The ''knot before loop'' technique for the endoscopic ligation and suture-instrument set - Knot formation and application

Background: In minimally invasive surgery intracorporal knot-tying is complicated by a limited field of vision and depth perception. Methods: The ''knot before loop'' technique aims to reduce intraabdominal movements in number and space needed. A grasping instrument 3 mm in diameter guides a slipfit hollow knot pusher with a notch to hold the thread, when extracorporally forming the knot on the instrument tip and an axial slot. The loop is finished under endoscopic vision, yet a second loop is created along the thread. The knot is tightened and secured by closing the second loop without troublesome instrument change. Results: The strength of the knot was tested and the feasibility of the instrument set was proven in pigs and 25 cholecystectomies and hernia repairs in humans. Conclusions: Endoscopic application of a secured slip knot is simplified by the ''knot before loop'' technique. The independent formation of the knot by the assisting personnel allows quick application, equivalent to the use of clips and staples. The benefit in cost saving is high.