# Skin Closure- Techniques & Materials

## 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

1. Always hold your needle holder in your dominant hand. Use a

   tripod grip.
   tripod grip.

2. Use toothed forceps to stabilise skin and unroll the edges of wounds outwards (evert), holding the forceps like a pencil.

3. Always handle the needle with your instruments, never with your fingers.

4. Until you are comfortable, align the wound in front of you so that it stretches from near to far, not side to side.

5. It is easier to start suturing from your dominant side, and these instructions assume that you do so.

6. Always pull sutures tight until the skin edges are touching, but no tighter (“approximate not strangulate”).

7. Space sutures evenly, and tie all your knots on the same side.

8. Start in the middle of the wound with your first suture and then in the middle of each half and so forth.

9. You may alternate simple sutures and mattress sutures for best effect.

## Simple interrupted sutures

This is the standard skin closure technique.

1. Hold the needle ⅔ from the tip in a needle holder.

2. Start at the midpoint of the wound. Enter the skin 5 mm from the edge of the wound, at a 90° angle to the skin. The needle should start with the curve upside-down like an arch.

3. Following the curvature of the needle, push the needle through the skin until the tip comes out inside the wound.

4. Grip the tip inside the wound, pull it out, and regrip the needle ⅔ from the tip.

5. From the inside of the wound, push the needle through and out the other side of the wound, again following the curvature of the needle (this time curving up) to land 5 mm from the edge of the wound.

6. Grip the needle and pull the suture material through until a ± 5 cm short tail of suture material is left on the entry side of the wound. Release the needle from the needle holder.

7. Tie the knot.
   Tie the knot.

   Align the needle holder with the length of the wound, so that it is positioned between the two lengths of the suture material.

   Wind the long section twice around your needle holder, throwing the loops from the outside, over the top of the needle holder.

   With the loops on, grip the tip of the short end with your needle holder.

   Allow the loops to slide off the needle holder as you pull it across to the side of the long end, while also pulling the long end with your non-dominant hand across to the side of the short end (your hands should cross, with the needle holder passing closest to you and your other hand passing further away). This will form the first half of your knot. Make sure it is lying flat against the skin. Pull tight. Release the suture material from the needle holder.

   Hold the needle holder along the length of the wound again. Wind the long section once around your needle holder, throwing the loops from the outside over the top of the needle holder.

   With the loop on, grip the tip of the short end with your needle holder.

   Allow the loop to slide off the needle holder as you pull it across to the side of the long end, while also pulling the long end with your non-dominant hand across to the side of the short end (your hands should uncross, with the needle holder passing closest to you and your other hand passing further away). This will form the second half of your knot. Pull tight and make sure it is lying flat against the skin.

   Hold the needle holder along the length of the wound again. Wind the long section once around your needle holder, throwing the loops from the outside over the top of the needle holder.

   With the loop on, grip the tip of the short end with your needle holder.

   Allow the loop to slide off the needle holder as you pull it across to the side of the long end, while also pulling the long end with your non-dominant hand across to the side of the short end (your hands should cross, with the needle holder passing closest to you and your other hand passing further away). This will form the last portion of your knot. Pull tight and make sure it is lying flat against the skin.

8. Cut the ends of the suturing material to 1 cm long.

9. You have now completed one simple interrupted suture. Repeat with even spacing to close the entire wound.

## 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.

1. Hold the needle ⅔ from the tip in a needle holder.

2. Start at the midpoint of the wound. Enter the skin 8 mm from the edge of the wound, at a 90° angle to the skin.

3. Following the curvature of the needle, push the needle through the skin to take a deep bite through the subcutaneous tissue, and emerge 8 mm on the other side of the wound.

4. Pull the suture material through until a ± 5 cm tail of suture material is left on the entry side of the wound.

5. Release the needle from the needle holder and regrip it so that it faces in the opposite direction. On the exit side of the wound, start a second, shallower stitch 2-3 mm from the edge of the wound, exiting back on the original entry side of the wound.

6. Pull the suture material through until there is no loop on the original exit side of the wound, and the wound edges are touching.

7. Tie the knot and cut the ends as for simple interrupted sutures, this time instead of aligning the needle holder with the wound, holding it parallel to it between the two lengths of suture material.

8. Repeat with even spacing until the wound is fully closed.

## 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.

1. Hold the needle ⅔ from the tip in a needle holder.

2. Start at the midpoint of the wound. Enter the skin 5 mm from the edge of the wound, at a 90° angle to the skin.

3. Following the curvature of the needle, push the needle through the skin to take a deep bite through the subcutaneous tissue, and emerge 5 mm on the other side of the wound.

4. Pull the suture material through until a ± 5 cm tail of suture material is left on the entry side of the wound.

5. Release the needle from the needle holder and regrip it so that it faces in the opposite direction. On the exit side of the wound, start a second, equally deep stitch, 5 cm to the side of the first stitch, exiting back on the original entry side of the wound.

6. Pull the suture material through until there is no loop on the original exit side of the wound, and the wound edges are touching.

7. Tie the knot and cut the ends as for simple interrupted sutures, this time instead of aligning the needle holder with the wound, holding it at crossways to it between the two lengths of suture material.

8. Repeat with even spacing until the wound is fully closed.

## Haemostatic figure-of-eight sutures

This suturing technique is used to achieve haemostasis.

1. Hold the needle ⅔ from the tip in a needle holder.

2. Enter the skin 5 mm from the edge of the wound, at a 90° angle to the skin.

3. Following the curvature of the needle, push the needle through the skin to take a deep bite through the subcutaneous tissue, and emerge 5 mm on the other side of the wound.

4. Pull the suture material through until a ± 5 cm tail of suture material is left on the entry side of the wound.

5. On the entry side of the wound, start a second, equally deep stitch, 5 cm to the side of the first stitch, exiting back on the original exit side of the wound.

6. Pull the suture material through until the wound edges are touching.

7. Tie the knot and cut the ends as for simple interrupted sutures.

## 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

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

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

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.

## References

1. Thomas RK. Practical Medical Procedures at a Glance. John Riley & Sons; 2015.

2. Zuber TJ. The mattress sutures: vertical, horizontal, and corner stitch. Am Fam Physician. 2002;66(12). 2231-2236.

3. Newell KA. Wound Closure. In: Essential Clinical Procedures, Third Edition. Philadelphia: Elsevier; 2013. 250-272.

4. Lipsett S. Closure of Minor Skin Wounds with Staples. Up to date.July 2021 https://www.uptodate.com/contents/closure-of-minor-skin-wounds-with-staples