Preclinical and clinical evaluation of a new flexible high pressure injection knife for endoscopic submucosal dissection.

We studied a newly developed high-pressure injection flexible knife, to offer potential procedural simplification in colorectal Endoscopic Submucosal Dissection (ESD). Animal study: open randomized controlled study using an anesthetized porcine model, five ESD novices alternated between the flexible high-pressure injection Knife (HPK) and a Standard Knife (SK). Clinical study: a prospective cohort study conducted in an expert center analyzed colorectal ESD performed with HPK or SK, with propensity score matching. Animal study: 41 gastric and 59 colorectal ESDs were performed. No significant differences were observed between HPK and SK. Operator satisfaction was significantly better with HPK. Clinical study: 379 colorectal ESDs were performed including 70 with HPK. After propensity score matching based on predictors of technical difficulty, 69 lesions per group (HPK vs. SK) were compared. Histological R0 resection rate was significantly higher with HPK than with SK (n = 64 (95.52%) vs. n = 56 (82.35%) p = 0.026), as was the curative resection rate (n = 62 (93.94%) vs. n = 53 (77.94%), p = 0.012). No significant differences were noted regarding procedural speed or perforation rates. HPK improves trainee satisfaction during animal ESD and yields superior histological and curative resection rates in complex colorectal ESD cases when used by experts, without increasing risks.