Module 8 Flashcards
1
Q
In aesthetic surgery, give examples of the use of regenerative and stem cell based therapies.
A
Lipofilling Stromal regenerative cells Expanded stem cells Collagen induction agents Platelet growth factors' rich products
2
Q
Define regenerative medicine.
A
RM seeks to devise new therapies for patients with severe injuries or chronic diseases in which the body’s own responses do not suffice to restore functional tissue.
RM introduces novel methods and strategies to replace or regenerate cells, tissues or organs in order to restore and establish normal function.
REPAIR or REPLACE
3
Q
What strategies are used in regenerative medicine?
A
Cell-based therapies
Biomaterials
Scaffolds seeded with cells
New: nano-medicine, tissue engineering, rehabilitation sciences + social/ethical/environmental/legal issues
4
Q
What types of cells have been used in transplantation?
A
Autologous or allogenic mature functional cells (cell replacement)
Modified human cells (cell based gene therapy)
Stem cells
5
Q
Describe scaffolds.
A
Basic tool for cell transplantation
Made by natural or synthetic materials with diverse bioactivity and mechanical strength
Provides appropriate environment for cellular growth and organogenesis
6
Q
Describe tissue regeneration.
A
Repair of damaged tissues and cells via cell/tissue transplantation, excluding organ transplants
Tissue engineering achieves this by combining materials design and engineering with cell therapy
7
Q
Describe biomaterials.
A
Provides physical support for engineered tissues and powerful topographical and chemical cues to guide cells
Involves synthesis, processing and characterisation of novel materials, including polymers, proteins, glasses, cements, composites and hybrids
8
Q
What are the two categories of cell-based therapies?
A
- Cells for structural repair or replacement (e.g. cultured dermal fibroblasts for skin replacement, chondrocytes for cartilage replacement)
- Cells for correction of a physiological or metabolic problem - autologous vs allogenic
9
Q
What are stem cells?
A
Cells with the ability to:
- self-renew, perhaps indefinitely
- propagate without becoming malignant or aneuploidy
10
Q
Define totipotent
A
Able to produce any cell type including the germ line e.g. fertilised oocyte
11
Q
Define pluripotent
A
Able to give rise to many cell types of main 3 germ layers e.g. early embryonic stem cells
12
Q
Define multipotent
A
Gives rise to a limited number of cell types e.g. bone marrow stem cells
13
Q
Define unipotent
A
Gives rise to a single cell type e.g. skin stem cells
14
Q
What are the 2 origins of stem cells?
A
- Embryonic stem cells
2. Adult stem cells
15
Q
What are the 4 essential features of embryonic stem cells?
A
- Capacity to self-renew, perhaps indefinitely, without change of their genotype or phenotype
- Pluripotent (or even totipotent): have the potential to differentiate into any somatic cell lineage, including derivatives of all 3 germ layers
- Can contribute to every tissue type including germ line
- Able to form teratocarinomas (undifferentiated malignant tumours composed of tissues resembling derivatives of all 3 germ layers) when introduced into adult tissue
16
Q
What factors maintain pluripotency of ES cells?
A
Cytokine leukaemia inhibitory factor (LIF)
Intracellular proteins - p21 and p53
17
Q
What are iPS cells?
A
Recently discovered that transfection of 4 transcription factors Sox2, Klf4, Myc and Oct3/4 is sufficient to cause somatic, differentiated cells to re-enter the cell cycle and become pluripotent
18
Q
What are mesenchymal stem cells?
A
Non-haematopoeitic stem cells found in bone marrow that constitute part of the stroma cell population.
- Plastic adherence in cell culture
- Specific surface antigen expression
- Multi-lineage differentiation in vitro
Easily cultured with high rate amplification at short term
Exert paracrine effect - enhance ability of tissue to repair itself
19
Q
What are adipose-derived stromal vascular fraction?
A
A collection of heterogenous cells most notably stromal cells, endothelial and endothelial progenitor cells, haematopoietic cells and pericytes
20
Q
What are adipose-derived stromal cells?
A
Multipotent cells - adipocytes, osteoblasts, chondroblasts, other mesodermic lineages
Derived from stromal counterpart of AD-SVF
21
Q
Examples of autologous cell products
A
Epicel - permanent skin replacement product
Carticel - chondrocyte based treatment
22
Q
Disadvantages of autologous vs allogenic
A
Autologous:
- bespoke, limited issues with tolerance
- limited by type of tissue, condition of tissue and patient factors, such as age, condition
- scheduling requirements for industrial scale manufacturing
Allogenic:
- easier in use, time and cost effective
- on demand
- immunosuppression may be required
23
Q
Examples of allogenic cell products
A
Dermagraft and Apligraft - expanded cells from foreskin of donors. Minimal immune rejection.
24
Q
Define cell-based therapies
A
- The administration of living cells, other than transfused blood products to humans for therapeutic or preventative purposes
- The cells are ex-vivo manipulated (selected, expanded, modified etc) to achieve their intended medicinal function
- May be delivered in many ways - infusion, injection, surgical implantation, aggregated with biomaterials or medicinal device
25
How does differentiation level affect cell therapy?
Differentiated functional cells:
- Drug cells behaving as in vivo sources of molecular species needed by the recipient (insulin supplied by allogenic pancreatic cells)
- Adoptive immunotherapy (cells to target cancer cells/infection)
Stem/progenitor cells:
- Long term substitution of injured cells
26
What does ECM consist of?
1. Structural proteins (collagen, fibrillins, elastin)
2. Specialised proteins (fibronectin, laminins, integrins)
3. Proteoglycans (composed of protein core to which is attached long chains of repeating disaccharide units termed of glycoaminoglycans)
27
What is epithelial to mesenchymal transition?
The process by which the epithelium generates mesenchymal stem cells
e.g. mesoderm formation from epiblasts, delimitation of neural crest cells from the neural tube, invasion of endothelial cells intro cardiac region, in adults wound healing, metastatic cancers
28
What are the components of the cell microenvironment that have an affect on the behaviour of cells?
1. ECM
2. surrounding cells
3. cytokines, GFs, hormones and other bioactive agents around the cell that are secreted by autocrine, paracrine and endocrine mechanisms
4. Nano/microscale orientation and physical properties of adjuvant cells and the ECM
5. Mechanical forces caused by the organism itself or movement of bodily fluids such as blood
Microenvironment controls plasticity, proliferation, differentiation and apoptosis
29
What are some ethical considerations in the use of stem cells?
- Where are cells coming from? How is it harvested? - use of embryos and cadaveric fetuses
- Affordability and accessibility
- Research is costly and time-consuming
- Patients may continue bad lifestyle habits and behaviours as RM can cure diseases
- Caring for an ageing population if RM helps people to live longer
30
Describe the ageing process.
1. Bone resorption and remodelling - consequences for positioning and support of soft tissue overlap
2. Fat compartments volume loss and redistribution - deep fat compartments decrease and superficial fat compartments increase
3. Muscle atrophy - with age, muscles straighten and shorten due to reduction and redistribution of deep fat compartment. Muscle action is in more contractive state. Loss of muscle size and strength.
4. Collagen loss - along with reduced elastin and hyaluronic acid, leading to loss of dermal support.
31
What is the mechanism of action of PLLA?
PLLA is a synthetic polymer that is both biocompatible and biodegradable. When constituted with sterile water for injection, it is injected deep into SC tissues or on the periosteum where it stimulates fibroblasts to produce new collagen.
32
What are the contraindications of PLLA?
Hx of autoimmune disease
Keloid scarring
Active skin infection
Allergy to one of product ingredients or to lidocaine
Excessive steroid use within the last year
Adverse reaction to previous injectables
33
Important considerations for consultation (PLLA).
- Ensure pt fully understands how PLLA works
- Does not give immediate results, except for few days following treatment
- Weeks to months for full effects
- Obtain signed consent
- Clinical photographs (pre- and post-)
- Complications education
34
What is the craniofacial protocol for clinical photographing?
Straight AP
True lateral
45 oblique degree
35
Which areas of the face is PLLA treatment effective for?
```
Malar area
Eyebrow (deep injection in contact of bone)
Cheeks (pre-auricular area)
Prejowl sulcus
Chin area along the mandibular border
Under the DAO muscle
Mental fold
```
36
Which areas of the face should PLLA not be injected in?
Thin skin areas such as eyelids or crows feet
Hyperdynamic areas such as DAO, commissures, peri-oral area and peri-orbital area
Lips for volume
Forehead lines to avoid collagen hyper-stimulation due to lack of fat
Superior white lip to avoid collagen hyper stimulation due to lack of fat
37
Which areas of the face should special care be taken for when injection PLLA?
Temples (vessels, temporalis artery)
Tear trough
Nasolabial folds (arteries, reflux needed, insect slowly)
Pre-auricular area (presence of parotid gland, reflux needed)
Medio jugal fold
38
What is the product composition of SCULPTRA (PLLA)?
PLLA powder - 150mg
Carboxymethylcellulose
Non-pyrogenic material
39
What other required instruments for PLLA?
Sterile water for injection
Sterile syringe single-needle 5 or 10ml and 1 to 3ml
Sterile needles 25G (long or short), 26G (short)
Antiseptic
Lidocaine 1% or 2% with or without epinephrine
Mepivacaine
40
How is PLLA product reconstituted?
Product diluted - 150mg vial of PLLA is diluted in 9mls water for injection
Product hydration - Leave product to stand at room temperature for at least 24 hours
Addition of local anaesthetic - add 2mls of 1 or 2% lidocaine or mepivacaine, roll until a homogenous translucid suspension is obtained
41
How is PLLA prepared for injection?
Injection amount and interval schedule:
- Max 1 vial per side of face per session
- At least 4 weeks between treatments for young patients and 6 for old patients
Preparation of injection syringes:
- Clean rubber stopper
- Use a second 18G needle to withdraw the appropriate amount of suspension into 1 or 3 ml syringe
- Once ready to inject change needle to 25G or 26G
- Discard each needle/syringe with product after each patient
42
What is the PLLA injection technique?
Inject supraperiosteal (from deep tissue to supraperiosteal area)
Use fanning or cross hatching as per anatomical area with maximum of 0.3ml/cm2
In SC areas such as deep folds and depressions, injections should be parallel to the skin with a maximum of 0.1ml/cm2
43
PLLA - aftercare?
Massage treated area for 1 to 2 min before continuing to next area
After whole treatment, intensive massage for 5 mins
Pt must massage treated areas for 5 mins BD for 1 week (prevent nodule formation)
Pts can use skin cream to massage skin
Massage method - rotative, bi-digital intra-oral massage
44
What are the immediate complications of PLLA?
Bruising
Swelling
Erythema
Haematoma
Usually self limiting and will resolve spontaneously within a few days
45
What are delayed complications of PLLA?
```
Oedema
Non-visible but palpable nodule
Visible papules
Nodules
Granuloma
```
46
PLLA complications: Granulomas vs Nodules
Granulomas:
- Suddenly, 6-24 months after injection, at all injected sites at same times
- Growing to size of a bean, with skin discolouration, oedema
- Grow fingerlike intro surrounding tissue
- If untreated, disappear after 1-5 years
- Foreign body granuloma; particles or microspheres are scattered
Nodules:
- 1-2 months after injection, after swelling vanishes, single nodules, close to facial muscles, particularly in the lip
- Remain the size of a lentil or pea
- Well confined to fibrosis capsule
- Until absorption (or permanent)
- Particles of microspheres form aggregates
47
How to prevent papule / nodule formation in PLLA treatment?
- Reconstitute product at least 24 hours before treatment
- Increase dilution with 9mls
- Inject appropriate areas
- Do not inject too superficially, intradermally or in hyperdynamic areas
- Do not overcorrect
- Do not treat patients with autoimmune diseases or patients prone to diseases requiring interferon therapy
- Always massage after injection
48
What is treatment of non-inflammatory nodules?
- Could wait for spontaneous resolution (reassure, wait and follow up)
- Vigorous massage
- Treat areas in between with hyaluronic acid fillers to even out surface
- Invasive treatment: Use small gauge needle (26G or 30G) with saline or lidocaine to break up the nodule
- If fails to response, inject intralesional corticosteroids inside lesion (triamcinolone acetonide). Injection should not exceed 0.1ml per cm nodule for 1-3 times depending on size and response. Should be separated by 3 weeks. If no response 2-4 weeks increase volume of injection.
49
What is treatment of granulomas?
- First line: Doxycycline or Minocycline for 6 weeks, can be combined with intralesional injection of cortiocosteroids
- Second line: Intralesional injection of corticosteroids
- 5FU +/- intralesional injection of corticosteroids
- Third line: Immunomodulotherapy + oral steroids 7-10 days
- Very rare cases: surgical excision
50
What are the properties of fat that make is an ideal choice for soft tissue augmentation?
- Biocompatible
- Autologous - readily available, less chances of rejection
- Remains stable once grafted
- Non-toxic
- Resistant to infection once grafted
- Totally integrates at recipient site and no longer detectable
- Natural
- Can be placed in all layers (superficial and deep) in face, hands and other parts of body
51
According to Sommer and Sattler, the success of autologous fat transfer is dependent on several factors. What are these?
1. Survival of fat cells after harvesting
2. The role of anaesthesia in the donor site
3. The role of cannula or needle used in harvesting and injection
4. The role of blood in transplanted flat trauma during cleaning process
5. Exposure to air
6. Contamination of graft
7. Histological fate of reinfected fat
8. Durability of the correction
9. The relationship between longevity of augmentation and fat cell survival
52
What is Coleman's recommended harvesting procedure?
1. Harvest fat as intact tissue parcels - small enough to be inserted through a small cannula, large enough to maintain tissue architecture
2. Harvesting sites should be selected only to enhance body contour (Padoin et al - increased ASC in lower abdomen fat)
3. Use No. 11 blade scalpel (3- or 4-mm incision)
4. Introduce blunt infiltration cannula to distribute tumescent solution
5. Avoid super-west or tumescent technique during harvesting due to shearing forces that may break up fatty tissue
6. Fatty tissue harvested through same infiltration incision
7. Fat is harvested with 10ml syncing attached to 2-holed Coleman cannula with blunt tip
8. Larger syringes can cause damaging negative pressure
9. Combination of slight negative pressure and curetting action allowed parcels of fatty tissue to move thought cannula through Luer-Lok into syringe
10. Do not use plunger-locking device due to high negative pressure
53
Choice of solution depends on donor area and the projected volume of fat to be removed...
Smaller volume of fat harvest:local anaesthesia using 0.5% lidocaine with 1:200,000 epinephrine solution
Larger volumes of fat harvest:local anaesthesia with sedation using 0.25% lidocaine with 1:400,000 epinephrine
Under GA or epidural: Ringer's lactate with 1:400,000 epinephrine is infiltrated
Approx 1ml solution per 1ml fat to be harvested
54
What are the recommended steps to refine harvested fat?
1. After harvesting fat, remove cannula from syringe and replace with Luer-Lok plug
2. After sealing syringe, remove plunger from proximal end
3. Centrifuge syringe for 3 mins at 3000rpm to separate viable and non-viable components
4. Decant oil layer, drain aqueous component
5. Use porous paper/neuropads to wick off remaining oil (make sure material from wicks does not shred into refined tissue)
6. Refined, unwashed fat is transferred to 1ml Luer-Lok syringe for use
55
How to ensure fat graft parcels has access to blood supply?
Place fat grafts separated from each other with with host tissue in between - enable maximal contact with vascularised host tissues. Also facilitated graft anchoring preventing migration.
56
What is the product composition of Ellanse?
70% aqueous CMC gel-carrier
| 30% synthetic PCL microspheres
57
Describe the Ellanse particles.
25-50 microns
| Smooth and spherical in shape
58
What is the MOA of Ellanse?
1. Immediate filling effect from CMC gel carrier
2. Stimulation of collagen by PCL
CMC gradually resorbed by macrophages over a period of several weeks
During this time PCL microspheres stimulate neo-collagenesis to replace this volume
Initially type III collagen, as it matures replaced by type I collagen
(PCL not phagocytosed because of their large size)
59
What is PCL?
Bio-resorbable medical polymer that stimulates neo-collagenesis
60
How is PCL resorbed?
Hydrolytic bioresorption of PCL occurs in 2 phases:
- gel first, then microspheres
- results in both mass and volume of implant to remain intact
- bioresorption of microspheres starts and the PCL based filler is excreted through normal metabolic pathways at CO2 and H20
61
What are the contraindications of PCL/CMC?
Hx of autoimmune disease
Keloid scarring
Active skin infection
Allergy to one of product ingredients or to lidocaine
Excessive steroid use within the last year
Adverse reaction to previous injectables
Pts with compromised immunity
Pts/sites with multiple previous skin augmentation procedures, esp permanent implants
Pregnancy
Uncontrolled diabetes/metabolic syndromes
62
What is timeframe post-other treatments to have PCL/CaHA?
HA filler - 9-12 months
| Other collagen stimulating agents - 24 months
63
How does Ellanse come?
Ready-to-use syringes filled to 1ml or 0.5ml and packaged as:
1ml option - 2 pouches each containing a syringe of Ellanse filled to 1ml with 4 needles (27G)
0.5ml option - 2 pouches each containing a syringe of Ellanse filled to 0.5ml with 4 needles (27G)
64
What are the different types of Ellanse and how do they differ?
```
Ellanse S - 1 year
Ellanse M - 2 years
Ellanse L - 3 years
Ellanse E - 4 years
Ellanse Hands-S - 1 year
Ellanse Hands-M - 2 years
```
65
How is Ellanse diluted?
DO NOT DILUTE ELLANSE
- dilute jeopardises maintenance of correction at long term
- alters product characteristics
66
What is the injection technique for Ellanse?
- Inject slowly with gentle moulding after Tx to obtain desired cosmetic results
- Over correction not necessary as volume will increase over time
- 0.1-0.2ml boluses
- Deep dermal and subdermal (face)
- Superficial placement (hand)
- Subdermal injection - fine threads in retrograde manner creating channels in desired area
- Fanning and cross hatching recommended
67
Which areas can be safely injected with Ellanse?
```
Midface
Malar (cheek) augmentation and volumisation
Submalar augmentation
Nasolabial folds
Mental crease
Jaw line & pre-jowl sulcus
Hands
```
68
Special attention should be given when injection Ellanse into the follow regions:
```
Temporal volumisation
Lateral brow lift
Tear trough
Marionnette lines
Oral commissures
Peri-oral lines
Nose reshaping
Chin augmentation
```
69
Which areas should Ellanse NOT be injected in?
Lips
Glabella
Eyelids
70
How would you inject Ellanse into the nasolabial fold?
Subdermal
| 0.2-0.5mls per side
71
How would you inject Ellanse into the malar region?
Supraperiosteal along tear trough
Small boluses 0.1-0.2ml
Total: 0.6-1ml per side
72
How would you inject Ellanse into the prejowl sulcus and jawline?
Deep sulcus - find deepest zone and inject at oblique angle, supra-periosteal bolus (0.1-0.2mls) in 1 or 2 locations
Subdermal plane
0.5-1ml per each sulcus
```
Posterior part of jawline
Vectoring-like technique
Use 2 points of entry
0.02-0.03ml for each vector
Add small boluses for volume (for more square shaped jaw)
```
73
How would you inject Ellanse into the hands?
Mark anatomical structures
Superficial
1-1.5ml per side
74
How would you inject Ellanse into the marionette lines?
One finger inside side insert needle at upper part of sulcus
Subdermal plane, slightly medial to line
Fanning and cross-hatch technique
0.2-0.5mls
75
How would you inject Ellanse into the nose?
Add volume to depressed areas on nose, lift tip of nose, smooth out bridge irregularities or opening labio-columella angle
Place above perichondrium and periosteum
Fanning technique
0.5-1ml per side
76
How would you inject Ellanse into the chin?
Supraperiosteal on midline or on 2 point either side
| 0.5-1ml
77
How would you inject Ellanse into the tear trough?
Deep peri-osteal
Multiple boluses of 0.1-0.2mls
0.3-0.6mls per side
78
What is aftercare advice for Ellanse?
- May be some swelling, redness at injection site, itching and tenderness after treatment (transient)
- Practitioner should massage product but not required for pt to continue doing so
- Avoid makeup for 24 hours
- Avoid vigorous exercise, prolonged sun exposure and excessive heat for 3 days
79
What is best way to inject Ellanse?
Pre-periosteal - deep volume and lifting of structure
Subdermal fat - biostimulation and fine volume alteration
Small volume boluses (0.1-0.2ml) or small volume per line (0.05-0.1ml)
Avoid scratching periosteum with needle (come into contact with it then lift 1-2mm)
Can mix product with lidocaine 1%
Do not dilute Ellanse
Do not overcorrect
80
What are the main reported adverse events of Ellanse and what is the treatment?
Pain at injection site:
- If superficial inject at slower rate
- Deep then mix with lidocaine
- If SEVERE pain occurs then stop immediately
Ecchymosis/bruise:
- Simple analgesia
Secondary oedema:
- If no spontaneous resolution then treat with steroids
Nodule formation:
- saline + lidocaine injection
81
What is the product composition of Radiesse?
70% aqueous sodium carboxymethylcellulose gel-carrier
30% synthetic calcium hydroxyapatite microspheres
Particle size range of 25-45 microns
Smooth and spherical in shape
Identical in composition to human bone and teeth
82
What is calcium hydroxylapatite?
Biocompatible - found naturally in human body
| Injectable calcium hydroxylapatite is non-toxic, non-irritating and non-antigenic
83
What is the MOA of CaHA?
When deposited in contact with human tissue, CaHA provides immediate soft tissue augmentation due to its gel carrier component
Later on this is gradually resorbed and CaHA particles induce histiocytic and fibroblastic response --> neocollagenesis
Up to 78 weeks
Overtime CaHA particles are metabolised into calcium and phosphate ions and eliminated through body's normal excretory process (although does remain up to 3 years)
84
What were initial indications of Radiesse?
Oral/maxillofacial defects
Vocal fold augmentation
Radiographic tissue marker
85
What are the contraindications to having Radiesse treatment?
Hx of autoimmune disease
Keloid scarring
Active skin infection
Allergy to one of product ingredients or to lidocaine
Excessive steroid use within the last year
Adverse reaction to previous injectables
Pts with compromised immunity
Pts/sites with multiple previous skin augmentation procedures, esp permanent implants
Pregnancy
Uncontrolled diabetes/metabolic syndromes
86
What is pre-procedure advice before Radiesse treatment?
- Prophylactic antiviral for patients with a history of facial herpes
- Avoid aspirin, NSAIDs, warfarin and vitamin E as increased risk of bleeding
- Arnica, bromelain and 1% phytonadoine cream as prophylaxis against bruising
87
What is the injection technique for Radiesse treatment?
- Larger 27G needle
- Subdermal plane - subcutaneous space superior to peri-osteum or onto peri-osteum to augment bony skeleton
- Placement on periosteum will stimulate collagen in this area
- Inject slowly in retrograde manner, usining threading, fanning or cross-hatching techqnique + gentle moulding
- Also be injected as bolus in supra-periosteal level
- Over correction not necessary as volume will slowly increase over 10-12 weeks
88
For which facial areas are Radiesse treatment effective for?
- Malar and infra-orbital augmentation
- Nasolabial fold
- Oral commissure
- Marionette lines
- Mandible and pre-jowl sulcus
89
What is the aftercare advice for Radiesse?
- May be some swelling, redness at injection site, itching and tenderness after treatment (transient)
- Practitioner should massage product but not required for pt to continue doing so
- Avoid makeup for 24 hours
- Avoid vigorous exercise, prolonged sun exposure and excessive heat for 3 days
- Immediate ice placement no injected areas reduce and limit tissue oedema and ecchymosis
- Sleep upright for remainder of the day to reduce degree of oedema
- Follow up 2-12 weeks
90
What are the side effects of Radiesse?
Redness, swelling and bruising - self limiting
Nodule formation
Blindness by intravascular embolisation (nasal contour correction, retrograde arterial injection of fillers into ophthalmic arterial system, if injected pressure is higher than systolic arterial pressure)
Nasal alar and facial necrosis - Tx is aggressive debridement, wound care pulse dye laser therapy
Pain at injection site:
- Superfical - inject slower
- Deep - pre-periosteal, add lidocaine
- If severe pain then STOP immediately
Ecchymosis:
- Conservative, reassurance, analgesia, NSAIDs
91
What are the advantages of Ellanse?
1. Full encapsulation after 1 month - no foreign body reaction
2. Stimulates type 1 collagen
3. Long lasting results
4. Broken down safely by the body and excreted by kidneys (no toxic products)
5. Choice of durations
6. Volume is greater than that injected (by 20-30%)
92
What are the advantages of Radiesse?
1. No calcification or ossification
2. No foreign body reaction
3. Does not interfere with radiographic imaging
4. Low risk of migration
93
How is new tissue formed by Radiesse?
1. New collagen formation type 1
2. New elastin formation
3. Increased dermal cells - e.g. fibroblasts
4. Angiogenesis
94
What is the after care advice for lipofilling?
1. Place dressing over incision site to help with swelling and brusing
2. Cold packs can be applied in first 72 hours
3. Advise to alleviate all infiltrated sites
4. Light touch can help lymph drainage
5. NO deep massage
95
What are possible complications of lipofilling?
```
Damage to underlying structures
Intravascular emboli
Migration of fatty tissue
Donor site deformity
Recipient site deformity, irregularity, over-correcting
Infection
```
96
How do you minimise risk of fat embolism?
Infiltrate grafted areas with adrenaline to cause vasoconstriction
Perform injections slowly, withdraw with lowest force
Use blunt tip cannula for deep locations
97
What is platelet rich plasma?
A suspension of platelets in plasma with a platelet concentration that is higher than its concentration in the original blood sample that it was taken from
98
How are platelets collected?
Collected whole blood is centrifuged in a tube, syringe or pouch so that formed blood elements (erythrocytes, leucocytes and platelets) are separated according to their different densities.
PRP is then obtained by collecting the plasma phase and platelets, which have the lowest density.
99
What is PAW classification system?
Standardises classification of various PRP products
- P = platelet concentration
- A = activation process
- W = WBC concentration
100
What is the MOA of platelets?
- produced when cytoplasmic fragments of bone marrow megakaryocytic are released into blood stream
- 2 um, round or oval shaped, no nuclei
- Their cytoplasmic membrane contains organelles ans structures: mitochondria, microtubules, granules
- Alpha granules - haemostatic properties, GF, cytokines
- Dense granules - factors that promote plt aggregation (ADP, calcium, serotonin)
- Activation of plts causes discharge of granule content (function depends on content of granules, their activation, subsequent cascade pf events)
- Effect appears to be concentration dependent e.g. can act as anti-inflammatory or pro-inflammatory
101
How does plt function in wound healing?
Forms first fibrin clot
Degranulation to release GF (10 mins)
Continue to synthesis and release GF (over 10 days)
Supports proliferation, angiogenesis, collagen production
102
What are growth factors?
Proteins and polypeptides, which have an important role in cellular growth and functional processes e.g. wound healing, immune defence mechanism and regeneration
Active component of PRP
103
What are some factors isolated from alpha granules?
IGF 1 - chemo-attractor of endothelial cells, role in osteoblast differentiation
TGF beta 1 - chemotactic of macrophages, neutrophils and fibroblasts, complex role in wound healing and tissue regeneration
FGF 1 - angiogenesis + fibroblast proliferation
PDGF - coordinates fibroblasts proliferation and production of ECM
EGF - induces epidermal cell and keratinocyte differentiation
VEGF - angiogenesis + mitotic action on endothelial cells
104
What effect do ANTICOAGULANTS have on PRP?
Sodium citrate - ph 8.6
Acid-citrate-dextrose (ACD-A) - acidic
Acidity influences platelet functions -
- more acid higher fibroblast proliferation
- neutral pH higher capacity of GF
105
What effect does PLT CONCENTRATION have on PRP?
Lower plt concentrations not sufficient for cellular processes
Optimum concentration is 2.5x that of its concentration in original sample of blood --> optimum osteoblast and fibroblast proliferation
When concentration is 6x has an inhibitory effect on tissue healing --> deregulation and desensitisation of GF receptors
106
What effect does LEUKOCYTE PRESENCE have on PRP?
Controversial
- Neutrophils are active immune cells that secrete over 40 hydrolytic and proteolytic enzymes
- Harmful to tissue intending to benefit from PRP
- Leukocyte poor PRP better for wound healing as LRPRP contains pro-inflammatory cytokines
- Some other studies show antimicrobial properties of leukocytes is good for wound healing
107
What effect does LOCAL ANAESTHESIA USE have on PRP?
- LA has adverse effect on functional properties of plts
| - Lidocaine may inhibit plt aggregation
108
What is the use of PRP in aesthetic medicine?
Counteracts the effect of ageing on skin and soft tissue:
1. Autologous skeletal volumetric regeneration (structure support)
2. Autologous dermal and subcutaneous volumetric regeneration (filling defect)
3. Autologous epidermal rejuvenation (improved skin properties)
GFs introduced to tissue have potential ability to repair it by stimulating angiogenesis, cellular proliferation and altering the production and degradation of ECM
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What are the contraindications for PRP treatment?
Hx of autoimmune disease
Keloid scarring
Active skin infection
Allergy to one of product ingredients or to lidocaine
Excessive steroid use within the last year
Adverse reaction to previous injectables
Pts with compromised immunity
Chronic disease such as renal failure or cancer
Severe anaemia or conditions leading to poor plt count
Pregnancy/breast feeding
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How do you prepare PRP product?
1. Venepuncture - obtain amount of blood required into anticoagulant prepared tube (5-50mls)
2. Centrifugation - separate plasma and platelets from red blood cells via centrifugation
(several protocols)
3. PRP isolation - plasma layer contains both PPP (top) and PRP (bottom), separate the PRP by differential aspiration of desired product
4. Plt activation - adding calcium chloride or biological thrombin to stimulate plt release of GF and chemo-attraction molecules
5. Tissue application - deliver to relevant tissues by intra-dermal/hypodermal injection (or topical)
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What is the injection technique for PRP?
- Injected by any needle size
- Any level of human tissue from topical to deep supra-periosteal (intradermal, superficial, deep SC layer, periosteum)
- Inject slowly in retrograde manner using linear threading/fanning, cross-hatching. Massage not necessary.
- Injected as aliquots NOT boluses
- Over correction not necessary - effect takes 6-12 weeks
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Where can PRP be injected in the face?
Upper face:
- Temples
- Zygomatic area
Mid-face:
- Malar and infra-orbital augmentation
Lower-face:
- Nasolabial fold
- Oral commissure
- Marionette lines
- Mandible and pre-jowl sulcus
Hands, décolletage, striae, scar and scalp
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What are the injection techniques for PRP in face?
- Small aliquots of injection placed superficially then work deep (depends on injectors preference)
- For optimum results, start on periosteum with criss-crossing thread injections
- Use cross-hatching and layer in subdermal and SC planes for uniform application
- Do not inject intravascularly
- Tx areas most affected by ageing first and then proceed to less affected area
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What are the injection techniques for PRP in hands, de-colletage, striae, scars and scalp?
- Mark anatomical structures like blood vessels and tendons
- Inject superficial to deep dermis
- Small amounts of PRP intro dermis then SC level, inject any unused product for superficial injection
- Massage
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Where to inject PRP for specific facial areas?
Intra-orbital area, temples and jawlines --> supra-periosteal
Nasolabial fold, malar prominence and perioral area --> intradermal, SC plane
Superficial injections of skin in superficial dermis as well as topical
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What is the aftercare advice for PRP?
- May be some swelling, localised redness, itching and tenderness at injection site (immediate, self resolving)
- Tx practitioner may mould and massage product gently
- Avoid makeup for 24 hours
- No restriction on exercise or sun exposure
- Place ice onto injected sites to limit tissue oedema
- Follow up 4-12 weeks
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What are the adverse effects of PRP?
- Where bovine thrombin used ?CJD, induce factor V deficiency leading to bleeding (use calcium chloride instead)
- Redness, swelling and bruising
- Pain at injection site - slower rate, take analgesia, if severe then stop
- Ecchymosis/bruises
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What is PRF?
Platelet rich fibrin
Platelet concentration derived only be centrifugation without the use of anticoagulants
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What does the fibrin matrix contain?
Plts, TGF1, PDGF, VEGF, IL1B, IL4, IL6
(aids cell mediated tissue repair by proliferation and differentiation of many cell lines inc fibroblasts and endothelial cells)
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Why is PRF consider an advancement to PRP?
1. PRF time and cost of prep is lower
2. 3D scaffold is formed which retains larger amount of cytokines ad GF
3. Fibrin matrix lasts longer in tissue as the scaffold dissolves slowly allowing release of cytokines and GF over a longer period of time
4. Long-lasting GF release allowed more complex intra- and inter-cellular interactions
5. PRF centrifugation takes place at lower spins does not disrupt cells
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Describe the preparation technique for PRF?
- Higher spin centrifugation leads to denser fibrin with less cells
- Lower spin centrifugation leads to thinner fibrin structures with larger inter fibrous space and more cells
1. Blood is drawn and collected in 10ml vacutainers
2. Immediately placed in centrifuge
3. Following, centrifugation, caps are removed and tubes place in sterile tube holder
4. If making A-PRF then clot is allowed to form for 4-5 mins
5. PRF clot is removed with sterile forceps and fibrin clot is separated from RC fragment, approximately 2mm below the immersion line, using scissors
6. Clots are placed in small sterile metallic box for PRF preparation and covered with lid (prevents dehydration)
7. Membranes are ready to use after 2 mins
8. If I-PRF is being prepared, then resulting preparation does not contain a clot but an upper fibrin-containing part which is readily collected and injected
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What are the 2 macroscopic types of PRF?
Clot like/Advanced PRF
- used as structured membrane or a whole clot implanted in desired tissue
- enriched with leukocytes + GF (TGF1, VEGF)
Liquid/Injectable PRF
- injection material
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What are PRF centrifugation protocols?
1. Original Choukroun's - 3000rpm/10mins (clot)
2. Dohan Ehrenfest's - 2700rpm/12mins (clot, leukocyte rich)
3. Choukroun's advanced PRF - 1500rpm/14mins (clot, leukocyte rich)
4. Choukroun's injectable PRF - 700rpm/8mins (liquid/gel)
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What is the effect of PRF on skin?
- Deep skin and tissue rehydration
- Localised enrichment of ECM by collagen induction and re-organisation
- Skin and soft tissue health and blood supply improvement
- Local tissue healing and repair
Enhancement of micro-environment and the promotion of intra/extracellular anabolic and restorative processes
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What are the uses of PRF in aesthetic medicine?
i-PRF - filler
a-PRF - clot as temporary autologous subdermal implant
1. Treating small rhytdes in perioral and periorbital regions
2. Augmenting cheekbones, temporal area, lips, chin, jawline (extra caution in infraorbital and tear trough)
3. Deeper functional wrinkles such as nasolabial fold, marionette lines
4. Facial overall skin area as skin booster
5. Prepare tissue pocket prior to fat grafting
6. Tx filler associated complications (granulomatous dermal and subdermal skin infection associated with complications after HA)
7. Improves hypertrophic scars (possibly atrophic scars and stretch marks)
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What are the adverse effects of PRF?
Low risk procedure
Mild erythema and swelling
Avoid in pregnancy and breast feeding
