Can white-light endoscopy or narrow-band imaging avoid biopsy of colorectal endoscopic mucosal resection scars? A multicenter randomized single-blind crossover trial

Abstract

Background and aims: Current guidelines suggest that routine biopsy of post-endoscopic mucosal resection (EMR) scars can be abandoned, provided that a standardized imaging protocol with virtual chromoendoscopy is used. However, few studies have examined the accuracy of advanced endoscopic imaging, such as Narrow Band Imaging (NBI) versus White Light Endoscopy (WLE) to predict histological recurrence. We aimed to assess whether NBI accuracy is superior to WLE and whether one or both techniques can replace biopsies. Patients and methods: Multicentre, randomized, patient-blinded, crossover trial, with consecutive patients undergoing the first colonoscopy after EMR of lesions ≥20mm. Computer-generated randomization and opaque envelope concealed allocation. Patients were randomly assigned to scar examination with NBI followed by WLE (NBI+WLE), or WLE followed by NBI (WLE+NBI). Histology was the reference method, with biopsies being performed in all tissues, either or not showing recurrence. Results: The study included 203 scars, 103 in group NBI+WLE and 100 in group WLE+NBI. Recurrence was confirmed histologically in 29.6% of the scars. The diagnostic accuracy of NBI was not statistically different from WLE 95% (95%CI, 92%-98%) vs. 94% (95%CI, 90%-97%); P=0.48). When assessing NBI vs. WLE, the negative predictive values were (NPV) 96% (95% CI, 93%-99%) vs. 93% (95% CI, 89%-97%), not reaching statistically significance (P=0.06). Conclusions: The accuracy of NBI for the diagnosis of recurrence was not superior to that of WLE. Endoscopic assessment of EMR scars with WLE and NBI achieved a NPV that precludes routine biopsy in cases of negative optical diagnosis.

Can we stop routine biopsy of post-endoscopic mucosal resection scars?

“…In this issue of Endoscopy, João et al report on a randomized controlled trial comparing HD-WLE with NBI for the prediction of histological recurrence after EMR of lesions ≥ 20 mm [10]. The study included 203 scars and RRA was confirmed histologi-cally in 29.6 %.…”

One-device colonoscopy: feasibility, cost savings, and plastic waste reduction by procedure indication, when performed by a high detecting colonoscopist

“…enhanced imaging [20]. Thus, abandoning this practice would further reduce forceps use in our practice (Table 3).…”

“…We performed large numbers of cold forceps biopsies of EMR scars to as we previously showed this approach increase d identification of residual polyp after EMR [7]. Recent studies found routine biopsy can be replaced by detailed inspection of the EMR scars using high definition enhanced imaging [2020 20 ]. Thus, abandoning this practice would further reduce forceps use in our practice (Table 3).…”

Endoscopic Management of Large Non-Pedunculated Colorectal Polyps

“…A recent multicentre single-blind cross-over trial (n = 203) to compare NBI and high definition white light for the assessment of recurrence or residual adenoma at a post-EMR scar reported a negative predictive value (NPV) > 90% (NPV 96% using NBI, NPV 93% using high definition white light) [58]. Use of NBI was not superior to high definition white light (p = 0.06) [58]. Expert consensus is that a biopsy is not needed for a bland scar with a uniform pit pattern [57].…”