WATER-POCKET ENDOSCOPIC SUBMUCOSAL DISSECTION FOR SUPERFICIAL COLORECTAL NEOPLASMS

Aims:

It is essential to obtain a clear view during the endoscopic submucosal dissection (ESD) to dissect the appropriate submucosal layer. Some advantages of underwater techniques for endoscopic resection compared with air insufflation have been reported. Therefore, we aimed to investigate the feasibility and safety of water-pocket ESD (WP-ESD) for superficial colorectal neoplasms.

Methods:

In total, we enrolled 45 patients treated with WP-ESD for superficial colorectal neoplasms between April 2017 and September 2017 and compared them with 45 patients treated with conventional ESD (C-ESD) who were selected by propensity score matching. In the WP-ESD group, a transparent ST hood was attached to the tip of the endoscope. After a small range of submucosal dissection, the ST hood was entered into the submucosal pocket, and the space between the pocket and the ST hood was continuously filled with saline solution during submucosal dissection using the water-jet function of the electrosurgical knife. The study was registered in the University Hospital Medical Network Clinical Trials Registry (UMIN000026317).

Results:

The en bloc resection rates in the WP-ESD group and the C-ESD group were 100%. Although the difference was not significant, the operation time was shorter in the WP-ESD group than in the C-ESD group (median [IQR], 31 [23 – 48] vs. 46 [23.8 – 63]; P = 0.067). However, the operation time was significantly shorter in the WP-ESD group than in the C-ESD group when submucosal fibrosis was present (median [IQR], 40.5 [27.3 – 57.3] vs. 57 [40 – 88]; P = 0.036). Perforation was not observed in either group.

Conclusions:

WP-ESD provided a clearer view and better traction of submucosal layer than C-ESD. We concluded that WP-ESD is an effective and safe approach for dissecting the submucosal layer, particularly in cases with submucosal fibrosis.