🩺 Suturing

Suturing is a fundamental minor surgical skill used to appose wound edges to promote primary intention healing and minimise scarring. It requires a sound understanding of anatomy, aseptic technique, and choice of materials. In the UK, this is a core competency for junior doctors working in Emergency Medicine, GP, and surgical specialties. Proper technique involves wound irrigation, local anaesthesia, and the precise placement of non-absorbable or absorbable sutures depending on the depth and location of the injury.

Suturing is indicated for the closure of linear skin lacerations where the wound edges are clean and can be apposed without significant tension. The primary goals are to facilitate primary intention healing, provide haemostasis, and achieve an acceptable cosmetic result. It is also used to secure surgical incisions and to repair deep tissue layers following trauma or surgery once the underlying structures have been assessed for integrity. In some cases, suturing is used specifically to stop haemorrhage from a scalp wound or deep vessel.

Absolute contraindications include wounds that are heavily contaminated, showing signs of active infection, or are more than 12–24 hours old (site-dependent, e.g., face has a longer window). Wounds with significant tissue loss where edges cannot be apposed without excessive tension should not be sutured primarily. Relative contraindications include the presence of foreign bodies that cannot be fully cleared or wounds involving deep structures like nerves, tendons, or arteries, which require specialist surgical repair rather than primary closure in the ED.

A standard suture kit typically includes a needle holder (e.g., Mayo-Hegar), Toothed or non-toothed Dissecting Forceps (Adson), and suture scissors. Consumables include sterile drapes, local anaesthetic (e.g., Lidocaine 1%), a syringe and needles for infiltration, and sterile saline for irrigation. The needle and suture material choice depends on the site; commonly a monofilament like Prolene or Ethilon (non-absorbable) for skin, or Vicryl (absorbable) for deep dermal layers. Skin cleansing solution such as Chlorhexidine 0.5% or Povidone-iodine is also required.

Begin by preparing the area: clean the wound thoroughly with saline or antiseptic and infiltrate with local anaesthetic. Once the area is numb, debride any devitalised tissue and explore for foreign bodies or deep injury. Using the needle holder, enter the skin at a 90-degree angle approximately 3-5mm from the wound edge. Rotate the needle through the tissue following its curvature, exiting through the opposite side at an equal distance and depth. Tie the suture using an instrument tie, ensuring the knot sits to one side of the wound (not over the line of injury), and repeat until the wound is closed.

Success is interpreted as a wound that is well-apposed with slightly everted edges (the 'mountain' look) to allow for flattening during scar maturation. A correctly sutured wound should show no gaps between stitches and no evidence of 'puckering' or 'railroading' from excessive tension. Ongoing assessment involves checking for signs of wound dehiscence or infection (erythema, warmth, purulent discharge). Interpretation of suture removal timing is also critical: usually 3-5 days for the face, 7-10 days for the trunk/limbs, and 10-14 days for joints.

Common mistakes include 'strangling' the wound by tying knots too tightly, which leads to tissue ischaemia and poor scarring. Failure to achieve wound edge eversion (resulting in inverted edges) significantly impairs healing. Inadequate wound debridement or failure to explore for deep structure damage (tendons/nerves) before closure is a frequent clinical oversight. Additionally, using an inappropriate suture material for the anatomical site, such as using heavy braided silk on the face, can lead to poor cosmetic outcomes and increased infection risk.

Ensure you ask about the patient's tetanus status and allergies (especially to local anaesthetics) before starting. Always 'load' the needle into the holder at the junction of the proximal one-third and distal two-thirds of the needle body. When tying knots, remember to perform two loops for the first throw (surgeons knot) to ensure tension is held, and alternate the direction of subsequent throws to create a stable square knot. Do not cut the tails too short; leave approximately 5-10mm to aid removal.

Relevant to MLA outcomes for 'Practical skills and procedures' and 'Management of trauma'. Students must be able to demonstrate aseptic non-touch technique (ANTT) throughout. Awareness of 'shark tooth' needle safety and proper disposal of sharps is high-yield for OSCE examiners. Understanding the difference between primary, secondary, and tertiary intention healing is a core knowledge requirement for the AKT.