4. EPIDERMIS
No blood vessels.
Relies on diffusion from
underlying tissues.
Stratified squamous
epithelium composed
primarily of keratinocytes.
Separated from the dermis
by a basement membrane.
protective barrier
(against mechanical
damage, microbe
invasion, & water loss)
high regenerative
capacity
Producer of skin
5. DERMIS
Composed of two “sub-
layers”: superficial
papillary & deep reticular.
The dermis contains
collagen, capillaries, elastic
fibers, fibroblasts, nerve
endings, etc.
mechanical strength
(collagen & elastin)
Barrier to microbe invasion
Sensation (point, temp,
pressure, proprioception)
Thermoregulation
(vasomotor activity of blood
6. Immunological surveillance
Most skin is thin, hair-bearing, has sebaceous
glands
Skin of palms/soles/flexor surface of digits is
thick, not hair-bearing, no sebaceous glands
Vascular supply confined to dermis
9. Graft
A skin graft is a tissue of epidermis and
varying amounts of dermis that is detached
from its own blood supply and placed in a new
area with a new blood supply.
Flap
Any tissue used for reconstruction or wound
closure that retains all or part of its original
blood supply after the tissue has been moved
to the recipient location.
11. 1. Autografts – A tissue transferred from one part
of the body to another.
2. Homografts/Allograft – tissue transferred from a
genetically different individual of the same
species.
3. Xenografts – a graft transferred from an
individual of one species to an individual of
another species.
12. Classification :
According to their donor sites & •
thickness:
Thin intermediate. Thick
Xenograft Allograft
Allograft
13. Grafts are typically described in terms of thickness or
depth.
Split Thickness(Partial): Contains 100% of the
epidermis and a portion of the dermis. Split
thickness grafts are further classified as thin or
thick.
Full Thickness: Contains 100% of the epidermis
and dermis.
16. Type of Graft
Thin Split
Thickness
Advantages
-Best Survival
-Heals Rapidly
Disadvantages
-Least resembles original skin.
-Least resistance to trauma.
-Poor Sensation
-Maximal Secondary
Contraction
Thick Split
Thickness
-Lower graft survival
-Slower healing.
Full
Thickness
-More qualities of normal
skin.
-Less Contraction
-Looks better
-Fair Sensation
-Most resembles normal
skin.
-Minimal Secondary
contraction
-Resistant to trauma
-Good Sensation
-Aesthetically pleasing
-Poorest survival.
-Donor site must be closed
surgically.
-Donor sites are limited.
18. Plasmatic Imbibition:
Initially graft ischaemic (24 – 48 hrs)
Fibrin adhesion
Imbibition allows the graft to survive this period
? Important for nutrition of graft
? Stops drying out
19. Inosculation & capillary ingrowth:
At 48 hrs
Through fibrin layer
Capillary buds from recipient bed contact graft
vessels
Open channels (neo-vascularization)
pink graft
20. Revascularization & fibrous attachment:
Connection of graft & host vessels via anastomoses
(inosculation)
Formation of new vascular channels by invasion of
graft (neovascularisation)
Combination of old & new vessels
(revascularisation)
Fibroblast proliferation: conversion of fibrin
adhesion fibrous tissue attachment (anchorage
within 4 days)
22. Appendages:
-sweating dependent on no. of transplanted
sweat glands & degree of sympathetic
reinnervation; will sweat like recipient site in
FTSG only
-sebaceous gland activity mostly in thicker
grafts: SSG usually dry & shiny
-hair grows from FTSG if well taken with no
complications
23. Initially white then pinkens with new blood
supply
Lymphatic drainage by day 6
Collagen replacement from day 7 to week 6
Vascular remodelling for months
24. Contraction:
- shrinks immediately due to elastic
recoil: – FTSG 40%; medium SSG 20%;
thin SSG 10%.
- secondary contracture as heals:
- FTSG remains same size after above
shrinkage;
- SSG will contract as much as possible;
- more dermis = less contraction
- ? Due to myofibroblasts
25. Reinnervation:
from margins to bed;
Depends on graft thickness and bed;
Uneventful healing leads to near normal 2PD;
Cold sensitivity can be a problem
26. Based on principle that wounds
reepithelialized from the periphery
Expansion provides larger areas from which
epithelium can grow
Larger areas can be covered with less skin
27. Meshing
- covers large area
- easier to contour
- fluid can drain through holes
- cosmetic results less than ideal
- various mesh ratio
28. Meshed graft or sheet graft :
Advantages
Lager area
Contours irregular surface
Drain blood & exudates
Increase edges _reepithilialization
Disadvantages
Much of wound heal with contracture
Cobble stone appearance
Sheet Graft
Joint
Hands
face
31. INDICATIONS OF SKIN GRAFT:
1 Skin loss:
- Post –traumatic
- Post surgical
- pathological process e.g venous ulcer
- Extensive burn
2 Mucosal loss:
- After excision of leukopakic patch in oral
cavity
- vaginal a genesis
32. Contraindications:
1 Avascular recipient areas :
- Cortical bone without periosteum
- Cartilage without perichondrim
- Tendon without paratenon
2- Infection :
a.heavily infected wound with copious
discharge(100 000 bact./ gram of tissue).
b. Infection by Beta haemolytic streptococcus
33. The ideal donor site would provide skin that is
identical to the skin surrounding the recipient
area.
Unfortunately, skin varies dramatically from one
anatomic site to another in terms of:
- Colour
- Thickness
- Hair
- Texture
35.
Post auricular skin
Upper eyelid skin
Supraclavicular skin
Flexural skin
Thigh and abdominal skin
FTG should be clear of fat
FTG sutured edge to edge while STG overlaps
the defect.
Use quilting / tie over
36.
Razor Blades
Grafting Knives (Blair, Ferris, Smith, Humbly,
Goulian)
Manual Drum Dermatomes (Padgett, Reese)
**Electric/Air Powered Dermatomes (Brown,
Padgett, Hall)
Electric & Air Powered tools are most commonly used.