A Novel Intra-corporeal Knotting Technique for Laparoendoscopic Surgery Philippe Grange, Paul Rouse, Amrith Rao, Anya Kypke, London, United Kingdom INTRODUCTION AND OBJECTIVE: Laparoendoscopic Single Site (LESS) urological procedures are gaining popularity across the globe. Most reported series/case reports of reconstructive LESS urological procedures such as partial nephrectomy and pyeloplasty describe the use of an additional port (2- 5mm) to aid dissection and to accomplish an intra-corporeal knot. We will demonstrate with this high-definition video, a step-by-step guide to achieve complete intra-corporeal knotting technique on the box trainer and subsequently the application of this technique to complex urological reconstructive procedures, in this case of laparoscopic partial nephrectomy. MATERIALS AND METHODS: Initial design of the knotting technique and proof of concept was on a box trainer. A commercially available single port device along with the needle holder and a grasper are used to demonstrate the knotting technique. Along with the video, clear illustrations that can be easily understood and reproduced by others will be shown. We have since applied this technique for complex LESS reconstructive procedures such as no-clamp partial nephrectomy and pyeloplasty. RESULTS: As demonstrated in the illustrations and the video, step one of the knotting involves the needle within the needle holder to rotate three times in a clockwise direction. This forms three loops around the shaft of the needle holder. The needle is then transferred across to the grasper, which frees the needle holder to grasp the short end of the suture. The knot is tightened by a push and pull method as opposed to the horizontal method that can be achieved in the traditional multiport laparoscopic technique. The knot is further secured by repeating the above steps in the opposite direction. CONCLUSIONS: We have demonstrated with the video demonstration a complete intra-corporeal knotting technique that can be utilized without the need for any additional port or clip devices achieving LESS procedure. This technique will be useful for pure LESS procedures such as such as partial nephrectomy, pyeloplasty and other reconstructive urological operations.