The Perfect Submucosal Cushion: 7 Steps to Dynamic Injection in EMR
Endoscopists have been injecting polyps since Professor Deyhle first introduced the technique in 1973. Yet, over 50 years later, many operators still rely on rigid, textbook rules—like mandatory four-quadrant injections—that can actually complicate resections. In this masterclass, Dr. Klaus Mönkemüller demonstrates why “dynamic injection” and “interventional chromoendoscopy” are the true keys to achieving a flawless submucosal cushion and an R0 resection.
The Challenge
First impressions in endoscopy can be deceiving. Often, polyps are bigger and nastier than they appear. A small-looking flat lesion (such as a 0-IIc) can hide elusive borders. Without an optimal submucosal cushion, it is difficult to fully expose all neoplastic tissue, leading to incomplete piecemeal resections or, worse, an increased risk of perforation.
Why This Matters
The submucosal cushion is not just a fluid bump; it is an active anatomical tool. It has great value for endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and third-space endoscopy.
As demonstrated in the video, a perfect cushion serves four vital functions:
It defines and physically raises the lesion.
The fluid performs some dissection of the submucosal space before you even start your incision.
It separates the lesion from the deeper layers below.
It provides a safety base against perforation.
Clinical Pearl: “Injection of a substance with blue color mixture—either indigo carmine, methylene blue, or toluidine blue—to improve the definition of the lesion’s borders and surface and submucosal space anatomy, thus improving interventional capabilities.” — Dr. Klaus Mönkemüller, defining the concept of interventional chromoendoscopy, a term his group introduced approximately 10–20 years ago. This applies to POEM and third-space endoscopy as well.
The full article includes:
The 7-step protocol for dynamic injection
Detailed visual analysis of scope torque and snare maneuvers
Pro tips for avoiding the “groove” effect during fluid delivery
The “Y-Trick” for capturing elusive polyps
Snare-tip knife-assisted resection (KAR) technique
Downloadable quick-reference card
