How to tie a suture knot | steps & what equipment to use
In surgery, surgical knots have a wide range of applications, and knot tying is an important skill for any surgeon to know and be proficient in.
A completed knot should be solid so that it is almost impossible for the knot to slip. Excessive stress applied through a knot, however, can cause both the suture and the tissue to be weakened, which can lead to poor wound healing and tissue necrosis. To avoid any extraneous body reactions, each knot should be as small as possible.
In this article, we will be discussing one of the most common methods used to tie a suture. Which is the instrument tie.
Equipment you need to tie a suture knot
A basic suturing kit includes the following:
- A needle holder.
- Toothed forceps, with a hook to handle tissue.
- Fine suturing scissors.
- The appropriate suturing material.
It’s very important to consider the suturing material that is used when operating. In turn, choosing the right suturing material is made easy by considering the location and tension of the wound.
Suture materials are generally of the following two types:
- Absorbable – This type of material is generally used for buried sutures that don’t require removal. They lose their tensile strength in less than 2 months and thus are highly absorbable.
- Non-absorbable – This type of material maintains the majority of tensile strength even after 2 months. It is non-absorbable and therefore used to close wounds on the skin’s surface and requires removal.
The needles used for suturing are made exclusively for such a purpose and comes in a variety of shapes and sizes for a specific wound.
How to tie an instrument surgeon’s knot
- Step 1
To prepare a suture for tying, pull it through the skin until a tail of about 2 cm remains. Although there are multiple techniques for an instrument-tying suture, one simple, easy-to-remember method is shown next.
A shorter suture tail (about 2 cm) is much easier to work with and better conserves suture than a long tail.
- Step 2
Be careful not to allow the running end of the suture to accidentally touch non-sterile areas and become contaminated. A simple way to avoid this and keep good control of the needle is to grasp the needle between the thumb and forefinger of the non-dominant hand and gently wrap (so as not to pull the tail through the wound) the excess suture around the three middle fingers during the tying procedure.
- Step 3
Start the tie by placing the needle driver parallel to and directly over the incision also described as “place the needle driver ‘in the valley.’” This will be the position to begin each throw of the knot. The dominant hand is holding the needle driver, and the non-dominant hand is grasping the running suture that has the needle on the end of it.
- Step 4
Without displacing the dominant hand or the needle driver, wrap the running end of the suture twice over the top of and around the needle driver.
- Step 5
Step five would be to Grab the tail of the suture with the jaws of the needle drivers.
- Step 6
Pull the dominant hand and needle driver toward the non-dominant side, while simultaneously pulling the nondominant hand and running suture toward the dominant side to place the first throw of the surgeon’s knot. This will result in the provider’s forearms being crossed, and this position will be maintained until the next throw is placed.
Do not let go of or reposition the hands, suture, or needle driver until the tie is completed. This method relies on the progressive placement of the hands in each step to correctly tie the knot.
- Step 7
Now place the needle driver back, parallel to, and directly over the incision in exactly the same position as in Step 2. Wrap the running end of the suture once over the top of and around the needle driver.
- Step 8
Grab the tail of the suture with the jaws of the needle drivers. Pull the dominant hand and needle driver back toward the dominant side while simultaneously pulling the nondominant hand and running suture toward the non-dominant side to place the second throw of the knot. Note that the provider’s arms should now be uncrossed.
- Step 9
Steps 2 through 5 are then repeated, with only single wraps for each pass, until the desired number of throws is placed. Cut the suture with suture scissors with approximately 0.5-cm ends.
When in doubt about the number of throws to use, note that for most sutures, five throws will work.