Upward lesion orientation on an endoscopic monitor is an independent factor affecting difficulty of colorectal endoscopic submucosal dissection: a retrospective study

To investigate the association between lesion orientation on the endoscopic monitor and colorectal endoscopic submucosal dissection (ESD) difficulty.We performed ESD for 406 consecutive colorectal tumors between January 2019 and August 2024.Multivariate logistic regression analysis was conducted on the following factors related to difficult ESD and incomplete ESD : tumor size ( 40 mm or 40 mm) , lesion location (right or left colon) , lesion orientation on the endoscopic monitor (upward or downward) , submucosal fibrosis (F0 / 1 or F2) , tumor invasion depth (Tis, T1a, or T1b) , and operators experience in colorectal ESD (beginner 20 cases or nonbeginner 20 cases ) .Procedures requiring 120min indicated difficult colorectal ESDs.The mean tumor size was 28.9 15.4 mm, and the mean procedure time was 82.6 64.1 min.Tumor size 40 mm (odds ratio OR , 9.30 ; 95 confidence interval CI , 4.93-18.00; p0.001) , upward lesion orientation on the endoscopic monitor (OR, 3.79 ; 95 CI, 2.06-7.04 ; p0.001) , and severe fibrosis (OR, 7.42 ; 95 CI, 2.97-19.00; p0.001) were independent factors that increased colorectal ESD difficulty.Meanwhile, severe fibrosis (OR, 3.52 ; 95 CI, 1.11-10.45; p0.033) , T1b invasion depth (OR, 3.30 ; 95 CI, 1.07-9.34; p0.039) , and beginner operator (OR, 2.97 ; 95 CI, 1.25- 7.25 ; p0.035) were independent factors contributing to incomplete ESD.In addition to known intrinsic factors, such as large tumor size and fibrosis, the upward orientation of the lesion on the endoscopic monitor was identified as an independent factor that increased the difficulty of colorectal ESD.