Dr Sarah Tonks discusses what you need to know when selecting a PRP method for your practice
The use of Platelet Rich Plasma (PRP) in aesthetics is relatively recent but has gained considerable publicity due to its adoption by celebrities such as Kim Kardashian and Bar Refaeli, who were both depicted with their faces smeared with whole blood rather than PRP, resulting in a dramatic effect. However, PRP has been used clinically in humans since the 1970s in opthalmic surgery, orthopaedics and sports medicine.
Much of the interest around PRP has come from the idea that this is an autologous substance and therefore considered to be ‘safer’ than traditional dermal fillers and botulinum toxins. WhatClinic.com reported an increase in enquiries regarding the procedure of 807% over the previous year in 2013. Although PRP is now offered by many clinics and there are numerous systems on the market, some uncertainty remains over its efficacy and proposed mode of action. Some have expressed doubts as to whether this truly represents evidence- based medicine due to the lack of robust clinical trials and outcomes. Indeed a recent Cochrane review in 2012 stated that at the moment there was insufficient evidence to support the use of PRP.1 However, at a microscopic level in a study of PRP treated fibroblasts, the PRP treated groups showed more proliferation and differentiation of fibroblasts into myofibroblasts which are essential for wound healing and increased contraction of the wound during healing time.2 PRP stimulates endothelial cells near their application site and favours the proliferation and formation of new capilliaries.3 Doctors report a high satisfaction and return rate from patients.
Generation of PRP involves centrifugation of autologous blood to separate the plasma and buffy coat portion of the blood, which contains high levels of platelets. Most people have a baseline blood platelet count of 200,000 (+/- 75,000) and although the ideal concentration of PRP is at the moment unclear, most PRP systems produce a substance containing concentrations of growth factors that are three- five times that in normal plasma. A count of 1,000,000/?L or 338% more than the normal total blood platelet count has been proposed as being the ideal.4 Studies have shown that PRP with a low platelet concentration does not work and too high concentrations have an inhibitory effect on cell growth. The concentration of PRP for bone regeneration was found to be best around 1,000,000/ ?L.5
PRP contains high concentrations of growth factors and more than 800 different proteins and it appears that the growth factors work together synergistically.8 Growth factor secretion begins 10 minutes after clotting with more than 95% of pre-synthesised growth factors secreted within an hour, however platelets continue to synthesise growth factors for at least seven days.9 Ideally the PRP must be used on the application site 10 minutes after activation to harness the growth factors. After the death of the platelet, the macrophage takes over wound healing by secreting some of the same growth factors.4
IMPORTANT COMPONENTS OF PRP
The major effects of PRP are derived from PRGF and TGF- ?1, which are concentrated in the alpha granule of the platelet and released during platelet activation. Both PRGF and TGF- ?1 stimulate cell proliferation and differentiation resulting in tissue formation.10
Although no undesirable effects have been reported, hypotheses exist as to the over expression of growth factors and their receptors related to tumour formation and dysplastic tissue. However it is thought that the circumstances leading to neoplasm growth require more continuous doses of growth factors over time than those in PRP, which degrade in seven-ten days.11 Nonetheless, the use of PRP should be avoided in patients with pre-cancerous lesions, in areas of epithelial dysplasia and those with a history of exposure to carcinogens.12
Several commercially available methods to obtain PRP are currently used in the clinical setting and there are many kits, centrifuges and vials available. The centrifugation process should be sterile and suited to platelet separation without lysing or damaging the platelets. Not all systems have been created to produce sufficiently viable platelet and this has led to criticism regarding the efficacy of PRP. When anti-coagulated blood is centrifuged, three layers form due to the differing densities of the blood components; the bottom layer consists of red blood cells, the middle of platelets and white blood cells, and the top plasma layer.3 It is important to reduce platelet fragmentation during centrifugation. Integrity of the membrane can be preserved by the use of acid citrate dextrose type A anticoagulant and low gravity forces during centrifugation.4 Dr Daniel Sister, anti-ageing and hormone specialist at BeautyWorksWest and pioneer of Dracula therapy, speaks on considerations when applying PRP. “The type of harvesting kit, centrifugation methods and time play a crucial role,” he says. “Plasma is autologous, so most new systems now come without the gel-like separation, because plasma is not totally hermetical and filaments of the gel get mixed with the plasma. All systems must be closed.” “There is also the cost per ml of active plasma to consider,” he says. “The new systems harvest 20cc in one kit and are more efficient, have better ration of growth factors and are cheaper than previous systems.” In the UK the most widely available kits available include Angel, Regen, Tropocells, BTI Technologies, Dracula and Selphyl.
|ANGEL||REGEN||SELPHYL||TROPOCELLS||BTI||DRACUT SKIN REJUVENATION|
|Amount of blood taken||50ml||8ml||18-36ml||10ml or 30ml||54ml||20ml|
|Method of taking blood||Needle and syringe. Has a specific kit with ACDA anticoagulant||Butterfly needle and vacutainer||Closed system||Butterfly set for 10ml blood draw. Needle and syringe could be used for 30ml blood draw||Butterfly cannula with vacutainer vials||Needle and syringe|
|Sterile blood tubes?||No tubes. Uses dedicated sterile hospital quality set||Yes||Yes||Yes||Yes, endotoxin free||Yes|
|Size of tubes||N/A||8ml||10ml||15ml or 50ml||9ml||20ml|
|Amount of PRP obtained||6-10ml||4-5ml||9-18ml||10ml blood draw = 6-2ml dedpending on platelet conc needed. 30ml blood draw = 18-6ml conc platelets||24ml dependent on haemocrit||Minimum 6ml|
|Centrifuge speed||First cycle: 3700rpm|
Second cycle: 2700rpm
|3200rpm||First cycle: 3800rpm|
Second cycle (optional): 1800rpm
|1500 RCF (or g) Only one cycle||580g||1800|
|Spinning angle of centrifuge||N/A||45°||90°||90° preferred or 45°||n/a under patent||30°|
|Activation substance||None- self activating when injected with small lumen needle||Calcium gluconate (optional)||Calcium chloride||None, activation in situ||Calcium chloride||Calcium gluconate optional|
|Number of treatments||3 treatments, 4-6 weeks apart and then every 6-18 months||3 treatments every 4 weeks apart and then every 6 months||3 treatments every 6 weeks||3 treatments every 4-6 weeks and then every 6-18 months||3 treatments at 3-4 weeks apart for 3 months, top up every 6-12 months||Twice a year|
|Method of separating PRP||LED cellular photospectometry and fractionation||Thixotropic gel||Mechanical with sodium citrate||Cycloaliphatic polymer inert gel, 100% biocompatible||Manually using a plasma transfer device||Mechanical filter|
The indications for PRP are numerous. There is evidence for its use to diminish dark circles around the eyes, hair growth and cutaneous regeneration.14,15 PRP is most often performed as a superficial treatment. It can be used intradermally with a 30g needle, in a linear thread, cross-hatching or using the fan technique. It can be used like mesotherapy, in a micro injection or micro papular technique with a 32g needle. Additionally, it is being used supraperiosteally to assist with slowing of bone remodelling and ageing, although at present there is no strong evidence base for this.16
PRP is being used in combination with fat to improve the survival of grafted fat with good results.17
Standardisation of PRP preparations is urgently needed to best compare systems. General opinion is that the majority of clinical studies do not have the statistical power to give conclusive results. Human trials do not take into account whether the platelets have been effectively concentrated, whether the PPP is discarded or not, whether early activation occurred or whether there were purification problems. Regarding skin rejuvenation, larger scale studies and randomised controlled trials which would decisively say which methods are most effective have not yet been performed. However, clinical experience suggests that in general, PRP, for skin rejuvenation and other aesthetic indications such as hair loss, can be a useful and attractive treatment.
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