Chapter 75: Primary Wound Closure Flashcards
What are the 3 divisions of the vascular supply to the skin?
Superficial/Subpapillary plexus
Middle/Cutaneous plexus
Deep/subdermal/subcutaneous plexus
What are the main differences between 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 cutaneous perforating vessels
These differences apply mainly to the trunk
Define the following:
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 initial injury, before granulation tissue development
Secondary Closure = Closure of the would after granulation tissue has formed in the wound bed
Second intention healing = Allow to heal without suturing - usually via contraction and epithelialization
What is the rate of epithelialization in primary wound healing?
1mm/day.
A perfectly apposed wound can therefore be epithelialized 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
What are 5 things that can affect wound healing?
Tension
Pressure
Motion
Self-Mutilation
Patient Health
What patient health factors can significantly retard epithelialization?
- Uremia
- Steroid excess (Cushing’s or drugs) Steroids prolong the inflammatory phase and delay cutaneous wound healing
- Geriatric age (Decreased cutaneous perfusion, increased skin fragility, increases risk of infection)
- Malnutrition
-Methionine, cysteine and arginine all important
-Fatty acids (within cell membranes, vital for cell function)
-Vitamin C (collagen synthesis, cell mitosis and monocyte migration)
-Zinc and iron (enzymatic reactions)
What are the reported benefits of using a scalpel for a skin incision over electrocautery/CO2 laser/radiowaves?
Scalpel incisions have approximately twice the wound strength at 10-12 days post-op compared to electrocautery
* Produce less drainage with faster and stronger healing
* Char will penetrate the skin with other methods
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 10^5 CFU per gram of tissue or per mL of exudate, at which point the risk of infection increases dramatically.
List some differences between dogs and cats in regards to wound healing:
Generally speaking - cats heal weaker and you should leave their sutures in a little longer.
* 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 epithelialization
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
What are the (5) techniques for correcting dog ears?
A: Removal of 2 small triangles
B: removal of one large triangle
C: Extension of fusiform incision
D: Removal of arrowhead
E: Half-Z correction
What are (6) methods of prevention/correction of dog ear formation in elliptical 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 center to ends with dog ear removal
F - Lengthening the short side with half of a fusiform
