
Biochemical factors:
This refers to the stress experienced by hair follicles when kept out of the body for a good amount of time. Various factors like lack of blood supply, oxygen, follicular nutrients, and exposure to extreme temperatures, including pH shift may stress the Graft. Ischemia-Reperfusion Injury is a kind of Biochemical factor that may lead to Graft injury, in which the extracted Graft is placed on the Tissue bed, and this may lead oxygen re-exposure, which may set off free radical production, that in turn, may have an effect on Graft survival.
Vascular factors:
This refers to the immediate Post-operative oxygenation & revascularization. When Hair Transplantation is done, there is a lack of Vascular Anastomosis, that is, whenever an Organ Transplant is done, the tissues get hooked onto a new blood vessel, but this does not happen with a the hair follicles. The Free Grafts have a tendency to absorb the necessary oxygen passively from the tissues that surround it.
Neo- vascularization of such free grafts are said to occur within a period of 36 - 48 hours.The factor that helps in assisting this process is the Platelet Rich Plasma(PRP), as it contains Growth Factors, and this helps in providing the Free Grafts with the essential antioxidants and nutrients, while also reducing the time taken for Neo - vascularization.