NCT07490574

Trial of Underwater Versus Gas-Insufflation Colorectal Endoscopic Submucosal DisseEtion

Underwater Versus Conventional Endoscopic Submucosal Dissection For Colorectal Neoplasia: A Multicenter, Randomised Controlled Trial

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 295 (actual)
• Sponsor: University of Roma La Sapienza · Academic / Other
• Sex: All
• Age: 19 Years
• Healthy volunteers: Not accepted

Summary

Colorectal endoscopic submucosal dissection (ESD) enables en bloc resection of large superficial colorectal neoplasia but remains technically demanding and may be limited by suboptimal visualization, intraprocedural bleeding, smoke accumulation, and prolonged procedural time. Underwater ESD (UESD), performed under saline immersion rather than gas insufflation, has been proposed as a strategy to improve the operative field and facilitate submucosal dissection. This prospective, multicenter, open-label, randomized controlled trial was designed to compare UESD with conventional gas-assisted ESD (GESD) for colorectal neoplasia referred for ESD across Italian tertiary centers. The primary objective was to assess non-inferiority of UESD versus GESD in terms of en bloc resection. Secondary objectives included comparison of histological resection quality, procedural efficiency, intraprocedural events, procedural field visualization, and post-procedural adverse events.

Detailed description

Colorectal ESD is an established organ-preserving technique for the en bloc resection of superficial colorectal neoplasia, particularly when conventional endoscopic mucosal resection is unlikely to achieve complete single-piece excision. However, colorectal ESD is technically demanding because of the thin colonic wall, unstable scope position, narrow submucosal space, intraprocedural bleeding, smoke generation, and difficulty in maintaining a stable dissection plane. Underwater ESD has emerged as a modified operative environment in which luminal insufflation is discontinued and the target segment is immersed in saline. Saline immersion may improve visualization of the submucosal layer and of submucosal vessels, limit smoke persistence in the operative field, and facilitate more stable dissection. Although initial retrospective and comparative experiences have suggested procedural advantages of underwater ESD, high-quality randomized comparative data remain limited, particularly in Western multicenter practice. This study was therefore designed as a prospective multicenter randomized trial across Italian tertiary referral centers to compare underwater ESD with conventional gas-assisted ESD for colorectal neoplasia referred for ESD. Patients were allocated 1:1 to either UESD or GESD. The primary endpoint was en bloc resection. Secondary endpoints included R0 resection, procedural time, dissection speed, intraprocedural bleeding, need for hemostatic forceps, smoke interference, vessel visualization, cutting-plane visualization, post-procedural pain, post-ESD coagulation syndrome, perforation, and delayed bleeding. The technical conduct of ESD apart from the assigned luminal environment was left to expert operator discretion in order to preserve real-world tertiary-center practice.

Conditions

• Colorectal Neoplasia
• Colorectal Superficial Neoplasia
• Colorectal Precancerous Lesions

Interventions

Type	Name	Description
PROCEDURE	Underwater ESD (UESD)	Underwater ESD (UESD) performed under saline immersion with luminal insufflation turned off.
PROCEDURE	Conventional Gas-Assisted ESD (GESD)	Conventional colorectal ESD was performed under gas insufflation according to standard practice at each participating center. Mucosal incision and submucosal dissection were carried out according to standard ESD technique. Device selection, generator settings, and technical dissection strategy were left to operator discretion. Hemostasis, when required, was achieved using hemostatic forceps.

Timeline

• Start date: 2024-12-01
• Primary completion: 2025-12-01
• Completion: 2026-03-01
• First posted: 2026-03-24
• Last updated: 2026-03-31

Locations

1 site across 1 country: Italy