Narrow Band Imaging Versus Conventional Colonoscopy for Screening Colonoscopy in a Private Practice Setting - A Large Prospective Randomized Trial

Abstract

Background: Narrow Band Imaging (NBI) has been implemented into GI endoscopy in order to better highlight endoluminal pathological structures and improve their contrast. Previous studies from referral centers could not show significant differences in terms of colonoscopic adenoma detection rate, but either very high adenoma rates or some numerical differences suggest that some benefit may exist which may become evident with average adenoma rates and/or larger case numbers. Patients and Methods: In a prospective randomized trial performed exclusively in a multicenter private practice setting involving 6 examiners with substantial life-time experience (> 15.000 colonoscopies) , 1256 patients (m:f=47%:53%, mean age 64.3 years) underwent screening colonoscopy with either NBI (625 patients) or conventional imaging technique (631 Patients) on instrument withdrawal, using HDTV technique in both arms. Primary outcome measure was the adenoma detection rate (ADR; adenomas per patient). Results: There was no difference between the two groups in terms of ADR (32.0 vs. 34.2%, p = 0.4), the total number of adenomas (200 vs. 216), the rates of adenomas per adenoma-carrier (200/140=1.43 vs. 216/137=1.58), nor in special subgroups (right sided lesions, advanced adenomas, flat adenomas). The times of instrument withdrawal were not significantly different either (8.5 vs. 7.9 min.). Conclusions: This large randomized trial in a homogeneous setting (private practices, screening patients) could not demonstrate any objective benefit of the NBI technique in terms of improved adenoma detection. It can be concluded that contrast enhancement in conventional imaging techniques will likely not contribute to reduce the adenoma miss rates of experienced colonoscopists.