The ENKI-2 water-jet system versus Dual Knife for endoscopic submucosal dissection of colorectal lesions: a randomized comparative animal study.

Background And Study Aims: The ENKI-2 water-jet system for endoscopic submucosal dissection (ESD) combines submucosal saline pressure injection with dissection. The aim of this study was to compare ENKI-2 with a standard device in terms of procedure time and perforation rate during colorectal ESD.

Methods: In this randomized comparative study, 10 30-mm-diameter lesions were created in the colon and rectum of 10 healthy adult pigs. The ESD procedure time and perforation rates were recorded for the ENKI-2 system and a standard Dual Knife method. Each pig had half the lesions dissected by ENKI-2 and half dissected by Dual Knife. One experienced and one inexperienced endoscopist took part in the study.

Results: A total of 95 lesions were dissected (47 by ENKI-2 and 48 by Dual Knife). The experienced endoscopist was able to excise comparably sized 30-mm lesions using both techniques. The dissection time was shorter for ENKI-2 (18.9 vs. 25.6 minutes; P = 0.034) and the perforation rate was lower compared with the Dual Knife (one perforation [4 %] vs. nine perforations [36 %]; P = 0.011). The inexperienced endoscopist performed significantly larger dissections using the ENKI-2 (934 ± 405 mm2 vs. 673 ± 312 mm2; P = 0.021) despite pre-marking similarly sized artificial lesions. Multivariate analysis demonstrated that for all lesions the dissection time was significantly longer for lesions in the proximal colon (P = 0.001) and the distal colon (P < 0.0001) and shorter for the experienced operator (P < 0.0001). ENKI-2 shortened the dissection time, but not significantly (P = 0.093).

Conclusions: In experienced hands, the ENKI-2 system shortens dissection time and reduces the perforation rate. This effect was not statistically significant for an inexperienced operator. Dissection was faster in the rectum than the colon.