The saline-immersion/irrigation technique (SITE) for colonic endoscopic submucosal dissection (ESD): A comprehensive evaluation of outcomes, efficacy, and safety

Endoscopic submucosal dissection (ESD) allows precise en-bloc resection of early gastrointestinal neoplasia, reducing recurrence, and increasing cure rates compared with conventional endoscopic mucosal resection. However, its use in the colon remains limited due to the technical complexity, restricted scope maneuverability, and the thin colonic wall. To address these challenges, procedural modifications such as the pocket-creation method (PCM) and traction-assisted techniques have been developed. Since its introduction in 2017, the saline immersion/irrigation technique (SITE) has emerged as an alternative platform to facilitate ESD. SITE differs from approaches referred to as "underwater-ESD" as it specifically uses isotonic saline, whose electrolyte content enhances electrical conductivity, enabling effective coagulation, reduced thermal injury, and improved procedural precision. Advantages of SITE include improved visualization through optical magnification and avoidance of smoke-clouding, natural buoyancy providing intrinsic traction, heat-dissipation limiting collateral tissue damage, and reduced luminal distension, contributing to improved patient comfort. When combined with PCM, SITE has been associated with increased dissection speed and reduced procedure time. Current evidence demonstrates that SITE-ESD achieves en-bloc and R0 resection rates comparable to conventional ESD, with similar rates of adverse events, including perforation, bleeding, and post-ESD coagulation syndrome (PECS). The heat-sink effect of saline may further contribute to reduced thermal injury and potentially lower PECS incidence. SITE may also facilitate ESD performance for less experienced endoscopists, expanding accessibility to colorectal ESD. Further large-scale prospective studies are needed to define its optimal role in clinical practice. The term "saline-immersion/irrigation technique" should be used to emphasize the importance of the ionic medium.