Scissor-type needle-knife for colorectal endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) has been increasingly used for resection of superficial gastrointestinal (GI) neoplastic lesions as it provides en bloc resection, which allows for accurate histological evaluation and lower recurrence rates. For colorectal lesions, ESD is a highly effective treatment modality with a 91 % en bloc resection rate and an 83 % R0 resection rate [1]. Despite its advantages, ESD is a technically demanding procedure and is associated with a high risk of perforation, particularly during the early part of the learning curve. Therefore, this procedure has not been widely adopted in non-Asian countries.

“This study provides data to support the use of the scissor-type needle-knife to perform successful colorectal ESD, even among endoscopists with minimal prior ESD experience.”

Traditionally, needle-knife devices for ESD are divided into two main types: the non-insulated-tip needle-knife devices (e. g. HookKnife, DualKnife, FlushKnife) and the insulated-tip knives (e. g. IT-2 Knife, IT-2 NanoKnife). These knives require the endoscopist to move the endoscope along the plane of dissection. In certain situations, such as at a curve of the bowel wall or behind a fold, it becomes difficult to maintain the proper cutting plane and this could lead to unintended injury to the muscularis propria and potentially to perforation.

In 2010, Honma et al. [2] developed a scissor-type grasping knife, called a “stag beetle (SB) Jr. knife” (Sumitomo Bakelite, Tokyo, Japan), for use in colorectal ESD. The length of this knife and its opening width are 3.5 mm and 4.5 mm, respectively. It can be used for mucosal incision, submucosal dissection, and as a hemostatic forceps. Dissection using this knife is by the “grasp and cut” method using electrosurgical current. The electrodes are located inside the two blades, with the outer surface of the forceps insulated to avoid burning the surrounding tissue. Only tissue grasped by the upper and lower electrodes can be cauterized. The tips of the SB Knife Jr. curve upward to reduce the risk of contact between the blade tips and the muscular layer, thereby reducing the risk of perforation. The device tip is rotatable 360° [2] [3]. Another example of a scissor-type knife is the ClutchCutter (Fujifilm Medical, Tokyo, Japan). Data reported on the utility of different types of electrocautery knife for colorectal ESD have been limited to small single-center case series [4] [5].

In this issue of Endoscopy, Kuwai et al. [6] report retrospective outcome data on colorectal ESD using the SB Knife in 247 colorectal lesions performed by four non-expert endoscopists (two with no previous conventional ESD experience and two with moderate experience). This study, which was conducted in two academic medical centers in Japan, demonstrates high rates of en bloc resection and curative resection (98 % and 85 %, respectively). One delayed perforation occurred, which was treated conservatively. Delayed bleeding was observed in 2.4 % of cases. Local recurrence occurred in 1.1 %, which is comparable to prior studies using other types of electrocautery knife [1]. The median procedure time was 76 minutes for an average lesion size of 34.3 mm, which may be slightly longer than previous series [7] [8]. Overall, this study provides data to support the use of the scissor-type needle-knife to perform successful colorectal ESD, even among endoscopists with minimal prior ESD experience.

There are limitations to this study. First, the present study included patients retrospectively and is prone to bias. Second, the results of this study suggest that the scissor-type needle-knife is safe and technically efficient for colorectal ESD among non-expert endoscopists. However, information on prior non-colorectal ESD experience was not provided. In Japan, endoscopists generally acquire significant experience in performing ESD in the stomach before starting to perform colorectal ESD. Gaining such experience is difficult in Western countries where the incidence of gastric cancer is low, so the results of this study may not be generalizable.

The advantages of the scissor-type device include safer dissection, particularly when the knife is perpendicular to the muscle layer or when respiratory movements interfere with the procedure. Therefore, it could be used solely for colorectal ESD by less experienced endoscopists or in conjunction with other needle-knives during the difficult part of dissections. The scissor-type grasping knife can be used to perform hemostasis, similar to the hemostatic forceps, and dissection at the same time, which may shorten total procedure time.

Future studies should be prospective and aim to assess the safety, efficacy, and learning curve for colorectal ESD using a scissor-type grasping knife as compared to conventional needle-knives. The studies should also evaluate safety and efficiency for challenging ESD, such as lesions with severe fibrosis or increased vascularity in the lower rectum.

• References

• 1 Fuccio L, Hassan C, Ponchon T. et al. Clinical outcomes after endoscopic submucosal dissection for colorectal neoplasia: a systematic review and meta-analysis. Gastrointest Endosc 2017; 86: 74-86 e17
• 2 Honma K, Kobayashi M, Watanabe H. et al. Endoscopic submucosal dissection for colorectal neoplasia. Dig Endosc 2010; 22: 307-311
• 3 BMV. SB Knife Jr; 2012 Available from: http://www.bvmmedical.com/bvm/wp-content/uploads/SBKnife_Jr_A4-2.pdf Accessed: 27 July 2017
• 4 Akahoshi K, Kubokawa M, Gibo J. et al. Endoscopic resection using the Clutch Cutter and a detachable snare for large pedunculated colonic polyps. Endoscopy 2017; 49: 54-58
• 5 Akahoshi K, Okamoto R, Akahane H. et al. Endoscopic submucosal dissection of early colorectal tumors using a grasping-type scissors forceps: a preliminary clinical study. Endoscopy 2010; 42: 419-422
• 6 Kuwai T, Yamaguchi T, Imagawa H. et al. Endoscopic submucosal dissection of early colorectal neoplasms with a monopolar scissor-type knife: short- to long-term outcomes. Endoscopy 2017; 49: 913-918
• 7 Cong ZJ, Hu LH, Ji JT. et al. A long-term follow-up study on the prognosis of endoscopic submucosal dissection for colorectal laterally spreading tumors. Gastrointest Endosc 2016; 83: 800-807
• 8 Hori K, Uraoka T, Harada K. et al. Predictive factors for technically difficult endoscopic submucosal dissection in the colorectum. Endoscopy 2014; 46: 862-870