KEY NOTES CHAPTER 9: AESTHETIC SURGERY - Liposuction & Lipofilling.

Question 0

What is the fat distribution in the neck?

Answer 0

Supraplatysmal (subcutaneous).
- can liposuck

Subplatysmal.
- excise (safer) or lipo

Question 1

Describe the layers of subcutaneous fat.

Answer 1

3 layers

1. Apical
   - immediately deep to reticular dermis.
   - fat surrounds sweat glands, hair follicles, blood and lymphatics.
   - injury to this layer results in serum, erythema, pigment change and skin necrosis.
2. Mantle
   - columnar fat cells within vertical fibrous stroma.
   - not present in eyelids, nail beds, dorsal of nose or penis.
3. Deep
   - between mantle layer and deep fascia.
   - main target of liposuction.

Question 2

What is the fat distribution in the abdomen?

Answer 2

Camper’s fascia - fat within loose fibrinous network.

Scarpa’s fascia (lower abdomen) - sub-Scarpa’s fat.

Question 3

Where is fat distributed in the hips and flanks?

Answer 3

The superficial fascial system divides fat into superficial and deep layers.
Zones of adherence connect SFS to muscle fascia at:
- gluteal crease
- distal thigh
- males: iliac crest (deep fat confined to abdomen)
females: lower than iliac crest (deep fat around hips).

Question 4

Where is fat distributed in the lower leg?

Answer 4

• almost all fat is in mantle layer, with no deep layer.

Question 5

How are patients assessed for liposuction?

Answer 5

Skin quality, elasticity, striae, wrinkles, laxity, dimpling, scars, cellulite (tethering of fibrous septa on skin, may worsen after liposuction).
BMI.
Circumference.
Gentle pinching.
Hernial orifices (abdomen)
Intra-abdominal vs subcutaneous fat.

Question 6

How do you offer pre-op counselling?

Answer 6

• GA (LA).
• small incisions.
• compression garments postop 6wks.
• off work 1 wk.
• back to normal activity 4 weeks.
• up to 6 months for swelling to subside.
• can gain weight again.

Question 7

What are the complications of liposuction?

Answer 7

up to 20% patients are dissatisfied due to:
- over / under correction.
- asymmetry.
- visible ridges, pitting, cobblestoning, rippling.
- sagging / bulging skin
troublesome scars.
- seroma infection, contour irregularity

Early

• paraesthesiae, hypersensitivity, numbness (transient usually).
• PE, fat embolism or DVT.
• hypovolaemia / fluid overload (pulmonary oedema).
• lidocaine toxicity.
• intra-abdominal, retroperioteal perforation.
• bleeding
• burns, friction injuries
• severe infection (NF/TSS)

Late

• persistent contour irregularities.
• pigmentation changes.

Question 8

What different techniques of liposuction do you know of?

Answer 8

Dry - substantial bruising & blood loss.
Wet - 200-300ml infiltrate per area. <30% blood loss of the aspirate.
Superwet 1:1 - 1% blood loss, less associated risks.
Tumescent 3:1 (Klein) - <1% blood loss.

Suction assisted.
Power-assisted.
Ultrasound-assisted.
Radiofrequency-assisted.

Question 9

What types of wetting solutions do you know?

Answer 9

Klein’s solution

• 1L normal saline
• 500-1000mg lidocaine
• 0.65mg epinephrine
• 10mEq/l sodium bicarb.

Hunstadt’s solution

• 1L Ringer’s lactate
• 500mg lidocaine
• 1mg epinephrine.

Can use up to 35mg/kg lidocaine, be aware plasma levels peak 10-12hrs following this administration, and onset of toxicity may be delayed.

Question 10

Take me through a liposuction procedure.

Answer 10

• Patient is marked with concentric circles in upright position pre-op.
• Avoid zones of adherence (mark).
• make multiple stab incisions to allow cross-tunnelling and feathering.
  Pretunnelling
  Remove deeper fat first, then superficial if necessary with finer cannula with openings facing downwards.
  End-points of liposuction:
• symmetry, shape and contour.
• skin pinch <1 inch.
• equal amounts of aspirate from each side.

Question 11

Describe the different types of liposuction.

Answer 11

pg 569

Question 12

Tell me about the history of fat transfer.

Answer 12

Neuber (1893) - fat graft from arm to face.
Czerny (1895) - lipoma from buttock for breast recon.
Hollaender (1910) - fat injection for facial atrophy.
Coleman (1997) - ‘liposculpture’.
Zuk (2001) - ADSCs in fat.
Rigotti (2007) - therapeutic effects of ADSCs on irradiated tissue.

Question 13

What are the different cell types in adipose tissue?

Answer 13

1. Mature adipocytes - very sensitive to environment and trauma.
2. Preadipocytes - differentiate to mature adipocytes, fat graft survival largely dependent on their proliferation.
3. ADSCs - can differentiate into all mesenchymal tissues: fat, bone, muscle, cartilage, blood vessels.

2 & 3 are predominantly found in stream vascular fraction of lipoaspirate.

Question 14

What are the theories behind graft take?

Answer 14

1. Cell survival theory
   - some transferred adipocytes survive.
2. Host replacement theory
   - recruitment of host adipocytes at site of injection.
3. Niche theory
   - cell’s physiology is regulated by it’s microenvironment (e.g. cell-cell interaction, ECM< endocrine and paracrine hormones), so stem cells differentiate according to their niche / host site.

Question 15

Describe the process of lipofilling.

Answer 15

As standardised by Sydney Coleman.
1. Harvesting.
2.Refinement.
3. Placement.
With minimal trauma of small enough parcels of fat to inject and large enough to preserve tissue architecture.

Question 16

Describe the harvesting process.

Answer 16

• abdo / flanks / medial thigh donor sites are injected with infiltrate (1:1).
• blunt 3mm harvesting cannula is connected to 10ml Luer-Lok syringe with 2cc negative pressure applied when harvesting.

Question 17

Describe the refinement process.

Answer 17

plug is placed on end of syringe, plunger is removed and centrifuged at 3000rpm for 3mins.
3 layers are produced:
1. Supernatant: oil from damaged adipocytes.
2. Middle: fatty tissue.
3. Subnatant: removed by releasing plug.

Question 18

What other refinement processes have you heard of?

Answer 18

Sedimentation 
Filtration
Towel-processing
No-touch technique
Washing

Question 19

Describe the placement process.

Answer 19

Refined fat transferred to 1 or 3mm Luer Lok syringes, and injected with blunt cannulas.
Aim: to maximise contact between fat parcel and recipient tissues.
Coleman: in face, <0.1ml of fat infected for each passage of cannula.

Question 20

What are the possible complications of fat grafting?

Answer 20

• infection.
• swelling.
• bruising.
• over / under correction, contour irregularities.
• fat resorption, fat necrosis, calcification, oil cysts.
• intravascular injection -> fat embolus, PE, stroke, blindness.
• donor site morbidity.