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Facial rejuvenation, in the nasolabial folds, lips, brows,
lower lids, jaw line, blending of the lid-cheek junction
Nanofat: facial
Rejuvenation to improve collagen and elastin
regeneration to improve skin texture and elasticity.
Inhibit melanin synthesis to improve skin pigmentation.
FAT GRAFTING TECHNIQUE
HARVESTING
Coleman technique
Method used to harvest macrofat.
3-mm incisions.
Blunt tip attached to 10-mL Luer-Lok syringe.
Cannula pushed through harvest site as surgeon uses
manipulation to create gentle negative pressure by pulling
back on plunger (ie, 1-2 cc with a 10-cc syringe).
Plunger removed and syringe placed in centrifuge for
processing.
Different providers have variable preferences/beliefs about the
effect of amount of suction during harvest, length of canula, and
size of collection.
Harvest can be done with handheld syringe or suction-assisted
liposuction. Compared with suction-assisted liposuction,
handheld syringe lipoaspirates have higher adipocyte count and
viability with the dry technique. No differences observed when
the wet technique was employed.
*Using a larger cannula size to harvest fat increases
viability, whereas no differences were observed between
multiperforated cannula vs single port cannula.
Donor site with the highest efficacy is the abdomen and thighs.
Superwet or tumescent techniques have not been shown to
be detrimental on fat graft viability, as this excess fluid is
generally removed during the processing step. Alternatively,
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tumescent fluid can be injected after harvesting for hemostasis
and pain control.
PROCESSING
Optimized to increase the number of viable adipocytes, SVF,
and ASCs in fat grafting.
Coleman technique: lipoaspirate is loaded into 10-mL syringes.
Adipose tissue centrifuged at 3000 rpm for 3 minutes
(variable).
Centrifugation: separates aspirate based on density.
Separated into the oil layer (top), adipose tissue, infranatant
(bottom), which includes blood, water, aqueous solution, or
tumescent.
Blood and tumescent fraction drained from the bottom layer
and the oil is decanted and wicked with a cotton pledget for
3 minutes from the top layer.
High-density fat contains greater concentration of SVF cells
and ASCs with greater graft take and regenerative
potential, first 1-3 cc of processed fat in the bottom of the
centrifuged syringe.
Telfa gauze rolling: removes excess fluids from the adipocytes
and cells. Results in large fat grafts with good structural integrity.
Sedimentation or gravity separation (ie, AquaVage, Red
Head): higher degree of resorption due to increase in fluid
retained in the process lipoaspirate.
Revolve: active filtration combined with washing and/or
centrifugation; closed system; an inline fat-processing system in
which lipoaspirate is harvested directly into a canister device
rather than a drain bag.
Puregraft: passive filtration combined with washing and/or
centrifugation; closed system; fat is harvested directly into a bag
and washed with LR.
LipiVage: used for smaller volumes; a filtration system within
the harvesting syringe, and the same syringe is used for
harvesting, processing, and lipofilling
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REINJECTION
Smaller gauge used than when harvesting.
Blunt tip allows less traumatic introduction (Coleman: 17-gauge
cannula with a 1-mL syringe, injecting tiny amounts with each
pass).
Fat should be placed with multiple passes laying down single
layer of fat and avoiding clumping.
Each injection should be a new tunnel creating multiple levels in
a three-dimensional manner.
*Reinjection speed plays a role in survival: slower
reinjection results in lower shear and higher cell viability.
If clump injected, flatten with digital manipulation.
Usually placed just under the dermis.
Augmentation over mandible and malar region should be
injected over periosteum to prevent nodule formation.
Possible methods to improve survival
Greater exposure of each adipocyte to vasculature.
Diffuse infiltration with multiple passes.
Small amount of placement per pass.
Large surface area of contact between fat and surrounding
tissue.
Pure fat.
*Graft soon after harvesting (ideally within 1-2 hours of
harvest).
Once you feel large open space with each pass, it is likely a
good indication to stop.
Three zones of healing among the adipocytes located in a
newly fat-grafted bed
Necrotic zone: innermost zone; no cells survive because of
hypoxia
Regenerating zone: revascularization starts from the
periphery toward the center
Most adipocytes in the regenerative and necrotic zones
die within the first 24 hours.
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Surviving zone: both adipocytes and ASCs survive;
outermost zone
OTHER CONSIDERATIONS
Special considerations for microfat grafting
Harvested either with a 2.1-mm cannula or macrofat
processed with several passes through two Luer-Lok
syringe with a 1.2- or 2.0-mm filter.
Can be injected more superficially given the smaller size.
Some surgeons inject subdermally to fill rhytids observed in
the forehead, glabella, lips, and neck.
Also used to blend the lid-cheek junction.
Special considerations for nanofat grafting
Processed from microfat through several passes through
two Luer-Lok syringes with a 1.2 and 2.0 filter followed by a
400 or 600 μm emulsifier to remove any adipocytes.
Enriched for SVF, ASCs, extracellular matrix proteins, and
growth factors.
Injected with a 27-gauge needle, microneedling, or
dissolved in a topical cream.
Injections can be carried out intradermally or subdermally
as there are no adipocytes and only SVF cells.
Graft survival and healing
Patients can have considerable postoperative edema due
to multiple passes with injection.
*In general, graft viability is 50%-80%. Survival rate
decreases with infection, trauma, and hypoxia.
Overcorrection needed to optimize results and account for
graft loss in the body but not in the face, as this is a
challenging problem to correct.
Final volume determined by:
Interactions between multiple cell types, including
ASCs, viable adipocytes, and necrotic adipocytes.
These cells stimulate maintenance of a set volume as
determined by the original composite of tissue
transferred into the wound bed.
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For most patients included in studies examining the effect
of fat grafting after thermal or radiation injury, an average of
two treatments are needed.
Often the second fat transplantation occurs 3 months after
the initial procedure.
SPECIFIC CLINICAL USES
Facial volume correction
Inject macrofat into the deep malar fat pad with an 18gauge blunt with 0.05 cc per pass.
Inject microfat into the upper lips and perinasal area with
16-gauge needle from stab incisions made on each side of
oral commissure. Inject into vermilion of lip to roll out
vermilion and give patient more red lip.
Periorbital rejuvenation: inject microfat along inferior orbital
rim in the plane close to the bone. Can inject nanofat into
the dermis over the lower eyelids.
Temporal rejuvenation: macrofat placed subcutaneously in
the plane above the temporalis fascia.
Breast augmentation
Generally appropriate for women who want a small
enhancement (~1 cup size) and likely requires serial fat
grafting to achieve the desired size.
Injection using 14-gauge Coleman side hole needle with
multiple sites of injection along inframammary fold.
Fat injected subcutaneously and not directly into the breast
tissue.
May lead to increased number of mammograms for cancer
surveillance.
Breast reconstruction
Fat grafting for primary reconstruction postmastectomy:
Pro: autologous reconstruction with no donor site
morbidity.
Cons: limited by donor fat availability, only small breast
volumes achievable (A/B cup), requires up to 6
procedures spaced at least 3 months apart to achieve
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desired breast size, radiation history tends to require
more sessions.
Mean total graft volumes range from 600 to 750 cc,
with ~200-300 cc per session.
Centrifugation most commonly used, with
sedimentation also reported.
Recipient site expansion methods include internal
expansion (internal expander deflated each session),
external expansion (BRAVA), or none.
Previous radiation predicts increased complications,
while mastectomy flap type does not.
Common complications include palpable lumps,
ulceration necrosis, and fat necrosis.
Fat-augmented latissimus dorsi flap
The latissimus dorsi flap provides inadequate volume for
breast reconstruction but can be augmented with fat
injected intramuscularly with multiple passes to increase
volume (eg, LIFT procedure).
Fat grafting occurs at the time of reconstruction with
subsequent grafting for insufficient volumes.
Other uses
Postlumpectomy deformity to improve contour.
Augment autologous-based reconstruction or improve
contour irregularities, such as softening the transition
between the flap and chest wall or improving areas of
fat necrosis.
In implant-based reconstruction, fat grafting can create
a more natural transition in the superior pole from the
implant to the chest wall; it can also improve animation
deformity.
Tuberous breast deformity.
Poland syndrome.
Gluteal augmentation: injection should be in the
subcutaneous tissue and never into the muscle as this
can cause fat embolism/death.
Cancer outcomes: clinical studies show no increase in
cancer recurrence when fat grafting is used in
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reconstruction.
COMPLICATIONS
*Fat embolism secondary to intramuscular injection of fat
for gluteal augmentation has resulted in death. Gluteal
augmentation with fat grafting should be performed in the
subcutaneous plane only, no intramuscular injections.
*Glabellar injection can cause blindness via retinal artery
occlusion or ophthalmic artery occlusion.
Skin necrosis.
Fat resorption and necrosis.
Irregularities.
Fat necrosis in breast cancer can lead to additional surveillance
studies.
Unknown risk in head and neck patients.
ADIPOSE-DERIVED STEM CELLS
Can be isolated from adipose tissue harvested either by
liposuction or by excision of tissue.
If harvested by liposuction, adipose tissue settles into two
layers.
Supernatant or processed lipoaspirate (PLA) layer:
consists of the suctioned adipocytes as well as their
surrounding endothelium and stroma.
The bottom layer or liposuction aspirate fluid: consists of
injected saline, erythrocytes, and denser pieces of the PLA
layer.
ASCs can be harvested from both layers; however, the
yield of adherent ASCs is significantly higher in the
adipocyte layer than in the liposuction aspirate fluid cells.
Terms for adipose-derived “stem cells” (ASCs):
adipose-derived adult stem cells, adipose-derived adult
stromal cells, adipose-derived stromal cells, adipose
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mesenchymal stem cells, lipoblast, pericyte,
preadipocyte, and PLA cells.
International Federation for Adipose Therapeutics
and Science reached a consensus: ASCs to describe
plastic-adherent, multipotent cell population.
Culturing of these cells eventually results in the
appearance of a relatively homogeneous population of
mesodermal or MSCs (usually after two to three
passages) after nonadherent cells from SVF are
washed away.
Beneficial impact of ASCs may be due to soluble
factors produced by ASCs rather than their
differentiation capability toward different mature
lineages.
ASCs secrete hepatocyte growth factor, vascular
endothelial growth factor, transforming growth factor-β,
insulinlike growth factor-1, basic fibroblast growth
factor, granulocyte-macrophage colony-stimulating
factor, tumor necrosis factor-α, interleukin-6,
interleukin-7, interleukin-8, interleukin-11, adiponectin,
angiotensin, and cathepsin D.
ASCs are mesodermal and can differentiate into
adipogenic, osteogenic, chondrogenic, myogenic,
cardiomyogenic, angiogenic, tenogenic, and
odontogenic lineages.
PEARLS
1. When harvesting fat for grafting, the goal is to reduce sheer
force on the adipocytes by using handheld syringe devices.
2. Graft soon after harvesting to increase cell viability.
3. Important to use many small passes or aliquots for laying fat
down to improve vascularity to fat grafts and decrease fat
necrosis.
4. Once recipient site for fat grafting feels like a large open space,
probably it is best to stop grafting.
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1.
2.
3.
4.
5. Rate of injection alters fat graft survival; faster injection speed
increases fat resorption due to injury to the adipocytes.
QUESTIONS YOU WILL BE ASKED
1. What is the 6-month viability of fat grafting?
Around 50%-80%.
2. Why is processing the lipoaspirate important?
Reduces resorption and the unpredictability of fat grafting.
3. What is the most common complication after fat grafting?
Resorption.
4. With fat grafting, why is it important for very small volumes to be
injected with each pass?
To promote maximal contact between graft and surrounding
bed.
Recommended Readings
Coleman SR. Structural fat grafting: more than a permanent filler. Plast
Reconstr Surg. 2006;118(3 Suppl):108S‐120S.
Gir P, Brown SA, Oni G, Kashefi N, Mojallal A, Rohrich RJ. Fat grafting:
evidence-based review on autologous fat harvesting, processing, reinjection,
and storage. Plast Reconstr Surg. 2012;130(1):249‐258.
Locke MB, de Chalain TM. Current practice in autologous fat transplantation:
suggested clinical guidelines based on a review of recent literature. Ann Plast
Surg. 2008;60(1):98‐102.
Strong AL, Cederna PS, Rubin JP, Coleman SR, Levi B. The current state of
fat grafting: a review of harvesting, processing, and injection techniques. Plast
Reconstr Surg. 2015;136(4):897‐912.
*
Denotes common in-service examination topics.
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7
Benign and Malignant Skin and
Soft Tissue Lesions
Naomi Briones
OVERVIEW
SKIN EMBRYOLOGY
Ectoderm: epidermis, pilosebaceous glands, apocrine glands,
eccrine sweat glands, nails
Mesoderm: dermis, Langerhans cells, macrophages, mast
cells, fibroblasts, blood vessels, lymph vessels, adipose cells
Neuroectoderm: *melanocytes, nerves, specialized sensory
receptors, Merkel cells
SKIN HISTOLOGY
Epidermis
Made up of five layers (superficial to deep): stratum
corneum, lucidum, granulosum, spinosum, basale
Keratinocytes: primary cell in epidermis
Starts in basal layer (stratum basale) and make their
way to surface to become a dead cornified layer
(stratum corneum)
Melanocytes: basal layer; protect against ultraviolet (UV)
radiation
Merkel cells: mechanoreceptors
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