Platelet-Rich Preparations to Improve Healing. Part I: Workable Options for Every Size Practice
Numerous studies have demonstrated that platelet-rich preparations applied to surgical sites, injuries, or wounds are a safe and effective way to promote soft tissue healing and bone growth. Various protocols have been developed for preparing platelet-rich preparations, with subtle but important differences between them. Unfortunately, only a minority of clinicians use platelet-rich preparations, such as platelet-rich plasma and platelet-rich fibrin, in their practice, possibly due to confusion about the different methods and their advantages and disadvantages. Therefore, the different types of preparations are described to help guide the selection of the best method for any size practice. Classic methods generally require large volumes of blood and can be expensive, complicated, and time-intensive. Simpler protocols have been developed recently, which require relatively inexpensive equipment and small blood volumes and, thus, may be more applicable for small clinical practices. Platelet-rich preparations accelerate healing at earlier time points to reduce discomfort and the potential for adverse outcomes, including infection, poor wound closure, and delays in forming strong bone for subsequent procedures (such as implants). However, platelet-rich preparations may also improve long-term outcomes in patients expected to have impaired healing, such as with lifestyle choices (eg, smoking), medications (eg, steroids), diseases (eg, diabetes, osteoporosis, atherosclerosis), and aging, by supplementing the deficient wound environment to restore proper healing. Therefore, both large and small clinical practices would benefit from utilizing platelet-rich preparations to enhance healing in their patients.
The speed of the first or only spin affects platelet location during platelet-rich plasma (PRP) preparation with anticoagulated blood. Whole blood plus anticoagulant is spun at low speed (soft spin) or high speed to separate the components. The blood separates into 3 layers: the top layer of plasma or platelet poor plasma (PPP), the middle layer or buffy coat, and the lower layer of red blood cells (RBC). The buffy coat contains leukocytes after the soft spin and the leukocytes and platelets after the hard spin. The platelets are located at the plasma/buffy coat interface after the soft spin and at the buffy coat/RBC interface after the hard spin. The collected fractions are noted by the brackets for the designated PRP preparations; the fractions outside the brackets are discarded. For the preparation rich in growth factors (PRGF) and simplified buffy coat PRP (BC-PRP), the PRP is composed of the collected fractions. For the classic PRP with either speed for the first spin, the collected fraction is spun in a separate tube to concentrate the platelets and leukocytes by removing most of the PPP after centrifugation.
Following are the centrifugation steps for preparing platelet-rich fibrin matrix with uncoagulated blood. To prepare platelet-rich fibrin matrix (PRFM), whole blood is mixed with anticoagulant in the disposal PRFM tubes containing the separator gel and centrifuged to separate the platelets and plasma above the gel and the red blood cells (RBC) and leukocytes below the gel. The plasma and platelets are mixed and transferred to a second tube and mixed with CaCl2. The fibrin matrix forms during the second spin.
The following describes platelet-rich fibrin preparation with coagulated blood. The products obtained during platelet-rich fibrin (PRF) preparation53 are shown. (a) Results of centrifugation of whole blood show the lower layer with compacted erythrocytes, the middle layer with the fibrin clot or PRF, and upper clear layer of serum. (b) The fibrin clot is removed from the tube with forceps. (c) The contents of the tube are placed on gauze to absorb the serum and the red blood cells. The red blood cell layer can also be cut away from the fibrin clot before blotting on the gauze. (d) The final PRF product for application in the wound is the white, autologous fibrin membrane after blotting.
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