13 Expert Tips for Mastering the ESD Submucosal Cushion

For many gastrointestinal lesions, Endoscopic Mucosal Resection (EMR) is a workhorse procedure. But for large, flat, or complex polyps, standard EMR often results in a piecemeal resection. This approach complicates pathological assessment and carries a higher risk of incomplete resection and local recurrence.

The definitive solution is Endoscopic Submucosal Dissection (ESD), an advanced technique that allows for en bloc (single piece) removal of large lesions, offering the highest chance for a curative, R0 oncological resection.

But ESD is not just “big EMR.” It’s a different conceptual approach. In this masterclass from Dr. Klaus Mönkemüller, we break down the fundamental principles of ESD, focusing on the single most critical step for success and safety: creating the perfect submucosal cushion.

The Core Concept: ESD is a “Submuc-osectomy”

To master ESD, we must first redefine our terms. A standard polypectomy is, in effect, a mucosectomy—it removes the mucosal layer.

In contrast, both EMR and ESD are fundamentally submuc-osectomies. The goal is to cut below the submucosal layer to ensure the entire lesion is removed, achieving a “safety base” of healthy tissue.

The slide contrasts a “Piecemeal EMR” (center), which shows a large, fragmented specimen, with an “ESD” specimen (right). The ESD specimen is a single, large, perfectly intact piece, allowing for precise histopathological analysis of deep and lateral margins. This visual underscores the oncological superiority of an en bloc resection.

The ultimate objective for any of these procedures is a complete endoscopic and, more importantly, oncological resection (R0). This means the entire neoplasia has been resected with clear margins. ESD provides the most reliable path to this goal for large lesions.

The essential concept of ESD, regardless of the specific knife or tool used, is a three-part process:

1. Inject: Create a deep submucosal cushion to lift the lesion and create a safety plane.

2. Incise: Use an ESD knife to make a circumferential incision in the mucosa around the lesion.

3. Dissect: Carefully tunnel under the lesion, dissecting it from the underlying muscularis propria.

Mastering step 1 is non-negotiable. Here are Dr. Mönkemüller’s top tips for getting the submucosal cushion right every time.

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To see all 13 expert tips, Dr. Mönkemüller’s 7-step protocol for a perfect injection, and visual analysis of the techniques, consider becoming a paid subscriber.

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13 Pro-Tips for a Successful ESD