Safety and Efficacy of Underwater Endoscopic Mucosal Resection for Type I Gastric Neuroendocrine Tumors Measuring 5-9 mm (POEM)

Safety and Efficacy of Underwater Endoscopic Mucosal Resection for Type I Gastric Neuroendocrine Tumors Measuring 5-9 mm: A Prospective Single-Centre Cohort Study

Study objectives:

Primary objective:

1.To determine the histologic R0 resection rate of UEMR for type I gastric NETs measuring 5-9 mm.

Secondary objectives:

To evaluate:

1. En bloc resection rate
2. Immediate and delayed adverse events
3. Procedure time
4. Histologic quality of resection (deep and lateral margins)
5. Residual disease at resection scar on surveillance endoscopy oMetachronous gastric NETs during follow-up

Study Overview

• Status: Recruiting
• Conditions: Stomach Neuroendocrine Neoplasm
• Intervention / Treatment: Procedure: Endoscopic mucosal resection under water

Detailed Description

Study design This is a prospective, single-centre, single-arm cohort study evaluating UEMR for type I gastric NETs. Outcomes will be assessed at the lesion level, with statistical methods accounting for clustering of multiple lesions within individual patients.

Study population Inclusion criteria Patient-level

1. Age ≥18 years
2. Fit for endoscopic therapy and sedation
3. Written informed consent Lesion-level

3.Endoscopically visible gastric neuroendocrine tumor 4.Size 5-9 mm (endoscopic estimation) 5.Clinical and/or histologic features consistent with type I gastric NET 6.No endoscopic features suggestive of deep invasion 7.Technically amenable to snare resection Exclusion criteria

Lesion-level

1. Lesions <5 mm (managed with surveillance in routine practice)
2. Lesions ≥10 mm
3. Type II or type III gastric NET
4. Evidence of muscularis propria invasion on EUS
5. Distant metastasis or nodal disease on DOTANOC PET-CT
6. Prior attempted resection at the same site with significant fibrosis
7. Non-lifting lesion due to scarring

Patient-level

1. Uncorrectable coagulopathy
2. Inability to manage antithrombotic therapy as per guidelines
3. Pregnancy
4. Inability to provide informed consent

Pre-procedure evaluation

1. Detailed clinical assessment and laboratory work-up as per institutional protocol
2. Endoscopic documentation of:
3. Lesion size, location, morphology
4. Number of lesions
5. Background mucosal atrophy
6. EUS performed for lesions ≥8 mm, atypical morphology, or suspected deeper invasion
7. DOTANOC PET-CT performed where clinically indicated to exclude metastatic disease

Intervention: Underwater EMR technique

1. Standard diagnostic gastroscope
2. Minimal insufflation followed by complete deflation of the gastric lumen
3. Lumen filled with normal saline to achieve complete submersion of the lesion
4. Optional marking for flat or ill-defined lesions
5. Snare capture with a 1-2 mm margin under water
6. Resection using standardized electrosurgical settings
7. Defect management (clips or coagulation) at endoscopist discretion
8. Retrieval of intact specimen
9. Specimen orientation and pinning on cork for histopathologic assessment

Histopathologic assessment:

All specimens will be evaluated by experienced gastrointestinal pathologists.

Reported parameters:

1. Tumor size
2. Tumor grade and Ki-67 index
3. Depth of invasion
4. Lateral and vertical margins
5. Lymphovascular invasion
6. Resection status classified as:
7. R0: negative lateral and vertical margins
8. R1: microscopic margin positivity
9. Rx: indeterminate margins

Outcome measures Primary outcome

1. R0 resection rate per lesion Secondary outcomes
2. En bloc resection rate
3. Immediate bleeding (requiring endoscopic hemostasis)
4. Delayed bleeding (within 14 days requiring medical attention)
5. Perforation
6. Procedure time (scope insertion to removal)
7. Residual disease at scar on surveillance endoscopy (3-6 months)
8. Metachronous lesions during follow-up

Follow-up protocol

1. Clinical follow-up at 24-72 hours and at 14 days
2. Surveillance endoscopy at 3-6 months post-resection
3. Further surveillance as per institutional protocol for type I gastric NETs

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rajesh Mr Goud, M.Pharmacy; Phone Number: 103 04023378888; Email: rajeshgoud761@gmail.com
• Study Contact Backup: Name: Shashavali Dr Maniyar, MD; Phone Number: 105 04023378888; Email: shashimaniyar@gmail.com

Study Locations

• India
  • Telangana
    • Hyderabad, Telangana, India, 500082
      • Recruiting
      • Asian Institute of Gastroenterology/AIG Hospitals
      • Contact: Dr SHASHEENDRA YANAGANDULA, MBBS MS; Phone Number: 9676050769; Email: shasheendra8@gmail.com
      • Contact: Dr Mohan Ramchandani, MBBS MD DM; Phone Number: 802 04023378888; Email: ramchandanimohan@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Patient-level

• Age ≥18 years
• Fit for endoscopic therapy and sedation
• Written informed consent

Exclusion Criteria:

Lesion-level

• Endoscopically visible gastric neuroendocrine tumor
• Size 5-9 mm (endoscopic estimation)
• Clinical and/or histologic features consistent with type I gastric NET
• No endoscopic features suggestive of deep invasion
• Technically amenable to snare resection

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Other: Type I Gastric Neuro Endocrine tumour; Lesion should be less than 10mm size

Procedure: Endoscopic mucosal resection under water; Standard diagnostic gastroscope; Minimal insufflation followed by complete deflation of the gastric lumen; Lumen filled with normal saline to achieve complete submersion of the lesion; Optional marking for flat or ill-defined lesions; Snare capture with a 1-2 mm margin under water; Resection using standardized electrosurgical settings; Defect management (clips or coagulation) at endoscopist discretion; Retrieval of intact specimen; Specimen orientation and pinning on cork for histopathologic assessment; Other Names: EMRUW

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
• To determine the histologic R0 resection rate of UEMR for type I gastric NETs measuring 5-9 mm.	No recurrence after 3 months of procedure	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Immediate and delayed adverse events	To check any possible adverse events post procedure	24 hours
Procedure time	To calculate the exact time of procedure	30 minutes
Histologic quality of resection (deep and lateral margins)	To check the depth of invasion of the tumour	5 days

Collaborators and Investigators

• Sponsor: Asian Institute of Gastroenterology, India
• Investigators: Principal Investigator: Zaheer Dr Nabi, MD, AIG HOSPITALS; Study Chair: Mohan Dr Ramchandani, MD, AIG HOSPITALS

Study record dates

Study Major Dates

• Study Start (Actual): July 17, 2026
• Primary Completion (Estimated): November 10, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: July 22, 2026
• First Submitted That Met QC Criteria: July 22, 2026
• First Posted (Actual): July 27, 2026

Study Record Updates

• Last Update Posted (Actual): July 27, 2026
• Last Update Submitted That Met QC Criteria: July 22, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: EMR01

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No