Flushing-Assisted Saline Immersion Endoscopic Submucosal Dissection in the Rectum: A Video-Based Feasibility Series

Flushing endoscopic submucosal dissection (ESD) is a refinement of saline immersion ESD in which energy-synchronized saline flushing from the knife tip is hypothesized to disperse micro-bubbles and facilitate more controlled coagulation at the tissue interface. We retrospectively evaluated the technical feasibility of this approach in 10 rectal procedures performed at a tertiary referral center. Complete procedural videos were reviewed to describe treated visible submucosal vessel burden, minor bleeding, episodes of transient loss of visualization, and hemostatic forceps use. En bloc and histologically margin-negative (R0) resection was achieved in all 10 cases, while curative endoscopic resection was achieved in nine cases (90%). No intraprocedural perforation, delayed bleeding, post-ESD coagulation syndrome, or unplanned repeat intervention occurred. Median lesion size was 55 mm (interquartile range, 40-69.5), median procedure duration was 102.5 min (100-167.5), and median treated visible vessel count was 21 (11.5-40.75), corresponding to 1.04 vessels/cm² (0.64-1.74). Minor bleeding and transient loss of visualization occurred during procedures but were controlled endoscopically. Hemostatic forceps were required therapeutically for active bleeding from one vessel across the series, and no procedure required abandonment or conversion to surgery. These findings support the technical feasibility of rectal flushing-assisted saline immersion ESD. The video-derived hemostatic measures are descriptive and may provide candidate endpoints for future prospective comparative studies; they do not establish comparative efficacy, hemostatic benefit, or safety. Trial Registration: N/A.