The surgical suture is used to hold body tissues together after injury or surgery. Sutures (or stitches) are typically applied using a needle with an attached piece of thread and are secured with surgical knots.
Suturing a wound is an important surgical skill to learn and become competent in. Wound suturing and closure is important in order to:
- Reduce dead space
- Support and strengthen wounds until healing
- Approximation of skin edges to reduce scaring
- Reduce the risk of bleeding and wound infection
In this article, we shall look at three types of suture – the interrupted suture, the continuous suture, and the mattress suture
Interrupted Suture
The interrupted suture is the most commonly used technique in wound closure. Its name is derived from the fact that the individual stitches are not connected.
Sutures performed with this technique have the advantage of being easy to place and have a high tensile strength. In addition, individual sutures can be removed (e.g in cases of infection) without jeopardising the closure.
However, they require a relatively long time to be placed and, as each suture requires its own knot, are at a greater risk of inducing infection.
Procedure
- Start in the middle of the wound, place sutures at 1cm intervals until wound is approximated without tension.
- For each suture, grasp and evert the skin edge (gently with the non-dominant hand).
- Pronate the dominant hand so that the needle will pierce perpendicular to the skin and drive the needle through the skin by supinating the hand before picking up the needle (2/3 from the tip) with the needle holders. A no touch needle technique is important, reducing sharps injury and infection risk
- Finish by carefully gathering the thread to create a long thread (with needle) and short thread, before performing a hand or instrument tie.
- Repeat with separate sutures to close the wound.
Continuous Suture
In the continuous suture, the stitches are connected along the wound. This technique tends to be faster, particularly for long wounds. However, the wound is at greater risk of dehiscence if the suture material breaks.
Procedure
- Start at the wound edge and work along the wound (traditionally this is done working towards yourself).
- For each suture, grasp and evert the skin edge (gently with the non-dominant hand).
- Pronate the dominant hand so that the needle will pierce perpendicular to the skin and drive the needle through the skin by supinating the hand (using the curve of the needle) before picking up the needle (2/3 from the tip) with the needle holders. A no touch needle technique is important, reducing sharps injury and infection risk.
- Place each suture as above, at 1cm intervals, until wound is approximated without tension. Carry this on along the wound.
- Finish by carefully gathering the thread to create a long thread (with needle) and short thread before performing a hand tie or instrument tie.
Note: care should be taken to apply the correct amount of tension to the suture material – if too much the skin becomes strangulated, if too little the wound edges may not be opposed correctly.
Mattress Suture
The mattress sutures, both horizontal and vertical, are one of the most commonly used methods for skin closure. Mattress sutures are used, especially when skin edges, must be closed under tension, as they achieve good skin eversion (which aids wound healing and produces less prominent scaring).
This type of suture tends to be performed using non-absorbable suture material, with the sutures removed 10-14 days on average after wound closure (however, typically less than this for closures on the head and neck).
Procedure
- Grasp the wound edge with the forceps.
- Drive the needle through the skin, using the needle holder, around 4-8mm away from the wound edge, passing the suture deep through the dermis.
- Pick up the needle with the forceps at the wound edge, before reloading the needle onto the needle holder.
- Grasp the opposing wound edge with the forceps, drive the needle deep through the other side of the wound, piercing the skin to re-emerge around 4-8mm away from the wound on the opposite side.
- Backwards load your needle in your needle holder.
- Grasp the second wound edge again with the forceps and drive the needle through the skin, in vertical alignment with the other puncture site, around 1-2mm away from the wound edge. This near placement should occur at a shallow depth and should pass though the upper dermis.
- Pick up the needle with the forceps at the wound edge, before reloading the needle onto the needle holder.
- Grasp the opposing wound edge with the forceps, drive the needle deep through the other side of the wound (also in the upper dermis layer), piercing the skin to re-emerge around 1-2mm away from the wound on the opposite side (also in vertical alignment with the other puncture site).
- Gently pull the suture to achieve the desired skin tension, as the wound edges close.
- Finish by performing a hand tie or instrument tie.