April 2020 HSC Section 4 - Plastic and Reconstructive Problems

Aesth Plast Surg (2015) 39:495–505

The 61 reports varied widely in measurable endpoints, so data extraction consisted in reporting individual results from each article included in the review.

Different platelet preparations available have been shown to have different properties. PRP is traditionally isolated by dual speed centrifugation. The first spin sepa- rates red blood cells from plasma and buffy coat. The second spin concentrates the platelet plug which separates from the platelet-poor plasma (PPP). By definition, PRP has five to eight times the concentration of platelets than whole blood. Leukocyte-rich PRP (L-PRP) has more white blood cells (WBCs) than traditional, ‘‘pure’’ PRP (P-PRP); these leukocytes release matrix metalloproteinases (MMPs) and create oxygen-free radicals. They also release several interleukins and have higher concentrations of PDGF and TGF-b compared to P-PRP. One potential drawback is that the concentrated leukocytes facilitate extracellular matrix breakdown and release collagenase and elastases which may be counterproductive to tissue augmentation and healing [ 2 ]. PRFM has a lower platelet concentration, a larger volume, and includes plasma and proteins. The in- cluded fibrin develops a matrix which binds GFs and cells and promotes migration. These factors allow this prepara- tion to act more like a natural clot with lower levels of growth factors released over a longer period of time [ 3 ]. In general, growth factors have been of particular in- terest to surgeons seeking to enhance their results. This is evident by the fact that platelet preparations are used in practice and experimentally in various surgical subspe- cialties, in particular orthopedics for joint and connective tissue repair and healing. These theoretical advantages in enhancing wound healing and augmenting tissue are of particular interest to the facial plastic surgeon for cosmetic use, enhanced recovery after surgery, and improved wound healing. This article represents the body of evidence available on the effects of platelet preparations on facial rejuvenation and wound healing as it pertains to plastic surgery. A literature search was conducted through PubMed for the terms PRP, PRFM, platelet - rich plasma, platelet - rich fib- rin matrix, platelet preparations, platelet therapy, growth factors, platelet facial, platelet facial rejuvenation, platelet wound healing, platelet plastic surgery. Articles pertaining to the use of platelet preparations in facial surgery and wound healing in plastic surgery after 2001 through 2014 were included. Abstracts and full articles were reviewed. The 61 reports identified from the search were divided into in vitro studies, animal studies, and case series/clinical trials, and analyzed further. Articles referring strictly to use in joints, tendons, and orthopedic uses were excluded. Also review articles, case reports, or descriptive articles with no measurable endpoint were not included. Materials and Methods

Results

In Vitro Studies

Thirteen in vitro studies were included in this review. In 2008, Rughetti et al. found that when used at specific con- centrations, P-PRP was able to induce proliferation and to stimulate motility and invasiveness of endothelial human cells. In this study, higher concentrations were less effective in promoting proliferation and motility [ 4 ]. Kakudo et al. showed that activated P-PRP was associated with the release of large amounts of PDGF-AB and TGF-beta1. These au- thors found that adding activated P-PRP or platelet-poor plasma (PPP) significantly promoted the proliferation of human adipose-derived stem cells and human dermal fi- broblasts. This effect was more pronounced with the P-PRP group, but still enhanced over controls with the PPP, sug- gesting a plasma effect in addition to that caused by GF release [ 5 ]. Kakudo et al. also assessed the effects of P-PRP on angiogenesis in an in vitro and in vivo study, and found P-PRP stimulated proliferation, migration, and tube forma- tion of human umbilical vein endothelial cells [ 6 ]. Giusti et al. studied different concentrations of platelet gel (PG) and their influence on angiogenesis. The concentration of PG- released supernatant (P-PRP) had a significant influence on the angiogenic potential of human endothelial cells. These authors were able to demonstrate an optimal concentration for the stimulation of angiogenesis. Lower or excessively high concentrations of PG displayed a lower angiogenic potential [ 7 ]. Mishra et al. looked at mesenchymal stem cells grown in control media vs. media enhanced with unactivated, buffered P-PRP, and found that proliferation 7 days after P-PRP treatment was increased, with the greatest mitogenic effect at a concentration of 10 % P-PRP [ 8 ]. Kushida et al. found that P-PRP-treated dermal fibrob- lasts demonstrated more marked contraction in a collagen gel model than the platelet-poor plasma treated or control groups. They concluded that P-PRP promotes proliferation, causes the differentiation of human dermal fibroblasts into myofibroblasts, and promotes wound contraction. They felt this could provide a potential therapeutic agent for skin wound healing [ 9 ]. Kim et al. also looked at the effect of P-PRP on dermal fibroblasts in order to predict an effect on skin rejuvenation. They found levels of procollagen type I carboxy-terminal peptide were highest in cells grown in the presence of 5 % P-PRP [ 10 ] (Table 1 ). More recently, Tajima et al. conducted an in vitro study that demonstrated that the levels of growth factors secreted

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