Flashcards in Autologous fat transfer (AFT) Deck (95):
Autologous fat transfer can be used to correct soft tissue defects and rhytides, in addition to skin atrophy associated with ageing.
It is essential to overcorrect when performed autologous fat transfer.
Small volumes preferred.
Autologous fat transfer has no potential for infectious disease transmission
Autologous fat transfer follows the patient’s anatomical landmarks by placing fat within or adjacent to facial muscles.
this is Fat autograft muscle injection (FAMI)
Rejuvenation of the dorsum of the hands is an indication for Autologous fat transfer (AFT)
usually 10mls per hand injected
although Coleman recommends 20–30 mL per hand
Potential complications of fat transfer are generally unavoidable.
Avoid by careful, sterile technique.
Autologous fat is harvested by gentle syringe aspiration then is universally directly injected into subcutaneous fat or muscle.
Often rinse or centrifuge prior to reinjection.
The transplanted fat becomes ischaemic following transfer to the recipient site.
Volumes of autologous fat up to 5mm diameter have optimal viability.
A volume of 20-100mL is needed to restore full facial volume.
this vol is not feasible with synthetic fillers
The outer thigh is often used for fat harvesting due to its non-fibrous nature and relative avascularity.
avascular fat may survive the transfer process better
Lignocaine has been reported to have negative effect on fat cell viability
But recent studies suggest it is better than other local anaesthetics and it is widely used
Normal saline, Klein’s solution or Ringer’s lactate can be used in fat harvesting.
Used to minimise contact with lignocaine and enhance fat cell viability.
Fat cells can be harvested by syringe, machine aspiration, or direct excision.
All techniques have similar fat cell viability.
Syringe aspiration with high negative pressures is the harvest technique most often recommended.
Low negative pressures.
pressure of 700mmHg or higher can cause partial rupture of fat cells
Gentlest harvesting is reported using 10mL syringes to minimise vacuum pressures with the plunger held back no more than 2-3mL.
some use larger syringes.
dont use needles less than 18 gauge as may disrup the adipocyte
The first step after fat harvesting is to stand syringes upright for 15-60 minutes to allow separation into supra- and infra-natant fractions.
After fat harvesting, the supranatant fraction is decanted off and discarded.
This is the fat to be transplanted.
infranatant is discarded and often the oil fraction on top is too
After separating the harvested fat, it can be washed with saline or Ringer’s lactate to remove lignocaine and blood.
Blood has no effect on phagocytosis of fat cells.
Stimulates phagocytosis so should avoid injecting blood with the fat
Centrifugation can be done as an alternative to rinsing harvested fat.
Centrifugation concentrates fat cells, resulting in a larger number of cells per mL of volume transferred.
removes blood products, proteases, free lipids, and lipases which may degrade freshly grafted adipocytes
When 10mL of fat is centrifuged at 3600rpm for 1-3 minutes, there is approximately 5-10% of the volume separated at the bottom as infranatant
Centrifuged fat may result in improved longevity and aesthetic results compared to non-centrifuged fat.
The most common placement for transplanted fat is within the subcutaneous fat.
When injecting harvested fat, overcorrection of 30-50% should be made to allow for fat degradation.
Minimal or no overcorrection.
Postoperative oedema is not directly related to the amount of fat transferred.
Anterograde injection with gentle pressure should be performed for fat transfers.
Retrograde – reduces risk of intravascular injection and injection of large fat bolus.
1 to 10 mL syringes can be used for fat injections.
smaller fat particles are dispensed if a smaller syringe is used and the pressure required is less with small syringes
Prolonged air exposure negatively impacts fat cell viability.
use female to female adaptor to transfer to syringes of different sizes without exposure to air
Blunt-tipped cannulae should not be used for fat transfer.
Can be used.
Also can use 14-25G needles
(some suggest not using needles smaller than 18g same as the rule for fat extraction)
unclear if any difference in bleeding risk or tissue trauma whn needles or cannulae used
The most common indications for fat augmentation of the face include the nasolabial fold and the marionette fold.
Other areas of the face that can be treated with fat transfer include the cheeks, malar area and chin.
Body areas which can be augmented with fat include the dorsal hands, buttocks, biceps, calf and breast.
There are no additional risk factors associated with fat augmentation of the breast.
F Calcifications may develop post operatively which can mimic breast ca.
Defects for disease or trauma can be treated with fat injection.
T Eg. acne scars, LE scars, cellulite.
Lipostructure ™ refers to full-face three-dimensional enhancement of youthful contours.
Using the Lipostructure ™ technique, minute quantities of fat are all placed within the subcutaneous tissue plane.
Placed in multiple planes eg adjacent to bone, fascia and muscle as well as subcut
Using the Lipostructure ™ technique, each droplet of fat is placed 'Within 1.5mm of living vascularised tissue'
30-40 injections (passes) per ml injected and over 100mls injected in a whole face
Using the Lipostructure ™ technique, there is often marked oedema for weeks or months post-operatively.
The method of ‘fat rebalancing’ involves the use of smaller procedures over a 1-2 year period.
uses similar laborious layering as lipostructure
also microliposuction of jowls or other areas
Fresh fat must be harvested at each visit for the method of ‘fat balancing’.
Can use frozen fat for subsequent visits.
Using the ‘fat rebalancing’ method, the entire face is treated with smaller total quantities (20-30mL).
Lipostructure ™ often exceeds 100mL in one procedure
The downtime after ‘fat rebalancing’ is 1-10 weeks.
F 1-10 days.
With the ‘fat rebalancing’ method, fat is placed exclusively in the subcutaneous space.
Microliposuction of hypertrophied fat areas can be performing during ‘fat rebalancing’.
An abundantly vascularised recipient site for transplanted fat will result in optimal survival of the fat.
FAMI refers to the technique of injecting fat into or immediately adjacent to the muscles of mastication
muscles of facial expression.
Volumes used for FAMI are similar to those of the Lipostructure ™ technique.
FAMI uses 70ml for full face and 20-30ml for partial face corrections
FAMI utilises a set of blunt-tipped cannulae which are curved and angle to conform to the skeletal contours of the face.
The FAMI technique has more apparent trauma that the Lipostructure ™ and ‘fat rebalancing’ techniques.
Less trauma as fewer passes with syringe
With FAMI a 1mL syringe is emptied in 1-3 passes (cf 30-40 with other techniques).
With FAMI, the fat is placed along vectors which parallel blood supply, minimising trauma to the vessels.
Patients have a downtime of 2-3 weeks after FAMI.
The FAMI method of fat transfer can have a longevity of 3-5 years.
FAMI is the preferred technique for treating localised volume loss on the lips.
FAMI should not be used after rhytidectomy.
Ideal for pts after rhytodectomy who have thin taut skin.
With the FAMI technique, the cannula is directed to the origin or insertion of the muscle, and fat is injected in a retrograde fashion with low injection pressure.
There is a second step in the FAMI technique which consists of supraperiosteal injections of highly centrifuged fat.
The postoperative course of FAMI typically consists of significant pain, bruising and oedema.
Usually unremarkable post-operatively.
downtime 7-10 days for full face and 3-5 days for partial face
Re fat transfer longevity, poor results are often seen in the lip.
most mobile region of face
Ongoing ageing and/or weight loss of patients generally does not require touch-up fat transfer procedures.
The use of frozen fat in transfer procedures results in an inferior outcome.
Results can be equal or better.
The complication rate is low with all fat augmentation techniques.
Fat augmentation of the face does not require nerve blocks.
The infraorbital area is most prone to overcorrection with fat augmentation
The infraorbital area should be treated using only minute quantities with low injection pressure
Visible superficial nodules may develop if the infraorbital area is overcorrected, or if too much fat is injected superficially
There is no way to treat overcorrection with fat augmentation.
F Low-dose steroid injection, massage, excision.
Weight loss or gain does not affect the result of fat augmentation.
Fat hypertrophy can occur with weight gain.
Patients undergoing fat transfer should be screened for concomitant, recurrent or chronic infections.
T Eg. sinus, dental or ocular regions.
Prophylactic antibiotics are not routine for fat transfer procedures.
Generally recommended in all patients to start day before for 7 days
eg cephlex 500mg BD or mino if pen allergic
Fat augmentation should be carried out as a sterile procedure
The most serious potential complication of fat augmentation is vascular occlusion caused by inadvertent intravascular injection.
Blindness has not been reported following fat injections.
has been reported after glabella and NLF injections
Occlusion or emboli are rare complications of fat transfer.
It is safe use sharp instrumentation and 10mL syringes with high injection pressures during fat transfer.
Should use blunt-tipped cannulae, low injection pressures, 1mL syringes to minimise the risk of intravascular injection
Retrograde fill reduces the risk of intravascular injection.
If there is evidence of vascular compromise during fat transfer, you should place the patient in Trendelenburg position, apply nitroglycerin paste and massage the area until the flush returns to the skin.
There are no additional side effects reported with intramuscular fat injection, compared to subcutaneous injection.
Potential dysfunction of facial muscles reported
The masseter muscle is injected in the FAMI procedure.
Longest survival after AFT when the recipient site is relatively immobile
Sites including scars of linear morphea, the forehead, infraorbital area
Future advances in fat transplantation lie in injection of preadiposites
T These are fibroblast-like fat cell precursors that are present in adipose tissue; survive ischemia better than mature adipocytes
Adipocyte stem cells are known to release angiogenic growth factors
T Has been used in clinical studies in patients with Perry Romberg disease
Potential complications of all fat transfer techniques include nodule formation due to overcorrection, fat necrosis, infection, and vascular occlusion
grafts of diameter 3.5mm or more get central necrosis with only a rim of viable fat cells at the periphery
AFT is only used on the face
other sites include buttocks, biceps, breast and calf and dorsal hands
Fat transfer into the breast can cause calcifications radiographically resembling those in breast cancer
Calcifications differ radiographically from those caused by breast cancer
but may still need biopsy
Centrifugation of the fat is a controversial factor in fat cell survival
Choice of harvesting site
Degree of negative pressure during harvesting
Diameter and type of harvesting cannula
Exposure of fat cells to air, blood, or lidocaine
Rinsing the fat
Vascularity and mobility of the recipient site
Diameter and type of injecting cannula or needle
Freezing fat for later use
lumpiness has been noted with centrifuged fat injected in breast, thigh or buttocks
some use non-centrifuged fat at these sites to avoid this
Pseudomonas has been cultured from centrifuges used for fat
must use sterilized canisters or sleeves within the centrifuge
Mephyton or arnica may be prescribed to minimise post op bruising in fat transfer
Transferred fat volumes tend to decrease with time
But increase has been shown in HIV pts between 2nd and 12th months
Longterm fat survival of 50-60% is achievable
Touch up procedures are common either due to need to split the initial treatmnet over multiple sessions or to replace volume loss with time or because pts want a fuller look