Primary wound closure

Question 1

What are the 3 vascular layers of the skin?

Answer 1

1. Superficial or subpapillary
2. Middle or cutaneous
3. Deep or subdermal/subcutaneous

Question 2

What is a cutaneous angiosome?

Answer 2

A region of skin supplied by a direct perforating cutaneous artery

Question 3

What are the primary differences between the vascular supply to the skin in the dog and cat?

Answer 3

The dog has greater collateral subcutaneous vasculature, the cat also has a smaller number and wider distribution of cutaneous perforating arteries.

Question 4

What are the different classifications of wound healing?

Answer 4

1. Primary closure or first intention healing.
2. Delayed primary closure: 2-5 days after wounding, before granulation tissue.
3. Secondary closure: after granulation tissue.
4. Second intention healing.

Question 5

What is the rate of reepithelialization in a closed wound?

Answer 5

1mm/d. This may create an epithelial seal within 24-48 hours.

Question 6

What is the strength of wounded skin at 14 days, 3-4 weeks, and several months post-op?

Answer 6

14 days: 5-10%
3-4 weeks: 25%
Several months: 70-80%

Question 7

What are the primary differences between cats and dogs when it comes to wound healing?

Answer 7

Cats had half the wound strength at 7 days compared to dogs, cats had decreased perfusion at 7 days, open cat wounds seem to heal more by contraction around the wound edges as compared to central pull in dog wounds

Question 8

How does removal of the subcutaneous tissues effect wound healing?

Answer 8

Reduced perfusion. Interestingly no change in healing in primarily closed wounds in 1 study

Question 9

What are some factors that may influence wound healing?

Answer 9

Tension, motion, self-mutilation, patient health (inflammation, age, malnutrition)

Question 10

How does age impact wound healing? How does malnutrition impeded healing?

Answer 10

Geriatric patients have decreased cutaneous perfusion, increased skin fragility and increased infection risk.

Malnutrition impedes wound healing by delayed neovascularization, decreased collagen synthesis, prolonged inflammatory phase, decreased mechanical skin strength.

Question 11

Is scalpel incision or electrocautery or laser preferred for skin incision in dogs and cats?

Answer 11

Unclear. Scalpel shown to have 2 x wound strength compared to electrocautery at 10-14 days in experimental study. Human review demonstrated less pain when electrocautery used. Char is a consideration with electrocautery and laser (~2mm of char formation).

Question 12

What is the golden period in wound healing?

Answer 12

3-6 hours, which is considered the time taken for bacteria to proliferate to 10 to the 5 per gram

Question 13

How long does it take for degree of tissue necrosis in wounds sustained in crushing trauma to become fully established?

Answer 13

3-7 days

Question 14

Describe the relative knot security of various sutures commonly used in closure

Answer 14

Question 15

What suture material is recommended for subcutaneous closure?

What about cutaneous closure?

Answer 15

Monofilament absorbable swaged onto a 1/2 circle taper needle.

Monofilament nonabsorbable swaged onto a reverse cutting 3/8 circle needle.

Question 16

In what areas should tacking sutures be avoided?

Answer 16

In locations were the subcutaneous tissues must move freely, such as over the thorax.

Question 17

Describe the different common cutaneous suture patterns.

Answer 17

Question 18

Was tissue reaction higher in dogs undergoing OHE with skin closure via intradermal pattern with Monocryl or interrupted cruciate sutures?

Answer 18

Intradermal pattern resulted in greater tissue reaction at 18-24 hours, but by 10-14 days had lower wound scores.

Question 19

What are two suture patterns that can be used to correct small dog ears (2cm or smaller)?

Answer 19

Apex cutaneous suture or dermal oblique horizontal mattress

Question 20

What is a step defect?

Answer 20

When wound edges are not apposed in a level fashion, often resulting in delayed healing.

Question 21

What are the displayed techniques for correction or prevention of dog ears in crescent shaped defects called?

Answer 21

Question 22

Describe techniques for dog-ear removal.

Answer 22

Question 23

What is the mechanism of action of lidocaine and bupivicaine?

Answer 23

Sodium channel blockers.

Question 24

What are the proposed effects of therapeutic lasers on primary wound healing?

Answer 24

Enhance leukocyte infiltration; increase growth factor and macrophage activity, neovascularization, and fibroblast and keratinocyte proliferation; promotion of early epithelialization.