Novel injectable needle-type knife, ProKnife for colorectal endoscopic submucosal dissection.

Abstract

Watch a video of this article. Although time-consuming, which may be partly attributable to the need to change devices for local injection, colorectal endoscopic submucosal dissection (ESD) is a valuable procedure.1 To overcome this problem, a water jet function has been developed;2 however, most devices deliver water from the base of the electrode rather than the tip. A novel injectable needle-type knife (ORISE ProKnife; Boston Scientific, Tokyo, Japan) has recently become available (Fig. 1A). The electrode shaft has a 0.5-mm diameter (Fig. 1B, arrow a), and the T-shaped tip has a 0.81-mm diameter (arrow b) with 0.15-mm thickness (arrow c). It provides excellent hemostasis in addition to enabling incision and dissection. A significant advantage is the large injection lumen diameter (0.3 mm) of the electrode, which is twice larger than that of an existing device, the HybridKnife. It allows the local injection of fluids, such as highly viscous hyaluronic acid preparations. Direct focal injection from the center of the needle tip provides a sustained lift without changing the device (Fig. 1C). Furthermore, the device handle has a cleaning tool to clear the lumen and re-inject once clogging occurs during the procedure (Video S1). Colonoscopy revealed a non-granular-pseudo-depressed 30-mm laterally spreading tumor in the splenic flexure (Fig. 2A). Initial submucosal lifting with hyaluronic acid solution stained with indigo-carmine was performed using a standard injection needle. Using ProKnife, a local injection of hyaluronic acid was administered while performing mucosal incision and submucosal dissection (Fig. 2B,C). Despite the poor maneuverability, ProKnife completed the ESD in 30 min without changing the device (Fig. 2D). ProKnife was able to consistently administer submucosal injections from the center of the needle tip, which enabled reliable lifting of the submucosa and improved the visibility of the dissecting plane during the procedure. The knife is a novel, efficacious time-saving surgical device. Authors declare no conflict of interest for this article. We would like to thank Mayuko Namioka for video editing and Takefumi Kikuchi and Shotaro Kawamura for the helpful discussion. We also would like to thank Editage (www.editage.com) for English language editing. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.