Linked-color imaging versus narrow-band imaging for colorectal polyp detection: a prospective randomized tandem colonoscopy study.

Leung WK1, Guo CG2, Ko MK2, To EW2, Mak LY2, Tong TS2, Chen LJ2, But DY2, Wong SY2, Liu KS2, Tsui V2, Lam FY2, Lui TK2, Cheung KS2, Lo SH2, Hung IF2.

Gastrointest Endosc. 2019 Jul 2. pii: S0016-5107(19)32019-X. doi: 10.1016/j.gie.2019.06.031. [Epub ahead of print]

Background and aims: Linked-color imaging (LCI) is a newly available image enhanced endoscopy (IEE) system, which emphasizes the red mucosal color. No study has yet compared LCI with other available IEE systems.

Aim: To compare the polyp detection rates of LCI with narrow band imaging (NBI).

Methods: This is a prospective randomized tandem colonoscopy study. Eligible patients who underwent colonoscopy for symptoms or screening/surveillance were randomized in a 1:1 ratio to receive tandem colonoscopy with both colonoscope withdrawals using LCI or NBI. The primary outcome was polyp detection rate.

Results: Two hundred seventy-two patients were randomized (mean age 62 years; 48.2% male; colonoscopy for symptoms: 72.8%) with 136 in each arm. During first colonoscopy, the NBI group had significantly higher polyp detection rate (71.3% vs 55.9%; P = 0.008), serrated lesion detection rate (34.6% vs 22.1%; P = 0.02), and mean number of polyps detected (2.04 vs 1.35; P = 0.02) than the LCI group. There was also a trend of higher adenoma detection rate in the NBI group (51.5% vs 39.7% in LCI; P = 0.05). Multivariable analysis confirmed that use of NBI (adjusted OR, 1.99; 95% CI, 1.09-3.68) and withdrawal time >8 minutes (aOR, 5.11; 95% CI, 2.79-9.67) were associated with polyp detection. Overall, 20.5% of polyps and 18.1% of adenoma were missed by first colonoscopy, but there was no significant difference in the miss rates between the 2 groups.

Conclusion: NBI was significantly better than LCI for colorectal polyp detection. However, both LCI and NBI missed 20.5% of polyps.

1 Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong
2 Department of Surgery, Queen Mary Hospital, University of Hong Kong, Hong Kong