Autologous Platelet-Leukocyte Enriched Gel. Basics and Efficacy. A Novel Method to Support Soft Tissue and Bone Healing
Strategies to reduce blood loss and transfusion of allogeneic blood products during surgery and following trauma are important in modern medicine. Therefore, it is desirable to reduce the use of homologous transfusions as much as possible. Furthermore, modern blood management strategies should incorporate not only red blood cell salvage but should also include the support of natural healing processes by using autologous prepared blood
components, which can then be applied on (surgical) wounds. Various approaches have now been developed where whole blood platelet-rich plasma (PRP) and platelet-poor plasma (PPP) sequestration is used to provide pre-operative autologous blood component therapy. This technique has proved to reduce the number of allogeneic blood transfusions during open-heart surgery, as well as in orthopedic operations.
Following the sequestration procedure, the prepared PRP and PPP blood components can be utilized to apply to tissues. Platelet-leukocyte gel is a substance containing of a mix of PRP, leukocytes, and thrombin, prepared from a unit of autologous freshly drawn whole blood. Platelet-leukocyte gel can either be applicated as a stand alone product, or can be added to autologous bone or bone substitutes, to create a “bioactive” bone graft. Thrombin will activate the PRP, inducing the platelet granules to release their platelet growth factors. Because of the high growth factor content, platelet-leukocyte gel is capable of executing the essential steps in wound healing by potentially increasing collagen production and improving the integrity of the wound repair. Moreover, platelet-leukocyte gel possesses antimicrobial effects, based on the release of antimicrobicidal proteins from platelet granules, along with functioning white blood cells.
Few hospitals in Europe routinely use autologous platelet-leukocyte gel application techniques as part of a peri-operative blood management program. In the United States, an increasing number of clinicians tend to employ platelet-leukocyte gel applications in various surgical settings, for both in, and out of hospital surgery. The question of why this novel and promising technique for the delivery of autologous growth factors has not yet been adopted on a broader scale needs to be addressed. The main reason may be the lack of convincing scientific data that provides information whether or not the use of PRP and platelet-leukocyte gels are appropriate in the clinical setting. To date there have been no well-designed scientific studies in which platelet-leukocyte gel has been used during orthopedic indications. Although there have been anecdotal reports, there are clearly many important questions to be answered.
The purpose of this thesis was to provide basic information on features which are important for the application of platelet-leukocyte gel, to overcome the conflicting data that have been reported in clinical studies and experimental research on the efficacy of platelet-leukocyte gel treatment. In-vitro, clinical, and experimental studies have been executed in order to provide this information. A good understanding of proper preparation techniques and application methods of autologous platelet growth factor delivery are mandatory to avoid inconsistent results in outcome.
