Ch 75 - Primary Wound Closure Flashcards
What are the 3 division of the vascular supply to the skin?
- Superficial/Subpapillary plexus
- Middle/Cutaneous plexus
- Deep/subdermal/subcutaneous plexus
What are the main differences regarind the cutaneous angiosomes in dogs and cats?
- Dogs have a greater density of collateral SQ vessels
- Cats have a smaller number and wider distribution of curaneous perforating vessels
These differences apply mainly to the trunk
Define the following terms in relation to wound closure:
- Primary wound closure (First intention healing)
- Delayed primary wound closure
- Secondary Closure (Third intention healing)
- Second intention healing
- Primary wound closure = Sutured wounds
- Delayed primary wound closure = suturing 2-5 days after wound initial, before granulation tissue development
- Secondary Closure = Closure of the would after granulation tissue has formed in the wound bed
- Second intention healing = Heals without suturing - usually va contraction and epithelialisation
What is the rate of epithelialisation in primary wound healing?
1mm/day.
A perfectly apposed wound can therefore be epitheliased within 24-48hr
What is the reported %strength of wounded skin in comparison to normal skin at the following time points:
- 14 days
- 3-4 weeks
- Several months
- 14 days - 5-10% strength
- 3-4 weeks - 25%
- Several months/1 year - 70 - 80% strength
How does tension affect wound healing?
Tension can disrupt cutaneous perfusion and retard wound healing
List the 5 braod categories which can effect wound healing
- Tension
- Pressure
- Motion
- Self-Mutilation
- Patient Health
What patient health factors can significantly retard epithelialisation?
- Uraemia
- Exogenous steroid excess
- Hyperadrenocorticism
- Steroids prolong the inflammatory phase and delay cutaneous wound healing
- Geriatric
- Decreased cutaneous perfusion, increased skin fragility, increases risk of infection
- Malnutrition
- delayed neovascularisation, decreased collagen synthesis, prolongation of inflammation, decreased leucocyte phagocytosis, B- and T-cell dysfunction, decreased mechanical skin strength
- Methionine, cysteine and arginine all important
- FAs (within cell membranes, vital for cell function)
- VitC (collagen synthesis, cell mitosis and monocyte migration)
- Zinc and iron (enzymatic reactions in production of DNA and RNA and proteins including collagen)
What are the reported benefits of using a scalpel for a skin incision over electrocautery/CO2 laser/radiowaves?
- Scalpel incision have approximately twice the wound strength at 10-12 days post-op compared to electrocautery
- Produce less drainage with faster and stronger healing
- Skin incised with radiowave, CO2 laser and monopolar, char will penetrate the skin laterally 0.172, 0.215 or 0.255mm respectively
In humans, studies have concluded that incision made with electrocautery were faster and resulted in less post-op pain with no difference in scar formation of post-op infection
What is meant by the ‘golden period’ for wound management?
The golden period is a period of 3-6hr during which the bacteria within a minimally contaminated wound can multiply to 105 per gram of tissue or per ml of exudate, at which point the risk of infection increased dramatically
List some differences between dogs and cats in regards to wound healing
- Cats have lower cutaneous perfusion for the first week (by 2 weeks, no difference)
- Cats have a significantly lower wound breaking strength 1 week post-op
- Open wounds in cat heal largely by contraction whereas dogs heal largely by central “pull” of fibroblasts and epithelialisation
Defects should generally be created and closed parallel to tension lines except for…
On distal limbs
How long may it take for the degree of trauma to be fully established after a crushing injury?
3-7 days
What is a chain stitch knot?
What are its advantages?
An aberdeen knot!
Greater relative knot security and less volume
What is the recommended suture tag length of buried knots?
3-5 mm
List some techniques for correcting dog ears
List some methods of prevention/correction of dog ear formation in ellipital incisions
- A - Fudging - placing sutures further apart on longer side when discrepancy is small
- B - Rule of halves
- C - Sutures from ends to center with dog ear removal
- D - Suturing from one end to the other with dog ear removal
- E - Suturing from centre to ends with dog ear removal
- F - Lengthening the short side with half of a fusiform
