseases

Rectal Diseases

Intestinal Polyps

Pathological Conditions, Anatomical

Water infusion in lieu of air insufflation for screening and surveillance colonoscopy

Air insufflation for screening and surveillance colonoscopy

Air pump is turned off, water is infused using a peristaltic pump to aid colonoscope insertion until the cecum is reached. Air pockets and dirty water are suctioned before clean water is infused (exchange) to facilitate scope insertion.

Water infusion in lieu of air insufflation

Conventional air method with minimal insufflation of air to aid scope insertion until the cecum is reached. Water in aliquots will be used for irrigation and cleansing.

Air method

Joseph Leung, MD

In a prospective, randomized, controlled study, two methods (water method vs. air method) of performing colonoscopy will be compared in patients undergoing unsedated colonoscopy for CRC screening. The investigators hypothesize that:

1. Study method increases overall cecal intubation with comparable assessment of current experience and patient willingness to repeat future colonoscopy compared with conventional colonoscopy
2. Study method improves bowel preparation and increases polyp pickup rate

Colorectal cancer (CRC) screening for the high and the low risk healthy asymptomatic Veterans Affairs (VA) patients is being promoted. Compliance with this Directive will result in an increased number of VA patients undergoing colonoscopy.

The demand for colonoscopy far exceeds the capacity available to perform the procedure in the VA system. The conventional practice for colonoscopy at VA facilities across the country is to perform colonoscopy under conscious sedation with air insufflation. Efficiency is governed by the fact that sedated patients require time and space for recovery and these are major limiting factors in the current setting for the use of colonoscopy for CRC screening.

In a prospective, randomized, controlled trial (RCT), two methods of performing colonoscopy will be compared in patients undergoing unsedated colonoscopy for CRC screening. We compared the water infusion in lieu of air insufflation (water method) with the conventional air insufflation method. We hypothesize that the water method (Study method) increases overall cecal intubation with comparable assessment of current experience and patient willingness to repeat future colonoscopy compared with conventional colonoscopy. In addition, the water method improves bowel preparation and increases polyp pickup rate.

Unsedated Colonoscopy for Colorectal Cancer Screening and Surveillance

Comparison of Study Method Versus Conventional Method for Performing Unsedated Colonoscopy for Colorectal Cancer Screening and Surveillance

VA Northern California Health Care System

Pain

Neoplasms, Glandular and Epithelial

Neoplasms by Histologic Type

Herbal and Botanical

All Drugs and Chemicals

Cola

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.

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.

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.

Air insufflation method.

Water Immersion during insertion, air insufflation during withdrawal.

Water Immersion method.

Water Exchange during insertion, air insufflation during withdrawal.

Water Exchange method.

Sergio Cadoni, MD

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.

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.

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

A Randomized, Controlled Trial Comparing Air Insufflation, Water Immersion and Water Exchange for Adenoma Detection Rate in Screening Colonoscopy

Applied as needed if advancement of the colonoscope fails.

Change in patient position as needed if advancement of the colonoscope fails.

Compression of abdomen if advancement of the colonoscope fails.

Amount of water infused and aspirated during insertion and withdrawal.

Patients willingness to repeat the examination based on overall satisfaction about procedure. Measured at discharge on a yes/no question.

Proportion of subjects with at least one adenoma of any size.

Proportion of subjects with at least one adenoma of any size in the proximal colon.

Proportion of subjects with at least one adenoma \<10 mm in the proximal colon.

Total number of adenomas resected per subject.

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.

Cecal intubation time will be defined as the time for passage of the colonoscope from the rectum to the cecum.

Total procedure time (including time required for polyp resection or biopsy).

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.

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.

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.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization	Link
Unsedated Colonoscopy for Colorectal Cancer Screening and Surveillance	NCT01383252	Colon Polyp	Water infusion ... Air method	50 Years - 75 Years	VA Northern California Health Care System
Water-aided Colonoscopy vs Air Insufflation Colonoscopy in Colorectal Cancer Screening	NCT02041507	Colorectal Canc... Colorectal Aden... Colorectal Poly... Pain	Air insufflatio... Water Immersion... Water Exchange ...	50 Years - 70 Years	Presidio Ospedaliero Santa Barbara

Spots Global Cancer Trial Database for unsedated colonoscopy