The Effect of Platelet Rich Pasma on Strenal Healing Post Median Strenotomy in Patients Undergoing Open Heart Surgery

1. INTRODUCTION Successful healing of the sternum after open heart surgery is a complicated phenomenon because of the natural body ability often fails to efficiently repaired of the sternum in patients after open cardiac surgery (Everts 2006). Recent evidence based data suggested new modalities to increase the quality and accerelate sternal healing in high risk patients after open heart surgery vulnerable for early sternal dehiscence (Liu 2002) . PRP considers as an attractive alternative option in that manner. Marx and associates demonstrated the positive influence of PRP on bone regeneration and healing since 1998 (Marx 1998 ) . Autologous PRP carries minimal risk of infectious diseases transmission, immunologic reactions, and rejection. PRP with concentrations 4 to 5 folds of the normal average platelet (1,100,000 platelets/μl ) proved to have a remarkable increase in bone mineral density and regeneration . the market for PRP grows from $45 million in 2009 to more than $120 million by 2016 (Dawood 2018 ). Multiple factors affect the PRP efficacy in sternal bone healing and regeneration process. Platelet preparation before surgical application is an area of concern with PRP. For this issue, an appropriate anticoagulant must be used to prevent the early spontaneous activation of the platelets (Kassolis 2000 ). Several anticoagulants have been employed for PRP preparation including heparin, citrate, acid-citrate-dextrose solution A or anticoagulant citrate dextrose-A ,citrate-phos phate-dextrose ,citrate-theophylline-adenosine- dipyrimadole and ethylene diamine tetra- acetic acid moreover, several manual or automated systems have been designed for preparing PRP including clinical laboratory methods and kits (Carlson 2002). PRP produced by single- or double-step centrifugation technology via platelet-pheresis (autologous selective filtration )and the cell separators,However, these methods are rarely used nowadays, due to several factors including high cost, large volume of peripheral blood should be harvested from the patients, and potentially damage to the platelet (Dhurat 2014) . Commercially available PRP kits and devices differ in ease of use, one or two step centrifugation protocols, centrifugation speed, final PRP volume, platelet count and activation, platelet and growth factor concentrations, and final RBCs' and WBCs' count.Nevertheless, the cost of the commercial kits for PRP processing is still a challenge (Trebinjac 2020) .
2. AIM/ OBJECTIVES :

To study the Effect of platlet rich plasma on sternal healing post median sternotomy in Patients undergoing open heart surgery 3. METHODOLOGY:

• Type of Study: prospective clinical trial propensity matched comparative study
• Study Setting: Patients refered to our Cardiothoracic department, Faculty of medicine, Ain Shams University and ain shams specialized hospital to perform open heart surgery who fulfill our inclusion charateria.
• Study Period: It will be performed between march 2020 and january2022
• Study Population:

• Inclusion Criteria: Patients with one of which

1. patients will under go open heart surgery with BMI >30 or
2. diabetic patients
3. patients with history of chest wall radiotherapy exposure or
4. bilateral internal mammary artery harvesting .
5. age > 70 years old -Exclusion Criteria: