Surgical Wound Healing Flashcards
- Involves epidermis and dermis w/o total penetration of dermis
- minimized scarring
- most surgical wounds healed by this
Primary Intention
- wound allowed to granulate
- process slowed by drainage from infection
- leaves big scar
Secondary Intention
- delayed primary closure
- wound cleaned, debrided, and observed 4-5 days prior to closure
- wound purposely left open
Tertiary intention
What hormone is decreased in response to injury?
TSH
-everything else is increased
What happens in the early phase of metabolic response to injury?
- dec body cell mass
- VASOCONSTRICTION -to conserve volume
- change in energy source
What are the stages of tissue healing?
- inflammation
- repair/fibroblastic
- remodeling
what factors are involved in the vascular and inflammatory phase?
- subendothelial factor VII
- hageman fator xii
- platelet derived growth factor
- histamine
what process is critical for a wound to be considered ‘healed’?
re-epithelization phase
what is the initial event of re-epithelization
-migration of undamaged epidermal cells from the wound edges
what is important for the migration of undamaged epidermal cells from wound margins?
water content because cells seek level of critical humidity
why do ulcers have a HPK rim?
there is increase in epithelial proliferation at wound margins
What is this?
- crosslinks with fibrin to provide matrix for cell adhesion and migration
- promotes phagocytosis
- forms scaffolding for collagen deposition
-Fibronectin
What is granulation tissue made up of?
- inflammatory cells
- fibroblasts
- new vasculature in hydrated matrix of glycoproteins
- collagen
- GAGs
What factors are involved in fibroplasia and matrix formation?
EGF-epidermal growth factor
MDGF-macrophage derived
PDGF-platelet derived
what are the processes of fibroplasia and matrix formation?
- differentiation of myofibroblast
- fibronectin crosslinks
- migration of myofibroblast
- type 3 collagen fibers on scaffold
what contracts in wound contraction?
-myofibroblasts and the attached surrounding tissue “fibronexus”
What is a fibronexus?
-intimate association between the membrane of myofibroblasts, intracellular actin and extracelluar fibronectin
What factors are involved in neovascularization?
- Fibronectin
- macrophage derived angiogenic factor
What is the initial event of neovascularization?
directed migration of endothelial cells
What is the process of neovascularization
- fragmentation of venule basement membrane
- endothelial cells develop pseudopodia
- pseudopodia protrude through the disrupted BM
- entire cell migrates into the perivascular space
-these are stimulated by hypoxic conditions
What factors are involved in matrix and collagen remodeling?
iron, copper, vitamin c
Processes of matrix and collagen remodelling?
Fibroblasts->procollagen->collagen
- collagen crosslinking
- fibronectin disappears
- water reabsorbed to allow collagen fibers to lie closer together
- Type 3 collagen replaced by type 1 collagen
Why is it important to manage your deadspace?
because it can fill with bacteria and cause hematoma formation
what is the consequence of ischemic tissue?
-decreases: cell proliferation, resistance to infection, and collagen production
What deficiency causes this?
-slow re-epithlization, decreased collagen synthesis, increased infection
vitamin a
What deficiency causes this?
-unstable collagen produced
vitamin c
-essential co-factor for collagen synthesis
which vitamin deficiency coincides with deficiency of clotting factors 2,7,9,10 and increased chance of hematoma
vitamin k
what deficiency causes this?
- impaired immune responses, decreased protein and collagen synthesis, interference with vitamin a transport
- dna/rna polymerases
zinc
What type of sutures are these?
- poly amide (nylon)
- poly ester (dacron)
- poly propylene (prolene)
synthetic non-absorbables
silk linen is a natural non-absorbable
what type of sutures are these?
- poly glactin (vicryl)
- poly glycolic acid (dexon)
- polyglyconate
synthetic absorbable
-catgut is natural absorbale
what are the characteristics of absorbable sutures?
- subq tissue
- eliminate dead space
- minimize tension on wound edges
- may spit if placed too superficially
-type of suture-
- absorbable braided synthetic
- homopolymer of glycolic acid
- hydrolytically absorbed
- good tensile str, excellent knot security
- 2 week duration, 65% of tensile str remains
Polyglycolic acid
-Dexon
-type of suture-
- synthetic heteropolymer
- braided, multifilament, coated
- hydrolytically absorbed
- stronger than dexon
- can be impregnated with antibiotic triclosan
Polyglactin
-vicryl
-Type of suture-
- absorbable synthetic
- monofilament; glycolic acid and trimethylene carbonate
- 75% of original str at 2 weeks
Polyglyconate
-maxon
characteristics of non-absorbable sutures
used on skin
- deep suture to provide prolonged mechanical support
- should be tight enough to approximate not strangulate tissues
-type of suture-
- monofilament, dyed or undyed
- isotactic crystalline stereoisomer of polypropylene
- BLUE
- polypropylene
- prolene
which suture has lots of memory and lots of knot slippage
Nylon
which suture technique is used for longer wounds?
- very strong
- easier to evert edges
- less time consuming
- easier to strangulate skin edges
Horizontal mattress
Which suture is good for deep wounds?
- aids in reapproximation of deep tissue
- pretty good for keeping tension off skin edges
- harder to evert skin edges
Vertical mattress
Which suture is used to take tension off the skin edges and provide deeper and wider support to the healing incision
-hard to evert skin edges
retention sutures
which suture technique leaves a pretty to absent scar if done correctly and has a high rate of dehiscnece if not done properly?
subcuticular suturing
what is the treatment for hypertrophic scars?
cortisone injections
- decreases the level of collagenase inhibitors and increase collagen degradation
- kenalog 40 directly into the scar
when do you remove dorsal, medial, or lateral sutures?
and when do you removed plantar sutures?
14 days
21 days
