Definition & Overview
A surgical suture is a medical device used to sew skin and other body tissues together to close up a surgical incision or a tear caused by an injury. The suture is applied using a surgical needle and thread and secured with a surgical knot.
Proper suturing techniques also help minimise the risk of bleeding and infection that accompany all surgical incisions and skin injuries.
The technique of suturing cutaneous tissue has been used for thousands of years now. Today, it is used by surgeons, physicians, dentists, nurses, medics, podiatrists, and other trained medical personnel who has received special training in suturing.
Who Should Undergo and Expected Results
Patients typically get sutures following an injury or open surgery that caused a large opening or tear in the skin. Examples of these injuries include a simple skin laceration on the arm or leg, a more complex facial laceration, an abdominal incision, or a median sternotomy.
The proper use of surgical sutures effectively:
- Repairs skin tissue
- Facilitates proper skin healing
- Minimises bleeding
- Minimises bacterial contamination
- Helps achieve skin hemostasis
- Restores the normal function of the injured body part
- Produces pleasant cosmetic results
There are two types of suture materials used for this procedure and these are:
Absorbable sutures - These are made from naturally occurring materials that break down when placed in the skin. The main material being used nowadays is chromic catgut, which consists of processed collagen taken from the submucosa of animal intestines. The material naturally breaks down after seven days, but it is treated with chromium salts to delay the process, allowing it to maintain its strength for up to 2-3 weeks. It is then completely absorbed by the body within 3 months. There are also synthetic absorbable sutures made using Vicryl and Monocryl polymers, which are broken down by hydrolysis and are known to help reduce tissue reactions that have been linked with chromic gut.
Non-absorbable sutures - These are made from silk, cotton, steel, nylon, Prolene, and Mersilene, among others. Since they cannot be broken down by the body’s enzymes or even through hydrolysis, they are removed once the skin has sufficiently healed and regained its tensile strength up to a certain extent. The specific length of time that the suture is removed is different in every situation but tends to follow a general pattern depending on the location of the sutures. For example, facial sutures are removed within 3 to 4 days, while scalp and trunk sutures in 5 to 7 days. Arm or leg sutures, on the other hand, are removed 7-10 days after the surgery, while foot sutures take the longest to regain strength, usually taking up to 10 to 14 days.
How is the Procedure Performed?
When applying sutures, a surgeon inserts the needle tip into the skin perpendicularly. Upon penetrating the topmost layers of the skin, the part of the body being stitched is twisted slightly to allow the needle to access the subcutaneous tissue before it comes out of the skin surface.
Aside from the suture material, medical practitioners also use scalpels, forceps, skin hooks, and needle holders while placing sutures.
There are many suturing techniques available and medical professionals typically choose the technique to use based on the characteristics of the skin opening. Each of the techniques has their own advantages and disadvantages.
- Simple interrupted suture – Interrupted sutures are known for their easy application, good tensile strength, and reduced risk of causing wound oedema. However, they take a long time to place and they have the tendency to cause crosshatched scars. To prevent this from happening, the sutures have to be removed early.
- Simple running suture – A simple running suture is a basic technique used mainly for longer wounds with good, clean edges. It has a reduced risk of scarring than the interrupted suture and is also easier to place. However, there is a risk of dehiscence (which can occur if the suture material accidentally ruptures) and puckering of the suture line, especially when it is used in patients with thin skin.
- Running locked suture – Running locked sutures are commonly used when the wound requires additional hemostasis due to oozing in its edges. It is known for its increased tensile strength but it places the patient at an increased risk of tissue strangulation as well as microcirculation around the wound. Thus, surgeons only use it in areas where there is good blood supply, such as the scalp.
- Pulley suture – The pulley suture is known for its ability to stretch the wound edges, making it particularly effective in restoring wound closure strength.
- Dermal-subdermal suture – This type of suture is placed superficially away from the edge of the wound to maximise wound eversion.
- Running subcuticular suture – Widely used in areas with minimal skin tension, this suturing technique is known for creating good cosmetic results as it penetrates only the epidermis at the beginning and end of the suture line. This means there is no risk at all of crosshatching. However, it is not known to provide significant wound strength.
- Running subcutaneous suture – This is used mainly to close up the deeper portions of surgical wounds, usually in place of buried dermal sutures in situations wherein a quicker wound closure is desired.
- Running subcutaneous corset plication stitch – Reserved for wounds wider than 4 cm in diameter in areas with excess tension, this technique is known for its natural wound eversion and its more precise wound edge approximation. However, it carries the risk of wound distortion and has a high rate of suture breakage.
- Deep tip stitch – This technique is used for M-plasty, W-plasty, and V-Y wounds as it can provide better long-term support compared to the traditional corner stitch.
There is also a variety of horizontal and vertical stitching techniques, including:
- Vertical mattress suture
- Half-buried vertical mattress suture
- Far-near near-far vertical mattress suture
- Horizontal mattress suture
- Half-buried horizontal suture
- Buried horizontal mattress suture
- Absorbable buried suture
Possible Risks and Complications
The following are the risks associated with the use of sutures:
To prevent or minimise these risks, patients are instructed on how to care for their sutured wound and are advised to call their doctor or surgeon if they notice unusual symptoms, such as reddening of the skin or red streaks around the wound, blood or pus discharge, fever, or when the suture breaks open.
Forsch R. “Essentials of skin laceration repair.” Am Fam Physician. 2008 Oct 15;78(8):945-951. http://www.aafp.org/afp/2008/1015/p945.html
LaMorte Wayne W. “Suturing Basics: Basics of wound closure and healing.” Boston University School of Medicine Surgery. http://www.bumc.bu.edu/surgery/training/technical-training/suturing-basics/
Mackay-Wiggan J. “Suturing Techniques.” Medscape. http://emedicine.medscape.com/article/1824895-overview#a5