The first technical aspect of hair transplantation is the extraction of the follicular units from the donor area, either by FUE, Follicular Unit Extraction or FUT Follicular Unit Transplant techniques.
The donor zone has to be assessed as to, skin laxity, hair density, hair characteristics, and size of the safe zone; these factors will determine how many grafts and how easy it is extract the follicular units
Skin laxity affects each techniques, FUT the length and width of the strip that can be safely removed. FUE can affect the punch extraction quality; skin type physiology can make for a good or bad candidate. Skin characteristics will also affect the healing process and either hamper or help how visible scarring is left over the donor area
Hair characteristics, can affect the quality of extraction, fair or white hair makes it harder to visualise within the skin tissues, even under magnification, and curly hair makes it harder to divide the individual FU´s with FUT
With FUE as the extraction is blind, difficult hair characteristics can reduce the numbers that can be extracted otherwise the transection rate can spiral. Curly hair can make it harder to determine the direction under the skin
Hair density; the follicular unit density is generally measured per cm², the density will differ around the sides compared to the back which has the highest density and greater number of multiple FU´s
The density should be measured in points around the extraction zone to take an average reading; with FUE to ensure an educated extraction pattern to leave an even density throughout and FUT to determine the length and width of the strip
The safe zone is the area around the sides and back of the head that the follicular units are not susceptible to genetic hair loss. The size of the safe zone will be determined by the long term pattern of hair loss.
A conservative approach is advised especially with FUE, in younger candidates with minor hair loss as the true pattern of hair loss cannot be gauged and the only indicator is family history, which cannot always be followed.
FUE especially as this technique relies on a wide safe zone to reach high numbers otherwise over harvesting may occur with obvious hair less areas and loss of density. FUT the safe zone is isolated along the occipital bone, approximately in the centre of the donor region therefore in the centre of the safe zone.
From the very first procedure the donor safe zone and hair characteristics need to be assessed for the long term harvesting protocol. To ensure the donor is left in the best condition possible and to maximise the number of FU´s available as hair loss progresses to a natural result and balanced coverage can be sustained.