A standardized imaging protocol is accurate in detecting recurrence after EMR

Area of Science:

• Gastroenterology
• Endoscopy
• Oncology

Background:

• Endoscopic mucosal resection (EMR) is a viable alternative to surgery for large laterally spreading lesions (LSL) in the colon.
• Post-EMR scar surveillance typically involves biopsies to detect residual or recurrent adenoma (RRA).
• The diagnostic accuracy of endoscopic imaging for post-EMR scar assessment is not well-established.

Purpose of the Study:

• To evaluate the accuracy of a standardized endoscopic imaging protocol for detecting RRA in post-EMR scars.
• To compare the efficacy of high-definition white light (HD-WL) and narrow-band imaging (NBI) in RRA detection.

Main Methods:

• Prospective analysis of data from the Australian Colonic EMR study.
• Consecutive patients with LSL undergoing EMR and first surveillance colonoscopy (SC1) were included.
• Scars were examined using HD-WL and NBI, followed by biopsies, with endoscopic findings compared to histology.

Main Results:

• 183 post-EMR scars were analyzed; 16.4% had RRA confirmed histologically.
• Endoscopic assessment detected RRA in 20.2% of scars with 94.0% overall diagnostic accuracy.
• Sensitivity and specificity for endoscopic RRA detection were 93.3% and 94.1%, respectively.
• Combined HD-WL and NBI improved sensitivity (93.3%) compared to HD-WL alone (66.7%), with NBI particularly useful for flat RRA morphology.

Conclusions:

• A standardized endoscopic imaging protocol utilizing HD-WL and NBI accurately detects RRA in post-EMR scars.
• This approach enables real-time detection and concurrent treatment of recurrence.
• The findings suggest that routine biopsy of post-EMR scars may be unnecessary, potentially streamlining surveillance.