The principle of the autologous micro-graft is simple: it involves removing from the donor area of the scalp (usually the part in back of the head) hair which we know is genetically programmed to ensure normal cycles for life and thus to never fall out, for the purpose of reimplanting it in the bare recipient area (generally the balding areas above the temples and the crown of the head also called the vertex) where it retains for life the ability to grow, with the longevity characteristics of the donor area.
Since the donor and the recipient are the same person, there is no risk of rejection. A hair graft from another person or a heterologous graft would be possible, on the condition of finding a perfectly compatible donor and taking an immunodepressor treatment to avoid any rejection, which seems very difficult and excessive, considering the significant side effects risked.
An autologous hair graft is thus a redistribution of the "hair asset" which the doctor will try to optimize to the utmost in terms of the condition of the hair and the age of the candidate for an autologous graft. In fact, although the hair reimplanted in the recipient area retains its normal cycles, as we have seen, it is clear that the pre-existing hair next to that hair will inexorably end up by falling out forever, requiring one or more new grafts, on the condition that the donor area is still dense enough with transplantable hair. This results in the concept of the operating strategy of the doctor, who must be able to extrapolate the medium- and long-term progress of the hair.
Follicular units of 1, 2, 3 hairs
Progress in hair grafts over the past five years has considerably improved the quality of transplanted hair: the density, natural appearance and homogeneity of the implants now constitute a real solution offered to men and women who no longer accept watching their hair inexorably grow thinner.
A graft of hair has become a graft of follicular units, providing totally natural density that blends in with the rest of the hair, thanks to following the nature of the patient's follicle. Gone is the doll's hair look or the corn rows of the 80s!
A follicular unit is a natural group of 1 to 4 hairs (although 18% of the follicles are single, a majority of 57% are by groups of 2 hairs, 21% by groups of 3 and only 3% by groups of 4 hairs). The follicular units are distinct anatomical entities, but each hair inside the unit has its own follicle.
These two hair transplantation techniques have the same objective: to implant in the recipient areas grafts (follicular units) taken from the donor area. They only differ in the way the grafts are extracted: