Near-focus mode for accurate operation during endoscopic submucosal tunneling procedure.

: Introduction: When using the endoscopic submucosal tunnel technique (ESTT), the working space in the submucosal tunnel is limited, and the visual field is obscured during close inspection or hemostasis. We aimed to evaluate the efficacy and safety of near-focus mode technique for accurate operation during the submucosal tunneling endoscopic procedure.Material and methods: A retrospective two-center study was designed. A total of 51 patients undergoing ESTT procedures with near-focus mode (n = 29) or traditional mode (n = 22) between February 2016 and May 2019 were included in this study.Results: When using the near-focus mode during the ESTT procedure, it is convenient to ensure a clear image and accurate operation. Adverse events occurred more frequently in the traditional group than in the near-focus group (45.5% vs 17.2%, p = .036). The near-focus group exhibited a lower rate of bleeding compared to the traditional group (0 vs 18.2%, p = .029). Furthermore, the mean hospital stay after the procedure was shorter in the near-focus group than in the traditional group (5.7 days vs 6.7 days, p = .013).Conclusions: The visual field is more clearly exposed during submucosal tunneling when using the near-focus mode than when using traditional procedures. This technique appears to be more efficient and secure than the traditional ESTT procedure.