IDDF2024-ABS-0153 Water-injecting endoscopic submucosal dissection for early gastric cancer: a pilot study

<h3>Background</h3> Endoscopic submucosal dissection (ESD) is a technically difficult and time-consuming procedure. Several water-jet knives have been developed to address this issue. We aimed to develop a new ESD method using continuous low-pressure water injection at 1-2 atmospheres with a tip-injected electric knife while dissection, electrocoagulation, and hemostasis, which was so-called water-injecting ESD (W-ESD) to treat early gastric cancer and compare the efficacy and safety with conventional methods (IDDF2024-ABS-0153 Figure 1. A, Single-use electrosurgical knife. B, The single-use electrosurgical knife and handle intergroup. C, When submucosal dissection is performed, the assistant rotates the piston to maintain continuous low-pressure water injection). <h3>Methods</h3> This was a single-center, pilot study. 48 ESDs were carried out at 4 different locations by the conventional method (n=24) and the W-ESD method (n=24). The primary outcomes were total procedure time, dissection time and speed. Secondary endpoints were completeness resection and adverse event rate. <h3>Results</h3> The total procedure time was significantly shorter in W-ESD than in conventional ESD (28.6 vs. 40.7 minutes; P&lt;0.05). The W-ESD group exhibited a markedly higher dissection speed than the conventional ESD group (56.5 vs. 29.7 mm²/min; P&lt;0.05). The number of muscular injuries was significantly lower using the W-ESD method than the conventional method (8 vs. 20; P&lt;0.05). The mean number of coagulation grasper changes was significantly reduced with the W-ESD method (0.3 vs. 2.1; P&lt;0.05). The mean intraoperative hemorrhage was significantly less in W-ESD than in conventional ESD (5.1 vs. 12.1 ml; P&lt;0.05). <h3>Conclusions</h3> This study demonstrated that using continuous low-pressure water injection during ESD is technically feasible, safe and effective for early gastric cancer. We recommended W-ESD as the optimal strategy for ESD to reduce procedure time and incidence of complications.