Does Inspection During Insertion Improve Adenoma Yields During Colonoscopy?

Colonoscopy is not a perfect test. It misses a substantial number of neoplastic lesions and has some risk of missing cancer. Nearly all work on detection during colonoscopy has focused on the withdrawal phase of the examination. This randomized, controlled trial will compare the additional effect on the rate of adenoma detection of mucosal inspection during colonoscope insertion, with inspection during instrument withdrawal, in patients undergoing colonoscopy for colorectal cancer screening or surveillance.

Study Overview

• Status: Completed
• Conditions: Colorectal Cancer; Colorectal Polyps
• Intervention / Treatment: Procedure: Inspection during insertion; Procedure: Inspection during withdrawal

Detailed Description

Background: Colonoscopy is not a perfect test. It misses a substantial number of neoplastic lesions and has some risk of missing cancer. Nearly all work on detection during colonoscopy has focused on the withdrawal phase of the examination. Thus, colonoscopy is typically performed by rapidly passing the instrument through the loops and bends of the colon in order to reach the tip of the cecum, and then performing a slow withdrawal in which the tip of the instrument is systematically deflected, and the mucosa is careful cleaned and suctioned, to expose all of the colonic mucosa for viewing.

Many experienced colonoscopists recognize that small polyps seen incidentally but not removed during insertion are sometimes quite difficult to find during withdrawal. The reason for this observation is probably because the colon is in a very different anatomical conformation during endoscope insertion and withdrawal. During insertion, the colon is in its natural conformation in which the sigmoid and transverse colon has several sharp bends or flexures, and the overall length has not yet been shortened. In this phase, the colon is often significantly stretched because of the formation of loops and bends in the colonoscope. This greatly affects the conformation of the colonic wall visualized proximal to the instrument tip. During withdrawal, the colon is shortened and pleated over the colonoscope, with successive regions of the colon being inspected as they slip off the end of the instrument. Thus, segments of visualized colon are often much straighter during withdrawal than during insertion. The insertion and withdrawal phases, therefore, expose somewhat different sections of the mucosal surface to the colonoscope and inspection on insertion and withdrawal are, quite possibly, complementary.

Aims: This randomized, controlled trial will compare the additional effect on the rate of adenoma detection of mucosal inspection during colonoscope insertion, with inspection during instrument withdrawal, in patients undergoing colonoscopy for colorectal cancer screening or surveillance.

Study procedure: In this study, we plan to investigate whether a specified interval of inspection during insertion can increase overall adenoma detection. We will conduct a randomized controlled trial, in which patients will be randomized to have all of the inspection performed during the withdrawal phase (as is usual care) versus having several minutes of examination specifically devoted to inspection during insertion.

• Study Type: Interventional
• Enrollment (Actual): 340
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Indiana
    • Indianapolis, Indiana, United States, 46202
      • Indiana University Hospital
    • Indianapolis, Indiana, United States, 46280
      • Beltway Surgery Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age ≥ 50 years
• Patients undergoing colonoscopy for screening or surveillance indications

Exclusion Criteria:

• Previous surgical resection of all or part of the colon.
• Inability to give informed consent.
• Ulcerative colitis or Crohn's disease.
• Polyposis syndrome or Lynch syndrome (HNPCC)
• Any comorbid condition which the investigator deems would put the patient at increased risk from a slightly prolonged procedure

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Insertion; Inspection on colonoscope insertion in addition to inspection during withdrawal from the cecum.	Procedure: Inspection during insertion; The colonic mucosa will be inspected for lesions during insertion of the instrument, and during withdrawal of the instrument.
Active Comparator: Withdrawal; Inspection during withdrawal (usual care) without deliberate inspection during insertion.	Procedure: Inspection during withdrawal; The colonic mucosa will be inspected for lesions only during withdrawal of the instrument from the cecum. The instrument will be inserted to the cecum without deliberate inspection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Adenoma detection rate	During colonoscopy

Secondary Outcome Measures

Outcome Measure	Time Frame
Sedation dose	During colonoscopy
Post procedural pain scores	Within 1 hour of colonoscopy
Proportion of patients with at least one adenoma detected	During colonoscopy

Collaborators and Investigators

• Sponsor: Indiana University School of Medicine
• Investigators: Principal Investigator: Douglas K Rex, M.D., Indiana University School of Medicine

Publications and helpful links

General Publications

• Hewett DG, Rex DK. Inspection on instrument insertion during colonoscopy: a randomized controlled trial. Gastrointest Endosc. 2012 Aug;76(2):381-7. doi: 10.1016/j.gie.2012.04.454.

Study record dates

Study Major Dates

• Study Start: December 1, 2009
• Primary Completion (Actual): December 1, 2010
• Study Completion (Actual): January 1, 2011

Study Registration Dates

• First Submitted: December 18, 2009
• First Submitted That Met QC Criteria: December 18, 2009
• First Posted (Estimate): December 21, 2009

Study Record Updates

• Last Update Posted (Actual): November 16, 2018
• Last Update Submitted That Met QC Criteria: November 15, 2018
• Last Verified: November 1, 2018

More Information

Terms related to this study

• Keywords: Colonoscopy; Colorectal polyps; Adenoma detection
• Additional Relevant MeSH Terms: Neoplasms by Histologic Type; Neoplasms; Neoplasms, Glandular and Epithelial; Adenoma
• Other Study ID Numbers: 0909-22

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO