Randomized trial and local biological effect of autologous platelets used as adjuvant therapy for chronic venous leg ulcers. A prospective, randomized, controlled trial of autologous platelet-rich plasma gel for the treatment of diabetic foot ulcers. Autologous platelet-rich plasmapheresis: risk versus benefit in repeat cardiac operations. A prospective randomized trial of autologous platelet-derived wound healing factors for treatment of chronic nonhealing wounds: a preliminary report. Use of platelet gel with connective tissue grafts for root coverage: a randomized-controlled trial. Does platelet-rich plasma promote remodeling of autologous bone grafts used for augmentation of the maxillary sinus floor?
Platelet products have been proposed as adjuvant therapy for wound healing. We undertook this study to determine the healing effect of topically applied frozen autologous platelets (FAP) on chronic venous ulcers, compared with effect of placebo, and whether use of topical FAP modifies local expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), interleukin 8 (IL-8), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in wound fluid.
                This randomized, placebo-controlled, double-blind trial was carried out in institutional practice, with ambulatory patients with proved chronic venous leg ulcers. In all patients, whole venous blood was drawn for preparation of FAP. FAP or normal saline solution was applied three times per week for up to 12 weeks, together with hydrocolloids and standardized compression bandages. Leg ulcer surface was assessed with numerical pictures. IL-8, VEGF, KGF, and TIMP-1 levels were determined (enzyme-linked immunosorbent assay) in wound fluid after each 4 weeks of treatment.
                Fifteen patients were randomized into two groups with comparable leg ulcer characteristics. Mean percent reduction in ulcer area was 26.2% in the FAP group versus 15.2% in the placebo group (P =.94). One ulcer in each group was completely healed at study end. Levels of TIMP-1 increased significantly during FAP treatment. IL-8 concentration was significantly lower in wound fluid of healing ulcers than in the fluid of nonhealing ulcers, in both FAP and placebo groups. Growth factor levels were not modified with FAP treatment.
                Topical autologous platelets have no significant adjuvant effect on healing of chronic venous leg ulcers and increased wound fluid TIMP-1 concentration. Ulcer healing is associated with a decrease in wound fluid IL-8. Nonhealing diabetic foot ulcers are a common cause of amputation. Emerging cellular therapies such as platelet-rich plasma gel provide ulcer management options to avoid loss of limb. The purpose of this prospective, randomized, controlled, blinded, multicenter clinical study was to evaluate the safety and efficacy of autologous platelet-rich plasma gel for the treatment of nonhealing diabetic foot ulcers. One hundred, twenty-nine (129) patients were screened; 72 completed a 7-day screening period and met the study inclusion criteria. Patients were randomized into two groups - the standard care with platelet-rich plasma gel or control (saline gel) dressing group - and evaluated biweekly for 12 weeks or until healing. Healing was confirmed 1 week following closure and monitored for another 11 weeks. An independent audit led to the exclusion of 32 patients from the final per-protocol analysis because of protocol violations and failure to complete treatment. In this group, 13 out of 19 (68.4%) of the platelet-rich plasma gel and nine out of 21 (42.9%) of the control wounds healed. After adjusting for wound size outliers (n = 5), significantly more platelet-rich plasma gel (13 out of 16, 81.3%) than control gel (eight out of 19, 42.1%) treated wounds healed (P = 0.036, Fisher's exact test). Kaplan-Meier time-to-healing also was significantly different between groups (log-rank, P = 0.0177). No treatment-related serious adverse events were reported and bovine thrombin used in the preparation of PRP did not cause Factor V inhibition. When used with good standards of care, the majority of nonhealing diabetic foot ulcers treated with autologous platelet-rich plasma gel can be expected to heal. Preoperative platelet-rich plasmapheresis has been suggested as a means of reducing homologous blood transfusions in cardiac surgical patients. The current study evaluated this technique in patients undergoing repeat cardiac operations. Fifty-two patients undergoing repeat myocardial revascularization and/or valve replacement were evaluated in a prospective randomized controlled study design. Autologous platelet-rich plasma (PRP) was harvested after the induction of anesthesia in the experimental group. After reversal of heparin, each patient received his or her autologous plasma. Patients in the control group did not have plasmapheresis and received standard transfusion therapy if coagulation variables were abnormal and a coagulopathy was clinically evident. Routine coagulation tests, thromboelastography (TEG), perioperative bleeding, and transfusion requirements were compared in the two groups. Forty-four patients completed the study. A significantly larger volume of packed red blood cells (PRBCs) was transfused in the PRP group than in the control group (P = 0.03). Platelet and fresh frozen plasma (FFP) transfusions did not differ between the two groups. Mediastinal tube drainage did not differ between the two groups. During PRP infusion, 60% of the patients required treatment for moderate hypotension (mean arterial pressure [MAP] < 60 mm Hg). Only 16% of control patients required treatment for hypotension during the comparable time period (P < 0.05). No patient who completed the study returned to the operating room for postoperative bleeding. These data suggest that PRP did not reduce postbypass bleeding or transfusion requirements in repeat cardiac surgical patients. Moreover, the incidence of hypotension during PRP reinfusion introduces a potential risk to the procedure in the absence of any obvious benefit. Previous studies have suggested that topically applied platelet-derived wound healing factors (PDWHF) accelerate wound healing by stimulating angiogenesis, fibroblast proliferation, and collagen synthesis. To assess the ability of platelet factors to facilitate healing of chronic cutaneous ulcers we performed a randomized, prospective, double-blind, placebo-controlled study of topical PDWHF in 18 patients with 26 lower extremity wounds refractory to conventional therapy. Wounds were present for at least 8 weeks (mean, 5.5 +/- 4.3 months). They were extensively debrided initially and were measured and photographed at weekly intervals for 12 weeks. Eight patients with nine wounds were treated with placebo solution (controls), and 10 patients with 17 wounds were treated with PDWHF (treatment group). Seventy-eight percent of patients had diabetes mellitus, 72% had occlusive peripheral vascular disease, and 28% had venous disease; distribution of these disorders was equivalent in both groups. Ankle-brachial indexes, which were often spuriously elevated, averaged 0.93 +/- 0.54 in controls and 1.04 +/- 0.56 in patients treated with PDWHF (p greater than 0.5). Mean transcutaneous oxygen tension was 37.8 +/- 11.9 mmHg in controls and 37.1 +/- 9.1 mmHg in patients treated with PDWHF. Initial wound area was larger in controls than in the patients treated with PDWHF (28.9 +/- 45.2 cm2 vs 13.0 +/- 4.4 cm2), but this difference was not statistically significant (p = 0.19). Three (33%) wounds (in two patients) healed in controls, and four (24%) wounds (in three patients) healed in the PDWHF group (p greater than 0.5). The rate of healing in controls was 1.9 +/- 2.7 cm2/week.(ABSTRACT TRUNCATED AT 250 WORDS) Platelet-rich plasma (PRP) was speculated to be a promoter of periodontal regeneration. There are only a few clinical comparative studies using PRP in the treatment of gingival recession. Aim: The aim of the present study was to compare connective tissue graft (CTG)+PRP with CTG alone in the treatment of gingival recession.
                Forty patients with Miller I/II recessions were included. Each recession was randomly treated with either CTG+PRP or CTG. Clinical variables were recorded at baseline and at 6 weeks, 6 and 12 months. Root coverage (RC) and attachment gain (AG) were also calculated.
                Probing depth, recession depth, clinical attachment level, keratinized tissue width and recession width (RW) were improved in both study groups. However, no difference was observed between groups, except RW. RW in the control group was statistically lower than the test group at all follow-up periods.
                Treatment of recession with CTG or a CTG-PRP combination resulted in favourable clinical outcomes. However, no difference could be found between CTG and CTG+PRP. Whether much longer follow-up studies with higher statistical power may change these results remains questionable. The aim of this study was to evaluate the effect of platelet-rich plasma (PRP) on remodeling of autologous bone grafts used for augmentation of the floor of the maxillary sinus. In five edentulous patients suffering from insufficient retention of their upper denture related to a severely resorbed maxilla, the floor of both maxillary sinus was augmented with an autologous bone graft from the iliac crest. Randomly, PRP was added to the bone graft used to augment the floor of the left or right sinus (split-mouth design). Three months after the reconstruction, bone biopsies were taken with a trephine from the planned implant sites (N=30). Subsequently, three implants were placed in the left and right posterior maxilla. Microradiograms were made of all biopsies (N=30), whereafter the biopsies were processed for light microscopic examination. In addition, clinical parameters were scored. Wound healing was uneventful, clinically no difference was observed between the side treated with PRP or not. Also microradiographical and histomorphological examination of the biopsies revealed no statistical difference between the PRP- and non-PRP side. One implant placed in the PRP side of the graft was lost during the healing phase. Implant-retained overdentures were fabricated 6 months after implantation. All patients functioned well (follow-up 20.2+/-4.3 months). In this study, no beneficial effect of PRP on wound healing and bone remodeling was observed. It is posed that PRP has no additional value in promoting healing of grafted non-critical size defects.
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.