Lecture 4: Surgical Skills Flashcards
What is a clean wound and how is it closed?
- Uninfected, no inflammation, no systemic tract (resp/GI)
- Closed by primary intention and no drainage.
What is a clean contaminated wound?
- Systemic tracts are entered under controlled conditions without contamination
- Ex: lung surgery, appendix, vaginal
What is a contaminated wound?
- Open traumatic wound
- Operations with spillage from GI/GUbiliary tracts
- Break in aseptic technique (open cardiac massage)
Infection can occur within 6 hours of contamination
What is an infected wound?
- Heavily contaminated/infected wound PRIOR to operation
- Ex: Perforated viscera, abscesses, necrotic tissue
What is primary intention?
Optimal closure method with no edge separation and minimal scar formation.
What are the 3 phases of primary intention?
- Inflammatory (hemostasis => extravasation) + increased tensile strength
- Proliferative (day 3, collagen matrix + increasing tensile strength)
- Remodeling (lasts for a year+, area turns paler and devascularization)
What determines tensile strength and wound healing in the inflammatory phase of primary intention?
How approximated edges are by suture material
What is wound contraction?
- Wound edges pulling together.
- Good in buttocks/trochanter
- Bad in hand, neck, or face, which can be reduced via skin grafting.
When is tensile strength greatest in primary intention?
10 weeks, at which point it is around 80%
When does secondary intention occur?
Wound fails to heal by primary intention
What is the concern with secondary intention?
Excessive granulation tissue, which may prevent epithelialization and require additional tx.
When is delayed primary closure used?
Contaminated and infected wounds with high tissue loss and risk of infection
How is delayed primary closure achieved?
- Debridement of nonviable tissue
- Leave wound open with packing/vacuum system
- Wound approximation within 3-5d of no infection
- If infection present, leave to secondary intention
Needle shapes image
Image of 5 needle points
What is the goal when choosing a suture needle and what is generally the MC?
Alter tissue to be sutured with as little as possible, usually with tapered/non-cutting needles.
Generally, taper for delicate, reverse for skin/tough
When should taper needles NOT be used?
Skin, which is dense and may bend the needle.
Otherwise taper is good.
What is the preferred cutting needle?
Reverse cutting
Good for skin, whereas taper is not.
What are the pros/cons of a memory/nylon/PDS suture?
- Pros: Returns to previous shape when deformed.
- Cons: Difficult to tie and unravel
What are the pros/cons of elasticity/monofilament sutures?
- Pros: Returns to original length once stretched
- Mainly used for edematous tissue
What is knot strength?
Force required for a knot to slip.
Surgeon’s knots are used when ligating
What are the 3 monofilament sutures and their features?
- PDS, Monocryl, Nylon
- Less traumatic due to less friction
- Lower rates of infection
- More likely to slip, requiring 5-6 throws vs 3 for multi
- Preferred for skin closure
What are the 2 multifilament sutures and their features?
- Vicryl and silk
- Easier to handle and tie, less likely to slip.
What are the non-absorbable suture materials?
- Natural: Silk (braided)/cotton/steel
- Synthetic: Prolene (mono), Ethilon (nylon-mono)
Left in place indefinitely or removed once adequate healing occurs.
What are the absorbable suture materials?
- Natural: catgut, collagen-based for 1 week.
- Natural: chromic catgut: collagen + chromium, take 3 months to breaht down.
- Synthetic: Vicryl is degraded by water, minimal reaction by tissue compared to catgut.
Catgut used on face commonly.
Monocryl and PDS are also broken down by hydrolysis.
Summary of absorbable suture materials
How is suture size scaled?
0 to 12/0
0 is largest, 12 is smallest.
They had to add on numbers as we got better technology, so higher number = smaller suture
Suture Removal Timings
- Face: 3-4d
- Scalp: 5d
- Trunk: 7d
- Limb: 7-10d
- Foot: 10-14d
You need more tensile strength in feet
