The influence of clips on scars after EMR: clip artifact

Laterally spreading lesions ≥20 mm are conventionally removed by EMR. Endoscopic clips are increasingly used to mitigate the risk of delayed bleeding. Clips may alter the endoscopic appearance of the scar after EMR, interfering with the assessment of adenoma recurrence. We aimed to evaluate this.

Prospective, single-center data from the Australian Colonic Endoscopic resection study (January 2011-May 2015) were analyzed. Patients undergoing EMR of laterally spreading lesions with endoscopic clips used at the EMR defect were eligible. Data included patient and lesion characteristics and procedural, clinical, and histologic outcomes.

Clips were used in 111 of 885 lesions (12.5%). A total of 62 of 111 clipped lesions had standardized, high-definition, white light, and narrow-band images of the scars after EMR at first surveillance colonoscopy, and the patients were enrolled. Analysis of the images showed 4 situations: a bland scar (N = 27), residual adenoma (N = 6), mucosal elevation with normal pit pattern (N = 14), or granulation tissue related to the presence of residual clips (N = 15). The latter 2 entities were termed post-EMR scar clip artifact (ESCA). Overall, 29 of 62 previously clipped EMR sites (46.8%) had ESCA at a median follow-up of 5.2 months. Twenty scars had residual clips, and 15 of 20 (75.0%) showed ESCA (P = .002). Lesions clipped for prophylaxis of bleeding were more likely to show ESCA than those clipped for deep mural injury or intraprocedural bleeding (65.5% vs 41.7%; P = .006). ESCA was associated with female sex (P = .010) and greater age (P = .011).

ESCA is characterized by a nodular elevation of the mucosa with a normal pit pattern and can occur with or without residual clips. Prophylactic clip closure and the presence of residual clips are associated with ESCA. (

NCT01368289.).