Clinical Impact of Intraoperative Perforation in Colorectal Underwater endoscopic submucosal dissection(UESD) Outstanding Award

[Background]UESD enhances visualization in the colorectum but raises concerns about peritonitis from content leakage during perforation. This study aimed to evaluate the safety of colorectal UESD, focusing on intraoperative perforations.[Method]This single–center retrospective study included colorectal ESD cases with intraoperative perforation from May 2010 to May 2024. The cases between UESD and conventional ESD (CESD) groups were compared. Measured outcomes included the clinical characteristics and postoperative course. [Result]Among 667 UESD and 893 CESD cases, 27 (4.0%) and 22 (2.5%) intraoperative perforation cases were analyzed. There were no significant differences between the two groups in terms of patient and lesion characteristics. Clip closure for perforation was successful in all cases. The median time from perforation to close was 11min [range,1.5–48 ] in UESD. There were also no significant differences in postoperative clinical outcomes, including fever (33% vs. 27%, p = 0.65), localized abdominal pain (48% vs. 36%, p = 0.40), and median hospital stay (3 days [range, 3–9] vs. 5 days [range, 3–8], p = 0.28).[Conclusion]The clinical impact of intraoperative perforation in UESD was comparable to CESD, with no significant differences in symptoms or hospital stay.