plastic surgery
TRANSCRIPT
Plastic Surgery
Plastic surgery principles.
Optimise wound by adequate debridement or resection
Wound or flap must have a good blood supply to heal
Place scars carefully – ‘lines of election’a
Replace defect with similar tissue – ‘like with like’b
Observe meticulous surgical technique Remember donor site ‘cost’ a:Lines of election – analogous to Langer’s lines of minimal skin tension. b: Millard DR. Principalization of plastic surgery. Boston: Little & Brown,
1986
Skin
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 appendages (hair,
nails, sweat & sebaceous glands)
Skin
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 vessels and sweat gland activity)
Schematic showing two neighbouring angiosomes. Note the choke vessels within the muscle spanning the two cutaneous territories of angiosome A and B – two common examples of myocutaneous flaps which utilise this physiology include the rectus abdominus and the latisimus dorsi flaps.
SKIN: Anatomy
SKIN: Anatomy
DefinitionsGraft
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.
“Grafts are tissues that are transferred without their blood supply, which therefore have to revascularise once they are in a new site.”
FlapAny 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.
“Flaps are tissues that are transferred with a blood supply. They therefore have the advantage of bringing vascularity to the new area”
Graft vs. FlapGraft
Does not maintainoriginal blood supply.
FlapMaintains original
bloodsupply.
Classification of Grafts1. 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.
Classification :
•According to their donor sites & thickness:
Thin intermediate. Thick
Xenograft AllograftAllograft
Types of GraftsGrafts 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.
Different type of skin graft depending on the thickness of graft
Type of Graft Advantages DisadvantagesThin Split Thickness
-Best Survival-Heals Rapidly
-Least resembles original skin.-Least resistance to trauma.-Poor Sensation-Maximal Secondary Contraction
Thick Split Thickness
-More qualities of normal skin.-Less Contraction-Looks better-Fair Sensation
-Lower graft survival-Slower healing.
Full Thickness
-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.
Skin Grafts: “Process of Take” 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
Skin Grafts: “Process of Take” Inosculation & capillary ingrowth:
At 48 hrs Through fibrin layer Capillary buds from recipient bed contact graft
vessels Open channels (neo-vascularization) pink graft
Skin Grafts: “Process of Take” 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)
Skin Grafts: “Process of Take”
Skin Graft Take 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
Skin Graft Healing 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
Skin Graft HealingContraction:- 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
Skin Graft Healing Reinnervation:
from margins to bed;
Depends on graft thickness and bed;
Uneventful healing leads to near normal;
Cold sensitivity can be a problem
Skin Graft Expansion 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
Skin Graft Expansion Meshing
- covers large area- easier to contour- fluid can drain through holes- cosmetic results less than ideal - various mesh ratio
Meshed graft or sheet graft :
AdvantagesLager areaContours irregular surface Drain blood & exudatesIncrease edges_______reepithilialization
DisadvantagesMuch of wound heal 2*______contracture Cobble stone appearance
Sheet GraftJ ointHandsface
Skin Graft Survival Meticulous technique Atraumatic graft handling Well vascularized bed Haemostasis Immobilization No proximal constricting bandages
Other Factors that Contribute to Graft Failure Systemic Factors
Malnutrition Sepsis Medical Conditions (Diabetes) Medications
Steroids Antineoplastic agents Vasonconstrictors (e.g. nicotine)
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
Contraindications: 1- Avascular recipient areas : - Cortical bone without periosteum - Cartilage without perichondrim - Tendon without paratenon2- Infection : a- heavily infected wound with copious
discharge(100 000 bact./ gram of tissue). b- Infection by Beta haemolytic
streptococcus
Donor SitesThe ideal donor site would provide skin that isidentical to the skin surrounding the recipient
area.Unfortunately, skin varies dramatically from one
anatomic site to another in terms of:
- Colour- Thickness- Hair - Texture
Donor Sites
Donor site for FTG 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
Harvesting Tools 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.
Mesh grafting
Contraction of the graft
LINEAR CLOSURE
SKIN GRAFT
SKIN FLAPS
FREE FLAPS
MYOCUTANEOUS /FASCIOCUTANEOUS
FLAPS
Flaps – a partially or completely isolated segment of tissue perfused with its own blood supply.
A vascularized block of tissue mobilized from its donor site and transferred to another location, adjacent or remote for reconstructive purposes.
May consist of skin, subcutaneous tissue, fascia, muscle, bone or viscera (e.g.. Omentum)
Reconstructive option of choice when padded and durable cover needed
Vary greatly in complexity… from simple skin flap to microvascular free flap
History of Flaps Origin in India -2500-1500 BC
Sushruta 800BC –forehead flap
Charak Samhita
Al-Zahrawi 10th century scholar
Branca family of Italy Sir Harold Gillies – work on facial injuries, modern
plastic surgery
Flaps Uses1. Replace tissue loss due to trauma or surgical
excision2. Provide skin coverage3. Provide padding over bony prominences4. Bring in better blood supply to poorly
vascularized bed5. Improve sensation to an area (sensate flap)6. Bring in specialized tissue for reconstruction
suchas bone or functioning muscle
Classification of Flaps Can be based on (five ‘C’ s)1. Congruity2. Configuration3. Components4. Circulation5. Conditioning
Congruity Local – immediately adjacent to defect
Regional – moved from adjacent region
Distant – moved from remote anatomic area
Pedicled – moved with intact tissue bridge for support
Islanded – no intact skin but moved under the skin for non contiguous defects.
Configuration By design and method of transfer1. Advancement
2. Rotation
3. Transposition
4. Interpolation
5. Pedicled
Components Skin flaps
Containing purely another component than skin e.g. muscle ,fascia ,bone ,bowel ,omentum etc.
Myocutaneous
Fasciocutaneous
Osteocutaneous
Circulation Random pattern flaps
Axial pattern flaps 1. Island axial pattern flaps 2. Free flaps
Conditioning Increasing flap safety – by enhancing its axiality
Used in older days
Invoking delay phenomenon
Classically done by cutting down on either sides of flap to be raised
It opens up choke vessels
Flap transferred 2-3 weeks later
Particularly useful in higher risk patients
e.g. Pedicled TRAM flap
SKIN FLAPS Use : 1.recipent bed with poor vascularity 2.coverage of vital structures ( to operate
later ) 3.reconstructing full thickness structures e.g.
eyelid ,cheek, nose, lip, ear etc. 4.padding bony prominences Disadvantage : it can’t sustain over contaminated
(infected ) bed. Types : 1.those rotating around a pivot point a)rotation b) transposition c)interpolation 2.advancement flaps a)single pedicled advancement b) V-Y
advancement c)bipedicled advancement
Muscle and Myocutaneous flapsMathes and Nahai classification
One vascular pedicle (eg, tensor fascia lata) Dominant pedicle(s) and minor pedicle(s) (eg, gracilis) Two dominant pedicles (eg, gluteus maximus) Segmental vascular pedicles (eg, sartorius) One dominant pedicle and secondary segmental pedicles
(eg, latissimus dorsi)
According to mode of innervation (Taylor)Type I – single unbranched nerve enters muscle.Type II- Single nerve, branches prior to entering.Type III – Multiple branches from same nerve trunk.Type IV – Multiple branches from different nerve trunks.
Affects suitability for functioning muscle transfer
Uses of muscle and myocutaneous flaps :1. Functional muscle flap for motor
reconstruction2. Sensate Myocutaneous flap for sensate
reconstruction3. Coverage of complex wounds4. Chronic vascular insufficiency5. Chronic radiation wounds6. Exposed or infected prosthesis
Local Flaps
Location of donor site
local flap
Pivotal (geometric)
flaps
rotation
transposition
interpolation
Advancement flaps
single pedicle
bipedicle
V-Y flaps
both
distant flap
pedicled
free
Local flapsAdvantages Best local cosmetic tissue match Often a simple procedure Local or regional anaesthesia option Disadvantages
Possible local tissue shortage Scarring may exacerbate the condition Surgeon may compromise local resection
Rotation Flap Movement is in the direction of an arc around
a fixed point and primarily in one plane. This is a semi-circular flap.
Transposition flap The rectangular flap is rotated on a pivot
point. The more the flap is rotated, the shorter the
flap becomes. Most commnly used in head and neck
Z plasty Creation of 2 triangular transposition flaps Length of both limbs must be same Angle may vary Uses : 1. Lengthning of scar2. Changing direction of scar into more
favorable one3. Interrupt scar linearity
Rhombic flaps Specially designed transposition flaps for
rhombic shaped defects Defect must have 60 and 120 angles
Bilobed flaps Another variation of transposition flap 2 transposition flaps sharing common pedicle First flap used to reconstruct defect ;second
used for donor site defect
Interpolation flaps Similar to transposition flap Difference is..pedicle rest over intervening
tissue Pedicle divided and inset at second stage after
revascularization E.g. median forehead flap, thenar flap
Advancement flaps Moved primarily in a straight line from the
donor site to the recipient site.
No rotational or lateral movement is applied.
E.g. rectangular advancement, V-Y advancement etc.
V-Y advancement flap Create a triangular-shaped flap with the base of the flap at
the cut edge of the skin where the amputation occurred. It should be as wide as the greatest width of the amputation
Skin incisions are made through the full thickness of the skin.
Advance the flap over the defected area and suture it to the nail bed.
Place corner stitches to avoid interference with the blood supply to the corners. Convert the V-shaped defect into a final Y-shaped wound
The V-Y pedicle plasty technique allows most patients to regain sensation and two-point discrimination in the fingertip.
The cosmetic results are usually excellent, with good contour and fingertip padding is preserved
Combined local flaps In some circumstances, such as burn
contracture release, local flaps can usefully be combined to import surplus tissue from a wide area adjacent to a scar or defect that needs removal.
Examples are the W-plasty and the multiple Y-
to-V plasty, which is a very versatile means of releasing an isolated band scar contracture over a flexion crease
REGIONAL FLAPS As the distance of required flap transposition
increases, the incorporation of a defined blood supply becomes critical.
Classified as axial, however most flaps have random pattern at their distal ends
Utilized to cover large defects which require
bulk Examples : 1. PMMF 2. DPF 3. Trapezius flap
Distant flaps
Pedicled flaps Distant flaps can be moved on long pedicles that contain the
blood supply. The pedicle may be buried beneath the skin to create an island
flap or left above the skin and formed into a tube. Moving flaps long distances while still attached are with a long
muscular pedicle that contains a dominant blood supply (a myocutaneous flap) or with a long fascial layer that likewise contains a major septal blood supply (a fasciocutaneous flap)
Free flaps With fine instruments and materials it has become commonplace
to be able to disconnect the blood supply of the flap from its donor site and reconnect it in a distant place using the operating microscope.
The free tissue transfer is now the best means of reconstructing major composite loss of tissue in the face, jaws, lower limb and many other body sites, as long as resources allow it.
Free muscle transfers should be reanastomosed within 1–2 hours.
Advantages Being able to select exactly the best tissue to
move Only takes what is necessary Minimises donor site morbidity
Disadvantages
More complex surgical technique Failure involves total loss of all transferred tissue Usually takes more time unless the surgeon is
experienced
Free-tissue donor sites
Principles of flap
surgery
Monitoring of the flapTissue colour
warmth and turgor
assess blanching capillary refill time.
• Seroma formation• Hematoma formation• Superficial skin necrosis • Wound separation with eventual
partial and/or complete flap loss• Fat necrosis• Donor site infection
Complications
Causes of flap failure
poor anatomical knowledge when raising the flap (such that the blood supply is
deficient from the start)
flap inset with too much tension
local sepsis or a septicaemic patient
the dressing applied too tightly around the pedicle;