Trial Information

Real Time Colorectal Polyp Diagnosis in Colorectal Cancer Screening Using Close Focus High Definition Narrow Band Imaging Colonoscopy Compared to Conventional Histopathology Diagnosis - the VALID (Veterans Affairs Lesion Interpretation and Diagnosis) Colonoscopy Study

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, measure advanced pathology and colon cancer at surveillance, and measure
complications.