Abstract: Endoscopic submucosal dissection (ESD) is becoming accepted for colorectal neoplasms (CRNs) in Japan; however, it is not widely used worldwide because of technical difficulty.

Indications: Flat CRNs≥20 mm indicating estimated invasion depth of M or SM superficial, which are difficult to treat by endoscopic mucosal resection.

Equipment: Needle knife and insulation-tipped knife with CO2 insufflation.

Results: En bloc resection rate was 90% among 806 ESDs. Median operation time was 90 min and mean resected specimens size was 40 mm with 2.9% perforations.

Conclusion: Despite longer procedure times, ESD is becoming a preferred treatment in Japan for large flat CRNs. This article is part of an expert video encyclopedia.