Prospective clinical trial of traction device-assisted endoscopic submucosal dissection of large superficial colorectal tumors using the S–O clip

Endoscopic submucosal dissection (ESD) allows en bloc resection of superficial colorectal tumors regardless of size. However, ESD is technically difficult, hazardous, and time consuming. New devices may help overcome these drawbacks. We focused on traction methods and designed a new traction device, the “S–O clip.” Its main advantage is that it allows direct visualization of the cutting line during submucosal dissection. Moreover, it can be used at any location without withdrawing the endoscope. The purpose of this study was to evaluate the efficacy and safety of traction device-assisted ESD for large colorectal tumors using the S–O clip. Between August 2010 and December 2011, ESD was performed in 70 patients with a superficial colorectal tumor ≥20 mm in diameter in our department. Patients were randomized into two groups: 27 cases in the S–O clip-assisted ESD group and 23 cases in the conventional ESD group. Included in the analysis were patient’s gender and age, tumor form, size, and location, rate of en bloc resection, procedure time, presence or absence of intraoperative perforation or delayed bleeding, and pathological findings. Subgroup analysis stratified by these factors and multivariate analyses were conducted. In the S–O clip-assisted ESD group, all 27 tumors were resected en bloc without any complications. Although a micro perforation occurred in one patient in the conventional ESD group, further surgical treatment was not required. None of the other 22 cases in the conventional ESD group experienced complications. The mean procedure time for the S–O clip-assisted ESD group was significantly shorter than for the conventional ESD group (37.4 ± 32.6 vs. 67.1 ± 44.1 min, p = 0.03). No significant between-group differences were found for the other factors. Our results demonstrated that S–O clip-assisted ESD is safe and fast for en bloc resection of large superficial colorectal tumors.