Platelet-rich plasma and platelet gel: a review

Abstract

Strategies to reduce blood loss and transfusion of allogeneic blood products during surgical procedures are important in modern times. The most important and well-known autologous techniques are preoperative autologous predonation, hemodilution, perioperative red cell salvage, postoperative wound blood autotransfusion, and pharmacologic modulation of the hemostatic process. At present, new developments in the preparation of preoperative autologous blood component therapy by whole blood platelet-rich plasma (PRP) and platelet-poor plasma (PPP) sequestration have evolved. This technique has been proven to reduce the number of allogeneic blood transfusions during open heart surgery and orthopedic operations. Moreover, platelet gel and fibrin sealant derived from PRP and PPP mixed with thrombin, respectively, can be exogenously applied to tissues to promote wound healing, bone growth, and tissue sealing. However, to our disappointment, not many well-designed scientific studies are available, and many anecdotic stories exist, whereas questions remain to be answered. We therefore decided to study perioperative blood management in more detail with emphasis on the application and production of autologous platelet gel and the use of fibrin sealant. This review addresses a large variety of aspects relevant to platelets, platelet-rich plasma, and the application of platelet gel. In addition, an overview of recent animal and human studies is presented.

Conflict of interest statement

The senior author has stated that authors have reported no material, financial or other relationship with any healthcare-related business or other entity whose products or services are discussed in this paper.

Figures

Figure 1.

Schematic overview of a resting and activated platelet. Normally platelets are in a resting, nonactivated state. On activation (e.g., by thrombin), platelets change their shape with the development of pseudopods to promote platelet aggregation and subsequent release of granule content through the open canalicular system (GP, glycoprotein).

Figure 2.

The different cascade stages in hemostasis after tissue injury.

Figure 3.

Schematic illustration of the role of PDGFs (numbers indicate the sequence of actions) during the different stages of the wound healing process (VEGF, vascular endothelial growth factor).

Figure 4.

Graphical representation of a bioengineered bone graft with PG. Sequestered autologous bone chips are mixed with PRP and thrombin. The result is a bone graft that is enriched with a high concentration of platelets releasing their growth factors. Because of the viscous PG, the bone chips will stick together, thus avoiding migration of bone particles.

Figure 5.

Diagram showing the mechanism by which PGF binds to the tyrosine kinase receptor. Extracellular PGF receptor binding results in intracellular signalling transmission to the cell nucleus.