Colorectal Endoscopic Submucosal Dissection Using the Double-Clips Traction Method
Article information
Abstract
Endoscopic submucosal dissection (ESD) is an advanced endoscopic technique used to remove large adenomas or early colorectal cancers. This paper presents a step-by-step introduction of the methodology for performing colorectal ESD using the double-clips traction method. The technique is designed to enhance visualization, shorten the procedure time, and improve the safety and efficacy of colorectal ESD, especially in challenging cases involving large or fibrotic lesions. By providing reliable traction, this method helps to maintain a stable and clear field of view throughout the procedure, which is critical for the success of the dissection.
Introduction
Endoscopic submucosal dissection (ESD) is an advanced and highly effective technique for the treatment of large and complex colorectal lesions [1,2]. This method has become increasingly important in the field of gastrointestinal oncology due to its minimally invasive nature and ability to achieve en bloc resection of tumors [1,3]. However, the procedure presents considerable technical challenges, such as maintaining a stable and clear field of view, accurately dissecting the submucosal layer, and minimizing the risk of perforation [4].
One of the most significant challenges in colorectal ESD is the difficulty in achieving adequate exposure of the submucosal layer, especially in cases where the lesion is located in a difficult-to-reach area or when fibrosis is present. Fibrosis, in particular, can make the dissection process more complex, increasing the risk of perforation [3,4]. The double clip traction method addresses these challenges by providing reliable tissue retraction, thereby enhancing visualization and enabling precise dissection [5,6]. In this paper, I’d like to introduce the step-by-step methodology for performing colorectal ESD using the double clips traction method.
Case Presentation
The patient underwent colonoscopy at a local clinic due to rectal bleeding and then visited our hospital due to a rectal tumor detected by the colonoscopy. A colonoscopy performed again at our hospital revealed a laterally spreading tumor measuring 5 cm in diameter, granular, nodular-mixed type, located 10–14 cm superior to the anal verge. A tissue biopsy confirmed it to be a tubulovillous adenoma, and it was decided to perform ESD. The ESD procedure was performed as follows (video). This report was approved for exemption from review by the institutional review board (No. NCC2024-0139).
Initial setup and marking
The initial setup of the colorectal ESD procedure is crucial for its success. The lesion is identified, and its boundaries are meticulously marked using the endoscopic knife. These marks serve as a guide for the endoscopist, helping to maintain orientation throughout the procedure. During this phase, the endoscopist also assesses the lesion's characteristics, including its size, shape, and location within the colon. This assessment is critical as it informs the subsequent steps of the procedure, particularly the placement of traction devices.
Injection and creation of the mucosal flap
A solution (often a mix of saline, epinephrine, and a dye) is injected into the submucosal layer to lift the lesion away from the muscularis propria, creating a safety cushion. For colorectal ESD, hyaluronic acid solution is commonly used because it provides the longest-lasting lifting effect. Initially, an appropriate amount was injected into the submucosal layer to elevate the lesion, and the solution was repeatedly injected as needed during the procedure.
After marking and injection, an initial mucosal incision was made around the lesion to create a flap. This flap was gently lifted to expose the underlying submucosal layer and confirm the exact dissection plane. To use the traction method, it was necessary to maintain the mucosal flap at an appropriate thickness and sufficient distance from the lesion so that it would not tear.
Application of endoscopic clips
An endoscopic hemoclip is applied to the edges of the mucosal flap to serve as anchor points for traction. To ensure stable placement of the clip, the mucosal incision should be made at a safe distance from the lesion to allow room for the clip to be fixed. Sutures, threads, or dental elastic bands are attached to the clip for traction of the mucosal flap. The free end of the thread attached to the first clip is pulled and secured to the second clip, which is then strategically placed in another part of the mucosa or on the opposite colonic wall. In this case, a self-made traction band was used by twisting two dental elastic bands. The dental bands provide effective traction and appropriate tension to elevate the mucosal flap by their elasticity. This allows for proper exposure of the submucosal layer, allowing for accurate and safe submucosal dissection.
Submucosal dissection
During a colorectal ESD procedure, the submucosal dissection is performed using a DualKnife (model KD-650L; Olympus), when a blood vessel was encountered, hemostasis was achieved using a Coagrasper (model FD-410LR; Olympus). Once hemostasis was secured, the dissection continued until the lesion was fully resected.
Tissue retrieval, fixation, and pathologic report
After completing the submucosal dissection, the resected specimen was retrieved using an endoscopic net. To retrieve the lesion, the second clip may be removed from the mucosa using forceps, or in some cases, the thread is cut using endoscopic scissors, leaving the second clip in place. The tissue is then oriented on a flat surface, pinned to maintain its shape, and submerged in formalin for fixation. Once the specimen is fixed, it is sent to the pathology lab.
In this case, the ESD procedure was completed without complications, and the total procedure time was 130 minutes. The final pathology results confirmed the lesion as a tubulovillous adenoma with focal high-grade dysplasia.
Discussion
The double clip traction method enhances visualization of the submucosal layer during colorectal ESD, which is crucial for a safe and effective procedure. It maintains consistent tension on the mucosal flap, reducing the risk of perforation and allowing precise targeting of the dissection plane. The technique is simple, effective, and adaptable, requiring minimal setup and no additional equipment, making it accessible to less experienced endoscopists in ESD [5,6]. Its versatility is particularly beneficial for both straightforward and complex resections, including those involving large or fibrotic lesions.
The double clip traction method presents exciting opportunities for further innovation and research. The integration of robotic assistance and AI-driven tools could also significantly improve the precision and safety of the procedure, providing real-time guidance and support to endoscopists. Continued research is essential to evaluate the long-term outcomes including recurrence rates and complication incidences and to compare these outcomes with those of other ESD techniques [6]. There is also considerable potential for the application of double-clip traction to other gastrointestinal procedures, which should be investigated to expand its impact and utility in clinical practice.
Notes
Disclosure
Dae Kyung Sohn is a member of the editorial board of the journal, but he was not involved in the peer reviewer selection, evaluation, or decision process of this article. No other potential conflicts of interest relevant to this article were reported.
Funding
This work was supported by a grant from the National Research Foundation of Korea (NRF-2022R1A2C2009757) funded by the Ministry of Education.