Endoscopic Submucosal Dissection (ESD) transformed the management of early gastrointestinal neoplasms by enabling en bloc resection of large or complex lesions with curative intent. The core is ESD knife-a group of specialized instruments designed to incise, dissect, coagulate, and in some cases inject fluid into the submucosal layer. With the continuous innovation in knife design, the ESD knife played a pivotal role in improving safety, efficiency, and accessibility of ESD across different regions and indications.
Types of ESD Knives
ESD knif is classified by their tip design and functionality. Needle-type knives, such as the DualKnife and FlushKnife, are widely used due to their simplicity and speed. Insulation-tipped knives (IT-Knife) reduce the risk of perforation by preventing unintended deep muscle injury. Hook knives allow targeted traction of submucosal tissue. More recently, scissor-type knives (e.g., SB Knife Jr., Clutch Cutter) and multifunctional knives (e.g., HybridKnife, One-Step Knife) have expanded the operator's toolbox by combining cutting, coagulation, and fluid injection capabilities in a single device.
Clinical Evidence and Comparative Studies
Multiple clinical trials and retrospective analyses have evaluated the efficacy and safety of different knife types:
1. Scissor-type knives: In a large retrospective series of 228 patients with colorectal tumors, the SB Knife Jr. achieved a 98.4% en bloc resection rate and a 93.9% complete resection rate, with no perforations and only 2.4% delayed bleeding. Five-year overall survival reached 94.1%, underscoring durable long-term outcomes. Another study demonstrated that scissor-type knives significantly reduced procedure times for esophageal ESD compared with conventional needle-type knives, without increasing complication rates.
The randomized controlled trials showed that non-expert endoscopists achieved higher completion rates when using scissor-type knives compared to needle-type knives. Ex vivo studies confirmed reduced procedure times and lower perforation rates, which supports their role as valuable training tools.
2. Needle-type knives: There're comparative studies indicate that needle-type knives still offer faster dissection speeds in colorectal ESD. However, they may carry a higher risk of inadvertent injury in fibrotic or anatomically complex lesions.
3. HybridKnife and multifunctional tools: HybridKnife, which integrates high-pressure water jet injection and electrosurgical dissection, demonstrated superior injection performance over DualKnife in porcine models, while maintaining comparable safety and hemostasis. The One-Step Knife (OSK), evaluated in a multicenter randomized trial, shortened injection and total procedure times, with high operator satisfaction, although differences did not always reach statistical significance.
Clinical Cases and Expanding Indications
Beyond routine gastric and colorectal ESD, novel knives have enabled treatment of unusual or challenging lesions. Case reports include successful resection of a bronchial leiomyoma in an adolescent using a HybridKnife, highlighting cross-disciplinary potential. Similarly, the Golden Knife was used in an endoscopic submucosal tunnel dissection (ESTD) for a giant gastric tumor (140 × 88 mm), achieving curative resection. Scissor-type knives have also proven useful in recurrent or fibrotic lesions involving diverticula, where conventional needle knives pose higher perforation risks.
Key Considerations for Knife Selection
The choice of ESD knife depends on lesion characteristics, operator experience, and institutional availability.
For trainees, scissor-type knives may provide a safer learning curve by enabling controlled grasp-and-cut dissection.
For experienced operators, needle-type knives remain effective for rapid dissection of straightforward lesions.
In complex settings such as fibrosis, angulated anatomy, or non-GI lesions, multifunctional and scissor-type knives may reduce risk and improve precision.
Proper accessory use, including traction methods and prophylactic closure devices (e.g., OTSC), further enhances outcomes.
Future Directions
Innovation in ESD knives continues to evolve toward multifunctionality, efficiency, and safety. Integration with robotics and artificial intelligence-such as AI-assisted recognition of dissection planes-may further standardize outcomes and shorten the learning curve. Disposable and cost-effective designs are also being developed to increase accessibility in Western centers, where ESD adoption has been relatively slow compared to Asia.
