Introduction
Objective: Surgical wound complications are associated with increased cost, morbidity, and mortality following cardiothoracic surgery.
Recent publications advocate the application of autologous blood components (PRP, PRF, l-PRP, i-PRF, etc.) as a tool to aid surgical closure during various surgical procedures. The aim of this study is to evaluate the safety and efficacy of applying autologous platelet-rich and platelet-poor plasma to the sternum closure and saphenous vein collection site during closure following a coronary artery bypass graft.
Patients and methods: A retrospective analysis of 1446 consecutive coronary artery bypass grafting procedures performed by two surgeons was conducted. A patient group in whom platelet-rich and platelet-poor plasma was applied topically during closure of chest and leg surgical incisions was compared with a patient population receiving standard care. Forty covariates were collected for each patient included in the study. Propensity scoring was used to adjust for baseline imbalance. Asymptotic logistic regression and exact statistical methods were used to determine the effect of autologous blood administration on infection and drainage of sternal and leg wounds.
Results: There were sufficient data for inclusion of one thousand one hundred and twenty-eight patients, 571 of whom received treatment, in the final analysis compared to 557 control patients. No treatment-related side effects were recorded, and the administration process did not significantly affect the duration of surgery.

Conclusion: This retrospective analysis of a consecutive series of patients undergoing coronary artery bypass grafting procedures concludes that the administration of platelet-rich and platelet-poor plasma significantly reduces the incidence of chest wound infection, chest drainage, and leg wound drainage. This novel therapy warrants further investigation.

1. Introduction
Postoperative wound disorders following cardiothoracic surgery, particularly surgical site infection, are associated with increased morbidity, mortality, and costs [1-2]. Sternal infection (mediastinitis) has been reported in up to 20% of cases, although most studies report an incidence rate of 1-2% [3]. The overall wound disorder rate for chest incision following cardiothoracic surgery is 8-10% [4,5]. Leg incision for saphenous vein harvesting can also be a site of significant postoperative wound complications. The trend towards endoscopic harvesting of the saphenous vein has reduced complication rates, but endoscopic harvesting of the saphenous vein still has an infection rate of 2-4% and an overall wound complication rate of 6-8% [6-8]. The high morbidity, mortality, and costs associated with these postoperative wound disorders make advancements that can reduce postoperative wound complications attractive to cardiothoracic surgeons. Topical application of platelet-rich plasma (PRP) and platelet-poor plasma (PPP) in combination with a coagulating agent (typically bovine thrombin) has been advocated for many indications [9-11]. The aim of PRP application is to accelerate the healing process through the effect of high cytokine concentrations released during platelet degranulation. Platelet-derived growth factor (PDGF), epidermal growth factor (EGF), vascular endothelial growth factor, and transforming growth factor beta (TGFb) are examples of cytokines shown to be present in concentrated levels in PRP [12]. These high cytokine levels are hypothesized to cause an accelerated healing response at the application site. PPP, produced as a byproduct during the centrifugation process used to produce the platelet-rich product, has been advocated as a tissue adhesive for topical hemostasis during surgical closure [11]. Two recent publications have reported improved postoperative outcomes following topical application of PRP and PPP in combination with bovine thrombin to the chest incision and venous collection site during surgical closure [13-15]. Englert et al. demonstrated a trend toward reduction in chest incision pain, leg incision pain, and measurable bruising in a randomized, blinded study of 30 patients [13]. Trowbridge et al. compared 382 patients receiving platelet-rich plasma with a non-randomized concurrent control group of 948 patients and a historical control group of 929 patients [14]. This analysis showed a significant reduction in the rate of superficial and deep chest wound infections in the platelet-rich plasma group compared to both concurrent and historical controls. These studies support the adjunctive use of autologous blood components in cardiothoracic procedures and warrant further investigation into the safety and efficacy of this technique. The following study is a retrospective analysis of 1446 consecutive coronary artery bypass graft (CABG) procedures. Autologous platelet-rich and thrombocytopenia grafts were injected into the sternal closure and saphenous vein collecting area.