Evaluation of the Hemostatic Effect of Red Dichromatic Imaging during Rectal Biopsy in Patients with Ulcerative Colitis

Aims Ulcerative colitis (UC) is a chronic inflammatory bowel disease requiring prolonged treatment and regular endoscopic monitoring. Endoscopic mucosal healing is widely used as a treat-to-target strategy for UC and is associated with favorable long-term outcomes. Histological healing has recently gained attention as a stringent therapeutic goal, leading to an increased frequency of rectal mucosal biopsies performed during surveillance endoscopy. However, spontaneous hemostasis of post-biopsy bleeding often fails in clinical practice, necessitating additional hemostatic interventions. This study aimed to evaluate the hemostatic effect of red dichromatic imaging (RDI) on post-biopsy bleeding in UC patients, utilizing the Olympus EVIS X1 (CV-1500) system.

Methods This prospective study included 40 patients who underwent colonoscopy at our institution between February, 2022 and August, 2024. Eligible patients were aged 20–80 with UC and showed endoscopic mucosal healing (Mayo endoscopic subscore of 0 or 1) during colonoscopy. Patients were randomly assigned to either white light imaging (WLI) (n=20) or RDI (n=20) group. Spontaneous hemostasis time was measured in both groups post-biopsy. After observing the entire colon, a single rectal biopsy was performed for each patient, with irrigation as required. With RDI, relatively large blood vessels (diameter over 500 μm) located from deep mucosal to submucosal layer can be observed. In the RDI group, these easily bleeding vessels are clearly visualized, allowing biopsy to be performed while avoiding these vessels under direct observation. The time from biopsy to hemostasis, as determined by the endoscopist, was recorded. Procedures were video-recorded and reviewed by two independent physicians to measure bleeding duration. The median of these measurements was used as the bleeding time and compared between the two groups.

Results The sex ratio (male/female) and median(IQR) age were 14:6 and 45(34.25-56.25) years in the WLI group, and 15:5 and 39(38.5-54.5) years in the RDI group. Disease distribution in both groups was as follows: pancolitis (10/8), left-sided colitis (6/7), proctitis (4/4), and other types (0/1). The median(IQR) treatment duration was 12(4-15.5) years in the WLI group and 8.5 years in the RDI group. Spontaneous hemostasis time was significantly shorter in the RDI group than in the WLI group (65.95±37.81 vs. 98.65±47.85 s; p=0.0215). Notably, spontaneous hemostasis was observed in both groups, with no need for additional hemostatic interventions.

Conclusions This study demonstrated that RDI during rectal biopsy significantly reduced bleeding time in UC patients, indicating its hemostatic efficacy. Although limited by a small sample size, these findings suggest that RDI may enhance biopsy safety in UC patients. Further studies with larger cohorts are warranted to validate these results.

Publication History

Article published online:
27 March 2025