A Randomized Controlled Trial Comparing Underwater Versus Conventional Preventive Coagulation for Intraprocedural Vessel Management During Peroral Endoscopic Myotomy (POEM)

Peroral Endoscopic Myotomy (POEM) has become an established, minimally invasive therapy for achalasia and esophageal motility disorders. Submucosal tunnelling is a critical phase of POEM and requires meticulous haemostasis to avoid bleeding, loss of orientation, reduced visibility, and prolonged procedural time.

The current standard method of vessel coagulation during POEM involves conventional coagulation under CO₂ insufflation using the hybrid knife (HK). However, this approach can require additional hemostatic devices-most commonly coagulation forceps-particularly when dealing with large-calibre vessels or resistant bleeding.

A novel technique-underwater preventive coagulation-leverages water as a conductive medium. Preliminary evidence suggests that:

• electrosurgical current in water is focalized at the interface of the vessel,
• allowing a soft sealing of the vessel wall,
• reducing the risk of vessel rupture or unintended deep thermal injury,
• and potentially eliminating the need to convert to coagulation forceps. Pilot data from our center demonstrate that underwater prophylactic sealing of large vessels during POEM is feasible, safe, and associated with markedly reduced need for rescue coagulation forceps. The technique is already used in practice but lacks systematic evidence from prospective randomized trials.

This study is designed to provide high-quality evidence on whether underwater vessel coagulation improves haemostatic efficiency, reduces intra-procedural bleeding, and minimizes device changes during POEM.

All POEM procedures will be performed under general anesthesia in the supine position using Fujifilm high-definition gastroscopes with a 2.8 mm channel and transparent distal cap.

Steps (Both Arms)

1. Identify the esophagogastric junction (EGJ).
2. Inject saline + methylene blue submucosally.
3. Create a 2 cm mucosal incision at 5-6 o'clock position, 10 cm above EGJ.
4. Enter the submucosal space.
5. Perform submucosal tunnelling down to EGJ and 2-3 cm into cardia.

6. Perform vessel haemostasis according to group allocation:

   • Underwater coagulation (intervention)
   • CO₂-based conventional coagulation (control)
7. Perform circular myotomy (with occasional full-thickness myotomy when indicated).
8. Close the mucosal entry using hemostatic clips.
9. Record procedure time, instrument exchanges, bleeding events, and forceps usage.

Equipment

• Hybrid Knife (Erbe Elektromedizin GmbH)
• VIO 3 generator + ERBEJet 2 water-jet system
• Methylene-blue tinted saline
• Electrosurgical settings: ENDO CUT Q 2-3-3 for mucosal incision and myotomy

Study Overview

• Status: Recruiting
• Conditions: Vessel Puncture Site Reaction
• Intervention / Treatment: Other: Under Water Preventive Coagulation

Detailed Description

Primary Objective

To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between:

1. Underwater preventive vessel coagulation, and 2. Conventional vessel coagulation under CO₂ insufflation. Secondary Objectives

1. To compare composite forceps use (rescue + prophylactic) between groups.
2. To evaluate the frequency of prophylactic-only forceps use.
3. To compare total number of forceps applications per procedure.
4. To determine differences in intra-procedural bleeding episodes.
5. To compare procedural efficiency (procedure time, number of instrument exchanges).
6. To compare hematological and inflammatory markers (Hb drop, Hct, CRP, WBC).
7. To compare delayed bleeding rates within 30 days.
8. To evaluate overall complication rates (intra- and post-procedural).
9. To assess patient-reported outcomes (pain, tolerability). A prospective, randomized, open-label, parallel-group, controlled clinical trial.

Study Arms Intervention Arm: Underwater Coagulation

• Vessel coagulation performed entirely underwater using the Hybrid Knife.
• SWIFT COAG: E3 (89 W) for POEM.
• Physiological saline instilled to completely displace air around the target vessel.

Control Arm: Conventional Coagulation (CO₂ Setting)

• Standard vessel isolation and coagulation under CO₂ insufflation.
• SWIFT COAG: E3 (89 W) for POEM.

• Study Type: Observational
• Enrollment (Estimated): 120

Contacts and Locations

• Study Contact: Name: Rajesh Goud Mr Maragoni, M.Pharm; Phone Number: 312 04023378888; Email: rajeshgoud761@gmail.com
• Study Contact Backup: Name: Zaheer Nabi Dr Mohammed, MD DNB; Phone Number: 427 04023378888; Email: zaheernabi1978@gmail.com

Study Locations

• India
  • Telangana
    • Hyderabad, Telangana, India, 500082
      • Recruiting
      • Asian Institute of Gastroenterology Hospital
      • Contact: Mohan Ramchandani, MBBS; Phone Number: 802 04023378888; Email: ramchandanimohan@gmail.com
      • Contact: Rajesh Goud Mr Maragoni, M.Pharm MBA; Phone Number: 301 04023378888; Email: rajeshgoud761@gmail.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Probability Sample

Study Population

120 (60 in each arm)

Description

Inclusion Criteria:

1. Age ≥ 18 years
2. Diagnosis of achalasia or esophageal motility disorder planned for POEM
3. Ability to provide informed consent

Exclusion Criteria:

1. Anticoagulant or antithrombotic therapy not safely stoppable
2. Known coagulopathy or platelet disorder
3. Esophageal/gastric varices
4. Previous POEM or Heller's myotomy
5. Prior treatment for same condition
6. Inability or refusal to consent
7. Visualized vessels smaller than the HK inner diameter (1.2 mm)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Under Water Coagulation; Intervention Arm: Underwater Coagulation; Vessel coagulation performed entirely underwater using the Hybrid Knife.; SWIFT COAG: E3 (89 W) for POEM.; Physiological saline instilled to completely displace air around the target vessel.	Other: Under Water Preventive Coagulation; Leverages water as a conductive medium. Preliminary evidence suggests that: electrosurgical current in water is focalized at the interface of the vessel,; allowing a soft sealing of the vessel wall,; reducing the risk of vessel rupture or unintended deep thermal injury,; and potentially eliminating the need to convert to coagulation forceps.
Conventional Coagulation; Control Arm: Conventional Coagulation (CO₂ Setting); Standard vessel isolation and coagulation under CO₂ insufflation.; SWIFT COAG: E3 (89 W) for POEM.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between:	Underwater preventive vessel coagulation, and; Conventional vessel coagulation under CO₂ insufflation.	60 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To compare composite forceps use (rescue + prophylactic) between groups.	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	60 minutes
To evaluate the frequency of prophylactic-only forceps use.	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	60 minutes
To compare total number of forceps applications per procedure.	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	60 minutes
To determine differences in intra-procedural bleeding episodes	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	60 minutes
To compare procedural efficiency (procedure time, number of instrument exchanges	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	60 minutes
To compare hematological and inflammatory markers (Hb drop, Hct, CRP, WBC)	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	24 hours
To compare delayed bleeding rates	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between:1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	30 days
To evaluate overall complication rates (intra- and post-procedural)	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	24 hours
To assess patient-reported outcomes (pain, tolerability).	To compare the proportion of POEM patients requiring rescue haemostasis with coagulation forceps (for active bleeding) between: 1.Underwater preventive vessel coagulation, and Conventional vessel coagulation under CO₂ insufflation	72 hours

Collaborators and Investigators

• Sponsor: Asian Institute of Gastroenterology, India
• Investigators: Study Director: Mohan Dr Ramchandani, MD DM, Asian Institute of Gastroenterology

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2026
• Primary Completion (Estimated): May 10, 2027
• Study Completion (Estimated): December 30, 2027

Study Registration Dates

• First Submitted: May 4, 2026
• First Submitted That Met QC Criteria: May 4, 2026
• First Posted (Actual): May 8, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 8, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: POEM UWC 2026

Drug and device information, study documents

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