Colorectal Neoplasia, Colorectal Precancerous Lesions, Colorectal Superficial Neoplasia
Conditions
Keywords
colorectal ESD, underwater ESD, endoscopic submucosal dissection, colorectal neoplasia, en bloc resection
Brief 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.
Interventions
PROCEDUREUnderwater ESD (UESD)
Underwater ESD (UESD) performed under saline immersion with luminal insufflation turned off.
PROCEDUREConventional 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.
Sponsors
University of Roma La Sapienza
Campus Bio-Medico University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
19 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Adults aged 19 years or older Colorectal neoplastic lesion referred for endoscopic submucosal dissection Lesion considered amenable to en bloc endoscopic resection by ESD according to expert pre-procedural endoscopic assessment Written informed consent provided
Exclusion criteria
Known or suspected deep invasive neoplasia Inflammatory bowel disease Uninterrupted antithrombotic therapy Known coagulopathy Any clinical or lesion-related condition considered unsuitable for colorectal ESD by the treating endoscopist
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| En bloc resection rate | During the index procedure | Proportion of lesions resected in a single specimen. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| R0 resection rate | During index procedure and histopathological assessment within 30 days | Proportion of lesions resected en bloc with histologically negative lateral and vertical margins. |
| Procedural time | During the index procedure | Time from submucosal injection to completion of lesion dissection. |
| Dissection speed | During the index procedure | Rate of dissection calculated by dividing specimen area by dissection time. |
| Intraprocedural bleeding rate | During the index procedure | Proportion of procedures with any bleeding occurring during ESD. |
| Use of hemostatic forceps | During the index procedure | Proportion of procedures requiring coagulation forceps for active bleeding or prophylactic vessel coagulation. |
| Smoke interference | During the index procedure | Proportion of procedures in which electrocautery-generated fumes/particulate matter impaired visualization and required repeated lens irrigation or temporary withdrawal. |
| Vessel visualization score | Immediately after the index procedure | Operator-reported 5-point Likert score assessing clarity of identification of submucosal vessels during dissection. Lower scores indicate better visualization. |
| Cutting-plane visualization score | Immediately after the index procedure | Operator-reported 5-point Likert score assessing clarity of the dissection interface between submucosa and muscularis propria. Lower scores indicate better visualization. |
| Post-procedural abdominal pain | 15, 30, and 60 minutes after the procedure | Post-procedural pain assessed on a 0-3 numerical scale by nursing staff. |
| Post-ESD coagulation syndrome (PECS) | Within 7 days | Proportion of patients with abdominal distension or pain at the resection site associated with fever or inflammatory response in the absence of documented perforation. |
| Perforation rate | From procedure to 30 days | Proportion of intraprocedural or delayed perforations. |
| Delayed bleeding rate | From procedure to 30 days | Proportion of patients with clinically overt post-procedural bleeding or hemoglobin decrease \>2 g/dL without another source. |
Countries
Italy
Outcome results
None listed