Comparison of Efficacy of Autologous Platelet-rich Fibrin versus Saline Dressing in Chronic Venous Leg Ulcers: A Randomised Controlled Trial

Treatment of vascular leg ulcers with leukocyte- and platelet-rich fibrin (L-PRF): A systematic review

Objectives: This systematic review aimed to assess the efficacy of Leukocyte- and Platelet-Rich Fibrin (L-PRF) for the treatment of vascular leg ulcers. Method: Following PRISMA guidelines, a literature search was done for studies where L-PRF was used to treat vascular leg ulcers. Results: Among six included articles, a total of 76 venous leg ulcers were treated with L-PRF. None of the studies included ulcers of arterial or lymphatic origin. Fifty-seven (75.0%) of the venous ulcers completely healed at end of follow-up. Mean time to complete healing was 6.7 weeks (SD = 5.0). All non-healed ulcers showed an important reduction in wound area. No adverse effects related to L-PRF therapy were reported. Conclusions: The results suggest that L-PRF could be a safe, simple to use and effective therapeutic option for the treatment of venous leg ulcers, however, caution is advised as the results are based on small sample sizes.

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.

A randomised Trial of Autologous Blood products, leukocyte and platelet-rich fibrin (L-PRF), to promote ulcer healing in LEprosy: The TABLE trial

INTRODUCTION

Autologous blood products like Platelet Rich Plasma (PRP) and Leukocyte and Platelets Rich Fibrin (L-PRF) have been used for many years across many types of skin ulcers. However, the effectiveness of autologous blood products on wound healing is not well established.

METHODS

We evaluated the 'second generation' autologous product- Leukocyte and Platelet- Rich Fibrin (L-PRF). Our trial was undertaken on patients suffering from neuropathic leprosy ulcers at the Anandaban hospital which serves the entire country of Nepal. We conducted a 1:1 (n = 130) individually randomised trial of L-PRF (intervention) vs. normal saline dressing (control) to compare rate of healing and time to complete healing. Rate of healing was estimated using blind assessments of ulcer areas based on three different measurement methods. Time to complete healing was measured by the local unblinded clinicians and by blind assessment of ulcer images.

RESULTS

The point estimates for both outcomes were favourable to L-PRF but the effect sizes were small. Unadjusted mean differences (intervention vs control) in mean daily healing rates (cm2) were respectively 0.012 (95% confidence interval 0.001 to 0.023, p = 0.027); 0.016 (0.004 to 0.027, p = 0.008) and 0.005 (-0.005 to 0.016, p = 0.313) across the three measurement methods. Time to complete healing at 42 days yielded Hazard Ratios (unadjusted) of 1.3 (0.8 to 2.1, p = 0.300) assessed by unblinded local clinicians and 1.2 (0.7 to 2.0, p = 0.462) on blind assessment.

CONCLUSION

Any benefit from L-PRF appears insufficient to justify routine use in care of neuropathic ulcers in leprosy.

TRIAL REGISTRATION

ISRCTN14933421. Date of trial registration: 16 June 2020.

Clinical efficacy of blood derivatives on wound healing: A systematic review and network meta-analysis

This study aims to evaluate the clinical effects of different blood derivatives on wound healing using network meta-analysis. PubMed, Embase, OVID, Web of Science, SCOPUS and Cochrane Central were searched to obtain studies about blood derivatives on wound healing until October 2023. R 4.2.0 and Stata 15.0 softwares were used for data analysis. Forty-four studies comprising 5164 patients were included. The results of network meta-analysis showed that the healing area from high to low was GF + ORCCB, ORCCB, GF, PRF, Unnas paste dressing, APG, PRP injection, PRP, PRP + thrombin gel, PPP, HPL, CT. The healing time from low to high was PRP + thrombin gel, GF, PRP, PC + K, PC, APG, PRF, CT, Silver sulfadiazine ointment. The number of patients cured from high to low was APG, PRP injection, PRP, Aurix, PRF, Leucopatch, HPL, Antimicrobial Ointment Dressing, CT, 60 μg/cm2 repifermin, 120 μg/cm2 repifermin, AFG, PPP. The order of analgesic effect from high to low was AFG, Aminogam gel, PRF, PRP, Oxidised oil, APG, GF, CT. The order of the number of wound infection cases from low to high is APG, 20 μg/cm2 repifermin, 60 μg/cm2 repifermin, PRP, LeucoPatch, CT, PPP, Antiseptic ointment dressing. Healing area: GF + ORCCB had the best effect; Healing time: PRP + thrombin gel took the shortest time. The number of cured patients and the reduction of wound infection: APG has the best effect. Analgesic effect: AFG has the best effect. More studies with large sample sizes are needed to confirm the above findings.

The role of orthobiologics in chronic wound healing

Chronic wounds, characterized by prolonged healing processes, pose a significant medical challenge with multifaceted aetiologies, including local and systemic factors. Here, it explores the complex pathogenesis of chronic wounds, emphasizing the disruption in the normal phases of wound healing, particularly the inflammatory phase, leading to an imbalance in extracellular matrix (ECM) dynamics and persistent inflammation. Senescent cell populations further contribute to impaired wound healing in chronic lesions. Traditional medical management focuses on addressing underlying causes, but many chronic wounds resist to conventional treatments, necessitating innovative approaches. Recent attention has turned to autologous orthobiologics, such as platelet-rich plasma (PRP), platelet-rich fibrin (PRF) and mesenchymal stem cells (MSCs), as potential regenerative interventions. These biologically derived materials, including bone marrow aspirate/concentrate (BMA/BMAC) and adipose tissue-derived stem cells (ADSCs), exhibit promising cytokine content and regenerative potential. MSCs, in particular, have emerged as key players in wound healing, influencing inflammation and promoting tissue regeneration. This paper reviews relevant scientific literature regarding basic science and brings real-world evidence regarding the use of orthobiologics in the treatment of chronic wounds, irrespective of aetiology. The discussion highlights the regenerative properties of PRP, PRF, BMA, BMAC and SVF, showcasing their potential to enhance wound healing. Despite advancements, further research is essential to elucidate the specific roles of each orthobiologic and determine optimal applications for different wound types. The conclusion underscores the evolving landscape in chronic wound management, with a call for more comprehensive studies to refine treatment strategies and maximize the benefits of regenerative medicine.

Autologous blood products: Leucocyte and Platelets Rich Fibrin (L-PRF) and Platelets Rich Plasma (PRP) gel to promote cutaneous ulcer healing - a systematic review

OBJECTIVE

To summarise evidence on the effectiveness of Platelet-Rich Plasma (PRP) gel and Leucocyte and Platelet Rich Fibrin (L-PRF) gel as agents promoting ulcer healing compared with the standard wound dressing techniques alone.

DESIGN

Systematic review.

ELIGIBILITY CRITERIA

Individual patient randomised controlled trials on skin ulcers of all types excluding traumatic lesions.Intervention group: treatment with topical application of L-PRF gel or PRP gel to the wound surface.

CONTROL GROUP

treatment with standard skin ulcer care using normal saline, normgel or hydrogel dressings.

INFORMATION SOURCES

Medline (Ovid), Excerpta Medica Database (EMBASE), Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Web of Science and manual search of studies from previous systematic reviews and meta-analyses. The papers published from 1946 to 2022 with no restriction on geography and language were included. The last date of the search was performed on 29 August 2022.

DATA EXTRACTION AND SYNTHESIS

Independent reviewers identified eligible studies, extracted data, assessed risk of bias using V.2 of the Cochrane risk-of-bias tool for randomised trials tool and assessed certainty of evidence by using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

MAIN OUTCOME MEASURES

Time to complete healing, proportion healed at a given time and rate of healing.

RESULTS

Seven studies met the inclusion criteria, five using PRP gel and two using L-PRF gel. One study showed a better proportion of complete healing, three reported reduced meantime to complete healing and five showed improved rate of healing per unit of time in the intervention group. The risk of bias was high across all studies with one exception and the GRADE showed very low certainty of evidence.

CONCLUSION

The findings show potential for better outcomes in the intervention; however, the evidence remains inconclusive highlighting a large research gap in ulcer treatment and warrant better-designed clinical trials.

PROSPERO REGISTRATION NUMBER

CRD42022352418.

Impact of autologous platelet concentrates on wound area reduction: A meta-analysis of randomized controlled trials

This meta-analysis aimed to evaluate the impact of autologous platelet concentrates (APCs) on wound area reduction based on randomized controlled trials (RCTs). A comprehensive search was conducted in PubMed, Embase, China National Knowledge Infrastructure (CNKI), Web of Science, and the Cochrane Library to identify relevant literature. The primary outcome measure was the percentage of wound area reduction. Secondary outcome measures included wound healing time and the incidence of infection. A total of 14 studies were included in the meta-analysis. The results showed that the percentage of wound area reduction was significantly greater in the APCs group compared to conventional treatments (standardized mean difference [SMD] 1.98, 95% confidence interval [CI]: 1.27-2.68, p < 0.001). Subgroup analysis revealed that the percentage of wound area reduction varied based on wound location, follow-up duration, and type of APCs used. The healing time and incidence of infection presented no significant difference between the two groups. The findings suggest that APCs can effectively reduce wound areas when compared to conventional treatments, without increasing the risk of infection. In addition, the effectiveness of APCs in wound area reduction may vary depending on factors such as wound location, type of APCs used, and follow-up duration.

Autologous platelet-rich fibrin promotes wound healing in cats

Street cats commonly present large skin wounds that pose significant challenges in veterinary practice. Platelet-rich fibrin (PRF) is a second-generation platelet concentrate increasingly used in humans to promote wound healing. Ease of use and clinical success in humans has prompted interest in using PRF in veterinary practice. However, until now, there is no reported study on the use of autologous PRF in feline wound management. This study evaluated the effect of application of autologous PRF in cats with naturally occurring cutaneous wounds. 16 cats with full-thickness cutaneous acute/subacute wounds were randomly allocated to PRF or Control (standard care) groups. Each cat was enrolled for 2 weeks. PRF was prepared according to previously described procedures. PRF was applied on Days 1 and 4 in addition to standard wound care. Wound size was measured using tracing planimetry. Wound surface area was calculated using SketchAndCalc^™ software on scanned tracing images. Average wound sizes at enrolment were 8.39 cm² (Control) (standard deviation (SD) 5.08 cm²) and 9.18 cm² (PRF) (SD 3.71 cm²) (range 2.42-15.97 cm²). By Day 14, the mean wound size for the Control group was 2.17 cm² (SD 1.52 cm²) and for the PRF was 0.62 cm² (SD 0.44 cm²) (p = 0.015). At Day 14, the PRF group showed mean 93.85% wound contraction with SD 3.66, while the control group showed mean 76.23% wound contraction with SD 5.30 (p = <0.0001). Based on the results, PRF could be further investigated to promote wound healing in cats as a low-risk and convenient adjunctive therapy.

Platelet-Rich Plasma in Chronic Wound Management: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND

Chronic wounds place a heavy burden on the healthcare system due to the prolonged, continuous need for human resources for wound management. Our aim was to investigate the therapeutic effects of platelet-rich plasma on the treatment of chronic wounds.

METHODS

The systematic literature search was performed in four databases. Randomized clinical trials reporting on patients with chronic wounds treated with platelet-rich plasma (PRP) were included, comparing PRP with conventional ulcer therapy. We pooled the data using the random effects model. Our primary outcome was the change in wound size.

RESULTS

Our systematic search provided 2688 articles, and we identified 48 eligible studies after the selection and citation search. Thirty-three study groups of 29 RCTs with a total of 2198 wounds showed that the odds for complete closure were significantly higher in the PRP group than in the control group (OR = 5.32; CI: 3.37; 8.40; I² = 58%).

CONCLUSIONS

PRP is a safe and effective modality to enhance wound healing. By implementing it in clinical practice, platelet-rich plasma could become a widely used, valuable tool as it could not only improve patients' quality of life but also decrease the healthcare burden of wound management.

A Clinical Study of Efficacy of Autologous Platelet-Rich Fibrin (PRF) in Chronic Non-Healing Ulcers

Background

Chronic ulcers are defined as the breakdown of the epidermal and dermal tissue lasting for more than 6 weeks. There will be a lack of necessary growth factors in chronic non-healing ulcers. This study is aimed at accessing the efficacy of autologous platelet-rich fibrin in chronic non-healing ulcers.

Aims and Objectives

To determine the efficacy of autologous platelet-rich fibrin in chronic non-healing ulcers and to compare the rate of healing in different ulcers based on aetiology.

Methods

A hospital-based prospective study was conducted at the Department of Dermatology, Venereology, and Leprosy, at a tertiary care centre in Central Karnataka with 50 cases of chronic non-healing ulcers over 2 years. In each case baseline data including age and gender was collected and thorough general physical, local, and systemic examinations were done with the help of a predesigned proforma. PRF dressing was done weekly for 4 weeks with ulcer volume measured each time and improvement accessed.

Results

In this study, the mean age of the study population was 43.56 ± 14.06 years, with 84% males. Good improvement in the volume of the ulcer was seen in 6 patients out of 50, moderate improvement was seen in 20 out of 50 patients and mild in the rest of the 24 patients. Improvement was more in the educated sector, more so in females and patients with trauma as the cause of ulcers without any comorbidities. Leprosy followed by diabetes was the main cause of chronic non-healing ulcers.

Conclusions

This study shows that autologous platelet-rich fibrin therapy provides faster wound healing in chronic non-healing ulcers with no adverse events.

PLASMA RICO EM PLAQUETAS NA CICATRIZAÇÃO DE ÚLCERA VENOSA: RELATO DE CASO

Objetivo:Avaliar a evolução da reparação tecidual de úlcera venosa (UV) tratada com plasma rico em plaquetas (PRP). Métodos: Trata-se de relato de caso com aplicação de PRP para tratamento de UV em uma clínica especializada de uma cidade do sul de Minas Gerais. A cada sessão foram coletados 20 mL de sangue distribuídos em quatro tubos com citrato de sódio. O sangue passou por centrifugação para a extração do PRP. O plasma foi aplicado na ferida após a limpeza com água destilada e solução de polihexametileno biguanida. Posteriormente, a lesão foi coberta com gazes impregnada com petrolato e gazes estéreis como cobertura secundária, associado à terapia compressiva elástica. Resultados: Anteriormente à terapia, a úlcera apresentava 1,18 cm² de área. Após quatro semanas de tratamento com PRP, ocorreu a completa cicatrização. Conclusão: O tratamento mostrou-se eficaz e houve 100% de redução de área.

PLATELET-RICH PLASMA IN VENOUS ULCER HEALING: CASE REPORT

Objective:To evaluate the evolution of tissue repair in venous ulcers treated with platelet-rich plasma. Methods: This is a case report with the application of platelet-rich plasma for the treatment of venous ulcers in a specialized clinic in a city in the south of Minas Gerais. At each session, 20 mL of blood was collected and distributed into four tubes with sodium citrate. The blood was centrifuged to extract platelet-rich plasma. Plasma was applied to the wound after cleaning with distilled water and polyhexamethylene biguanide solution. Subsequently, the lesion was covered with gauze impregnated with petrolatum and sterile gauze as a secondary coverage, associated with elastic compression therapy. Results: Prior to therapy, the ulcer had an area of 1.18 cm². After five weeks of treatment with platelet-rich plasma, complete healing has occurred. Conclusion: Tissue repair occurred after five weeks of treatment without any complications.

PRP Versus Standard of Care for Venous leg Ulcers: A Systematic Review and Meta-Analysis of Prospective Comparative Studies

Venous leg ulcers (VLUs) are chronic and recalcitrant lower limb wounds that affect millions of patients annually, severely reducing their quality of life, and causing a significant burden on the health care system. Recently, Platelet rich plasma (PRP) has been used to improve healing of VLUs. This systematic review aimed at evaluating the effectiveness of PRP versus the standard of care commonly used to treat VLUs. Ten prospective studies (8 randomized) met the inclusion criteria comprising 451 patients with 527 VLUs. Results were as follows: a) the weighted Odds Ratio (OR) of the mean healing rate was 2.84 (95% CI = 1.160 to 5.056, I2 = 41.4%, p = 0.0004), b) the mean healed ulcer areas were 79.2 ± 19% for the PRP group and 51.7 ± 36% for the control group (p = 0.007) in favor of the PRP group, and c) the weighted infection OR showed no significant difference between both groups. Additionally, negative correlations were found between healing rate and duration of VLUs and initial size of the ulcers. This meta-analysis demonstrated significant beneficial effects of PRP versus standard of care on healing rate, reduction in surface, and reduction in healing time of VLUs. Infection and other complications were similar to standard of care. Therefore, our analytical data would support the use of PRP as a safe and effective treatment for VLUs.

Comparison of Autologous Platelet-Rich Fibrin Matrix and Transplantation of Autologous Noncultured Epidermal Cell Suspension in the Treatment of Chronic Non Healing Ulcer: Randomized Comparative Study

Context

Chronic non-healing ulcer causes significant morbidity, high cost and reduced quality of life.

Aims

To compare autologous platelet-rich fibrin matrix and transplantation of autologous non-cultured epidermal cell suspension in the treatment of chronic non-healing ulcers.

Methods

The study was single-centre, prospective, randomised comparative study conducted in a tertiary care center in North India. Patients with chronic non-healing ulcer were included and randomly divided into two treatment groups- Group 1: Platelet-rich fibrin matrix (PRFM) procedure was done every 2 weeks with maximum three sittings and in Group 2: Transplantation of autologous noncultured epidermal cell suspension (NCES) procedure was done once. Follow-up was done every 2 weeks for 8 weeks then monthly for up to 5 months to evaluate the healing of the ulcer. The data were analysed by statistical package for social science (SPSS) trial version 22. To find out a significant difference in mean value between groups, the Chi-square test, student's t-test, and Mann-Whitney U test were used.

Results

A total of 41 patients were included in the study. Complete healing of ulcers occurred in 89.5% of the patients in the PRFM group and 93.8% of the patients in the NCES group at the end of 5 months (P = 0.33). The mean duration of complete healing in PRFM was 1.7 months and in NCES was 2.13 months (P = 0.20).

Conclusions

Both procedures were effective, and there was no significant difference between the two procedures.

Chronic Venous Leg Ulcer in Klinefelter Syndrome Treated with Platelet-Rich Fibrin: A Case Report

Venous leg ulcers (VLUs) are the most common causes of leg ulcers due to venous insufficiency. Most cases persist for more than 6 weeks, referred to as chronic VLUs. These chronic ulcers have been described as a manifestation of Klinefelter syndrome (KS). Platelet-rich fibrin (PRF) is a second-generation platelet concentrate, which contains growth factors required for chronic wound healing. The use of PRF in the management of VLUs in KS has not been reported, to the best of our knowledge. We report a case of chronic VLU associated with KS in a 41-year-old man treated with PRF. Dermatological examination showed a tender, shallow, irregular ulcer partly covered with hard, yellow necrotic tissue on the anterior side of the lower-left leg and hyperpigmented indurated skin on both lower legs. The diagnosis of venous ulcer was established based on clinical manifestation and supported by the result of Doppler ultrasound showed chronic venous insufficiency. Histopathological examination, which showed epidermal acanthosis, dermal fibrosis, and thickening with hemosiderin deposits consistent with the diagnosis of venous ulcer. The patient presented with eunuchoid features characterized by long extremities, gynecomastia, increased fat distribution around the hips, scanty pubic hairs, and small testes. Laboratory tests found decreased levels of testosterone, increased levels of follicle-stimulating and luteinizing hormone, and bilateral testicular atrophy was found from testicular ultrasound. These physical examinations and laboratory findings supported the diagnosis of KS. The patient was treated with PRF dressing once a week. After 7 weeks of treatment with PRF, the ulcer almost reached complete closure. PRF gives a good result in a chronic VLU with KS.

Effect of topical application of platelet-rich plasma on chronic venous leg ulcerations

Wound products that reliably support healing of chronic leg ulcers remain a huge unmet need in clinical practice. Due to the lack of standardized comparable protocols and different systems for platelet-rich plasma (PRP) preparation, there is limited data on healing rates in chronic venous ulcers. In our case series with a total of seven chronic leg ulcers in four patients, we investigated the healing rates based on standardized digital photographs of chronic venous ulcers after application of topical PRP using a digital imaging software. In 5 out of 7 ulcers, the PRP-treated wound half showed faster healing as compared the control half of the wound. In this case series, PRP-treated sides of chronic venous leg ulcers showed a tendency for accelerated healing as compared to nontreated collateral wound side. Our data support the evaluation of topical PRP treatment in the management of chronic venous leg ulcers.

Efficacy of Local Autologous Platelet-Rich Plasma in the Treatment of Pressure Ulcer in Spinal Cord Injury Patients

BACKGROUND

Pressure ulcer is one of the common complications occurring in spinal cord injury (SCI) patients. Platelet-rich plasma (PRP) has been found useful in the treatment of pressure ulcers in few studies. The purpose of this study was to evaluate the role of PRP in pressure ulcer healing in comparison to hydrogel dressing in SCI patients.

METHODS

In this randomized interventional study, 52 patients of SCI having pressure ulcers of grade III/IV were randomized into two groups of 26 each. In group A patients, hydrogel dressing was done while freshly prepared PRP was used in patients of group B. Pressure ulcers were evaluated at baseline and after three weeks and six weeks in terms of ulcer surface area, volume, Pressure Ulcer Scale for Healing (PUSH) score, histopathology, and ulcer healing parameters. Data were collected and quantitative variables were compared using unpaired t-test or Mann-Whitney test between the two groups and qualitative variables were compared using the chi-square test or Fisher's exact test. A p-value of <0.05 was considered statistically significant.

RESULTS

 Baseline characteristics were comparable in both groups. There was a significant improvement in ulcers in terms of surface area, volume, and PUSH score in both the groups but it was comparable (p-value >0.05). There was a significant improvement in the PRP group as compared to the other group in terms of epithelization, granulation, and neovascularization at three and six-week follow-up.

CONCLUSIONS

This study suggests that PRP is a possible and better alternative to conventional dressing methods for the treatment of pressure ulcers.

Growth factors for treating chronic venous leg ulcers: A systematic review and meta-analysis

Chronic venous leg ulcers (VLU) are wounds that commonly occur due to venous insufficiency. Many growth factors have been introduced over the past two decades to treat VLU. This systematic review and meta-analysis evaluates the impact of growth factor treatments of VLU in comparison to control for complete wound healing, percent reduction in wound area, time to wound healing, and adverse events. A systematic review and meta-analysis of randomised trials was conducted. MEDLINE and EMBASE were searched up to December 2020. Studies were included if they compared a growth factor versus placebo or standard care in patients with VLU. From 1645 articles, 13 trials were included (n = 991). There was a significant difference between any growth factor and placebo in complete wound healing (P = 0.04). Any growth factor compared to placebo significantly increased the likelihood of percent wound reduction by 48.80% (P = <0.00001). There was no difference in overall adverse event rate. Most comparisons have low certainty of evidence according to Grading of Recommendations, Assessment, Development, and Evaluation. This meta-analysis suggests that growth factors have a beneficial effect in complete wound healing of VLU. Growth factors may also increase percent reduction in wound area. The suggestion of benefit for growth factors identified in this review is not a strong one based on the low quality of evidence.

Canine-Origin Platelet-Rich Fibrin as an Effective Biomaterial for Wound Healing in Domestic Cats: A Preliminary Study

Platelet-rich fibrin (PRF) is a recent platelet-based biomaterial, poised as an innovative regenerative strategy for the treatment of wounds from different etiologies. PRF is defined as a biodegradable scaffold containing elevated amounts of platelets and leukocytes having the capability to release high concentrations of bioactive structural proteins and acting as a temporal release healing hemoderivative. This study aimed to evaluate the performance of canine-origin PRF, obtained from blood of screened donors, as a regenerative biomaterial suitable for the treatment of critical wounds in felines. Four short-hair felines with naturally occurring wounds were enrolled in this study. Three of the wounds were considered infected. Each PRF treatment was the result of the grafting of newly produced PRFs at the recipient area. The PRF treatment was initially performed two to three times per week, followed by single weekly treatments. The study was finalized when complete wound closure was achieved. No topical antimicrobial/antiseptic treatment was applied. The present research demonstrated that xenogenic PRFs significantly induced healthy vascularized granulation tissue in lesions with soft tissue deficit, also prompting the epithelization at the injured site. No rejection, necrosis, or infection signs were recorded. Additionally, PRF-therapy was revealed to be a biological cost-effective treatment, accelerating the wound healing process.

Review of the Current Evidence for Topical Treatment for Venous Leg Ulcers

OBJECTIVE

The development of a venous leg ulcer (VLU) represents the most severe clinical manifestation of a chronic venous disease. Despite major progress, there is a limited understanding of VLU pathogenesis and wound healing biology. Treatment of VLUs remains a serious challenge for physicians of different specialties. This communication focuses on describing the rationale and scientific basis for topical wound care in the management of VLUs.

METHODS

A literature review was performed to summarize methods with proven efficacy in VLU management. A systematic literature search was also performed to identify new evidence from the randomized controlled trials published within 2014-2021. The scientific challenges, clinical practice concerns, economic obstacles, and possible directions for further research have been discussed.

RESULTS

Hundreds of topical products have been advertised for the treatment of VLUs. Published data on topical treatment of venous ulcers is insufficient, scattered, weak, and has significant methodological flaws. Forty-three randomized controlled trials on topical treatment of VLUs have been published within 2014-2021. Clinical practice guidelines need to be updated. Major gaps in knowledge have been identified, and suggestions for future research directions have been provided.

CONCLUSIONS

The American Venous Forum Research Committee would like to bring attention to topical wound care for VLUs as a critical gap in knowledge, and encourage scientists, practitioners, and industry to collaborate to fill this gap.

Objective assessment of Platelet-Rich Plasma (PRP) potentiality in the treatment of Chronic leg Ulcer: RCT on 80 patients with Venous ulcer

BACKGROUND

Chronic venous leg ulcer reduces the patients' activities and their overall quality of life. Platelet-rich plasma (PRP) was previously investigated as promising less invasive management for leg ulcers.

THIS STUDY AIMS

To re-assess the efficacy and safety of PRP in the management of chronic leg ulcers due to venous factors.

PATIENTS/METHODS

RCT enrolled 80 patients who clinically presented with chronic venous leg ulcers. Forty patients were allocated randomly for the treatment with autologous platelet-rich plasma (PRP). Intradermal and subdermal injection of PRP by 27guage syringe weekly, in all edges and in the granular floor of the ulcer for 4-6 sessions. Another 40 patients managed by conventional treatment by compression and dressing for the same period were allocated as Group B. Objective assessment achieved by the percentage of reduction of the size of the ulcer area, rate of healing, incidence of recurrence, and if side effects have been reported.

RESULTS

PRP therapy showed better results and high p value significance when compared to conventional therapy.

CONCLUSION

This study shows that PRP is effective and significant in promoting the wound healing process in chronic leg venous ulcers. PRP is simple, safe, and has a short learning curve technique.

Cost and effectiveness of Platelet Rich Plasma in the healing of varicose ulcer: Meta-analysis

OBJECTIVES

to analyze the evidence on the cost and effectiveness of Plaque Rich Plasma in the treatment of venous ulcers compared to other topical therapies.

METHODS

systematic review, with search in the databases: COCHRANE, EMBASE, MEDLINE via PubMed, LILACS, CINAHL, SCOPUS, without temporal cut and in the English, Portuguese and Spanish languages.

RESULTS

fifteen articles were included, a cost-minimization analysis showed that the cost of Plaque Rich Plasma is € 163.00 ± 65.90, slightly higher than the cost of standard dressing. Regarding effectiveness, the results of the studies associated with the meta-analysis suggest a tendency that Plaque Rich Plasma is effective in the healing of venous ulcers.

CONCLUSIONS

it is concluded that there are few studies about the cost of Platelet Rich Plasma and this product tends to be effective in the healing of venous ulcers. However, more controlled and randomized clinical studies are necessary in order to establish a stronger recommendation.

Extensive characterization of the composition and functional activities of five preparations of human platelet lysates for dedicated clinical uses

Human platelet lysates (HPLs), rich in various growth factors and cell growth-promoting molecules, encompass a new range of blood products that are being used for regenerative medicine, cell therapies, and tissue engineering. Well-characterized dedicated preparations, tailor-made to best fit specific therapeutic applications, are needed for optimal clinical efficacy and safety. Here, five types of HPL were prepared from the same platelet concentrates and extensively characterized to determine and compare their proteins, growth factors, cytokines, biochemical profiles, thrombin-generating capacities, thrombin-associated proteolytic activities, phospholipid-associated procoagulant potential, contents of extracellular vesicles expressing phosphatidylserine and tissue factor, and antioxidative properties. Our results revealed that all five HPL preparations contained detectable supraphysiological levels, in the ca. 0.1 ~ 350-ng/ml range, of all growth factors assessed, except insulin-like growth factor-1 detected only in HPL containing plasma. There were significant differences observed among these HPLs in total protein content, fibrinogen, complement components C3 and C4, albumin, and immunoglobulin G, and, most importantly, in their functional coagulant and procoagulant activities and antioxidative capacities. Our data revealed that the biochemical and functional properties of HPL preparations greatly vary depending upon their mode of production, with potential impacts on the safety and efficacy for certain clinical indications. Modes of preparation of HPLs should be carefully designed, and the product properties carefully evaluated based on the intended therapeutic use to ensure optimal clinical outcomes.

Vivostat Platelet-Rich Fibrin® for Complicated or Chronic Wounds-A Pilot Study

Vivostat Platelet-Rich Fibrin^® (PRF) is an autologous platelet concentrate used for the local treatment of chronic or complicated wounds. Still, its application for this indication is not evidence-based. Therefore, we performed this monocentric retrospective pilot study investigating the clinical outcome of a local treatment of chronic or complicated wounds in 35 patients (23 male, 12 female, mean age 68.7 years) treated with Vivostat PRF^®. This study population is the largest among published studies analyzing the clinical efficacy of Vivostat PRF^® on chronic wounds so far. Using the perpendicular method we divided the wounds into three sizes (<10, 10–30, and >30 cm²). The clinical efficacy of the Vivostat PRF treatment was the primary endpoint and was divided into three groups of increasing degrees of wound improvement: (1) no improvement of the wound (wound area was not reduced > 10% under Vivostat PRF^® treatment), (2) improvement of the wound (reduced area > 10% under Vivostat PRF^® treatment) and (3) complete epithelialization (wounds that were completely re-epithelialized after Vivostat PRF^® treatment). We included patients’ diagnosis and concomitant diseases (peripheral arterial occlusive disease (PAOD)), chronic venous insufficiency (CVI)), diabetic foot syndrome (DFS)) in our data analysis in order to investigate their potential impact on the wound healing capacity of Vivostat PRF^®. Our results show that in the entire study population, 13 out of 35 (37.1%) patients experienced wound improvement and 14 out of 35 (40%) patients showed complete epithelialization of their wound under Vivostat PRF^® treatment. In summary, 77.1% of the treated patients benefited from the Vivostat PRF^® therapy. These positive wound healing effects were all observed within the first three to six Vivostat PRF^® applications. Subgroup analyses showed that Vivostat PRF^® appeared to be more efficient in patients without CVI in comparison to patients with CVI (p = 0.02). Moreover, Vivostat PRF^® treatment seems to be particularly efficient in PAOD-related wounds with a reduced crural arterial blood supply (p = 0.01). Additionally, we performed an experimental human in vivo study on ten male students where we artificially generated bilateral gluteal wounds and analyzed the influence of the Vivostat PRF^® treatment on the expression of two genes (human beta Defensin-2, ((hBD-2) and human beta-Defensin-3 (hBD-3)) in keratinocytes of resected wound specimens that are induced during wound healing. Interestingly, this analysis revealed that only seven of out ten individuals showed a relevant hBD-2 and hBD-3 gene induction after Vivostat PRF^® treatment. This led to the novel “key-lock-hypothesis”. With the goal of an individualized precision medicine approach with optimized wound treatment strategies in the future, this is an important observation that demands further experimental and clinical studies.

Platelet-Released Growth Factors and Platelet-Rich Fibrin Induce Expression of Factors Involved in Extracellular Matrix Organization in Human Keratinocytes

Platelet-released growth factor (PRGF) is a thrombocyte concentrate lysate which, like its clinically equivalent variations (e.g., Vivostat PRF^® (platelet-rich fibrin)), is known to support the healing of chronic and hard-to-heal wounds. However, studies on the effect of PRGF on keratinocytes remain scarce. This study aims to identify genes in keratinocytes that are significantly influenced by PRGF. Therefore, we performed a whole transcriptome and gene ontology (GO) enrichment analysis of PRGF-stimulated human primary keratinocytes. This revealed an increased expression of genes involved in extracellular matrix (ECM) organization. Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) analysis confirmed the PRGF-mediated induction of selected ECM-related factors such as transforming growth factor beta-induced protein, fibronectin 1, matrix metalloproteinase-9, transglutaminase 2, fermitin family member 1, collagen type I alpha 1 and collagen type XXII alpha 1. PRGF-induced expression of the above factors was influenced by blockade of the epidermal growth factor receptor (EGFR), a receptor playing a crucial role in wound healing. A differential induction of the investigated factors was also detected in skin explants exposed to PRGF and in experimentally generated in vivo wounds treated with Vivostat PRF^®. Together, our study indicates that the induction of ECM-related factors may contribute to the beneficial wound-healing effects of PRGF-based formulations.

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.

Autologous platelet-rich plasma injection enhances healing of chronic venous leg ulcer: A prospective randomised study

Our aim was to compare the efficacy and safety of platelet-rich plasma (PRP) application versus PRP injection for chronic venous leg ulcer (VLU) healing compared with compression therapy as a control. From July 2018 to December 2019, 90 chronic VLU patients were randomly assigned to PRP dressings (n = 30), local PRP injections (n = 30), and compression therapy alone (n = 30). Standard compression accompanied both PRP groups. The main endpoints were ulcer healing and area reduction within 3, 6, and 12 months. Complications and ulcer recurrence were also recorded. The study included 72 (80.0%) males and 18 (20.0%) females aged 22 to 66 years, having VLUs for 1 to 11 years. PRP injection promoted healing (24/30, 80%) more than PRP application (20/30, 66.7%) and compression (14/30, 46.7%), P = .007. Healing time was significantly shorter after PRP injection compared with the other two groups. A greater area reduction was observed after PRP injection compared with compression at all follow-up visits, P = .013, .002, and < .001, and compared with PRP application only at 3 months post-treatment, P = .016. Recurrence and complications were comparable among the groups. PRP injection enhances the healing of chronic venous ulcers more than each of PRP application and compression therapy. All had comparable recurrence and safety.

Platelet-rich fibrin prevents postoperative intestinal adhesion

Platelet-rich fibrin (PRF) was prepared from the blood of BALB/C inbred mice to explore potential effects on postoperative intestinal adhesion. A murine model of intestinal adhesion characterized by abdominal wall defect/and cecum damage was established by scraping caecum serosa and cutting peritoneum and muscles in the abdominal wall. The wound was covered with PRF (group A), sodium hyaluronate (group B), or left alone (blank control; group C). All animals were monitored for 28 days. The incidence of adhesion was 35.0, 66.7, and 73.7% in groups A, B, and C, respectively. The incidence of adhesion in group A was significantly lower than that in group C (p < .05). Histopathologically, severity of fibrosis and the number of fibroblasts or inflammatory cells in group A were lower than those in groups B and C (p < .05), whereas the number of mesothelial cells was higher (p = .001). Furthermore, the severity of fibrosis and number of fibroblasts or inflammatory cells were lower in low grade than those in high grade of adhesion (p < .05), whereas the number of mesothelial cells was higher (p < .05). Collectively, PRF applied to abdominal surgery may reduce the incidence of intestinal adhesion by promoting proliferation of mesothelial cells whereas inhibiting proliferation of fibroblasts and infiltration of inflammatory cells.

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.

Comparison of Efficacy of Autologous Platelet-Rich Fibrin versus Unna's Paste Dressing in Chronic Venous Leg Ulcers: A Comparative Study

Background:

Chronic venous leg ulcers are difficult to treat and recurrences are common. Among various modalities of treatment, platelet-rich fibrin (PRF) has shown promising results in ulcer healing by providing necessary growth factors. Unna's paste dressing has also proven to enhance wound healing.

Aim:

The aim of this study is to compare the efficacy of autologous PRF versus Unna's paste dressing in chronic venous leg ulcer patients and to compare the mean reduction in ulcer area at the end of 4 weeks.

Materials and Methods:

Twenty patients with chronic venous leg ulcers were randomly divided into two groups. Group 1: Patients received PRF dressing which was repeated every week for 4 weeks. Group 2: Patients received Unna's paste dressing once a week for 4 weeks. The ulcer size was assessed with the help of photographs, and ulcer area was measured.

Results:

The mean reduction in the area of the ulcer size in the PRF group was 86.03% and in the Unna's paste group was 71.97%, which was not statistically significant with a P value of 0.223.

Conclusion:

We conclude that though there was no statistical significance between the groups, PRF showed a significant reduction in ulcer size.

Production cost of autologous platelet rich plasma gel

Objective:

to estimate the direct cost of producing autologous platelet rich plasma gel.

Method:

an economic, prospective, longitudinal study with direct cost estimation, from the perspective of the Unified Health System, conducted in a university hospital in the state of Rio de Janeiro, over a period of 12 weeks. It was approved by the Ethics Committee of the School of Medicine. Direct observation of 18 participants was conducted. Material and human resources categories were analyzed for production costs.

Results:

the cost of producing platelet rich plasma gel was US $4.88 per session, for a total of US $5.16, when the material resources per unit were considered in the Unified Health System. The time to complete the procedure was approximately 22 minutes.

Conclusion:

the production of platelet rich plasma gel involves low cost material resources for both blood collection and preparation, enabling universal access to treatment. The procedure requires trained staff in an appropriate location; it is a safe and inexpensive technology.

Effects of leukocyte- and platelet-rich fibrin associated or not with bovine bone graft on the healing of bone defects in rats with osteoporosis induced by ovariectomy

OBJECTIVE

To evaluate the healing of critical size defects (CSDs) in calvaria of rats with osteoporosis induced by ovariectomy and treated with leukocyte- and platelet-rich fibrin (L-PRF) associated or not with bovine bone graft (XENO).

MATERIAL AND METHODS

A total of 32 rats underwent a bilateral ovariectomy procedure. After 3 months, one 5 mm in diameter CSD was created in the middle of the calvaria of each animal. In group C, defect was filled with blood clot only. In PRF, XENO, and PRF-XENO groups, defects were filled with 0.1 ml of L-PRF, 0.1 ml of XENO, and a mixture of 0.1 ml of L-PRF plus 0.1 ml of XENO, respectively. L-PRF compressed clots were used to cover the defects in PRF and PRF-XENO groups. Animals were submitted to euthanasia at 30 postoperative days. Histomorphometric, microtomographic, and immunohistochemical analyses were performed.

RESULTS

PRF-XENO group presented greater amount of neoformed bone (NB) when compared with XENO group, as well as higher expression of vascular endothelial growth factor (VEGF), osteocalcin (OCN), and bone morphogenetic protein (BMP-2/4) (p < .05). PRF group presented increased amount of NB and higher expression of VEGF, OCN, BMP-2/4, and Runt-related transcription factor 2 (RUNX-2) when compared with group C (p < .05).

CONCLUSIONS

(a) The isolated use of L-PRF clot can improve bone neoformation in CSDs in rats with osteoporosis induced by ovariectomy, but seems to lead to decreased amount of bone neoformation when compared to the isolated use of XENO; (b) L-PRF potentiates the healing of XENO in rats with osteoporosis induced by ovariectomy.

Treatment of venous ulcers with growth factors: systematic review and meta-analysis

OBJECTIVE

To identify evidence about the effects of growth factor application on venous ulcer healing.

METHOD

Systematic review and meta-analysis, including Randomized Clinical Trials. Searches: Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, LILACS, Web of Science, Digital Library of Theses and Dissertations; Google Scholar and list of references.

RESULTS

802 participants were recruited from the 10 included studies: 472 in the intervention group (growth factors) and 330 as control. The relative risk for the complete healing outcome was 1.06 [95% CI 0.92-1.22], p = 0.41. Participants who received Platelet-Rich Plasma and Epidermal Growth Factor showed a slight tendency to achieve complete healing, but without statistical relevance (p <0.05). Most of the studies were classified as moderate risk of bias.

CONCLUSION

The effect of the application of growth factors for complete healing in venous ulcers is not clear, and clinical trials with methodological quality are required for more accurate recommendations.

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.

Dressings and topical agents for treating venous leg ulcers

BACKGROUND

Venous leg ulcers are open skin wounds on the lower leg which can be slow to heal, and are both painful and costly. The point prevalence of open venous leg ulcers in the UK is about 3 cases per 10,000 people, and many people experience recurrent episodes of prolonged ulceration. First-line treatment for venous leg ulcers is compression therapy, but a wide range of dressings and topical treatments are also used. This diversity of treatments makes evidence-based decision-making challenging, and a clear and current overview of all the evidence is required. This review is a network meta-analysis (NMA) which assesses the probability of complete ulcer healing associated with alternative dressings and topical agents.

OBJECTIVES

To assess the effects of (1) dressings and (2) topical agents for healing venous leg ulcers in any care setting and to rank treatments in order of effectiveness, with assessment of uncertainty and evidence quality.

SEARCH METHODS

In March 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also scanned reference lists of relevant included studies as well as reviews, meta-analyses, guidelines and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. We updated this search in March 2018; as a result several studies are awaiting classification.

SELECTION CRITERIA

We included published or unpublished randomised controlled trials (RCTs) that enrolled adults with venous leg ulcers and compared the effects of at least one of the following interventions with any other intervention in the treatment of venous leg ulcers: any dressing, or any topical agent applied directly to an open venous leg ulcer and left in situ. We excluded from this review dressings attached to external devices such as negative pressure wound therapies, skin grafts, growth factors and other biological agents, larval therapy and treatments such as laser, heat or ultrasound. Studies were required to report complete wound healing to be eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction. We conducted this NMA using frequentist meta-regression methods for the efficacy outcome; the probability of complete healing. We assumed that treatment effects were similar within dressings classes (e.g. hydrocolloid, foam). We present estimates of effect with their 95% confidence intervals (CIs) for individual treatments focusing on comparisons with widely used dressing classes, and we report ranking probabilities for each intervention (probability of being the best, second best, etc treatment). We assessed the certainty (quality) of the body of evidence using GRADE for each network comparison and for the network as whole.

MAIN RESULTS

We included 78 RCTs (7014 participants) in this review. Of these, 59 studies (5156 participants, 25 different interventions) were included in the NMA; resulting in 40 direct contrasts which informed 300 mixed-treatment contrasts.The evidence for the network as a whole was of low certainty. This judgement was based on the sparsity of the network leading to imprecision and the general high risk of bias in the included studies. Sensitivity analyses also demonstrated instability in key aspects of the network and results are reported for the extended sensitivity analysis. Evidence for individual contrasts was mainly judged to be low or very low certainty.The uncertainty was perpetuated when the results were considered by ranking the treatments in terms of the probability that they were the most effective for ulcer healing, with many treatments having similar, low, probabilities of being the best treatment. The two most highly-ranked treatments both had more than 50% probability of being the best (sucralfate and silver dressings). However, the data for sucralfate was from one small study, which means that this finding should be interpreted with caution. When exploring the data for silver and sucralfate compared with widely-used dressing classes, there was some evidence that silver dressings may increase the probability of venous leg ulcer healing, compared with nonadherent dressings: RR 2.43, 95% CI 1.58 to 3.74 (moderate-certainty evidence in the context of a low-certainty network). For all other combinations of these five interventions it was unclear whether the intervention increased the probability of healing; in each case this was low- or very low-certainty evidence as a consequence of one or more of imprecision, risk of bias and inconsistency.

AUTHORS' CONCLUSIONS

More research is needed to determine whether particular dressings or topical agents improve the probability of healing of venous leg ulcers. However, the NMA is uninformative regarding which interventions might best be included in a large trial, largely because of the low certainty of the whole network and of individual comparisons.The results of this NMA focus exclusively on complete healing; whilst this is of key importance to people living with venous leg ulcers, clinicians may wish to take into account other patient-important outcomes and factors such as patient preference and cost.

A Novel and Convenient Method for the Preparation and Activation of PRP without Any Additives: Temperature Controlled PRP

Platelet rich plasma (PRP) is a concentrate of autologous platelets which contain enrichment growth factors (GFs). However, the addition of exogenous anticoagulant and procoagulant may result in clinical side effects and raise the price of PRP. Herein, we report a novel method named temperature controlled PRP (t-PRP), in which exogenous additives are dispensable in the preparation and activation process. Human blood samples were processed by a two-step centrifugation process under hypothermic conditions (4°C) to obtain t-PRP and rewarming up to 37°C to activate t-PRP. Contemporary PRP (c-PRP) was processed as the control. t-PRP showed a physiological pH value between 7.46 and 7.48 and up to 6.58 ± 0.45-fold significantly higher platelet concentration than that of whole blood compared with c-PRP (4.06-fold) in the preparation process. Meanwhile, t-PRP also maintained a stable GF level between plasma and PRP. After activation, t-PRP demonstrated natural fiber scaffolding, which trapped more platelet and GFs, and exhibited a slow release and degradation rate of GFs. In addition, t-PRP exhibited the function of promoting wound healing. t-PRP is a novel and convenient method for the preparation and activation of PRP without any additives. Compared to c-PRP, t-PRP reflects more physiologic characteristics while maintaining high quality.