The limiting step in hair transplantation is the amount of donor hair available. This makes efficient utilization of donor hair essential. Currently there are two methods employed:
1) Elliptical donor harvesting.
2) Follicular unit extraction.
Elliptical donor harvesting is used in 90 % of the procedures. Elliptical donor harvesting follows the same principles as other skin surgeries such as removing a mole or skin cancer. The hair bearing skin in the back of the scalp is numbed with local anesthesia. The length and width of the donor ellipse is determined by the donor density and desired number of grafts. It is better to take a longer and narrower donor ellipse to minimize the scar. Once the ellipse is removed the surgical site is closed with either stitches or staples which remain in place seven to ten days. Elliptical donor harvesting is safe and allows the removal of hundreds to thousands hair follicles minimal damage to the follicles.
Follicular unit extraction (FUE) is an alternative method for removing hair. This technique is most often utilized for patients that like to wear their hair short in the back. The overwhelming majority of patients we transplant do not shave their hair in the donor area and therefore having a minimal scar in the back is of no practical concern but, for those that do, follicular extraction is an excellent alternative for donor harvesting. FUE removes individual follicular groupings using a 1 mm - 1.3 mm wide punch. Hundreds of follicular groupings can be removed during each session. The incisions are so small no stitches are needed and the wounds generally heal with no visible scar. The chief disadvantage of follicular unit extraction is that one cannot harvest as many hair follicles in each session as with the donor ellipse. In addition, there is a higher rate of damage to the hair follicles upon removal, which may compromise the yield of the transplanted hair on the frontal scalp.