Endoscopic submucosal dissection (ESD) is increasingly used for en bloc removal of GI lesions. Current ESD techniques have limitations including long procedure times, technical difficulty, and complications.

To compare mesna with saline solution for ESD.

Blinded, randomized, controlled, porcine study in live animals.

Animal laboratory.

Twelve gastric lesions were marked by using electrocautery. After submucosal injection, a circumferential mucosal incision was created, and ESD was performed by using a flexible Maryland dissector. Half of the ESDs were performed with submucosal injection of mesna.

Primary outcome was the time to dissect the submucosal plane. Secondary outcomes were total ESD time, specimen size, and procedure related complications.

The average (± SD) time for dissecting the submucosal plane was 15 minutes (range 10-22 ± 4.8 min) in the group with submucosal mesna injection and 16 minutes (range 8-29 ± 8.3 min) in the control group (P = 1.0). Complete en bloc resection including all of the electrocautery markings was achieved in all cases. Injection of mesna did not provide any benefit over saline solution in terms of overall ESD time (24 ± 7.3 min vs 28 ± 11 min; P = .42). There were no perforations. Four hemorrhages requiring intervention were encountered during the procedures in the control group, compared with no bleeding in the mesna group (P = .09).

Animal model, limited sample size.

Submucosal mesna injection did not affect procedure times but was associated with a trend toward a lower incidence of intraprocedural bleeding.