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.
The theory of knot tying
Updated on 12th October 2020