Effect of Topical Autologous Platelet-Rich Fibrin versus No Intervention on Epithelialization of Donor Sites and Meshed Split-Thickness Skin Autografts: A Randomized Clinical Trial:

Deficient functional wound closure as measured by elevated trans-epidermal water loss predicts chronic wound recurrence: An exploratory observational study

A single-center, prospective, observational pilot study was performed to evaluate wound healing endpoint and recurrence by measuring transepidermal water loss (TEWL) post-closure at the site of wound repair. Patients with clinically-defined chronic wounds (such as pressure ulcers, diabetic ulcers, and trauma wounds) who visited the Plastic Surgery outpatient department or were in-patients at the All India Institute of Medical Sciences, Rishikesh, India, and were referred for chronic wound management, were enrolled. Non-invasive point-of-care TEWL measurements were obtained, from closed wound-site and contralateral healthy skin site, starting from confirmation of closure (post-closure, V0) continuing every 2 weeks for a maximum of five visits or until the wound recurred. Statistical analyses of the data involved logistic regression and likelihood ratio chi-square tests to assess differences in TEWL at visit 0 (V0) between the closed wound site and reference skin, with the TEWL score as the sole predictor of recurrence. Of the 72 subjects that completed the study, 44 (61%) showed no recurrence and 28 (39%) had wounds that recurred over a period of 12 weeks. A significant association was found between the V0 (post-closure) TEWL score and the odds of wound recurrence, both in univariate analysis (OR [95%CI] = 1.26[1.14,1.42] (p < 0.001) and after adjusting for covariates in multivariable analysis (OR [95%CI] = 1.34[1.19,1.61] (p < 0.001). The likelihood ratio chi-square analysis demonstrated that the V0 TEWL score is a significant universal predictor of recurrence across all wound types studied. Cases of closed wounds with subsequent recurrence showed an overall higher post-closure V0 TEWL score, compared to those who did not have a wound recurrence, across visits. The TEWL score cut-off value predictive of recurrence was 24.1 g.m-2.h-1 (AUC = 0.967). The outcome of this pilot study on a wide range of chronic wounds leads to the hypothesis that post-closure TEWL at the site of wound healing is a reliable biomarker of wound recurrence. It also raises the question whether the clinical endpoint of wound closure should include re-establishment of skin barrier function as additional criterion. The current standard of care wound closure endpoint calls for re-epithelialization of the wound with no discharge for two consecutive weeks disregarding the functional parameter of restoration of skin barrier function at the wound-site.

A Prospective, Interventional, Comparative Study to Evaluate the Efficacy of Using Combined Platelet-Rich Plasma and Platelet-Rich Fibrin Over Standard Cleaning and Dressing in Chronic Wounds

INTRODUCTION

Chronic wounds are defined as wounds that have failed to proceed through the orderly process that produces satisfactory anatomic and functional integrity or that have proceeded through the repair process without producing an adequate anatomic and functional result. The majority of wounds that have not healed in three months are considered chronic, although a duration as low as four weeks has been used to indicate chronicity. Our study aimed to compare the efficacy of autologous platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) versus standard cleaning and dressing as a regenerative medicine strategy to promote healing in chronic wounds.

METHODS

 A prospective randomized controlled trial was undertaken to test the efficacy of autologous PRP and PRF in the healing of chronic wounds. A series of 60 cases was compiled from patients attending the outpatient department regularly for the management of chronic wounds. A total of 30 cases were randomly chosen for study with autologous PRP and PRF and 30 cases received conventional dressing.

RESULTS

 The average healing duration in the study was significantly shorter for the PRP & PRF group. The mean healing time for this group was 4.45 weeks (31.2 ± 3.07 days) compared to 9.61 weeks (67.27 ± 9.19 days) for the conventional dressing group.

CONCLUSION

 PRP and PRF belong to a new generation of platelet concentrates that help efficaciously for enhanced healing and functional recovery, safely and cost-effectively. They help by shortening the recovery period overall, improving the quality of life of patients, and altogether eliminating the additional morbidity of operative procedures.

Efficacy of platelet-rich plasma in alleviating split skin graft morbidities

Introduction

Skin grafting is a routinely employed technique to cover the skin defect. Though the skin grafts are technically effortless, they are tiresome because of the prolonged duration of hospital stay, labor-intensive, demanding repeated dressings, and also create a second wound. Platelet-rich plasma (PRP) is one that has a higher concentration of platelets than the blood. Alpha granules of the platelets are rich in growth factors.

Aims and Objectives

To assess the effect of PRP on split-thickness skin graft uptake and donor site healing.

Materials and Methods

In a single-center-based prospective study done from August 2018 to June 2020, 60 patients with acute and chronic wounds were divided into two equal groups. Autologous PRP was applied on the recipient wound bed and donor site in PRP group, and conventional methods like staples/sutures were used to anchor the skin grafts and standard of care of the donor site in a control group.

Results

Instantaneous graft adhesion was observed in all patients of PRP group. The first graft inspection was delayed. Seroma, hematoma, total number of dressings, and duration of stay in hospital were significantly reduced in the PRP group. Donor site pain in the postoperative period was notably reduced in PRP group. PRP also remarkably hastened the donor site healing.

Conclusion

The application of PRP promotes graft take, minimizes complications, enhances donor site wound healing, mitigates donor site pain, and has immense economic benefits due to the reduced number of dressing changes and shorter hospital stay.

Efficiency of platelet-rich plasma in the management of burn wounds: A meta-analysis

The meta-analysis aimed to assess the efficiency of platelet-rich plasma (PRP) in the management of burn wounds (BWs). Using dichotomous or contentious random- or fixed-effects models, the outcomes of this meta-analysis were examined and the odds ratio (OR) and the mean difference (MD) with 95% confidence intervals (CIs) were computed. Thirteen examinations from 2009 to 2023 were enrolled for the present meta-analysis, including 808 individuals with BWs. PRP had significantly shorter healing time (MD, -5.80; 95% CI, -7.73 to -3.88, p < 0.001), higher healing rate (OR, 3.14; 95% CI, 2.05-4.80, p < 0.001), higher healed area percent (MD, 12.67; 95% CI, 9.79-15.55, p < 0.001) and higher graft take area percent (MD, 4.39; 95% CI, 1.51-7.26, p = 0.003) compared with standard therapy in patients with BW. However, no significant difference was found between PRP and standard therapy in graft take ratio (OR, 1.70; 95% CI, 0.86-3.34, p = 0.13) and infection rate (OR, 0.55; 95% CI, 0.20-1.47, p = 0.23) in patients with BW. The examined data revealed that PRP had a significantly shorter healing time, a higher healing rate, a higher healed area percent and a higher graft take area percent; however, no significant difference was found in graft take ratio or infection rate compared with standard therapy in patients with BW. Yet, attention should be paid to its values since all of the selected examinations had a low sample size and some comparisons had a low number of selected studies.

Role for platelet rich plasma as an adjuvant therapy in wound healing and burns

Background

Platelet rich plasma (PRP) contains high concentrations of growth factors. Intuitively, these were thought to be of potential benefit in healing of chronic wounds, skin grafts and graft donor sites. This was echoed in retrospective studies and an individual case basis but had not been randomized.

Methods

A systematic search was carried out by two individuals, independently, on the MEDLINE, EMBASE and COCHRANE databases, according to PRISMA guidelines. All data analysis and statistics was pooled and analysed using the Cochrane RevMan Software.

Results

Split thickness grafts have been described by numerous authors, but PRP use did not offer a significant advantage in graft take in pooled results (MD 5.83, 95% CI − 0.69 to 12.25, random-effects, p = 0.08). The analysis of included randomized controlled trials has shown favourable split-thickness skin graft donor site healing in the PRP group (MD − 5.55, 95% CI − 7.40 to − 3.69, random-effects, p =  < 0.00001) compared to the control group. For carpal tunnel syndrome, the pooled results showed no difference in functional scores vs steroid injections (SMD − 0.68, 95% CI − 1.47 to 0.10, randomeffects, p = 0.09) or indeed splinting groups.

Conclusions

With the current body of evidence, we conclude that the use of PRP as an adjuvant therapy in skin grafts, burns, carpal tunnel surgery or scars cannot be rationalised. A potential use of PRP is in donor site management but the cost of this would be difficult to justify.

Level of evidence: Not ratable.

"Platelet-Rich Fibrin Membrane-as a novel biomaterial for pressure injury healing in a person with spinal cord injury: A case report"

INTRODUCTION

Pressure injury (PI) impacts the quality of life, and socioeconomic and psychological well-being negatively in persons with Spinal Cord Injury (SCI). Autologous Platelet Rich Plasma (PRP) and Platelet Rich Fibrin (PRF) showed promising roles in wound healing. PRF is considered a second-generation PRP, contains more growth factors and is more biocompatible than PRP. It possesses an additional favourable impact on wound healing due to its three-dimensional fibrin architecture, and antimicrobial property. There are no studies on PRF membrane use for PI healing in SCI.

CASE PRESENTATION

A 25-year-old male with operated traumatic T10 American Spinal Injury Association Impairment Scale grade A paraplegia with neurogenic bowel, and bladder and a stage II PI over the left greater trochanter, was admitted for inpatient rehabilitation. The chronic non-healing PI which did not show any improvement following normal saline (0.9%) dressing for the past 3 months, was treated with autologous PRF membrane weekly for four weeks. The PI healed completely and no adverse events were noted. Weekly total scores of the Spinal Cord Impairment Pressure Ulcer Monitoring Tool and Pressure Ulcer Scale for Healing were 6, 6, 5, 2, 0 and 12, 10, 10, 3, and 0 respectively.

DISCUSSION

To the best of our knowledge, this is the first case report on the healing of PI in SCI with the use of PRF. This novel biomaterial is a safe and effective promising agent for PI management in SCI. But further randomized trials are needed to establish stronger evidence regarding feasibility and effectiveness.

Biomarkers of Skin Graft Healing in Venous Leg Ulcers

There is a need for biomarkers that predict the success of transplantation of venous leg ulcers (with autologous split-thickness skin grafts). The primary objective of this exploratory study was to investigate the association between split-thickness skin graft healing in venous leg ulcers and candidate wound fluid biomarkers representing inflammatory cell and endogenous proteinase activities, and bioactivity. A secondary objective was to compare biomarker levels of the 17 venous leg ulcers with sterile split-thickness skin graft donor-site wounds in another 10 patients with venous leg ulcers. Wound fluids were collected for 24 h using a validated method. The concentration of pre-operative matrix metalloproteinase-9 in wound fluid was higher in venous leg ulcers showing good healing (n = 10) than in venous leg ulcers showing poor healing (n = 7) 12 weeks after transplantation with meshed split-thickness skin grafts. The diagnostic value of matrix metalloproteinase-9 was good according to receiver-operating characteristic curve analysis. Matrix metalloproteinase activity in wound fluids from split-thickness skin graft donor-site wounds increased as a function of time and healing, but was still lower than matrix metalloproteinase activity in venous leg ulcer wound fluids, which showed increased levels of most biomarkers except for matrix metalloproteinase-9 and matrix metalloproteinase-2. In conclusion, wound fluid matrix metalloproteinase-9 concentration is a potential predictive biomarker of split-thickness skin graft healing in venous leg ulcers.

Platelet-derived concentrates influence human keratinocyte proliferation in vitro and induce wound healing in a prospective case series of chronic wounds of different entities in vivo

Objectives

Soft tissues defects can extend into the fat layer or even deeper and can cause significant clinical disadvantages like pain, infections, and loss of function. In particular, chronic wounds are difficult to treat, as split-thickness skin grafts (STSGs) have varying success rates. To improve wound healing in chronic wounds, the authors have studied the application of platelet-mediator concentrate (PMC) in a human keratinocyte culture model in vitro and of autologous platelet concentrates (PRP) in a combination with surgical procedures in vivo as second line therapy in patients with initially failed wound closure.

Methods

For in vitro testing on keratinocytes, a PMC was processed with a commercially available bedside system (ATR^®, Curasan, Germany). In a clinical, nonrandomized study, five in-house patients with chronic wounds were treated using a combination of surgical debridement and autologous PRP. Time of healing as determined by epithelization as well as laser Doppler imaging to visualize blood flow was analyzed. Additionally, changes in ease of surgical wound closure were determined. Finally, the quality of life of patients was assessed using a validated questionnaire (clinicaltrials.gov # NCT03667638).

Results

In vitro testing shows a significant effect of PMC on keratinocyte proliferation in cell culture. Clinical studies showed that patients treated with PRP had initiation of wound closure, higher blood flow after PRP injection, and easier wound closure as well as improved quality of life.

Conclusions

The injection of platelet concentrates to treat chronic wound defects presents a favorable addition to treatment where single surgical procedures have failed and may improve current therapy options.

Changes in Elastic Moduli of Fibrin Hydrogels Within the Myogenic Range Alter Behavior of Murine C2C12 and Human C25 Myoblasts Differently

Fibrin hydrogels have proven highly suitable scaffold materials for skeletal muscle tissue engineering in the past. Certain parameters of those types of scaffolds, however, greatly affect cellular mechanobiology and therefore the myogenic outcome. The aim of this study was to identify the influence of apparent elastic properties of fibrin scaffolds in 2D and 3D on myoblasts and evaluate if those effects differ between murine and human cells. Therefore, myoblasts were cultured on fibrin-coated multiwell plates (“2D”) or embedded in fibrin hydrogels (“3D”) with different elastic moduli. Firstly, we established an almost linear correlation between hydrogels’ fibrinogen concentrations and apparent elastic moduli in the range of 7.5 mg/ml to 30 mg/ml fibrinogen (corresponds to a range of 7.7–30.9 kPa). The effects of fibrin hydrogel elastic modulus on myoblast proliferation changed depending on culture type (2D vs 3D) with an inhibitory effect at higher fibrinogen concentrations in 3D gels and vice versa in 2D. The opposite effect was evident in differentiating myoblasts as shown by gene expression analysis of myogenesis marker genes and altered myotube morphology. Furthermore, culture in a 3D environment slowed down proliferation compared to 2D, with a significantly more pronounced effect on human myoblasts. Differentiation potential was also substantially impaired upon incorporation into 3D gels in human, but not in murine, myoblasts. With this study, we gained further insight in the influence of apparent elastic modulus and culture type on cellular behavior and myogenic outcome of skeletal muscle tissue engineering approaches. Furthermore, the results highlight the need to adapt parameters of 3D culture setups established for murine cells when applied to human cells.

Automatic wound detection and size estimation using deep learning algorithms

Evaluating and tracking wound size is a fundamental metric for the wound assessment process. Good location and size estimates can enable proper diagnosis and effective treatment. Traditionally, laboratory wound healing studies include a collection of images at uniform time intervals exhibiting the wounded area and the healing process in the test animal, often a mouse. These images are then manually observed to determine key metrics -such as wound size progress- relevant to the study. However, this task is a time-consuming and laborious process. In addition, defining the wound edge could be subjective and can vary from one individual to another even among experts. Furthermore, as our understanding of the healing process grows, so does our need to efficiently and accurately track these key factors for high throughput (e.g., over large-scale and long-term experiments). Thus, in this study, we develop a deep learning-based image analysis pipeline that aims to intake non-uniform wound images and extract relevant information such as the location of interest, wound only image crops, and wound periphery size over-time metrics. In particular, our work focuses on images of wounded laboratory mice that are used widely for translationally relevant wound studies and leverages a commonly used ring-shaped splint present in most images to predict wound size. We apply the method to a dataset that was never meant to be quantified and, thus, presents many visual challenges. Additionally, the data set was not meant for training deep learning models and so is relatively small in size with only 256 images. We compare results to that of expert measurements and demonstrate preservation of information relevant to predicting wound closure despite variability from machine-to-expert and even expert-to-expert. The proposed system resulted in high fidelity results on unseen data with minimal human intervention. Furthermore, the pipeline estimates acceptable wound sizes when less than 50% of the images are missing reference objects.

Reducing split-thickness skin grafting donor site agony; faster healing and decreased pain-role of platelet-rich plasma

INTRODUCTION

The split-thickness skin graft harvested donor site is associated with prolonged healing, discomfort, and pain. Platelet-rich plasma (PRP) contains platelet-derived growth factors and has been widely used in chronic wounds and skin graft donor sites. PRP application is known to accelerate wound epithelialization rates, and also reduce postoperative wound site pain.

MATERIALS AND METHODS

We assessed 20 patients admitted to our hospital service who underwent split-thickness skin grafting (STSGs) with proximal half of the donor site treated with PRP. The dressing was conducted on postoperative day 7, 14, and 21. The donor site healing was assessed with serial photographs and donor site pain measured by numerical rating scale.

RESULTS

Complete healing of wounds (epithelialization) was present in 12 (60%) patients dressed with PRP. Pain on opening dressing was an average of 3.5 in PRP dressed wounds and 6.35 in control wounds. Patients dressed without PRP, none of them had complete epithelialization. All patients had partial healing and were less than the donor site dressed with PRP. Based on these results, skin graft donor site with PRP showed accelerated healing and reduced pain and discomfort compared to control without PRP.

CONCLUSION

PRP is a beneficial adjunct for reducing donor site pain and increased healing of donor site following STSG harvest.

Safeguarding Skin Grafts: An Evidence-Based Summary of Fixation Techniques

BACKGROUND

Effective skin graft fixation is vital in preventing sheering forces, seroma, and hematoma from compromising graft take. Yet, selecting the ideal technique for securing skin grafts remains a contentious subject, with significant variation in practice existing between surgeons. There is, therefore, benefit to be derived from assessing the literature for evidence-based recommendations to guide the decision-making process.

METHODS

A search of Medline and Embase was performed using appropriate key terms, yielding 419 articles. Reference lists were analyzed. Inclusion and exclusion criteria were composed. Level I to III studies, as defined by the Centre for Evidence-Based Medicine, that compared skin graft fixation methods were analyzed. Rayyan QCRI was used for abstract and title screening. After full text screening, 41 studies were included for qualitative analysis. All included randomized control trials (RCTs) were assessed for risk of bias using the Cochrane Risk-of-Bias 2 (ROB2) tool.

RESULTS

We identified 4 groups of fixation technique: "tie-over bolster" (TOB), "no TOB," "adhesive glues," and "negative pressure wound therapy" (NPWT). Twelve studies compared TOB with no TOB, with no difference in graft take demonstrated. Sixteen studies compared adhesive glues with traditional methods, with no difference in graft take demonstrated. Thirteen studies compared NPWT with traditional methods, with enhanced graft take demonstrated. Risk of bias was deemed low in 1 of 13 RCTs.

CONCLUSIONS

Based on the current evidence, only NPWT is associated with enhanced graft take. However, there is a scarcity of robust level I evidence comparing different fixation techniques, meaning that strong recommendations cannot be made. We propose examples of hypothesis-driven RCTs, in predetermined clinical settings, based on the theoretical benefits of the techniques that would add value to clinical practice.

Platelet rich plasma and plasma rich in growth factors for split-thickness skin graft donor site treatment in the burn patient setting: A randomized clinical trial

INTRODUCTION

Management of donor site morbidity in the setting of split thickness skin graft (STSG) is of crucial importance with no superior wound dressing described to date and the growing need of decreasing epithelializing time. The purpose of the study was to compare the standard of care using a hydrocolloid dressing to platelet rich plasma (PRP) and plasma rich in growth factors (PRGF) in order to determine its therapeutic potential in this setting.

METHODS

A randomized clinical trial was conducted in which each patient served as its own control. PRGF was obtained by means of freeze-thaw out of the PRP from the subject of the study. Patients from the study had three donor sites and each donor site received either to PRP, PRGF or the standard of care, hydrocolloid. The main variable was time to epithelialization, and secondary variables subject to study were pain, quality of the scar, complications and cost.

RESULTS

20 patients were recruited with a total number of 60 donor sites to study. On the 8th post-operative day 55% and 45% of the sites treated with PRP and PRGF, respectively, complete epithelialization was observed as compared to 20% of the sites treated with hydrocolloid, statistical significance was achieved between the latter two (p = 0.036). The areas treated with PRP and PRGF received inferior values on the visual analog scale on post-op day 5 and 8 compared to hydrocolloid. Values on wound healing metrics were lower in the PRP when compared to hydrocolloid. No adverse effects were recorded.

CONCLUSION

Donor site of STSG treated with PRP in the setting of the burn patient decreased time to epithelialization. In our study a better pain control and in scar quality was observed in both, the PRP and PRGF group.

The wound healing effect of local leukocyte platelet-rich plasma after total hip arthroplasty: A randomized controlled trial

Rapid wound closure is important after arthroplasty procedures to prevent postoperative complications. Platelets are rich in growth factors and leukocytes contribute to innate immunity. We hypothesized that topical leukocyte platelet-rich plasma (L-PRP) derived from the blood of patients would be beneficial to wound healing. In this randomized controlled trial, patients subjected to elective total hip arthroplasty (THA) were assigned by concealed allocation either L-PRP application onto the sutured fascia or no application (control) after the THA intervention. In addition, all patients received 1.5 g protein/kg, 5 g L-arginine, 500 mg vitamin C and 44 mg zinc daily over the 4-week postoperative period to obtain optimal nutrition. The primary endpoint was complete healing of the skin incision. The secondary endpoints were blood transfusions, length of hospital stay, pain and wound infections. Sixteen patients in the L-PRP group and 17 patients in the control group completed the trial. L-PRP treatment accelerated complete wound healing after 3 weeks (seven in the L-PRP group vs. zero in the control group, p = 0.003) and after 4 weeks (12 in the L-PRP group vs. six in the control group, p = 0.037). No postoperative superficial wound infections occurred within 4 weeks, and there were no significant differences in the other secondary outcomes. L-PRP generated in 10 sex-matched healthy volunteers revealed increased concentrations of platelets (5.8-fold) and leukocytes (2.3-fold) compared with those in whole blood. Furthermore, the concentration of keratinocyte mitogen epidermal growth factor in L-PRP (380 ± 130 pg/ml, mean ± SD) was higher (p < 0.001) than that in serum (130 ± 26 pg/ml). In conclusion, a single intraoperative local application of L-PRP promoted wound healing after THA, possibly mediated by EGF receptor agonists.

Autologous platelet-rich fibrin: a novel method for tracheoesophageal puncture site closure: a case report

Closure of a tracheoesophageal puncture site performed during voice prosthesis implantation may sometimes be required. Besides local techniques, more elaborate procedures, such as closure by means of free microvascular flaps, have been advocated. In this report, we describe a case of local treatment of a hard-to-heal fistula with local application of autologous platelet-rich fibrin matrix in a 77-year-old male patient. At one-week follow-up, the size of the fistula had decreased dramatically but some leakage remained when drinking. After one month, the patient was able to drink and eat normally without any leakage. There was no recurrence of the leakage at two years' follow-up. In summary, local application of platelet-rich fibrin seems to be a simple, safe and effective procedure for tracheoesophageal fistula closure.

The use of platelet-rich products for skin graft donor site healing: a systematic review and meta-analysis

Split thickness skin grafting is a common reconstructive technique which carries unavoidable donor site morbidity. The aim of this systematic review and meta-analysis is to present the evidence for the use of platelet rich plasma as an adjunct to donor site wound healing. A comprehensive literature search was performed, according to PRISMA guidelines from inception to August 2020, for studies regarding platelet rich plasma and skin graft donor site healing. Animal studies, case series of less than three cases and studies reporting histological outcomes only were excluded. The literature search identified 114 articles. After applying the exclusion criteria, four randomised control trials and two case-control studies remained, incorporating a total of 218 wounds in 139 patients. Four out of six studies reported total healing times for donor site wounds. Pooled analysis showed a significant reduction in healing time when donor wounds were treated with PRP versus controls [MD 5.95, 95% CI 5.04-6.85, p < 0.001]. Of the five studies which reported pain at dressing change, four showed significantly reduced pain scores for the platelet rich plasma treated wounds versus control. There were no significant complications recorded in the treated wounds. The current evidence basis for platelet rich plasma in donor site healing is limited by heterogeneous methodology and reporting outcomes and low powered studies. Nevertheless, the preponderance of data supports its use for accelerating wound healing and reducing pain at dressing change. These preliminary findings need to be substantiated with higher powered randomised controlled trials with standardised PRP manufacture and reporting structures.

[The use of platelet rich plasma in bone-reconstructive in cranio-maxillo-facial surgery]

PRP-therapy - method, based on local application platelet rich plasma. Efficiency of this method is investigated and approved both in vitro and in vivo. PRP includes growth factors: platelet derived growth factor, transforming growth factor, epidermal growth factor, insulin-like growth factor, vascular endothelial growth factor, which significantly accelerate regenerative process. PRP-therapy reduces pain syndrome, accelerates tissue regeneration and has an anti-inflammatory effect.

Platelet-rich fibrin can accelerate the healing of common bile duct anastomosis in a rat

Objectives

This study aimed to evaluate the effect of platelet-rich fibrin (PRF) concentrate on the bile duct anastomosis healing process in rats.

Material and Methods

Thirty male Sprague Dawley (SD) rats were used for the study. The animals were allocated into three groups: Group I Control Group (n=10): Anastomosis to the common bile duct (CBD) with a stent. Group II PRF Group (n=10): Anastomosis to the CBD with a stent and covered with PRF. Group III Sham Group (n=10): Preparation of the common bile duct, no anastomosis. The animals were followed up for 1 month, then sacrificed. Study parameters were adhesions around the anastomosis, thickness of the bridging bile duct tissue over the stent, and histopathologic examination of the bridging bile duct tissue.

Results

CBD anastomosis using a stent caused severe adhesion around the anastomosis, bridging bile duct tissues were weak and histopathologically, healing was incomplete in most of the control animals. However, PRF application significantly reduced the adhesions, increased the quality of the bridging bile duct tissues, and caused complete healing histologically.

Conclusion

PRF is an autologous, easily prepared membrane. The present study findings show that PRF prevents local complications and increases the healing capacity of the bile duct after CBD anastomosis. Therefore, it might be a new treatment option for preventing complications following common bile duct anastomosis in liver transplantation patients.

Effectiveness of fibrin glue in skin graft survival: A systematic review and meta-analysis

Background

The objective of this study is to assess the current literature on the effectiveness of fibrin glue on survival of skin grafts. Fibrin glue is a possible alternative to secure skin grafts instead of traditional methods (i.e. sutures or staples).

Methods

Data Sources: MEDLINE, Scopus, Embase, Informit, CINAHL and the Cochrane Central Register of Controlled Trials, no limit on the earliest date of publication.

Study eligibility criteria

Randomised, non-randomised controlled trials and cohort studies.

Participants

and Interventions: Participants were patients with skin grafting/skin transplantation. The intervention was fibrin glue in any form (bovine, human pooled plasma or autologous) and comparator any form of affixing skin grafts (e.g. sutures or staples).

Study Appraisal and Synthesis Methods: Studies were appraised using the Cochrane risk of bias tool and assessed for clinical heterogeneity. Effect sizes were calculated and illustrated with forest plots.

Results

190 publications were narrowed to 15 relevant publications, of which eight were pooled in meta-analysis. The outcomes examined were: graft survival by percentage; graft survival reported as events; post-operative incidence of haematoma or seroma; pain reported after dressing changes via a visual analogue scale; length of stay in days (Glass's delta 2 was 0.48 95% CI 0.09, 0.97); and surgical time in minutes. Only length of stay showed a difference between groups and it favoured fibrin glue.

Conclusions

While there may be benefits to the use of fibrin glue in skin graft patients, it is difficult to conclude this from the current evidence. Limitations were significant heterogeneity in outcomes measured and exclusion off non-English papers.

•

Largest systematic review of fibrin glue in skin grafts to date.

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Both clinical and patient reported outcomes important in assessing skin grafts.

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Significant Improvement in length of stay for skin graft patients with fibrin glue.

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Meta-Analysis of graft survival, pain and operative time for skin graft patients who had fibrin glue.

Autologous Matrix of Platelet-Rich Fibrin in Wound Care Settings: A Systematic Review of Randomized Clinical Trials

Platelet-rich fibrin (PRF) consists of a matrix that provides the necessary elements for wound healing, acting as a biodegradable scaffold for cell migration, proliferation, and differentiation, in addition to the delivery of growth factors and angiogenesis. This study aims to determine the effectiveness of the autologous PRF in the treatment of wounds of different etiologies. We carried out a systematic review of randomized clinical trials, guided by the recommendations of the Cochrane Collaboration using the following databases: Pubmed/MEDLINE, EMBASE, Web of Science, and CENTRAL. The search strategy resulted in the inclusion of ten studies that evaluated the use of PRF dressings for the healing of acute or chronic wounds of multiple etiologies. Among the 172 participants treated with PRF in wounds of varying etiologies and different segment times, 130 presented favorable events with the use of the intervention. Among the 10 studies included, only two of them did not demonstrate better results than the control group. The studies showed clinical heterogeneity, making it impossible to perform a meta-analysis. The findings do not provide enough evidence to support the routine use of PRF dressings as the first line of treatment for the healing of acute or chronic wounds of different etiologies. There was great variability in the application of the various protocols and the ways to prepare the PRF, resulting in clinical heterogeneity. Therefore, it makes it impossible to synthesize and to collect evidence from different types of studies in the meta-analysis, which affects the results and their proper discussion.

Evaluation of the Effect of Platelet-Rich Fibrin on Wound Healing at Split-Thickness Skin Graft Donor Sites: A Randomized, Placebo-Controlled, Triple-Blind Study

Split-thickness skin grafting (STSG) is widely used to heal wounds resulting from trauma, burns, and chronic wounds. This study aimed to determine the true effect of platelet-rich fibrin (PRF) on patients with burn wounds requiring STSG during treatment of donor wounds. This randomized, triple-blind clinical trial was conducted on patients who referred to the burn ward of Vasei Hospital of Sabzevar, Iran, from May 2017 to May 2018. The donor site was randomly divided into 2 groups: PRF and control (Vaseline petrolatum gauze) using Vaseline gauze. In the intervention group, the PRF gel was applied to the wound and covered with Vaseline gauze and wet dressing. Conversely, only Vaseline gauze and wet dressing were applied to the control group. Outcome evaluation was conducted using paired t test and Wilcoxon signed rank-sum test, as appropriate, on days 8 and 15. The mean age of the patients was 33.10 ± 2.60 years, and 51.50% were male. The mean wound healing time in the PRF and control groups was 11.80 ± 3.51 and 16.30 ± 4.32 days, respectively ( P < .001). The PRF group showed significantly higher wound healing rates than the control group at 8 and 15 days dressing ( P < .001 and P < .001, respectively). Moreover, the mean wound healing for all wound healing indices diagnosed by 2 specialists in PRF was higher than control group on days 8 and 15 ( P < .001). We found a statistically significant difference on days 8 and 15 regarding the mean pain levels between the 2 groups ( P < .001). The findings showed that PRF can significantly increase the time and rate of donor wound healing compared with conventional treatment and also reduce the severity of pain.

A Novel Method of Obtaining Platelet Rich Fibrin from Rats and Quantifying Platelet Count

Background and objectives: Rat experimentation is the first line of research by which a medical hypothesis is usually tested. Platelet Rich Fibrin (PRF) is a relatively new bio-material that has shown promise to enhance healing in the field of bone research and tissue engineering. In order to perform PRF based experiments on rats, a proper protocol of obtaining PRF from rats needs to be established. Materials and Methods: 35 Wistar rats were used to obtain PRF by using cardiac puncture blood draw and quick subsequent centrifugation. The PRF samples wereanalyzed and compared to standard literature PRF composition. Results: PRF samples analysis showed persistent results pertaining to known PRF composition. Conclusions: Our experiment has shown that our protocol of obtaining PRF is capable of providing high quality PRF from rats.

Efficacy and safety of platelet-rich plasma in treating cutaneous ulceration: A meta-analysis of randomized controlled trials

BACKGROUND

The biological mechanisms underlying the use of platelet-rich plasma (PRP), as well as the efficacy and possible adverse effects of PRP, have not yet been fully elucidated. Prior studies have evaluated PRP for cutaneous ulceration. However, the benefits from PRP still remain controversial and few have assessed the effects of ulceration etiologies. The purpose of our study is to determine the efficacy and safety of PRP and which kind of ulcer is more suitable for PRP by analyzing the effects of PRP on ulcers with different causes.

METHODS

A comprehensive search was performed to identify randomized controlled trials (RCTs) regarding the application of PRP from PubMed, EMBASE, Scopus, and the Cochrane Library. The data were analyzed using Review Manager 5.3.

RESULTS

A total of nineteen RCTs (909 patients) were included. In contrast with conventional treatments, PRP achieved higher healing rate, higher percentage of area reduction, and smaller final area in vascular ulcers. However, the advantage disappeared in diabetic and pressure ulcers. Concerning adverse events, PRP showed lower incidence in the short term, but higher in the long term. No significant differences were found in ulcer closure velocity and healing time.

CONCLUSION

Platelet-rich plasma effectiveness and safety in treating cutaneous ulceration depend on what is the ulceration etiology. For diabetic ulcers, PRP showed no satisfactory results suggesting that PRP may not be suitable for diabetic patients. However, PRP could be efficient and more beneficial for vascular ulcers and effects on pressure ulcers remain unclear. Thus, PRP option should be carefully considered for each patient in accordance with their ulceration etiologies.

Use of platelet-rich plasma to facilitate wound healing

Platelet-rich plasma (PRP) is widely used nowadays in different fields of medicine, affecting physiological processes including tissue regeneration. The use of PRP in maxillofacial surgical interventions and its efficiency in the improvement of postoperative wound healing were analysed. Patients undergoing plastic and reconstructive surgeries in the maxillofacial region were recruited: 50 patients were enrolled into a control group (received no PPRP injection) and 50 patients were enrolled into a treatment group, where PRP was applied during the surgical procedure. Evaluation of treatment outcomes was carried out by determination of IL-1β, TNFα, and IL-6 cytokines levels in the wound-drain fluid. The stages of wound healing were assessed by cytological analyses and ultrasound within a month period. The use of the PRP has substantially positive effects, contributing to the improvement of the healing process. In the treatment group, fibroblasts, macrophages, and collagen fibres appeared and their quantities increased earlier than when compared with control group patients. The concentration of IL-1β and TNFα in wound fluid on day 1 and day 5 after operation was higher for the treatment group as opposed to the control group, which was linked to the influence of PRP on inflammatory and granulation phases of the healing process. An ultrasound examination showed less oedema and infiltration in the tissues around the wound of the treatment group.

Role of platelet-rich fibrin on intestinal anastomosis wound healing in a rat

OBJECTIVES

The aim of the present study is to investigate the role of platelet-rich fibrin (PRF) on the intestinal anastomotic wound healing in a mesenteric ischemia/reperfusion (I/R) rat model.

METHODS

Forty male Sprague Dawley rats were allocated into four groups: Group I (n = 10): anastomosis to normal bowel; Group II (n = 10): anastomosis after I/R injury; Group III (n = 10): anastomosis and PRF; Group IV: anastomosis after I/R and PRF. Animals were followed up for 7 days, then sacrificed. Anastomotic complications, anastomosis bursting pressures and histopathologic evaluations of the anastomoses were the study parameters.

RESULTS

The I/R injury caused more anastomotic adhesion and very low anastomotic bursting pressure when compared with the other groups (p < 0.01). Application of PRF onto the bowel, however, dramatically decreased the local complications and significantly increased the anastomosis bursting pressures (p < 0.01). Histologic evaluation of the anastomoses showed almost complete healing in all animals. The mean histologic scores of the animals were not different between the groups.

CONCLUSION

PRF has a beneficial effect on the intestinal healing process by prevention of local complications and increases the tensile strain of the anastomosis. This effect was more prominent, particularly when healing is disrupted. Therefore, we conclude that PRF could be an alternative treatment option to prevent anastomotic complications for elderly, co-morbid and emergency patients.

Clinical Application of Platelet-Rich Fibrin in Plastic and Reconstructive Surgery: A Systematic Review

BACKGROUND

Platelet-rich fibrin (PRF) has been applied in the clinical field for more than a decade, but largely in oral surgery and implant dentistry. Its utilization in plastic and reconstructive surgery is limited and lacking a comprehensive review. Hence, this article focuses on the various clinical applications of PRF pertaining to the plastic and reconstructive field through a systematic review.

METHODS

In this review, articles describing the clinical application of PRF in plastic and reconstructive surgery were screened using predetermined inclusion and exclusion criteria. The articles were summarized and divided into groups based on the utilization of PRF. The effects and complications of PRF were analyzed and concluded.

RESULTS

Among the 634 articles searched, 7 articles describing 151 cases are eligible. PRF was applied on 116 (76.8%) wounds to facilitate tissue healing, and the complete wound closure rate was 91.4% (106/116). Otherwise, PRF was applied in 10 (6.6%) cases of zygomaticomaxillary fracture to reconstruct orbital floor defects and in 25 (16.6%) cases of facial autologous fat grafts to increase the fat retention rate successfully. There is no report of PRF-related complications.

CONCLUSIONS

PRF could facilitate wound healing, including the healing of soft tissues and bony tissues, and facilitate fat survival rate. Further studies are needed to test the mechanism of PRF and expand its scope of application in plastic and reconstructive surgery.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The use of fibrin sealant during non-emergency surgery: a systematic review of evidence of benefits and harms

BACKGROUND

Fibrin sealants are used in different types of surgery to prevent the accumulation of post-operative fluid (seroma) or blood (haematoma) or to arrest haemorrhage (bleeding). However, there is uncertainty around the benefits and harms of fibrin sealant use.

OBJECTIVES

To systematically review the evidence on the benefits and harms of fibrin sealants in non-emergency surgery in adults.

DATA SOURCES

Electronic databases [MEDLINE, EMBASE and The Cochrane Library (including the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Health Technology Assessment database and the Cochrane Central Register of Controlled Trials)] were searched from inception to May 2015. The websites of regulatory bodies (the Medicines and Healthcare products Regulatory Agency, the European Medicines Agency and the Food and Drug Administration) were also searched to identify evidence of harms.

REVIEW METHODS

This review included randomised controlled trials (RCTs) and observational studies using any type of fibrin sealant compared with standard care in non-emergency surgery in adults. The primary outcome was risk of developing seroma and haematoma. Only RCTs were used to inform clinical effectiveness and both RCTs and observational studies were used for the assessment of harms related to the use of fibrin sealant. Two reviewers independently screened all titles and abstracts to identify potentially relevant studies. Data extraction was undertaken by one reviewer and validated by a second. The quality of included studies was assessed independently by two reviewers using the Cochrane Collaboration risk-of-bias tool for RCTs and the Centre for Reviews and Dissemination guidance for adverse events for observational studies. A fixed-effects model was used for meta-analysis.

RESULTS

We included 186 RCTs and eight observational studies across 14 surgical specialties and five reports from the regulatory bodies. Most RCTs were judged to be at an unclear risk of bias. Adverse events were inappropriately reported in observational studies. Meta-analysis across non-emergency surgical specialties did not show a statistically significant difference in the risk of seroma for fibrin sealants versus standard care in 32 RCTs analysed [n = 3472, odds ratio (OR) 0.84, 95% confidence interval (CI) 0.68 to 1.04; p = 0.13; I² = 12.7%], but a statistically significant benefit was found on haematoma development in 24 RCTs (n = 2403, OR 0.62, 95% CI 0.44 to 0.86; p = 0.01; I² = 0%). Adverse events related to fibrin sealant use were reported in 10 RCTs and eight observational studies across surgical specialties, and 22 RCTs explicitly stated that there were no adverse events. One RCT reported a single death but no other study reported mortality or any serious adverse events. Five regulatory body reports noted death from air emboli associated with fibrin sprays.

LIMITATIONS

It was not possible to provide a detailed evaluation of individual RCTs in their specific contexts because of the limited resources that were available for this research. In addition, the number of RCTs that were identified made it impractical to conduct independent data extraction by two reviewers in the time available.

CONCLUSIONS

The effectiveness of fibrin sealants does not appear to vary according to surgical procedures with regard to reducing the risk of seroma or haematoma. Surgeons should note the potential risk of gas embolism if spray application of fibrin sealants is used and not to exceed the recommended pressure and spraying distance. Future research should be carried out in surgery specialties for which only limited data were found, including neurological, gynaecological, oral and maxillofacial, urology, colorectal and orthopaedics surgery (for any outcome); breast surgery and upper gastrointestinal (development of haematoma); and cardiothoracic heart or lung surgery (reoperation rates). In addition, studies need to use adequate sample sizes, to blind participants and outcome assessors, and to follow reporting guidelines.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020710.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Adjuvant Biological Therapies in Chronic Leg Ulcers

Current biological treatments for non-healing wounds aim to address the common deviations in healing mechanisms, mainly inflammation, inadequate angiogenesis and reduced synthesis of extracellular matrix. In this context, regenerative medicine strategies, i.e., platelet rich plasmas and mesenchymal stromal cell products, may form part of adjuvant interventions in an integral patient management. We synthesized the clinical experience on ulcer management using these two categories of biological adjuvants. The results of ten controlled trials that are included in this systematic review favor the use of mesenchymal stromal cell based-adjuvants for impaired wound healing, but the number and quality of studies is moderate-low and are complicated by the diversity of biological products. Regarding platelet-derived products, 18 controlled studies investigated their efficacy in chronic wounds in the lower limb, but the heterogeneity of products and protocols hinders clinically meaningful quantitative synthesis. Most patients were diabetic, emphasizing an unmet medical need in this condition. Overall, there is not sufficient evidence to inform routine care, and further clinical research is necessary to realize the full potential of adjuvant regenerative medicine strategies in the management of chronic leg ulcers.

Apprising the diverse facets of Platelet rich fibrin in surgery through a systematic review

CONTEXT

Comprehensive reviews on clinical applications of Platelet rich fibrin (PRF) in surgery are limited despite its extensive utilization resulting in a dearth of knowledge on its effectiveness. Hence this article focuses on shedding light to the various applications of PRF pertaining to surgery through a systematic review.

OBJECTIVE

The systematic review is aimed at evaluating the value of PRF in different areas of surgery.

DATA SOURCES

A systematic review of articles sourced from MEDLINE-pubmed (2008-2017(July)) was done. Additional articles were searched through GOOGLE SCHOLAR and SCIENCE DIRECT. Search terms such as Platelet rich fibrin; Platelet rich fibrin, surgery; Platelet concentrate; second generation concentrate; Applications of PRF in surgery were used.

STUDY SELECTION

Systematic reviews, Randomized control trials, Pilot studies and Case reports were included. Non English articles, in-vitro and animal studies were excluded.

DATA EXTRACTION

Independent sourcing of articles by 3 authors using a set of predefined criteria.

DATA SYNTHESIS

Out of the 25 articles covering various surgical procedures that met the inclusion criteria, positive outcomes were noted in most. Although categorization into one specific type of study was not done, the overall success rate with PRF usage was 78%.No differences between test and control groups were observed in 2 studies and 3 studies showed no significant improvements with the usage of PRF.

LIMITATIONS

The systematic review did not categorize the study designs while evaluating success rates which might be considered as a shortcoming as case reports were also included.

CONCLUSIONS

The future propositions are vast and point towards innovative applications of this bio-material possibly in transplant and burn cases if a method of obtaining large amounts can be devised. However since we rely on evidence-based results, further long term studies are needed in distinct areas of applications to decisively prove its effectiveness.

Platelet-Rich Fibrin and Soft Tissue Wound Healing: A Systematic Review

The growing multidisciplinary field of tissue engineering aims at predictably regenerating, enhancing, or replacing damaged or missing tissues for a variety of conditions caused by trauma, disease, and old age. One area of research that has gained tremendous awareness in recent years is that of platelet-rich fibrin (PRF), which has been utilized across a wide variety of medical fields for the regeneration of soft tissues. This systematic review gathered all the currently available in vitro, in vivo, and clinical literature utilizing PRF for soft tissue regeneration, augmentation, and/or wound healing. In total, 164 publications met the original search criteria, with a total of 48 publications meeting inclusion criteria (kappa score = 94%). These studies were divided into 7 in vitro, 11 in vivo, and 31 clinical studies. In summary, 6 out of 7 (85.7%) and 11 out of 11 (100%) of the in vitro and in vivo studies, respectively, demonstrated a statistically significant advantage for combining PRF to their regenerative therapies. Out of the remaining 31 clinical studies, a total of 8 reported the effects of PRF in a randomized clinical trial, with 5 additional studies (13 total) reporting appropriate controls. In those clinical studies, 9 out of the 13 studies (69.2%) demonstrated a statistically relevant positive outcome for the primary endpoints measured. In total, 18 studies (58% of clinical studies) reported positive wound-healing events associated with the use of PRF, despite using controls. Furthermore, 27 of the 31 clinical studies (87%) supported the use of PRF for soft tissue regeneration and wound healing for a variety of procedures in medicine and dentistry. In conclusion, the results from the present systematic review highlight the positive effects of PRF on wound healing after regenerative therapy for the management of various soft tissue defects found in medicine and dentistry.

The application of platelet-rich plasma in the treatment of deep dermal burns: A randomized, double-blind, intra-patient controlled study

Platelet-rich plasma (PRP) is a fraction of blood with a platelet concentration above baseline. When platelets get activated, growth factors involved in wound healing are released. The application of PRP has shown good results in wound care, however, up to date no substantial research has been performed on the effect of PRP in burn treatment. This randomized double blind intra-patient controlled study investigates the effect of autologous PRP on wound healing in burns that require surgery with a meshed split skin graft (SSG). Fifty-two patients with various areas of deep dermal to full thickness burns, receiving surgery with a SSG were included after informed consent. Comparable study areas A and B (intra-patient) were appointed, randomized and either treated with a SSG and PRP or with a SSG alone. At day 5 to 7 postoperative, the epithelialization and graft take rate were assessed. Three, six, and twelve months postoperative, follow-up measurements were performed in the form of POSAS-questionnaires, DermoSpectroMeter, and Cutometer measurements. There was no statistically significant difference between the mean take rate nor the mean epithelialization rate at day 5-7 between the PRP-treated and control areas. However, PRP-treated wound areas showed more often better or equal epithelialization and take rates at day 5-7 than the standard treated areas. Minor effects were also seen in the reoperated and early operated subgroups. At 3, 6, and 12 months postoperative, POSAS scores from the patients and the observers, Dermaspectro-, and Cutometer measurements did not depict a significant difference between the PRP and standard treated areas. Concluding, the addition of PRP in the treatment of burn wounds did not result in improved graft take and epithelialization, nor could we demonstrate better scar quality. There was, however, a considerable variation in our clinical population.

Autologous platelet-rich plasma for treating chronic wounds

BACKGROUND

Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors with the potential to improve the healing of chronic wounds. This is the first update of a review first published in 2012.

OBJECTIVES

To determine whether autologous PRP promotes the healing of chronic wounds.

SEARCH METHODS

In June 2015, for this first update, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library): Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also searched for ongoing and unpublished clinical trials in the WHO International Clinical Trials Registry Platform (ICTRP) (searched January 2015). We did not impose any restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults. We did not apply any date or language restrictions.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology, including two reviewers independently selecting studies for inclusion, extracting data, and assessing risk of bias.

MAIN RESULTS

The search identified one new RCT, making a total of 10 included RCTs (442 participants, 42% women). The median number of participants per RCT was 29 (range 10 to 117). Four RCTs recruited people with a range of chronic wounds; three RCTs recruited people with venous leg ulcers, and three RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range 8 to 40 weeks).It is unclear whether autologous PRP improves the healing of chronic wounds generally compared with standard treatment (with or without placebo) (risk ratio (RR) 1.19, 95% confidence interval (CI) 0.95 to 1.50; I(2) = 27%, low quality evidence, 8 RCTs, 391 participants). Autologous PRP may increase the healing of foot ulcers in people with diabetes compared with standard care (with or without placebo) (RR 1.22, 95% CI 1.01 to 1.49; I(2) = 0%, low quality evidence, 2 RCTs, 189 participants). It is unclear if autologous PRP affects the healing of venous leg ulcers (RR 1.02, 95% CI 0.81 to 1.27; I(2) = 0% ). It is unclear if there is a difference in the risk of adverse events in people treated with PRP or standard care (RR 1.05, 95% CI 0.29 to 3.88; I(2) = 0%, low quality evidence from 3 trials, 102 participants).

AUTHORS' CONCLUSIONS

PRP may improve the healing of foot ulcers associated with diabetes, but this conclusion is based on low quality evidence from two small RCTs. It is unclear whether PRP influences the healing of other chronic wounds. The overall quality of evidence of autologous PRP for treating chronic wounds is low. There are very few RCTs evaluating PRP, they are underpowered to detect treatment effects, if they exist, and are generally at high or unclear risk of bias. Well designed and adequately powered clinical trials are needed.

S100A8/A9 is an important host defence mediator in neuropathic foot ulcers in patients with type 2 diabetes mellitus

Chronic wounds and in particular diabetic foot ulcers (DFUs) are a growing clinical challenge, but the underlying molecular pathophysiological mechanisms are unclear. Recently, we reported reduced levels of the immunomodulating and antimicrobial S100A8/A9 in non-healing venous leg ulcers (VLUs), while another study found increased S100A8/A9 in DFUs. To clarify these apparently contradictory findings, we compared S100A8/A9 as well as an inducer, lipopolysaccharide (LPS) and selected innate immune response mediators in wound fluids from non-healing DFUs and VLUs with healing wounds. Wound fluids were collected from neuropathic DFUs (n = 6) and VLUs (n = 9) of median 2-year duration, and split-thickness skin graft donor site wounds (n = 10) by standardized method. None of the patients had ischaemic extremities or clinically infected wounds. LPS was determined by limulus amoebocyte lysate test, and S100A8/A9, granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-10 and vascular endothelial growth factor (VEGF) by immunospecific quantitative assays. LPS levels were median 8.7 (interquartile range 5.4-21.2) ng/ml in DFUs compared with 121 (22-2000) ng/ml in VLUs. S100A8/A9 was higher (p = 0.020) in DFUs [718 (634-811) µg/ml] than in VLUs [303 (252-533) µg/ml]. Neither G-CSF nor IL-10 wound fluid levels differed significantly between the chronic wound groups. VEGF levels correlated with LPS (r = 0.758, p = 0.011, n = 10) and were higher (p = 0.024) in VLU wound fluids. LPS (p < 0.0001), S100A8/A9 (p = 0.005), G-CSF (p = 0.003), IL-10 (p = 0.003) and VEGF (p = 0.005) were increased in chronic wound fluids combined compared with the sterile donor site wound fluids. The protein alterations in the wounds were not reflected in the patients' sera. Low S100A8/A9 levels may contribute to poor wound healing in colonized chronic wounds with striking difference between DFUs and VLUs.

UV fluorescence excitation imaging of healing of wounds in skin: Evaluation of wound closure in organ culture model

BACKGROUND AND OBJECTIVE

Molecules native to tissue that fluoresce upon light excitation can serve as reporters of cellular activity and protein structure. In skin, the fluorescence ascribed to tryptophan is a marker of cellular proliferation, whereas the fluorescence ascribed to cross-links of collagen is a structural marker. In this work, we introduce and demonstrate a simple but robust optical method to image the functional process of epithelialization and the exposed dermal collagen in wound healing of human skin in an organ culture model.

MATERIALS AND METHODS

Non-closing non-grafted, partial closing non-grafted, and grafted wounds were created in ex vivo human skin and kept in culture. A wide-field UV fluorescence excitation imaging system was used to visualize epithelialization of the exposed dermis and quantitate wound area, closure, and gap. Histology (H&E staining) was also used to evaluate epithelialization.

RESULTS

The endogenous fluorescence excitation of cross-links of collagen at 335 nm clearly shows the dermis missing epithelium, while the endogenous fluorescence excitation of tryptophan at 295 nm shows keratinocytes in higher proliferating state. The size of the non-closing wound was 11.4 ± 1.8 mm and remained constant during the observation period, while the partial-close wound reached 65.5 ± 4.9% closure by day 16. Evaluations of wound gaps using fluorescence excitation images and histology images are in agreement.

CONCLUSIONS

We have established a fluorescence imaging method for studying epithelialization processes, evaluating keratinocyte proliferation, and quantitating closure during wound healing of skin in an organ culture model: the dermal fluorescence of pepsin-digestible collagen cross-links can be used to quantitate wound size, closure extents, and gaps; and, the epidermal fluorescence ascribed to tryptophan can be used to monitor and quantitate functional states of epithelialization. UV fluorescence excitation imaging has the potential to become a valuable tool for research, diagnostic and educational purposes on evaluating the healing of wounds. Lasers Surg. Med. 48:678-685, 2016. © 2016 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Growth Factor Release from Lyophilized Porcine Platelet-Rich Plasma: Quantitative Analysis and Implications for Clinical Applications

BACKGROUND

Freeze-dried platelet-rich plasma (FD PRP) is of potential value for clinical applications. However, growth factors released from FD PRP have not been well studied. Our study investigates growth factor release from FD PRP preparations, compared with other PRP samples, to further facilitate such clinical use.

METHODS

We used four experimental groups: (1) Fresh porcine PRP (PRP), (2) PRP activated by calcium chloride (CaCl2) (Ca PRP), (3) PRP activated by CaCl2, followed by freeze drying (Ca-FD PRP), and (4) PRP freeze-dried first, then activated by CaCl2 (FD-Ca PRP). All FD PRP samples were kept for up to 4 weeks at room temperature (22 °C) and reconstituted prior to analysis. Transforming growth factor-β1 (TGF-β1), platelet-derived growth factor AB (PDGF-AB), and vascular endothelial growth factor (VEGF) were quantitated by ELISA at 15 min and 1 h incubation times.

RESULTS

The concentrations of all growth factors in Ca PRP, measured at 1 h, were significantly higher than those in PRP (p < 0.05). PDGF-AB concentrations in FD-Ca PRP were not significantly different than in Ca PRP (p > 0.05). Levels of VEGF in Ca-FD PRP were not significantly different than in Ca PRP (p > 0.05). However, TGF-β1 concentrations in Ca-FD PRP, measured at 15 min, were higher than those in Ca PRP (p < 0.05).

CONCLUSIONS

PRP was activated efficiently by calcium chloride. Freeze-dried PRP remained rich in growth factors after storage for 4 weeks at room temperature, indicating its ease of use and wider possibilities for clinical applications.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Platelet Preparations for Use in Facial Rejuvenation and Wound Healing: A Critical Review of Current Literature

In facial plastic surgery, the potential for direct delivery of growth factors from platelet preparations has been of particular interest for use in facial rejuvenation, recovery after facial surgery, and wound healing. A literature search was conducted through PubMed for the terms PRP, PRFM, platelet-rich plasma, platelet-rich fibrin 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 were included. Thirteen in vitro studies showed use of platelet-rich plasma (PRP) and platelet-rich fibrin matrix (PRFM) had a significant effect on cellular activity. Twenty-four out of 28 animal studies exhibited favorable results with use of a platelet preparation, including five of six studies that showed enhanced fat graft survival with addition of a platelet preparation. Twenty-three case series and clinical trials were identified, only two of which showed no differences. Twenty-one reported favorable results with use of various platelet preparations. A total of 47 studies used PRP, four studies evaluated Leukocyte-rich PRP, and fourteen studies used PRFM. The vast majority of studies examined show a significant and measurable effect on cellular changes, wound healing, and facial esthetic outcomes with use of platelet preparations, both topical and injectable. One must also consider possible publication bias against null results that may have had an influence on the data that were available for review. However, the preponderance of studies suggests that platelet preparations might represent an as-of-yet untapped adjunct in facial plastic surgery.

Reduction of pain via platelet-rich plasma in split-thickness skin graft donor sites: a series of matched pairs

In the past decade, autologous platelet-rich plasma (PRP) therapy has seen increasingly widespread integration into medical specialties. PRP application is known to accelerate wound epithelialization rates, and may also reduce postoperative wound site pain. Recently, we observed an increase in patient satisfaction following PRP gel (Angel, Cytomedix, Rockville, MD) application to split-thickness skin graft (STSG) donor sites. We assessed all patients known to our university-based hospital service who underwent multiple STSGs up to the year 2014, with at least one treated with topical PRP. Based on these criteria, five patients aged 48.4±17.6 (80% male) were identified who could serve as their own control, with mean time of 4.4±5.1 years between operations. In both therapies, initial dressing changes occurred on postoperative day (POD) 7, with donor site pain measured by Likert visual pain scale. Paired t-tests compared the size and thickness of harvested skin graft and patient pain level, and STSG thickness and surface area were comparable between control and PRP interventions (p>0.05 for all). Donor site pain was reduced from an average of 7.2 (±2.6) to 3 (±3.7), an average reduction in pain of 4.2 (standard error 1.1, p=0.0098) following PRP use. Based on these results, the authors suggest PRP as a beneficial adjunct for reducing donor site pain following STSG harvest.

Considerations on the use of platelet-rich plasma, specifically for burn treatment

Platelet-rich plasma (PRP) is a fraction of blood plasma with a platelet concentration above baseline. After activation of the platelets, growth factors are released, which are involved in wound-healing processes. Application of a multitude of growth factors seems to boost the healing process. In this review the authors provide a comprehensive overview of the many different aspects of PRP; this is followed by a short outline of the evidence for a wide range of applications and finally narrowing down to a more in-depth analysis of the literature on the potential use of PRP in burn treatment. The authors performed an extensive search on PRP and the different biological, as well as practical aspects for the different applications. Furthermore, we performed a systematic search on PRP in the treatment of burn wounds. A high variety exists in PRP products, procedures, and content. This makes interpretation and comparison of the evidence difficult. PRP has been reported to have beneficial effects on wound healing in different fields of surgery and in the treatment of acute, chronic, and diabetic wounds. Literature on the use of PRP in burns is scarce. Separate growth factors have shown beneficial results in the treatment of burns. Furthermore, an animal study and several case reports showed improved burn wound-healing time after the application of PRP. A deep dermal burn could benefit from PRP through its hemostatic antimicrobial abilities and the positive effects seen in wound healing. However, burn patients have an altered physiological state and it is unknown how this may affect platelet function and quality. Furthermore, the effect of PRP on scarring has not been evaluated properly. Future research is needed to elucidate the role of PRP in the treatment of burns.

Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair

BACKGROUND AND OBJECTIVES

Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods.

MATERIALS AND METHODS

Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays.

RESULTS

The number of leucocytes and erythrocytes was reduced (P < 0·001), whereas platelets increased (P < 0·001) in fibrin-I versus whole blood. PRF contained 982 ± 206 × 10(9) platelets/l representing 3·9-fold (P < 0·001) enrichment relative to whole blood. Growth factor abundance in Vivostat PRF and serum was in descending order: transforming growth factor-β1 [5·1-fold higher in PRF than serum, P < 0·001] > platelet-derived growth factor (PDGF)-AB [2·5-fold, P < 0·01] > PDGF-BB [1·6-fold, P < 0·05] > vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P < 0·001]. MMP-9 was reduced 139-fold (P < 0·001) compared with serum, reflecting leucocyte depletion in PRF.

CONCLUSION

The gained knowledge on platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications.

Efficacy of leukocyte- and platelet-rich fibrin in wound healing: a randomized controlled clinical trial

BACKGROUND

Application of platelet concentrates to wounds could speed healing. Leukocyte- and platelet-rich fibrin, a relatively recent development, stands out from the other preparations. This prospective, randomized, controlled clinical trial studied the rate of healing of postoperative hand wounds after a single application of leukocyte- and platelet-rich fibrin.

METHODS

Eligible patients were healthy individuals older than 18 years who had been scheduled for elective McCash (open palm) surgery for Dupuytren disease at the Plastic and Hand Surgery Department of Nice's University Hospital between August of 2007 and February of 2010. The control group received the reference care of petroleum jelly mesh (Vaselitulle), and test patients had leukocyte- and platelet-rich fibrin applied. The primary endpoint was healing delay measured in postoperative days. Secondary endpoints included pain, bleeding, and wound exudate. The trial was carried out as a single-blind trial.

RESULTS

Among the 68 randomized patients, 33 patients in the leukocyte- and platelet-rich fibrin group and 31 in the Vaselitulle group were analyzed. Primary endpoint analysis showed a median healing delay of 24 days (interquartile range, 18 to 28 days) for the fibrin group and 29 days (interquartile range, 26 to 35 days) for the Vaselitulle group (p = 0.014, log-rank test). Postoperative pain assessment, bleeding, and exudate were always lower for the fibrin group, but not significantly so.

CONCLUSION

The authors trial demonstrates that a single leukocyte- and platelet-rich fibrin application on fresh postoperative hand wounds shows a median improvement of 5 days in comparison with the standard treatment.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

The use of platelet-rich plasma in plastic surgery: a systematic review

OBJECTIVE

The study's aim was to evaluate the available evidence regarding the use of platelet-rich plasma in plastic and reconstructive surgery, through implementation of a systematic review of the literature.

DATA SOURCES

PubMed and The Cochrane Library were searched using MeSH terms: 'platelet rich plasma' and 'plastic surgery' for all publications up to July 2011. All English, German, French and Dutch papers were included. In addition, the reference lists of relevant articles were searched for potentially appropriate publications.

STUDY SELECTION

Included studies needed to report on topics related to plastic and reconstructive surgery, mentioning at least one clinical end point. Both in vivo and in vitro comparative studies, performed in humans or animals, were included. A total of 82 publications were found, of which 40 studies met the inclusion criteria and were relevant to be used in this systematic review.

DATA EXTRACTION

Data from retrieved studies were reviewed and tabulated according to year of publication, study design, human or animal studies, characteristics of the population, mode of application, outcomes and preparation method.

DATA SYNTHESIS

A total of 15 randomised controlled trials and 25 case-control studies were found. Thirty-six publications demonstrated favourable outcomes with the use of platelet-rich plasma. The included articles were divided into three topics related to plastic surgery: wound healing, fat grafting and bone grafting.

CONCLUSIONS

This systematic review describes a substantially beneficial effect of platelet-rich plasma for several indications, including a better wound healing rate, an increased survival rate of fat grafts and an enhancement of bone graft regeneration.

Autologous platelet-rich plasma for treating chronic wounds

BACKGROUND

Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors and has the potential to aid wound healing.

OBJECTIVES

To determine whether autologous PRP promotes the healing of chronic wounds.

SEARCH METHODS

We searched the Cochrane Wounds Group Specialised Register (searched 15 August 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8); Ovid MEDLINE (1950 to August Week 1 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, August 14, 2012); Ovid EMBASE (1980 to 2012 Week 32); EBSCO CINAHL (1982 to 10 August 2012) and International Clinical Trials Registry Platform (ICTRP)(accessed 22 August 2012). No date or language restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each study against the inclusion criteria, extracted data and assessed risk of bias for all included trials. We calculated the risk ratio (RR) or the mean difference (MD) and time to wound healing was analysed as survival data using the hazard ratio (HR). We considered heterogeneity as significant when I(2) was >75%.

MAIN RESULTS

Nine eligible RCTs were included, with a total of 325 participants of whom 44% were women. The median number of participants per RCT was 26 (range 10 to 86). Four RCTs recruited people with mixed chronic wounds (there were participants with wounds caused by more than one aetiology and participants who had wounds of several aetiologies in the same trial), three RCTs recruited people with venous leg ulcers and two RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range eight to 40 weeks).One study was at low risk of bias, three studies were at high risk of bias with the remainder being at overall unclear risk of bias. The proportion of completely healed chronic wounds was reported in seven RCTs that compared PRP with standard treatment or placebo, with no statistically significant difference between the groups, in diabetic foot ulcers (RR 1.16; 95% CI 0.57 to 2.35), in venous leg ulcers (pooled RR 1.02; 95% CI 0.81 to 1.27; I(2)=0% ) and in mixed chronic wounds (pooled RR 1.85; 95% CI 0.76 to 4.51; I(2)=42%). The total area epithelialised at the end of the intervention was reported in three RCTs of mixed chronic wounds, there was no statistically significant difference between the groups (pooled MD -1.94 cm(2); 95% CI -4.74 to 0.86; I(2)=47%). The percentage of wound area healed was reported in two RCTs of mixed chronic wounds, and results were statistically significant in favour of the PRP group (RR 51.78%; 95% CI 32.70 to 70.86; I(2)= 0%). Wound complications like infection or necrosis were reported by three RCTs, and there was no statistically significant difference between groups (RR 1.08; 95% CI 0.31 to 3.73). Adverse effects were reported by three studies and there was no statistically significant difference between people treated with PRP and those not given PRP (pooled RR 1.07; 95% CI 0.32 to 3.58; I(2)=0%).

AUTHORS' CONCLUSIONS

There is currently no evidence to suggest that autologous PRP is of value for treating chronic wounds. However, current evidence is based on a small number of RCTs, most of which are either at high or unclear risk of bias. Well-designed and adequately powered clinical trials are needed.

Platelet-rich fibrin matrix for facial plastic surgery

Platelets are known primarily for their role in hemostasis, but there is increasing interest in the effect of platelets on wound healing. Platelet isolates such as platelet-rich plasma have been advocated to enhance and accelerate wound healing. This article describes the use of a novel preparation, platelet-rich fibrin matrix (PRFM), for facial plastic surgery applications such as volume augmentation, fat transfer supplementation, and as an adjunct to open surgical procedures.