
Overview
This submodule describes
- the different types of sutures and when to use them
- how to perform common skin sutures using an instrumental tie technique, and other skin closure techniques.
Suture materials
Filament types
Filaments can be braided or monofilament, absorbable (dissolves over a month to a year) or non-absorbable (does not dissolve), and naturally occurring or synthetic.
Commonly used suture types include:
- Nylon & prolene: monofilament, non-absorbable, synthetic
- Silk: braided, non-absorbable, natural
- Vicryl: braided, absorbable, synthetic
- Monocryl: monofilament, absorbable, synthetic
For simple skin closure, you will almost always use nylon.
Suture sizes
Suture sizes vary, from tiny size 11-0 sutures for microsurgery, to thick size 2 sutures for large tendon repairs. Sutures used for simple skin closure are:
- Scalp: 4-0 or 5-0
- Face: usually 5-0 or 6-0 for eyelids
- Trunk and limbs: 4-0 or 5-0
- Hands: 5-0
- Soles of feet: 3-0 or 4-0
- Penis: 5-0
Thicker, tougher skin is generally closed with thicker sutures, and thin, fragile skin with thinner sutures.
Needle types
Curvatures
The commonest curvatures used for skin closure are ½ and ⅜ circle needles.
Edges
Cutting and reverse cutting needles are most commonly used for skin closure. Cutting needles have 3 cutting edges: the sides and the inner edge of the needle. Reverse cutting needles have the outer edge of the needle as the third cutting edge, and are used on tough tissues.
Other types of needles (like taper needles) are sometimes used for surgery.
Technique tips
Simple interrupted sutures

This is the standard skin closure technique.
Vertical mattress sutures

This suturing technique is used when the wound edges tend to roll inwards, like on the neck or behind the knee. Mattress sutures should be removed after 5 days. Remember this as a "far-far, near-near" approach.
Horizontal mattress sutures

This suturing technique is used when the wound is under extra tension, where skin is fragile (elderly patients), and typically on scalp wounds. It causes more scarring, but draws the edges together better, and stops bleeding very well. Mattress sutures should be removed after 5 days.
Haemostatic figure-of-eight sutures

This suturing technique is used to achieve haemostasis.
Steri-strips

Use steri-strips to close small wounds in areas with little skin tension (like eyebrows). The wound should be clean, not bleeding, and the skin should be dry and not greasy.
Stick one end of a steri-strip on one side of the wound, then pull it across to the other side of the wound to close it. Repeat until the
entire wound is closed
The edges should come and remain together easily with steri-strips. If not, consider sutures.
, with the wound edges lying straight against each other, not rolled inwards.
Skin staples

Use skin staples to close larger wounds, and when you have little time to suture. Staples are an acceptable
alternative
Avoid staples on patients requiring CT or MRI because they cause scan artefacts and may be avulsed by the powerful magnetic field.
for linear lacerations through the dermis that have straight, sharp edges and are located on the
scalp, trunk, arms and legs
Avoid staple use on the face and neck because of a poor cosmetic result. Avoid staples on the hands and feet because of discomfort.
. Staples heal as fast as sutures, and have similar infection rates. Ensure wound edges are everted, as the stapler has a tendency to invert the edges, producing a less satisfying cosmetic result.
- Start in the centre of the wound. Pull the wound edges together with forceps, if necessary, and evert the edges.
- Place the staple gun firmly across the wound.
- Press the trigger to place a staple.
- Space the staples similarly to sutures, until the whole wound is closed, with the edges lying straight against each other, not rolled inwards.
Remember that using a staple extractor for staple removal is a sterile procedure.
Tissue adhesives

Use tissue adhesives to close small wounds in areas with little skin tension (like eyebrows). The wound should be clean with no bleeding. Apply the adhesive to the edges of the wound, not inside the wound. Pull the wound edges together firmly and hold to allow the adhesive to weld for a minute. You may add steri-strips to support the wound. Tissue adhesives do not require removal.
Troubleshooting
See Skin Suturing.