A randomised study of hydro-jet vs. needle injection for lifting colorectal lesions prior to endoscopic resection

Submucosal lifting of lesions prior to endoscopic resection is crucial to reduce complications and improve the technical feasibility of the procedure.

To compare a self-assembled hydro-jet system vs. standard needle injection for tissue elevation prior to endoscopic resection of colorectal lesions.

Randomised study performed at a single tertiary care institution. Consecutive patients with colonoscopic diagnosis of sessile polyps or non-polypoid lesions >5 mm or laterally spreading tumours.

successful elevation, time to proper elevation, completeness of excision, cautery damage, and general histological diagnostic quality (blinded pathologic assessment).

79 patients were randomised to hydro-jet (40 patients, group A) and needle (39 patients, group B) elevation. Successful elevation was achieved in 97.5% and 94.8%, respectively. Time to proper elevation was 8+/-5 s vs. 18+/-3 s (p<0.05). In group A, histology showed selective accumulation of fluid in the submucosa with intact collagen fibres. Damage to muscularis mucosa was never noted in the specimens of group A and in 7 cases of group B (p<0.01). Artefacts from "cautery effect" were very limited. Radial margins of resection could be adequately evaluated in all cases and were negative.

The hydro-jet system is as effective and safe as standard needle injection for tissue elevation prior to endoscopic resection of colorectal lesions, but it is significantly faster.