title: Endoscopic suturing and knot tying: theory into practice.
abstract: 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.
  
  
  BACKGROUND
  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.
  
  
  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.
authors.affiliation: St. John of God Hospital, Geelong, Victoria, Australia. mertieinfo@mertie.com
authors.forename: D L
authors.initials: DL
authors.lastname: Murphy
mesh_terms: D004724:Endoscopy; D013525:Surgical Instruments; D013536:Suture Techniques / Q000295:instrumentation