Clinical Study of Real Time Colorectal Polyp Diagnosis During Colonoscopy - the VALID Colonoscopy Study

Not Applicable

Completed

Conditions: Colorectal Neoplasm
Colonic Polyps

Interventions: Device: Close focus HD NBI Colonoscopy System

Registration Number: NCT01288833

Lead Sponsor: VA Palo Alto Health Care System

Brief Summary: The investigators hypothesize that high definition colonoscopy with close focus narrow band imaging features has a high diagnostic accuracy for colorectal polyp histology, and can replace formal pathologic assessment in cases of high diagnostic confidence.

Detailed Description: A recent single arm prospective cohort study suggested that high definition colonoscopy with narrow band imaging is an acceptable strategy to diagnose polyp histology and determine future surveillance intervals. Endoscopic proficiency in macroscopic features to differentiate polyp histology can be attained in a relatively short time period. A new high definition colonoscope with close focus narrow band imaging features may further improve diagnostic accuracy for polyp differentiation, and can replace formal pathologic assessment in cases of high diagnostic confidence.

Primary Aim: Compare the diagnostic accuracy of high definition narrow band imaging colonoscopy with and without close focus features for the macroscopic differentiation of neoplastic and non-neoplastic colorectal lesions using histopathologic diagnosis as the reference standard.

Secondary Aims: Compare diagnostic characteristics of the colonoscopes, measure concordance of high confidence and accuracy, compare accuracy of predicted versus actual surveillance interval recommendations, perform a cost-effective analysis of endoscopic versus pathologic diagnoses, and measure complications.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 558

Inclusion Criteria

Adult patients referred for routine colonoscopy

Exclusion Criteria

Known inflammatory bowel disease
Personal or family history of polyposis or non-polyposis syndrome
Presentation for emergency endoscopy
Inability to remove polyp due to coagulopathy or thrombocytopenia
Inability to provide informed consent

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Close focus HD NBI Colonoscopy System	Close focus HD NBI Colonoscopy System	Use of close focus to make optical diagnosis

Primary Outcome Measures

Name	Time	Method
Rate of Accurate High Confidence Polyp Histology Predictions by the Endoscopist in the Two Groups.	At the time of procedure	Measure of the percentage of accurate high confidence predictions by the endoscopist in the differentiation of neoplastic from non-neoplastic colorectal lesions, using the high definition NBI colonoscopy with and without close focus features. High confidence was assigned if the polyp had one or more features of Type 2 (neoplasia) or Type 1 (nonneoplasia) in the NICE classification and no features associated with the other histology Note: one patient may have multiple polyps.

Secondary Outcome Measures

Name	Time	Method
Learning Curve	At time of procedure.	Examine the impact of a learning curve (i.e. NPV of high confidence at each of endoscopist's first 50% of exams versus last 50% exams to endoscopically predict polyp histology). NPV is defined as "number of histologically confirmed hyperplastic polyps out of all endoscopic predictions of hyperplastic (non-neoplastic) polyps.
Cost	At the time of procedure	Measure the cost of colonoscopy with macroscopic histopathologic diagnosis of colorectal lesions compared to colonoscopy with conventional microscopic histopathologic diagnosis, on the lesions that were managed based on an accurate endoscopic diagnosis. A reduction in pathology specimens may improve the efficiency of the procedure and has direct pathology cost savings (as well as indirect savings, which were not measured).
Diagnostic Characteristics	At time of procedure	Compare the diagnostic characteristics (sensitivity, specificity, positive predictive value and negative predictive value) using the high definition narrow band imaging colonoscopy with and without close focus features. Accuracy: number of endoscopic predictions of adenomatous polyps histologically confirmed to be adenomatous/number of predicted hyperplastic polyps confirmed to be hyperplastic out of all polyps Sensitivity: number of endoscopic predictions (optical diagnosis) of adenomatous (neoplastic) polyps out of all histologically confirmed polyps Specificity: number of endoscopic predictions of hyperplastic (non-neoplastic) polyps out of all histologically confirmed polyps PPV: number of histologically confirmed adenomatous polyps out of all endoscopic predictions of adenomatous polyps NPV: number of histologically confirmed hyperplastic polyps out of all endoscopic predictions of hyperplastic (non-neoplastic) polyps Note: a patient may have multiple polyps
Accuracy of Predicted Versus Actual Surveillance Intervals	At the time of procedure	Compared the accuracy of predicted versus actual surveillance colonoscopy interval recommendations by determining number of patients with correct surveillance interval recommendation.

Trial Locations

Locations (2): Veterans Affairs Palo Alto
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Palo Alto, California, United States
Veterans Affairs Kansas City
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Kansas City, Missouri, United States