From the very first procedure the donor safe zone and hair characteristics need to be assessed for the long term harvesting protocol
To perform a hair transplant the first aspect of the actual procedure is to extract the follicular units from the donor area safe zone; either by FUE, Follicular Unit Extraction or FUT Follicular Unit Transplant techniques
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
FUT the safe zone is isolated along the occipital bone, approximately in the centre of the donor region therefor in the centre of the safe zone. FUE relies on a wide safe zone to reach high numbers otherwise over harvesting may occur with obvious hair less areas and loss of density
Other aspects that need to be considered; skin laxity, hair density, hair characteristics, these factors will determine how many grafts and how easy it is extract the follicular units.
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.
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. The closure with FUT is vital to the healing and eventual linear scar left; too aggressive or poor post op healing may cause stretch back
With FUE some skin types can split the hair when being punched; this can damage the follicular units and impair healing
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
To ensure the donor is left in the best condition possible and to maximise the number of FU´s available these factors play an important role. Especially as hair loss progresses good donor management becomes more important to be able to treat high levels of hair loss with a balanced coverage