Efficacy of an Endo-Knife With a Water-Jet Function (Flushknife) for Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms

OBJECTIVES: Endoscopic submucosal dissection (ESD) is currently not a common treatment for colorectal neoplasms because it is time consuming and technically difficult. Flushknife-an electrosurgical endo-knife with a water-jet function-is expected to reduce the difficulty of colorectal ESD. The objective of this study was to investigate the efficacy of a water-jet function for colorectal ESD. METHODS: This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. A total of 49 patients, with a total of 51 superficial colorectal neoplasms (median tumor size of 30 mm), were enrolled and randomly assigned to undergo ESD using either the Flexknife (electrosurgical endo-knife without a water-jet function) or the Flushknife. Tumors were resected by ESD using each endo-knife. The procedures were conducted by two endoscopists. Operation time was defined as the main outcome measure. RESULTS: En bloc resection was achieved in 23 out of 26 (88%) lesions in the Flexknife group and in 24 out of 24 (100%) lesions in the Flushknife group. The mean operation time (95% confidence interval) was 87.3 (71.3-103.4) min in the Flexknife group and 61.0 (49.3-72.7) min in the Flushknife group (P = 0.02). The Flushknife reduced the number of endoscopic device changes (P = 0.001), the number of submucosal injections (P = 0.001), and the mean amount of injected hyaluronate sodium (P = 0.001) compared with the Flexknife. No severe adverse events were observed in either group. CONCLUSIONS: Without increasing adverse events, the endo-knife with a water-jet function efficiently reduced the operation time of colorectal ESD in patients with large superficial colorectal neoplasms. (University hospital Medical Information Network Clinical Trials Registry number UMIN000001302)