High-pressure injection of glycerol with HybridKnife for ESD is feasible and increases the ease and speed of the procedure: an in vivo study in pigs and first use in human.

Background And Aims: The HybridKnife water-jet system (ERBE, Tubingen, Germany) has been shown to increase dissection speed and decreased the risk of perforation during endoscopic submucosal dissection (ESD). Glycerol mixture is a viscous, long-lasting solution preferentially used by Japanese ESD experts. The combination of the HybridKnife system with a glycerol solution has not been evaluated to date.

Materials And Methods: A prospective non-randomised comparative study of ESD with HybridKnife injecting of either a glycerol mixture or normal saline was performed. Twenty dissections (ten per group) were performed on four anaesthetised domestic mini-pigs. Dissection speed (mm(2)/min), size of the specimen (mm(2)), duration (min), en bloc resection rate, and bleeding and perforation rates were prospectively recorded. An evaluation of operator comfort and perception of safety (dissection score) was performed using a visual analogue scale with 0 being the worst score and 10 the best.

Results: High-pressure injection of the glycerol mixture and dissection with the HybridKnife was feasible without complications. Dissection was significantly more rapid (1.67-fold) with glycerol injection than normal saline injection (27.44 vs. 16.44 mm(2)/min; p < 0.001). The dissection score was significantly higher in the glycerol group than in the normal saline group (5.9 vs. 2.9; p < 0.001). No differences were observed in the rates of en bloc resection, bleeding and perforation. Seven first human cases were also easy without need of preliminary incision and technical complication.

Conclusion: High-pressure jet injection of glycerol with HybridKnife for ESD is feasible and increases the speed and safety of the procedure compared with use of normal saline.