Evaluation of the Effectiveness of Longitudinal Incision for Endoscopic Submucosal Excavation of Gastric Subepithelial Lesions
April 28th, 2026
This protocol describes longitudinal incision endoscopic submucosal excavation, a technique designed to facilitate the resection and defect closure of gastric subepithelial lesions.
This research compares longitudinal versus circular incision for endoscopic submucosal excavation to determine which is faster and safer. Circular incision creates large defects that are hard to close. Longitudinal incision simplifies closure and shortens operative time.
This technique is ideal for endoscopic removal of small gastric subepithelial lesions measuring two centimeters or less. To begin, using a single-use electrosurgical knife, mark several dots along the lesion margin in a circular pattern, three to five millimeters outside the lesion edge, to define the resection boundaries. For submucosal injection of indigo rouge, advance the needle deep into the tissue.
Inject while slowly withdrawing to ensure that the tip remains within the mid-submucosal layer. Confirm that the mucosal surface elevates rapidly, uniformly, and persistently to form a smooth, dome-shaped mucosal elevation. Next, using the single-use electrosurgical knife, make a longitudinal incision through the mucosa and submucosa along the central axis of the lesion, ensuring that it surpasses the entire longitudinal dimension of the lesion.
Carefully dissect and separate the submucosal connective tissue beneath the lesion using the electrosurgical knife. Next, fully expose the lesion and completely free it from its attachments while preserving the underlying muscle layer as much as possible. If bleeding is detected during the separation process, use the electrosurgical knife to coagulate minor bleeding vessels.
Thoroughly inspect the resection defect for active bleeding or visible vessels. Treat any bleeding points or high-risk vessels with single-use electrosurgical hemostatic forceps to prevent delayed bleeding. To close the defect, first, moderately aspirate intragastric gas to approximate the defect edges and reduce the tissue gap for clipping.
Engage the mucosal edge on the proximal side of the defect with one jaw of the clip. Then hook the distal mucosal edge with the opposite jaw. Close the clip while maintaining continuous suction.
Next, apply clips sequentially to approximate the mucosal edges until the entire defect is fully apposed. No statistically significant differences were found in most baseline demographic and clinical variables between the improved group and the conventional group. The improved group had a significantly shorter mean operation time compared to the conventional group.
No serious postoperative complications, such as perforation, abdominal abscess, fever, or severe abdominal pain, occurred in either group. The incidence of major complications was 0%in both groups, and no statistically significant difference was found. This protocol allows precise measurement of operative time, success rates, and complications between the two incision techniques.
The key challenge is ensuring the longitudinal incision is exactly centered over the lesion's long axis.
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Overview
This article details a protocol for longitudinal incision endoscopic submucosal excavation (ESE) as an improved method for removing small gastric subepithelial lesions (SELs ≤ 2 cm). The longitudinal incision technique is compared to the conventional circular incision, demonstrating advantages in operative efficiency, defect closure, and safety.
Key Study Components
Area of Science
- Gastroenterology
- Endoscopic surgery
- Minimally invasive procedures
Background
- Endoscopic submucosal excavation (ESE) is used to manage gastric subepithelial lesions.
- Traditional circular incisions can create large defects that are difficult to close.
- Efficient closure and reduced operative time are important for patient outcomes.
- There is a need for improved techniques to optimize ESE for small gastric SELs.
Purpose of Study
- To present a detailed protocol for longitudinal incision ESE.
- To compare the longitudinal incision technique with the conventional circular incision in terms of procedural success, operative time, and safety.
- To assess the feasibility and technical outcomes of the new approach.
Methods Used
- Marking the lesion margin with dots in a circular pattern, 3–5 mm outside the lesion edge.
- Submucosal injection of indigo rouge to elevate the mucosa.
- Making a longitudinal incision along the central axis of the lesion using an electrosurgical knife.
- Dissecting and separating submucosal tissue to fully expose and free the lesion.
- Hemostasis using electrosurgical knife and hemostatic forceps as needed.
- Primary closure of the defect with sequential application of metal clips under suction.
- Retrospective comparison of outcomes between longitudinal (n=21) and circular (n=31) incision groups.
Main Results
- The longitudinal incision group achieved a 100% procedural success rate.
- Mean operation time was significantly shorter for the longitudinal group (51.43 ± 5.56 min) compared to the circular group (70.00 ± 6.96 min, P=0.0179).
- Reduced need for advanced closure devices in the longitudinal group (5% vs. 28%).
- Low complication rates in both groups, with no serious postoperative events.
Conclusions
- The longitudinal incision ESE technique is safe, effective, and feasible for gastric SELs ≤ 2 cm.
- This method offers practical advantages in operative efficiency and defect management.
- It may reduce the need for additional closure devices and consumables.
Frequently Asked Questions
Executive Industry Relevance
Efficient and reproducible tissue resection methods are critical for translational research models and preclinical tool development in gastrointestinal disease. The longitudinal incision protocol for endoscopic submucosal excavation (ESE) offers improved operative efficiency and defect management, supporting standardized workflows for small gastric subepithelial lesion removal. This technique enables precise measurement of procedural variables, facilitating robust comparison and optimization in discovery-stage tool validation.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables controlled hypothesis testing of tissue resection strategies in disease-relevant gastric models.
- Supports mechanistic de-risking by reducing procedural variability and improving closure outcomes.
- Facilitates functional validation of endoscopic tools and closure devices in preclinical settings.
Screening & Assay Development
- Provides a standardized protocol for generating reproducible tissue defects for device or biomarker assay development.
- Improves assay readiness by minimizing closure complexity and consumable variability.
- Enables quantitative measurement of operative time, success rates, and complication profiles for comparative studies.
Translational & Preclinical Research
- Aligns with translational models requiring precise, low-complication tissue manipulation.
- Supports continuity from discovery through preclinical validation by enabling consistent procedural endpoints.
- Reduces risk in advancing new endoscopic technologies or closure devices toward clinical evaluation.
Pipeline & Workflow Integration
This protocol fits within the continuum from early discovery tool validation to preclinical model optimization for gastrointestinal research and device development.
- Discovery Biology: Supports hypothesis-driven comparison of incision and closure strategies in gastric tissue models.
- Screening: Provides reproducible, quantitative outputs for evaluating device performance and closure efficacy.
- Analytics: Enables direct measurement of operative time, procedural success, and complication rates for robust statistical analysis.
- Translational Research: Facilitates risk-adjusted advancement of endoscopic techniques and closure devices in preclinical pipelines.
- Enterprise Reuse: Establishes a reusable protocol for standardized tissue resection and closure studies across research teams.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in procedural outcomes and reduces mechanistic ambiguity in tissue resection studies.
- Operational Value: Enhances standardization, reproducibility, and scalability of endoscopic protocols for research and development.
- Strategic Value: Supports better go/no-go decisions for device and technique advancement, improving capital efficiency.
- Portfolio Impact: Enables risk-adjusted prioritization of endoscopic technologies and closure solutions in translational pipelines.
Implementation Considerations
- Requires expertise in endoscopic technique and precise lesion localization.
- Needs access to electrosurgical knives, hemostatic forceps, and standardized closure devices.
- Demands cross-team protocol standardization for reproducible outcomes.
- Adaptation may be needed for lesions larger than 2 cm or in non-gastric tissues.
- Centering the incision over the lesion's long axis is a key technical challenge.
