HybridKnife high-pressure glycerol jet injection for endoscopic submucosal dissection increases procedural ease and speed: a randomised study in pigs and a human case series.

Background and Aims: Good use of the submucosal space is key during endoscopic submucosal dissection (ESD). High-pressure injection of a long-lasting viscous solution using the HybridKnife water-jet system has been demonstrated to be feasible. We compared jet injection of glycerol and normal saline during pig gastric ESD and assessed its feasibility and efficiency during human ESD.
Materials and Methods: A blinded randomised controlled study of ESD with the HybridKnife injecting either a glycerol mixture or normal saline and a prospective human case series were performed. Twenty gastric pig dissections (10/group) and 38 human ESDs along the gastrointestinal tract were performed. Dissection speed, specimen size, procedure duration, rates of en bloc and R0 resection, and rates of bleeding and perforation were prospectively recorded. An evaluation of operator comfort and perceived safety (dissection score) was performed using a visual analogue scale with zero being the worst score and ten the best.
Results: Dissection was significantly more rapid (1.38-fold) with glycerol injection than with normal saline injection (28.94 vs. 20.91 mm(2)/min; p = 0.037). The dissection score was significantly higher in the glycerol group than in the normal saline group (7.3 vs. 4.7; p = 0.0064). No differences were observed in the rates of en bloc resection, bleeding, or perforation. The 38 human cases along the gastrointestinal tract revealed good results (en bloc resection rate = 100 %, R0 resection rate = 90 %) without any complications.
Conclusion: High-pressure jet injection of glycerol with the HybridKnife for ESD increased the speed and operator comfort of the procedure compared with the use of normal saline, and the procedure was safe and efficient for human ESD. The advantages of using a combination of the HybridKnife system and a viscous glycerol solution will help to spread the use of the ESD technique, particularly in non-Asian countries.