1045 knife-assisted SNARE resection (KAR) for dysplasia-associated lesions or masses

Introduction: The risk of colonic neoplasia is increased in inflammatory bowel disease. Dysplasia-associated lesion or mass (DALM) can be difficult to detect and challenging to resect endoscopically. Conventional endoscopic mucosal resection (EMR) has been used but as these lesions are often flat morphologically, the snare slips off. Endoscopic submucosal dissection (ESD) has been shown to be able to resect flat lesions, however, they carry a high perforation rate. Knife assisted snare resection (KAR) is a novel technique that combines the principles of EMR and ESD. We aim to evaluate the safety and efficacy of this technique in resecting DALMS.

Methods: Data of all KARs undertaken by a single endoscopist in our institution from 2012 to 2014 were prospectively compiled in a pre-designed database. 2 independent researchers interrogated the database. Endoscopic follow-up was performed to identify recurrence.

Results: 9 patients underwent KAR during this period. 8 patients had ulcerative colitis and 1 had Crohn’s colitis. The mean polyp size was 29mm (10-60mm). Scarring was noted in 89% of resections despite no previous resection attempts. En-bloc resection was achieved in 7 patients (78%). Endoscopic curative resection was achieved in 7 patients and 1 patient is awaiting endoscopic follow-up. 1 patient experienced a delayed perforation, which was managed surgically. Histological assessment of the resected polyps revealed 5 adenomas, 3 DALMs and 1 intramucosal cancer.

Conclusion: DALMs are difficult to detect and challenging to resect endoscopically using conventional methods. We have demonstrated that KAR as a novel technique is safe and effective in resecting DALMs. As the learning curve of KAR is not as steep as ESD, we believe that is a viable endoscopic resection technique of DALMs in inflammatory bowel disease.