CAN ROUTINE BIOPSY OF COLORECTAL ENDOSCOPIC MUCOSAL RESECTION SCARS BE ABANDONED? – PRELIMINARY DATA OF A MULTICENTRE RANDOMIZED SINGLE-BLINDED CROSSOVER TRIAL

Aims Current ESGE guideline suggests that routine biopsy of 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 for the prediction of histological recurrence. We aimed to assess the incremental benefit of narrow band imaging (NBI) versus white light endoscopy (WLE) by randomizing the initial technique for the endoscopic detection of post-EMR recurrence and to assess if NBI achieves a diagnostic accuracy that replaces the need for biopsy.

Methods Multicenter, randomized, crossover trial, with consecutive patients undergoing the first colonoscopy after EMR of lesions≥20mm. Computer-generated randomization and opaque envelope concealed allocation. Patients randomly assigned to scar examination with NBI followed by WLE (NBI>WLE) or WLE followed by NBI (WLE>NBI) with biopsies in recurrence- and normal-appearing tissue were performed.

Results We included 112 scars, 61 in group NBI>WLE and 57 in group WLE>NBI. Recurrence was confirmed histologically in 32%. Comparing NBI vs. WLE assessment sensitivity 89% vs. 82%, specificity 98% vs. 99%, positive predictive value 94% vs. 97% and negative predictive values 95% vs. 92% did not reach a statistically significance. Diagnostic accuracy of NBI vs. WLE for diagnosis of recurrence was improved (95% vs. 93%; P<0.01).

Conclusions Endoscopic assessment of EMR scars with WLE has an already high accuracy for diagnosis of recurrence but the use of NBI can further improve recurrence detection, precluding the routine biopsy in cases of negative optical diagnosis.

Publication History

Article published online:
14 April 2022