plastic surgery

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;