Submucosal pocket creation using a traction device in colorectal endoscopic submucosal dissection.

Colorectal endoscopic submucosal dissection (ESD) can be difficult for various reasons, and a thin muscular layer is associated with increased perforation rates and longer procedure times. The submucosal pocket creation method was recently reported to overcome these difficulties [1,2]. Mucosal flap formation is an important and difficult initial step. In contrast, several countertraction systems that facilitate ESD procedures for colorectal cancers have been reported [3]. We combined the submucosal pocket creation method with a traction device (TD) to achieve a safer and more efficient colorectal ESD procedure. The TD was designed to be fixed with nylon thread and clips on the free edges of mucosal overlays to deflect the diseased mucosa away from the dissection plane (Fig. 1). The key feature is the connection of the TD to the anal mucosa at approximately 10 mm from the distal side of the tumor, after submucosal injection prior to the initial mucosal incision (Fig. 2A). It is possible to attach the TD with adequate submucosal injection and to prevent complications, such as clip attachment to the muscle layer, as incision and dissection have not been performed (Fig. 2B). When repeated minimal incision and dissection were performed in this case, the mucosa was grasped with the TD to allow for exposure of the submucosa (Fig. 2C). Mucosal flap formation and submucosal pocket creation using the TD became easier (Fig. 2D). The submucosal cutting layer was clearly visualized and the appropriate amount of tension was created using the TD and submucosal pocket, facilitating dissection.

Figure 1

Diagram of nylon thread traction device

Figure 2

Procedure of submucosal pocket creation with a traction device for colorectal endoscopic submucosal dissection. (A, B) The traction device is connected to the anal mucosa from the distal side of the tumor after submucosal injection, without an initial mucosal incision. (C) A minimal incision is made from the distal side of the connected traction device. (D) Submucosal pocket creation is facilitated when repeated minimal incision and dissection are performed