Selective tissue elevation by pressure injection (STEP) facilitates endoscopic mucosal resection (EMR).

Area of Science:

• Gastroenterology
• Endoscopic Surgery
• Medical Device Technology

Background:

• Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are increasingly used for gastrointestinal tract flat superficial tumors.
• Submucosal injection aids these procedures but has limitations, especially for extensive colonic lesions.
• The water-jet dissector shows potential for selective cutting.

Purpose of the Study:

• To evaluate a new indication for transmucosal mucosal elevation using submucosal fluid injection.
• To assess the clinical feasibility and results of Selective Tissue Elevation by Pressure Injection (STEP).
• To compare the efficacy of different carrier fluids for submucosal injection in EMR.

Main Methods:

• Animal experiments were conducted to study physical properties using animal preparations and human specimens.
• Six carrier fluids (HES, Gelafusal, Infukoll, Glucose 50, saline) were injected into pigs, with fluid cushion height measured endosonographically.
• EMR was performed on 18 lesions in 12 patients using NaCl cartridges for elevation, followed by histological assessment.

Main Results:

• All tested substances were successfully applied using the Helix HydroJet system.
• Plasma expanders (HES, Gelafundin) created more durable submucosal fluid cushions than isotonic solutions.
• Histological analysis confirmed selective submucosal fluid accumulation, preserving mucosal and muscular layers; EMR was successful in all cases.

Conclusions:

• Selective Tissue Elevation by Pressure Injection (STEP) is a novel technique for transmucosal mucosal elevation in EMR.
• STEP facilitates EMR and expands its application to larger lesions, with plasma expanders offering prolonged cushion duration.
• This technique shows promise for improving endoscopic treatment of gastrointestinal tumors, with potential for future technological integration.