Tips for ESD and defect closure under water conditions: Immersion world

In recent years, many therapeutic endoscopic methods underwater conditions have been reported. We have reported a gas-free immersion (GFI) system that uses a tapered attachment (CAST hood; TOP) and fluid delivery in the direction of the scope lens to create a turbulence in hood without CO2 gas insufflation. In the event of bleeding, temporary compression hemostasis can be achieved using the wide sides of the CAST hood, and because the use of water directed towards the lens creates turbulence inside the hood, it is possible to stop the bleeding without inserting the bleeding into the hood.
We have closed more than 100 colorectal ESD defects using a method we call the Reopenable-clip over the line method (ROLM), which uses the holes in the teeth of a reopenable-clip and a line. When closing using the ROLM, we use the CAST hood and the GFI system under water conditions, which allows us to maintain an appropriate field of view and to achieve complete closure even in narrow lumens.
We also reported for the first time that the bubbles generated are a mixture of hydrogen and oxygen, and that there is a possibility of an explosion [Endoscopy 2024]. However this hydrogen explosion could be easily solved by diluting with carbon dioxide or sucking it out. On the day of the presentation, we will show videos of ESD and endoscopic closure tips underwater conditions.