the saline-Immersion/irrigation Technique (SITE) endoscopic submucosal dissection (ESD) has been reported for improving the feasibility and safety of ESD (1-5). In 2023, drainage-tubes were introduced to reduce bowel overdistension and facilitate dissection during SITE-ESD, (6-8). In our practice, we now employ a drainage-tube for all colonic SITE-ESD, by using a slim 8Fr fenestrated nasal-jejunal feeding tube wrapped around the scope and secured with vinyl-tape to enhance the advantaged of SITE-ESD.  This tube, which we named the ‘Asclepius tube’, given its similarity to the medical symbol of the snake around the rod of Asclepius, has the objective of draining redundant fluid from continuous saline-irrigation and diathermy-generated gas, obviating the need for scope aspiration. This approach aims to enhance dissection efficiency, visual clarity and patient comfort. A retrospective study by Kagaya et al. demonstrated that drainage improved ESD efficiency in the rectum (9).

We aimed to compare procedural and clinical outcomes between colonic SITE-ESD performed with and without drainage tube placement.

We retrospectively analyzed 137 colonic SITE-ESDs (50 without drainage, 87 with drainage) performed between May 2018 and October 2025 at a tertiary endoscopy unit. Baseline demographic, procedural, and histopathological parameters were compared. Primary outcomes included resection speed, total procedure duration, R0 resection rate, and adverse events. Statistical analysis was performed using IBM SPSS v30.0.

Groups were comparable in age, gender, ASA score, lesion diameter, and location (all p >0.05). While median procedure duration was similar (120 min vs 120 min; p=0.97), our resection speed was significantly higher with drainage (11.4 mm²/min vs 6.9 mm²/min; p=0.006). R0 resection rates (88.5% vs 92%; p=0.78) and delayed adverse events (4.6% vs 4%; p=0.86) did not differ significantly.

Drainage-assisted colonic SITE-ESD significantly increased resection speed while maintaining similar safety and histological outcomes. Its use may enhance procedural performance and stability in complex colonic resections. Further prospective comparative studies are merited.