Security is vital, otherwise, the closed wound or ligated blood vessel will not remain in that state for long! Knot security depends on the type of knot used, the friction provided by the suture material (coated materials lessen tissue drag but also decrease knot security) and the technique used when tying the knot. It takes practice to establish a good surgical technique and the ability to tie secure knots is a vital part of this.
Success in knotting
- Use the simplest knot available to give the security required.
- Keep the cut ends of the suture as short as possible (1-2mm for Vicryl) but do not jeopardise knot security.
- Do not over-tighten knots, this cuts off tissue blood supply, the tissue dies and then breaks down, the end result is a knot that is no longer securing anything.
- Once the first throw has been laid down take care not to disturb it / tug at it as the rest of the knot is being formed. If this occurs a hitched knot will be tied and this will slip.
- Sutures are damaged and weakened if instruments are clamped onto them. For this reason it is very important not to apply any crushing instruments (haemostats, needle holders) to any part of the suture that will remain in the tissues.