Introduction: Platelet-rich plasma (PRP) is gaining popularity and is applied in a variety of clinical settings. This review aims to present and evaluate available evidence regarding the use of PRP in various applications in plastic surgery. Methods: PubMed, Web of Science, Medline, and Embase were searched using predefined MeSH terms to identify studies concerning the application of PRP alone or in combination with fat grafting for plastic surgery. The search was limited to articles in English or German. Animal studies, in vitro studies, case reports, and case series were excluded. Results: Of 50 studies included in this review, eleven studies used PRP for reconstruction or wound treatment, eleven for cosmetic procedures, four for hand surgery, two for burn injuries, five for craniofacial disorders, and 17 as an adjuvant to fat grafting. Individual study characteristics were summarized. Considerable variation in preparation protocols and treatment strategies were observed. Even though several beneficial effects of PRP therapy were described, significance was not always demonstrated, and some studies yielded conflicting results. Efficacy of PRP was not universally proven in every field of application. Conclusion: This study presents an overview of current PRP treatment options and outcomes in plastic surgery. PRP may be beneficial for some indications explored in this review; however, currently available data are insufficient and systematic evaluation is limited due to high heterogeneity in PRP preparation and treatment regimens. Further randomized controlled trials employing standardized protocols are warranted.

Over the past years, autologous platelet-rich plasma (PRP) has gained significant attention among various medical specialties, including, but not limited to, orthopedics, dermatology, gynecology, oro-maxillofacial surgery, and plastic surgery. PRP has been applied in a variety of clinical settings based on the assumption that it stimulates tissue regeneration, among other postulated positive effects, due to the presence of growth factors and cytokines [1].

The anticipated impact on tissue repair drives increased consideration for use of PRP in treating chronic wounds, burn injuries, and scars, hence establishing a promising supplemental approach in reconstructive plastic surgery. The application of PRP has also become more frequent in aesthetic surgery, i.e., in facial rejuvenation or in treatment of alopecia [2]. As a carrier-containing anti-inflammatory mediator, PRP is believed suppress inflammation in osteoarthritis, thereby promoting cartilage repair and temporizing pain [3]. In addition, PRP is used in bone grafting to support osseointegration and increase the odds of graft survival [4]. PRP is also introduced as an adjuvant to lipofilling since it is theorized to increase fat graft survival rates [5]. In addition to its beneficial therapeutic effects, it is easily obtained and cost-effective.

Despite increasing clinical popularity, the efficacy of PRP remains controversial due to the lack of consistent data and discord among researchers concerning the classification of PRP. Even though PRP is employed in a variety of medical fields, such as the different pillars of plastic surgery, current studies show notable inhomogeneity concerning the preparation process, control groups (CGs), and objective outcomes [6]. The purpose of this study was to demonstrate the current role of PRP and its application in plastic surgery, identify different techniques of preparation, and present current evidence for the use of PRP.

PRP is defined as the portion of the plasma fraction of blood with a platelet count above baseline [7]. Platelets carry secretory alpha granules, which release a high number of biologically active proteins including platelet-derived growth factor (PDGF), epidermal growth factor, basic fibroblastic growth factor, vascular growth factor, transforming growth factor, and fibroblast growth factor. As a result, tissue regeneration and remodeling, angiogenesis, re-epithelialization, and collagen formation are promoted [6].

The preparation process for PRP varies since no standardized protocol has been established so far. The procedure involves drawing venous blood – in most cases a small volume between 5 and 50 mL – followed by centrifugation. The duration, force, and number of centrifugation cycles depend on the device. This step separates the blood in the tube into three different layers: red and white blood cells (bottom), PRP (middle), and platelet-poor plasma (PPP, top). After extracting the platelet-rich component, platelets can be activated by adding thrombin (Thrb) and calcium chloride (CaCl). However, some authors argue that this step is not a requirement [2]. Anticoagulation is necessary to stabilize the platelets and prevent clotting. In most cases, the tube used for the venipuncture already contains an anticoagulant coat [5].

Various classification systems for different types of PRP and platelet-rich concentrations in general have been proposed, but there is still no consensus on which classification system is the most suitable. One of the most common classification systems was established by Dohan Ehrenfest et al. [65]. The authors suggested dividing PRP into four main groups, depending on the presence of white blood cells (leucocyte rich or poor) and the density of the fibrin network (high or low density). The classification system according to Mishra et al. [66] separates PRP in four different categories as well. The most important factors for this classification are the platelet concentration and the absence or presence of leucocytes [8]. The DEPA classification by Magalon et al. [67] which was introduced in 2016 is based on the dose of platelets injected, as well as the efficiency, purity, and activation of PRP [2]. Recently, Lana et al. [8] proposed a new classification system called “MARSPILL,” which is based on eight parameters concerning the preparation and application of PRP: method (automated or handmade), activation, red blood cells (rich or poor), spin (one or two spins), platelet number, image guidance, leucocyte concentration, and light activation.

The hypothesis that the growth factors and cytokines provided by PRP support tissue regeneration, thereby restoring structure and function, has been confirmed in various in vitro studies and animal models. These effects may provide a major advantage in clinical settings of plastic surgery, since effective union of damaged tissue is crucial for satisfactory clinical outcome in this field. PRP has emerged as a promising treatment approach in various areas and subdomains of plastic surgery; however, the extent of its clinical efficacy remains uncertain due to lack of standardized research [9]. We performed a systematic review in order to present the currently available studies on PRP therapy within all branches of plastic surgery, evaluate evidentiary support for the efficacy of PRP treatment, and discuss preparation methods.

Literature Search

The databases PubMed, Web of Science (core collection), Embase, and Medline (via Ovid) were queried for studies concerning the therapeutic use of PRP in plastic surgery. A systematic search was performed until the December 1, 2021. To cover all pillars of plastic surgery, the following subject headings were used:

(“Plastic surgery” OR “aesthetic surgery” OR “reconstructive surgery” OR “hand surgery” OR “breast surgery” OR “burns”) AND (“platelet-rich plasma” OR “PRP”).

Depending on the database, further search restrictions (article type, search category, language, studied species) were predefined to optimize the results and exclude nonrelevant material by adjusting the search filter. The added limitations are portrayed in Table 1.

Table 1.

Limitations added to query via refinement filters

Limitations added to query via refinement filters
Limitations added to query via refinement filters

Inclusion and Exclusion Criteria

The search was limited to studies in English or German. Only clinical studies that investigated the treatment with autologous PRP alone or as an adjuvant in fat grafting (FG) in humans were included. All animal and in vitro studies were excluded, as well as case reports and case reviews. Trials were only included if the product they investigated was defined as “platelet-rich plasma” in their report. PRP-related products, for example, platelet-rich fibrin (PRF) or its derivatives (platelet-rich fibrin matrix), were not explored in this review.

All studies had to be conducted at a department for plastic surgery or by a physician who specializes in that field. Publications concerning medical specialties such as dermatology, orthopedics/trauma, oro-maxillofacial surgery, ophthalmology, periodontology, or any other center that was not defined as a division or subdivision of plastic surgery were eliminated.

Data Extraction

Following the assembly of the findings of all databases, duplicates were manually removed. First, all titles and abstracts were screened for eligibility, followed by a full-text review of the remaining studies. The study selection process has been highlighted in the flowchart shown in Figure 1.

Fig. 1.

Flowchart describing the review process.

Fig. 1.

Flowchart describing the review process.

Close modal

A total of 895 results were obtained through literature search. Three records were identified through other sources. After deduplication, 800 articles remained and were screened thoroughly. Fifty papers met the previously described inclusion criteria and were included in this review.

These studies were divided into sections according to their field of application in plastic surgery, namely: reconstructive surgery, aesthetic surgery, hand surgery, craniofacial surgery, and burn injury treatment. The use of PRP in FG was classified as an independent segment.

Eleven studies investigating the application of PRP in reconstructive plastic surgery were included. Five of them treated chronic wounds or ulcers with PRP injections or gel application [10-14]. Two randomized controlled trials (RCTs) compared PRP application to conventional fixation with split-thickness skin grafts (STSGs) [15, 16]. In 1 case, PRP was applied to the donor site to accelerate wound healing [17]. Two studies aimed to reduce postoperative complications after breast reconstruction with PRP application [18, 19]. Another study investigated the effects of PRP injections in keloid scars with the objective to improve scar quality and reduce pain [20].

In total, eleven studies reported the use of PRP in aesthetic plastic surgery, which was further subcategorized into “facial” and “hair growth” interventions. The most common indications were androgenetic alopecia (AGA) and alopecia areata. One paper described the use of PRP as a preservation solution for hair transplantation [21]. Three studies had a PRP and a placebo group, whereas one compared different types of PRP (activated vs. nonactivated autologous vs. homologous PRP) without a CG in AGA therapy [22-25]. In one study, plasma was enhanced with dalteparin and protamine microparticles to evaluate if these growth factor carriers would result in better hair growth than conventional PRP, and one author explored the effects of the plant derivative QR678 in contrast to intradermal PRP injections in a randomized controlled study [26, 27]. The bioengineered formulation of QR678 was introduced by Kapoor and Shome in 2018. It contains a variety of biomimetic peptides, as well as vitamins, minerals, and amino acids and has been proven to be an efficient therapeutic approach for AGA for both male and female patients [26].

Two studies injected PRP to achieve facial rejuvenation [28, 29]. PRP gel was applied in two trials: one of them performed blepharoplasty, and the second one used it to improve face lifting outcome [30, 31].

The field of hand surgery is considered a sub-specialty that is shared between plastic, orthopedic, and general surgeons. Therefore, all studies concerning PRP therapy for procedures that are of interest for the plastic hand surgeon were included, regardless of the main medical specialty of the investigator. In total, four articles concerning plastic surgery of the hand were retrieved [32-35]. In a comparative study (CS), patients with mild carpal tunnel syndrome (CTS) were treated with either PRP or corticosteroid injections. Three authors performed intra-articular PRP injections as a treatment for carpometacarpal arthritis of the thumb joint. Two RCTs focused on the treatment of severe burns with PRP-enhanced skin grafts (SGs) [36, 37].

Craniofacial procedures fall under the scope of oro-maxillofacial surgery, as well as plastic surgery. A total of five studies conducted by plastic surgeons investigated the efficacy of PRP in bone grafting for alveolar cleft treatment, temporomandibular joint (TMJ) disorders, or other maxillofacial conditions [38-42]. All these studies were either CS or case-control (CC) study, and no RCTs were found.

Seventeen studies concerning to combination of PRP application and fat grafts were found, and three of those were RCTs [43-59]. Eight articles fell under the category “reconstruction,” focusing on chronic ulcers and wounds (three), scars (three), or breast reconstruction (two). Another eight studies administered PRP and autologous fat to improve the aesthetic outcome of lipofilling to the face and hand (six), the calf region (one), or the gluteal area (one). One study explored the effects of PRP mixed-microfat in 3 patients with wrist osteoarthritis. For a better overview, analysis and detailed descriptions of the included trials are presented in tabular form in Table 2.

Table 2.

Study details

Study details
Study details

Complications

Overall, little to no side effects were observed. Only three out of 50 studies reported isolated occurrences of hematomas [18, 28, 37]. One patient developed a palmar wrist ganglion, which receded quickly and without need for intervention [33]. The most common side effect of PRP injections to the scalp or to the face was mild discomfort or light-headedness during the injection, which subsided shortly after the procedure [24, 26-28]. The 5 patients that exhibited signs of infection had all been treated with PRP-enhanced FG; therefore, one cannot be certain whether the PRP or the lipofilling itself was responsible for these side effects [43, 55, 58]. However, most patients did not experience any negative effects related to PRP application. No serious adverse event (AE) occurred in any of the studies. All authors concurred that the therapeutic use of PRP is safe.

PRP Preparation

The studies included in this review showed notable heterogeneity in terms of PRP preparation methods. Many factors had to be considered, such as differences in number of PRP applications or the use of activators. In seventeen studies [10, 11, 13-15, 21, 24, 27, 31, 34, 35, 38, 40-42, 50, 53], double spin centrifugation was performed, 21 studies used a single spin protocol [16, 17, 19-23, 29, 30, 32, 33, 36, 37, 43-49, 51, 58], and twelve authors merely disclosed the name of the device used, or no information about this process at all [12, 18, 25, 26, 28, 39, 52, 54-57, 59]. Twenty-two authors reported the use of CaCl and/or Thrb for platelet activation [11, 13-15, 18, 19, 21, 24, 28, 30, 31, 37, 39, 42-47, 50, 51, 58]. Nonactivated PRP (na-PRP) was applied in 6 cases [34, 52-55, 57], and two authors reported the use of both na-PRP and a-PRP [22, 23]. One author applied photo-activated PRP [40]. The remaining studies did not mention this step of the process [10, 12, 16, 17, 20, 25-27, 29, 32, 33, 35, 36, 38, 41, 48, 49, 56, 59]. High variation was seen in the number of PRP treatments and in the volume of obtained/applied PRP. The reporting of PRP protocols showed inconsistencies, especially in terms of platelet count or platelet concentrate. Merely, a few studies included these details when describing the PRP preparation and treatment process [19, 20, 22, 23, 27, 29, 31-33, 37, 42, 50, 52, 53]. PRP preparation methods of each included study are portrayed in Table 3.

Table 3.

Preparation methods for PRP

Preparation methods for PRP
Preparation methods for PRP

Reconstructive Surgery

According to Dhua et al. [15] and Waiker and Shivalingappa [16], PRP showed significantly better results in skin grafting when compared to conventional mechanical fixation. Graft loss, morbidity, and time of hospitalization were reduced. A particularly beneficial outcome was the occurrence of instant graft uptake in the PRP group.

PRP showed positive effects in wound treatment in all studies. Healing time and overall results in chronic leg ulcers were significantly better when treated with PRP, according to Helmy et al. [10]; furthermore, there was no reoccurrence in the treatment group (TG) in contrast to the eleven cases in the CG. Similar results were presented by Xie et al. [14] and Rainys et al. [12]. According to these studies, PRP can reduce wound size, induce granulation tissue formation, and shorten hospital stay, which leads to reduced costs for both patients and hospitals. PRP may also decrease pain in wounds, as described by Moghazy et al. [11]. They treated 40 patients suffering from “complex wounds” – defined as acute or chronic wounds that challenge medical teams in terms of treatment and healing – with either PRP gel or vacuum-assisted closure (VAC). The patients included in this study had suffered from pressure sores, burn injuries, venous ulcers, diabetic ulcers, surgical wounds, or traumatic wounds. The authors reported significantly lower VAS scores and shorter, but nonsignificant, duration of hospital stays in the PRP group. However, the PRP group showed inferior results in reduction rates concerning the amount of wound exudate when compared to VAC treatment.

The effects of PRP in scar treatment and breast reconstructive surgery were not as conclusive. Hersant et al. [20] reported complete remission in 53% of keloids treated with PRP; however, 29% showed complete relapse. PRP seemed to have a significant beneficial effect on pruritus severity and the Vancouver Scar Scale (VSS) score, which may indicate that PRP is an effective method in scar treatment. The same authors described the efficacy of PRP in breast reduction and limb lifting surgery [19]. Patients treated with PRP showed significantly less hematoma and seroma than the CG; however, this effect was not observed in abdominoplasty patients. The scar quality did not improve in the TG. In contrast, PRP did not show any favorable results in breast reconstruction with a latissimus dorsi flap performed by Harper et al. [18], and no reduction of hematoma or seroma formation was reported compared to the CG.

Aesthetic Surgery

Hair Growth

PRP appears to be a safe and suitable alternative in managing hair loss, according to all studies collected for this review. The most relevant factors were hair regrowth, hair density, and hair count. Gentile et al. [22], Kumar et al. [24], and Singh [25] findings showed improvement in all mentioned parameters. However, the results were not always statistically significant and superiority over other therapeutic approaches, such as the plant derivate QR678 applied in the CS by Kapoor et al. [26], was not proven. In fact, intradermal QR678 injections resulted in higher hair density and shaft diameter. Adding growth factor carriers to PRP yielded similar yet not better results than injecting PRP alone. PRP may also serve as a preservation solution for hair transplantation, since Abdelkader et al. [21] reported higher hair graft uptake and accelerated hair growth in their RCT. No AEs occurred in connection with PRP injections in any of the studies, suggesting it is a safe treatment.

Face Lifting and Skin Rejuvenation

The outcomes of three studies by Davis and Augenstein [28], Hersant et al. [29], and Powell et al. [31] did not show significant results after applying PRP in rhytidectomy or facial rejuvenation. Hersant et al. [29] reported a major benefit for facial appearance and skin elasticity when combining PRP and hyaluronic acid (HA) as opposed to PRP or HA alone. These findings are consistent with a prospective study the authors published in 2017, indicating a positive synergistic effect of HA combined with PRP in cosmetic surgery [60]. Powell et al. [31] let three blinded surgeons evaluate the effects of the PRP application in rhytidectomy. Each facial side treated with PRP gel that showed less edema or ecchymosis than the control side was interpreted as a “positive” response; an “equal” response correlated with no noticeable difference and a “negative” response indicated the non-PRP side showed a better outcome. The treatment did receive some positive feedback from the judges, but no clinically significant difference compared to the control side was observed. Vick et al. [30] provided data suggesting PRP may reduce edema in blepharoplasty, since patients presented with less edema at day one and day thirty in the PRP group, but no significant clinical effects were reported. Similar to the findings of Powell et al. [31], ecchymosis was not reduced significantly, neither was postoperative discomfort. Overall, PRP alone does not seem to have major beneficial effects on aging correction or face lifts; however, further investigation of the combination of PRP and HA may yield more promising results. The studies showed that PRP therapy is safe, and any complications that occurred were minor and temporary. This corresponds to the results of a systematic review on PRP treatment for stria distensae performed by Sawetz et al. [61] in 2021. Their findings demonstrated that (multiple) PRP injections are a safe treatment option for stretch marks; however, the lack of comparability among the included reports made it impossible to draw clear conclusions about the efficacy of PRP in that field. This was due to a variety of limiting factors, a major one being the broad range of PRP preparation protocols, an issue we have come across in this review as well.

Hand Surgery

In a CS, Uzun et al. [32] reported the application of PRP in plastic surgery of the hand. Their research demonstrated that PRP is an effective method to reduce symptom severity and improve hand function in patients with mild CTS, judged by the Boston Carpal Tunnel Questionnaire (BCTQ). Three months after the procedure, BCTQ scores were significantly improved in the PRP group compared to the group that had received cortisone; however, this significance was no longer maintained after 6 months. The treatments showed equal improvements in sensory nerve conduction.

Recently, PRP has sparked interest in treating carpometacarpal arthritis of the thumb joint (CMC-1 arthritis). To our knowledge, only three studies have published studies investigating PRP injections for CMC-1 arthritis so far. PRP shows promising results in terms of pain decrease, according to Loibl et al. [33], Malahias et al. [34], and Abdelsabor Sabah et al. [35]. Intra-articular PRP injections can also result in improved function (measured via quick-disability of shoulder and hand questionnaire [DASH] or AUSCAN questionnaire), higher patient satisfaction, and more grip and pinch strength, as demonstrated by Malahias et al. [34] and Abdelsabor Sabah et al. [35]. The latter reported that these effects were no longer present at the second follow-up examination (3 months post-intervention), which does not correspond to the findings of Malahias et al. [34], who reported satisfactory result even after 1 year. This may be owed to the fact that Abdelsabor Sabah et al. [35] only performed one injection of 1 mL, whereas Malahias et al. [34] performed two intra-articular injections of 2 mL each. More extensive research in that field may yield further insight into the efficacy of PRP therapy for this condition and provide data to optimize frequency and volume of intra-articular PRP injections.

Burn Injuries

Similar to hand surgery, little evidence for PRP application in burn treatment is available. The randomized controlled studies by Gupta et al. [36] and Marck et al. [37] both investigated the addition of PRP to skin grafting for the treatment of burn wounds. Gupta et al. [36] demonstrated a significantly higher graft take and a lower complication rate, respectively, hematomas, compared to the CG. Marck et al. [37], conversely, did not report any significant benefit to graft adherence, re-epithelization rate, or scar quality in patients treated with PRP, and all observed effects were minor. However, the inhomogeneity of the study population may have been responsible for these findings. No serious complications were observed. Enhanced graft survival with PRP application in burn treatment was recently demonstrated by Zheng et al. [62] and published in the Chinese journal of burns. They recommend the use of PRP in skin grafting for burn injuries since their trial showed improved survival and fusion rates.

Due to the scarcity of current data in that field, no clear statement on the efficacy of PRP in burn treatment can be made. Further research in that area needs to be provided.

Craniofacial Surgery

PRP appears to be more efficient than arthrocentesis in treating TMJ disorders, as demonstrated by Hanci et al. [40]. Their results showed significantly better pain relief and decrease in pathological joint movement sounds, as well as improved range of motion (ROM). Gentile et al. [39] observed high patient satisfaction and low morbidity rate in patients undergoing maxillofacial surgery and PRP gel application. Pain levels and infection rates were reduced significantly. Also, applying platelet gel resulted in a 16% higher bone regeneration rate. PRP is believed to promote bone growth and soft tissue healing. This effect was observed a study by Oyama et al. [41]: CT imaging showed higher rate in regenerated bone volume after additional PRP treatment for alveolar bone grafting compared to the CG, indicating PRP in fact induces osteogenesis. These findings were not confirmed by Chen et al. [38] and Sakio et al. [42], who conducted similar studies, but did not report statistically significant benefits of adding PRP to the graft regarding newly formed bone volume. However, Chen et al. [38] did show less graft failure and a faster recovery in patients receiving the PRP-enhanced bone graft. Overall, the results presented no clear evidence about the effect of PRP in alveolar cleft surgery. Larger studies in a randomized controlled study design are necessary to evaluate the potential of PRP in craniofacial plastic surgery.

PRP as an Adjuvant to FG

The combination of PRP and lipofilling is based on the assumption that pro-angiogenic and anti-inflammatory effects of PRP enhance fat grafts [63]. The vascular component of PRP was demonstrated by Rigotti et al. [50], who observed higher vascular reactivity when adding PRP to facial lipofilling. It is also theorized that the growth factors released from the platelets induce proliferation and differentiation of adipose-derived stem cells), thereby further improving the graft outcome [63].

Cervelli et al. [44], Segreto et al. [54], and Smith et al. [55] evaluated the combination of PRP and FG for wound healing purposes, proving feasibility and safety. Pain reduction and over 50% complete healing rate were reported by Segreto et al. [54]; however, there was no CG to compare these results to. PRP-enhanced lipofilling appears to accelerate the re-epithelization process in ulcers compared to HA and collagen, according to Cervelli et al. [44]. Although Smith et al. [55] did not report any significant clinical improvement in their RCT, the authors concluded that the procedure was safe and recommended conducting larger randomized controlled studies to further evaluate the efficacy of PRP-enhanced FG in wound treatment.

PRP improves aesthetic perception and skin quality in scar treatment as demonstrated by Tenna et al. [56] and Majani and Majani [48]. Significant superiority over fat graft alone was not observed by the latter, but results were more durable with PRP.

The outcome of PRP-enhanced fat grafts in facial lipofilling procedures does not differ significantly from FG alone, according to Fontdevila et al. [45], Sasaki [52], and Willemsen et al. [59]. Nevertheless, PRP may still be of interest for cosmetic surgery since the RCT of Willemsen et al. [59] reported significantly shorter recovery in the PRP group. This may be attributed to the effect of PRP on fibroblast growth and differentiation. PRP-enhanced lipofilling is a safe procedure for gluteal augmentation, according to Willemsen et al. [58], and may even, as described in “PRP-enhanced fat graft augmentation of the calf region” by Bilkay et al. [43], reduce the number of sessions necessary to achieve satisfactory results. This effect was not observed in breast reconstructive surgery performed by Salgarello et al. [51], neither was a better clinical outcome in the PRP group when compared to the conventional Coleman technique, questioning the role of PRP in this field.

A few authors compared the effects of PRP in lipofilling to those of stromal vascular fraction (SVF) as an adjuvant to FG. van Dongen et al. [57] and Sasaki [53] provided data suggesting PRP is equally effective in facial lipofilling compared to SVF. The outcome of two studies by Gentile et al. [46, 47] demonstrates significantly higher graft maintenance in breast reconstruction and scar therapy for both PRP- and SVF-enhanced lipofilling; however, PRP showed slightly better results in both studies. These findings support PRP efficacy in lipofilling and may indicate superior effects of PRP over SVF as an adjuvant in FG.

As previously mentioned, the application of PRP in plastic surgery of the hand is a relatively unexplored field. Mayoly et al. [49] performed intra-articular injection PRP and microfat on 3 patients with radio-carpal osteoarthritis and proved feasibility and safety for this procedure. Preliminary results showed positive short-term outcomes, indicating a potential efficacy which should be explored on a greater scale (more patients, longer follow-up periods).

Limitations

There are some limitations to this review. Many studies had different endpoints or different evaluation approaches, and in some cases, the primary and secondary endpoints were not clearly defined. This posed a challenge in comparing and analyzing results. The previously mentioned (nm) heterogeneity in PRP preparation and application must be taken into account as well. The considerable variations in PRP extraction, activation, and frequency of application can lead to significant discrepancies between study results and diminish comparability. Furthermore, the vast majority of the authors did not disclose the final platelet concentration and the platelet count in their report.

The issue of high variation in PRP preparation protocols has been addressed on several occasions [3-5]. One of the contributing factors is the broad range of suggested classification systems. Historically, Dohan Ehrenfest et al. [65] provided the first classification system in 2009. They suggested dividing platelet-rich preparations according to their contents – whether they contain leucocytes or not – and the density of the fibrin network: [2]

•P-PRP: leucocyte-poor, low-density fibrin network (pure PRP).

•L-PRP: leucocyte-rich, low-density fibrin network (leucocyte-rich PRP).

•P-PRF: leucocyte-poor, high-density fibrin network (pure PRF).

•L-PRF: leucocyte-rich, high-density fibrin network (leucocyte-rich PRF).

Other authors support labeling different PRP products according to the DEPA classification by Magalon et al. [67] which is based on the dose of injected platelets, the efficiency of the production (percentage of platelets retrieves from blood), the purity of PRP (ratio of platelets compared to red and white blood cells), and the activation process [2].

Mishra’s classification, which has mainly gained recognition in sports medicine, separates PRP into four groups, mainly focusing on the platelet concentration and the presence of leucocytes [8]. In 2017, Lana et al. [8] proposed a new classification system called MARSPILL – an acronym for M ethod, A ctivation, R ed blood cells, S pin, P latelet number, I mage guidance, L eucocytes, L ight activation – which provides a precise description of the most important steps in PRP preparation and pays special attention to the peripheral blood mononuclear cell component of PRP preparation. The authors argued that the presence of peripheral blood mononuclear cells has a crucial impact on the regenerative potential of PRP and that its quantity should therefore be the main focus in labeling PRP products [8]. The issue of confusing terminology and varying PRP preparation methods has been addressed by many authors, such as Everts et al. [64]. The authors pointed out that the magnitude of PRP products and the lack of detailed bioformulation descriptions contribute to inconsistent patient outcomes [64].

The different approaches and the lack of a categorization standard pose a problem in interpreting and comparing data. Standardized terminology, guidelines for the preparation protocols of PRP and other platelet products, and consistent and detailed reporting of said protocols would facilitate conducting – and analyzing – research in this field [2].

PRP therapy is widely used in plastic surgery, and numerous trials have investigated its effects in reconstruction, cosmetic surgery, burn treatment, hand surgery, and bone or FG. The majority of the literature focuses on the benefits of PRP in reconstructive and aesthetic surgery. Its use in hand surgery or burn treatment has only been reported by a small number of studies. Particularly good outcomes of PRP treatment can be achieved in wound healing and pain reduction. Since no serious complications or side effects are associated with PRP application, PRP presents a safe treatment option in the field of autologous blood products.

Even though several beneficial effects of PRP were identified, the evidence presented in current studies is conflicting and treatment regimens and evaluation methods show considerable heterogeneity. Moreover, PRP preparation protocols differ between one another and are often only partially disclosed.

The use of PRP shows promising results and is certainly justified in some areas, but its efficacy has not been proven in all fields of application. Further prospective randomized controlled studies with standardized preparation protocols and treatment regimens should be conducted to determine the efficacy of PRP in plastic surgery.

An ethics statement is not applicable because this study is based exclusively on published literature.

The authors have no conflicts of interest to declare.

The authors received no financial support for this article.

All authors provided meaningful input in the development and design of this work, or the analysis and interpretation of data for the work and the drafting of the work or revising the intellectual content.

The data that support the findings of this study were obtained from online databases (PubMed, Ovid, Web of Science), journal websites, or other research platforms where restrictions or charges may apply. Such dataset may be requested from the respective journals or by contacting the authors directly.

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