STSC-HybridAPC Trial

Snare Tip Soft Coagulation Versus Hybrid APC (ERBE) for Post-EMR Margin Thermal Ablation - A Prospective Randomized Controlled Trial

Margin thermal ablation after piecemeal EMR significantly reduces recurrence of large colorectal polyps. As recurrence rates are now low, the key implementation question relates to efficiency and reproducibility of different ablation techniques. This randomized controlled trial compares snare tip soft coagulation (STSC) with Hybrid APC (ERBE), with procedural time as the primary endpoint.

Study Overview

• Status: Not yet recruiting
• Conditions: Colon Adenomas; Colon Adenomatous Polyp
• Intervention / Treatment: Procedure: Snare Tip Soft Coagulation (STSC); Procedure: Hybrid APC (ERBE)

Detailed Description

Piecemeal endoscopic mucosal resection (EMR) of large (≥20 mm) non-pedunculated colorectal lesions was historically associated with local recurrence rates in the range of 15-20% at first surveillance when no systematic margin therapy was applied¹. The introduction of structured post-EMR margin thermal ablation has substantially altered this landscape. In a landmark randomized controlled trial, systematic thermal ablation of the resection margin reduced recurrence from 21% to 5%². Subsequent prospective and multicenter studies performed in high-volume expert centers using standardized circumferential snare-tip soft coagulation (STSC) protocols have demonstrated further reductions, with reported recurrence rates approaching 1-2%³. Most recently, Gauci et al. demonstrated that complete margin thermal ablation eliminates lesion size as a risk factor for recurrence following piecemeal EMR of large non-pedunculated colorectal polyps, reinforcing the durability and consistency of this approach in contemporary practice⁴. These findings are supported by meta-analytic data confirming that thermal margin ablation significantly reduces recurrence compared with no ablation without increasing clinically meaningful adverse events⁵. Accordingly, current international guidelines strongly recommend routine thermal ablation of the post-EMR mucosal defect margin following piecemeal resection of large colorectal lesions⁶.

Given that recurrence rates are now low when complete circumferential ablation is systematically performed, additional trials powered for recurrence would require prohibitively large sample sizes to detect incremental differences. The remaining clinically relevant gap therefore relates not to efficacy, but to procedural efficiency, reproducibility, and implementation, particularly in early-career or non-advanced interventional endoscopists.

Snare-tip soft coagulation requires precise contact-based application of thermal energy at each point sequentially along the entire resection margin, demanding consistent tip positioning and repeated fine manipulations. This technical precision may be particularly challenging for endoscopists with limited experience, increasing the risk of incomplete ablation or prolonged procedural time.

Hybrid APC (ERBE) delivers thermal energy via a non-contact argon plasma beam with a broader coagulation footprint per activation, potentially enabling faster and more reproducible circumferential coverage with fewer individual applications. The wider energy spread of Hybrid APC may therefore reduce operator-dependent variability and facilitate more consistent margin treatment, particularly in the hands of early-career endoscopists. Whether this translates into a meaningful reduction in net ablation time and improved completion rates compared with STSC has not been prospectively evaluated.

• Study Type: Interventional
• Enrollment (Estimated): 140
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kathleen Goodrick, BN; Phone Number: +612 88905555; Email: kathleen.goodrick@health.nsw.gov.au
• Study Contact Backup: Name: Mayan Eitan, MD; Phone Number: +612 88905555; Email: mayan.eitan@health.nsw.gov.au

Study Locations

• Australia
  • New South Wales
    • Sydney, New South Wales, Australia, 2145
      • Westmead Hospital
      • Contact: Kathleen Goodrick, BN; Phone Number: +612 88905555; Email: kathleen.goodrick@health.nsw.gov.au

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age ≥18 years
• Undergoing piecemeal EMR of a non-pedunculated colorectal lesion ≥20 mm in size
• Macroscopically complete resection achieved prior to margin ablation (no visible residual adenomatous tissue at the resection base)
• Ability to provide written informed consent

Exclusion Criteria:

• Lesions requiring en bloc resection by ESD
• Lesions with suspected deep submucosal invasion based on endoscopic assessment (e.g., depressed morphology, non-lifting sign, NICE type 3 pattern, or equivalent advanced imaging criteria)
• Inflammatory bowel disease with active colitis at the lesion site
• Overt invasive carcinoma requiring surgical management
• Pregnancy
• Inability to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Snare Tip Soft Coagulation (STSC); Circumferential thermal ablation of the resection margin will be performed using the distal tip of a standard polypectomy snare in soft coagulation mode. The tip will be applied sequentially to the entire visible mucosal defect margin to achieve complete circumferential treatment.	Procedure: Snare Tip Soft Coagulation (STSC); Circumferential thermal ablation of the resection margin will be performed using the distal tip of a standard polypectomy snare in soft coagulation mode. The tip will be applied sequentially to the entire visible mucosal defect margin to achieve complete circumferential treatment.
Active Comparator: Hybrid APC (ERBE); Circumferential thermal ablation of the resection margin will be performed using Hybrid APC (ERBE) in standard APC mode. The argon plasma beam will be applied sequentially to the entire visible mucosal defect margin to achieve complete circumferential treatment. Electrosurgical settings will be standardized according to unit protocol (effect and wattage predefined for Hybrid APC use).	Procedure: Hybrid APC (ERBE); Circumferential thermal ablation of the resection margin will be performed using Hybrid APC (ERBE) in standard APC mode. The argon plasma beam will be applied sequentially to the entire visible mucosal defect margin to achieve complete circumferential treatment. Electrosurgical settings will be standardized according to unit protocol (effect and wattage predefined for Hybrid APC use).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Net margin ablation time	Net margin ablation time (seconds), defined as the elapsed time from the first application of thermal energy to the resection margin (first activation in soft coagulation mode) until the operator declares completion of circumferential margin ablation. Time will be recorded using a standardized stopwatch method by a trained assistant/nurse (or captured from time-stamped video, if available). Interruptions unrelated to margin ablation (e.g., equipment troubleshooting) will be documented and excluded from net time where feasible, with sensitivity analyses planned.	during the procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time (total)	Total procedure time (minutes): from first endoscopic view of the lesion to scope withdrawal.	during procedure
Technical success of margin ablation	Technical success of margin ablation: completion of circumferential thermal treatment of the entire visible mucosal defect margin as judged by the supervising endoscopist and recorded as yes/no.	during procedure
Instrument exchanges (count)	Instrument exchanges (count): number of device exchanges required after completion of EMR to achieve margin ablation.	during procedure
Need for additional haemostatic therapy (yes/no)	Need for additional haemostatic therapy (yes/no): including clips, APC outside assigned intervention, injectable agents, or other modalities used for bleeding control.	during procedure
Operator-rated ease of use (VAS 0-10)	Operator-rated ease of use (VAS 0-10): recorded immediately post-procedure (0 = very difficult, 10 = very easy)	during procedure
Operator confidence (VAS 0-10)	Operator confidence (VAS 0-10): confidence that ablation was complete (0 = not confident, 10 = fully confident).	during procedure
Immediate adverse events	Immediate adverse events: intraprocedural and early post-procedural events as per standard definitions (bleeding requiring endoscopic therapy, perforation, post-polypectomy syndrome, unplanned admission). Severity will be graded using an accepted endoscopy AE severity framework (e.g., ASGE lexicon).	during procedure
Cost impact (exploratory)	Cost impact (exploratory): incremental procedural cost derived from device utilization (snare tip vs Hybrid APC), number of exchanges, and additional haemostatic devices used.	during procedure
Rate of incomplete STSC margin ablation by trainee operators (yes/no, Arm A only)	Rate of incomplete STSC margin ablation by trainee operators (yes/no, Arm A only): proportion of Arm A cases in which the supervising endoscopist judged circumferential margin ablation to be incomplete at the conclusion of the trainee's attempt, necessitating supplementary ablation by the supervisor.	during procedure

Collaborators and Investigators

• Sponsor: Western Sydney Local Health District
• Investigators: Principal Investigator: Michael J Bourke, MBBS, WSLHD

Publications and helpful links

General Publications

• Belderbos TD, Leenders M, Moons LM, Siersema PD. Local recurrence after endoscopic mucosal resection of nonpedunculated colorectal lesions: systematic review and meta-analysis. Endoscopy. 2014 May;46(5):388-402. doi: 10.1055/s-0034-1364970. Epub 2014 Mar 26.
• Ferlitsch M, Hassan C, Bisschops R, Bhandari P, Dinis-Ribeiro M, Risio M, Paspatis GA, Moss A, Libanio D, Lorenzo-Zuniga V, Voiosu AM, Rutter MD, Pellise M, Moons LMG, Probst A, Awadie H, Amato A, Takeuchi Y, Repici A, Rahmi G, Koecklin HU, Albeniz E, Rockenbauer LM, Waldmann E, Messmann H, Triantafyllou K, Jover R, Gralnek IM, Dekker E, Bourke MJ. Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024. Endoscopy. 2024 Jul;56(7):516-545. doi: 10.1055/a-2304-3219. Epub 2024 Apr 26.
• Gauci JL, Mandarino FV, Kerrison C, Whitfield AM, O'Sullivan T, Gupta S, Lam B, Perananthan V, Cronin O, Lee EY, Williams SJ, Burgess N, Bourke MJ. Margin thermal ablation eliminates size as a risk factor for recurrence after piecemeal endoscopic mucosal resection of large non-pedunculated colorectal polyps. Gut. 2025 Apr 7;74(5):752-760. doi: 10.1136/gutjnl-2024-333563.

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 15, 2027

Study Registration Dates

• First Submitted: June 26, 2026
• First Submitted That Met QC Criteria: June 26, 2026
• First Posted (Actual): July 6, 2026

Study Record Updates

• Last Update Posted (Actual): July 6, 2026
• Last Update Submitted That Met QC Criteria: June 26, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2026/PID01713

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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