Efficacy of hybrid endoscopic submucosal dissection with SOUTEN in gastric lesions: An ex vivo porcine model basic study

BACKGROUND Hybrid endoscopic submucosal dissection (ESD) that comprises mucosal incision and partial submucosal dissection followed by snaring in a planned manner, has been developed for endoscopic resection of gastrointestinal neoplasms to overcome the technical barrier of ESD. Although the superiority of hybrid ESD with SOUTEN, a single multifunctional device, over conventional ESD has been indicated, the actual effect of snaring itself remains unclear since SOUTEN could be applied to hybrid ESD group, but not to the conventional ESD group, due to ethical issue in clinical practice. AIM To determine whether and how hybrid ESD was superior to conventional ESD in the endoscopic treatment of gastric lesions in an ex vivo porcine model basic study. METHODS Sixteen endoscopists participated in this basic study in August 2020 at Kyushu University, performing 32 procedures each for hybrid ESD and conventional ESD. Mock lesions (10-15 mm, diameter) were created in the porcine stomach. The primary outcome was total procedure time and secondary outcomes were en bloc or complete resection, perforation, procedure time/speed for both, mucosal incision, and submucosal dissection. Factors associated with difficulty in ESD including longer procedure time, incomplete resection, and perforation, were also investigated. Categorical and continuous data were analyzed using the chi-square test or Fisher's exact test and the Mann-Whitney U test, respectively. RESULTS The median total procedure time of hybrid ESD was significantly shorter than that of conventional ESD (median: 8.3 min vs 16.2 min, P < 0.001). Time, speed, and the amount of hyaluronic acid during submucosal dissection were more favorable in hybrid ESD than conventional ESD (time, 5.2 min vs 10.4 min, P < 0.001; speed, 43.7 mm(2)/min vs 23.8 mm(2)/min, P < 0.00; injection volume, 1.5 mL vs 3.0 mL, P < 0.001), although no significant differences in those factors were observed between both groups during mucosal incision. There was also no significant difference between both groups in the en bloc/complete resection rate and perforation rate (complete resection, 93.8% vs 87.5%, P = 0.67; perforation, 0% vs 3.1%, P = 1). Selection of conventional ESD as the treatment method was significantly associated with difficulties during ESD (odds ratio = 10.2; highest among factors). CONCLUSION Hybrid ESD with SOUTEN improves the treatment outcomes of gastric lesions. It also has the potential to reduce medical costs since SOUTEN is a single multifunctional device that is inexpensive.