Effect of the Insulated‐Tip Knife on Procedure Time in Endoscopic Submucosal Dissection for Colorectal Neoplasms: A Single‐Center, Randomized Controlled Trial (NANO Study)

ABSTRACT Background and Aim The insulated‐tip (IT) knife nano is a high‐frequency electrosurgical knife designed to enhance the safety and efficiency of endoscopic submucosal dissection (ESD), particularly in anatomically narrow lumens such as the colorectum. Although it is commonly used in combination with needle knives for colorectal ESD, its efficacy in this context has not been substantiated through randomized controlled trials (RCTs). We aimed to evaluate whether the adjunctive use of the ITknife nano significantly reduces ESD procedure time for colorectal neoplasms. Methods A single‐center RCT involving patients with colorectal neoplasms measuring 30–50 mm was randomized to receive ESD with either the DualKnife J alone (D‐group) or the addition of the ITknife nano (IT‐group). Allocation adjustment factors included lesion location, tumor size, and macroscopic type. The primary outcome was the ESD procedure time. Secondary outcomes included submucosal dissection speed, en bloc and R0 resection rate, and incidence of adverse events. Results A total of 108 and 106 lesions in the D‐ and IT‐groups, respectively, were analyzed. There was no significant difference in procedure time between groups (111.8 min vs. 114.3 min, p = 0.789) nor in submucosal dissection speed (22.9 mm 2 /min vs. 22.1 mm 2 /min, p = 0.669). However, subgroup analysis on allocation factors revealed significantly faster dissection speed for rectum lesions in the D‐group (24.7 mm 2 /min vs. 16.2 mm 2 /min, p = 0.0496). Resection and safety outcomes were comparable between groups. Conclusions The adjunctive use of the ITknife nano with the DualKnife J did not significantly reduce procedure time in colorectal ESD (jRCT1042180137). Trial Registration: University Hospital Medical Network Clinical Trials Registry: UMIN000030068; Japan Registry of Clinical Trials: jRCT1042180137