Wound healing - to stitch or not to stitch

A recent case illustrated an excellent outcome of successful wound management.  Overall outcomes may range from excellent, as can be seen in these photos of a wound to the head of a foal, to absolute disasters despite all the best of efforts.

Wound pre-surgery
                  Pre-surgery

 Post-surgery
                  Post-surgery

 4 months post-surgery
     4 months post-surgery

The best outcome of a wound healing is healing by first intention, such as occurs in surgical wounds.  Healing time is short (2-3 weeks) and scar formation is minimal.  If healing by first intention does not occur, the open wound repairs by second intention healing.  The defect is filled with granulation tissue and repair takes longer (6 weeks to 6 months or longer) and leaves more scarring.

The aim of wound management is to achieve first intention healing if possible.  Depending on the type of wound and conditions, this is not always the case.

Factors that determine wound healing can be grouped as follows

  • Type of injury - clean, straight wounds are likely to be better cases for first intention healing. Jagged cuts with flaps, exposed bone and tendons are likely to heal slower. Bruising and tissue damage will complicate healing.
  • Blood supply - wounds in areas of lower blood supply (e.g. lower limbs), or where blood supply is damaged by injury, heal slower. Blood supply to flaps of skin may be compromised and result in part, or all, of the flap dying.
  • Location of injury - wounds to the lower limbs generally heal slower than wounds to the head, trunk and upper limbs.
  • Movement - wounds involving joints, tendons, and some muscles, and in directions opposite to the plane of movement, heal slower. Immobilisation of the animal and/or the injured area (bandaging or casting) will assist healing in these cases.
  • Contamination of wounds with dirt and material at the time of injury is likely to result in infection and delay healing. Lower limb wounds are more likely to get post-surgery infection.
  • Time since injury - the longer after injury, the greater risk of contamination, further damage from unrestricted movement, and swelling of the area.
  • Age and health of the patient - healing is slower in older, unhealthy patients, particularly if the injury involves tissue already affected by disease or previous injury.

When these factors are applied to horse wounds, generally

  • Wounds to the upper limbs, head and trunk heal quicker and are more likely to be suitable for stitching.
  • Wounds to the limbs below the knee and hock are often not suitable for stitching and heal slower.
  • Wounds that are clean with minimal tissue damage or loss are more likely to be suitable for stitching.
  • Skin flap wounds may not be suitable for stitching and better removed.
  • If stitching is not possible, healing will have to be by second intention, with or without bandaging and appropriate dressings.

If you decide a wound needs veterinary attention

  • Call Totally Vets ASAP- a delay of 6-12 hours will probably mean the wound is not able to be stitched.
  • Don't apply any medication or dressing to fresh wounds.
  • Prevent further contamination by applying a temporary covering and moving to a clean area if possible.
  • Control bleeding by pressure with a clean towel, cloth or bandage.
  • Prevent further damage by restricting movement.

Remember

  • Not all wounds are suitable for stitching.
  • Very satisfactory results can be achieved with procedures appropriate for that wound.
  • Some stitched wounds will break-down and require further surgery and treatment.
  • Complications can occur that delay wound healing and adversely affect the final outcome