FUE donor management is full of pit falls as greater numbers are looked to be harvested to treat higher Norwood scale patients. Miniaturization need to be taken into consideration when measuring the starting donor hair density, it must also be taken into consideration when managing an extraction pattern so as not to create excessive trauma to the donor area due to the harvesting extraction points being close together, either by reducing or limiting the size of the donor area or by attempting to reach high graft numbers.
When graft numbers are mentioned and what can be achieved it is obviously possible to reach high numbers, but the question asked should be at what cost. An important aspect to remember is FUE reduces the density or amount of hair in the donor, the actual skin surface area remains the same just the amount of hair left in the area is reduced.
Each procedure performed reduces the amount of hair left so it it important that long term planning is taken into consideration to ensure that the goals can be met and or if hair loss progresses it can be treated effectively to maintain a natural looking result, whilst not diminishing the donor hair to the point it becomes too thin.
An average donor hair density is around 75 follicular units per cm2, once the safe zone is measured out, taking into account potential future loss. The density of hair will alter dependent on the area of the scalp, as will the average hairs per follicular unit; the sides of the head generally have a lower hair density and lower hair to FU count compared to the back. It is important to maintain this differential in density in these areas and not to remove too much hair over a small area otherwise it will compromise the donor area and minimize what can be removed.
How much can be removed, 20,30,50% or more? the illusion of thickness works similar in the recipient as in the donor, it is the blocking of light reflection off the scalp, and the lay of the hair allowing for each hair to overlap the other; in the donor area this is achieved because the hair generally lays downwards so each hair (assuming not cut too short) will cover the hair below. When half the hair is removed from the donor to treat the recipient area it will impact not only on the visual look of the donor area with larger hair less areas being visible but also potentially reduce the donor hair density to a level no future procedures can be performed. Due to the nature of FUE, multiple individual extraction points it will impact on the healing over a wide area, skin characteristics and hair quality can alter the higher number of grafts are extracted; this can be tempered dependent on the technique of FUE used and the size of the punch, so these issues again must be considered when deciding on the number of grafts that can be safely removed to treat the recipient area.