Endoscopic Suturing and Knot Tying: Theory Into Practice

Objective To advance modern surgical techniques of endoscopic knot tying, encompassing a new appreciation of knot-tying theory and the application of second-generation, purpose-designed instruments. Summary Background Data During open surgery, surgeons automatically create the surgical half-hitch by using either instrument or hand/finger knot-tying methods (figure 4). Each of these methods, which are mirror images of each other, forms the same result, the half-hitch. Two opposing half-hitches are needed to form a square knot. There are many ways for new-generation instruments to create a secure square knot during endoscopic surgery. An overview of the current endoscopic knot-tying methods is presented. Figure 4: Diagrammatic display of how the jaw and spur operate to form a half hitch. (A) Spur action alone. The role of the right instrument and appendage spur is shown capturing and controlling the bight to form forward-directed loops. (B) Combined jaw and spur action. (a) The jaws of the right instrument hold the suture tail. (b) With forward right instrument movement and counterclockwise rotation, the spur appendage of this instrument captures and directionally controls the bight section of the suture. (c) One full rotation of right. (d) One-and-a-half rotations, then through the loop, carrying the suture tail to complete a forward-directed loop of a half-hitch. Multiple instrument rotations are easily performed to create extra loops, as in a surgical half-hitch. First-generation endoscopic needle holders do not easily perform this task. The partner left instrument (not shown) in turn holds the standing part of the suture coaxially with the rotating right instrument.Methods The author presents a theoretical analysis of square knot-tying techniques as applied during instrument and hand/finger movements. The application of a mirror-image concept was considered in the analysis of these two contrasting methods. Results There are 12 ways to create a square knot, some of which have previously not been described or needed in open surgery. Some of these methods have particular application in endoscopic surgery. Conclusions A new understanding of knot-tying theory has been developed, with innovative methods being defined for tissue approximation during endoscopic surgery. These ergonomic, efficient, and contrasting methods of knot tying are described using second-generation endoscopic instruments. The new techniques have direct and broad application in many fields of minimally invasive surgery.