What is the difference between Follicular Unit Extraction (FUE) and Follicular Unit Transplantation (FUT)?
Hair transplantation can be done by the classical, popular FUT (strip) method or by the FUE method. The difference between the two methods lies in how the grafts are obtained, not in how the grafts are planted. Several years ago the FUE method of extraction was done by most surgeons manually. Lately this method of extraction has become motorized and its popularity has increased somewhat – sometimes justly and sometimes unjustly.
FUT method: a “strip” of scalp is obtained surgically from the donor site in the back of the head and then the strip is dissected down into individual grafts. The skin edges of this surgical excision are then stitched closed. After the wound heals a horizontal line scar remains. This scar is hidden from view by the hair above that covers it up, and probably your barber will not notice it, unless you tell him. A two layered closure (deep stitches and superficial stitches) and the Trichophytic closure technique for the strip method can minimize the scar formation further.
FUE method (extraction method): a tiny circular cutting punch (usually a 0.8mm to 1mm size punch) instrument is used to harvest grafts one by one from the donor scalp area. Years ago most FUE procedures were done manually; In the last few years the punches have become motorized. Numerous tiny circular polka-dot scars and permanent discoloration occurs on the scalp skin, but if done properly is not noticed as the surrounding hair hides it. There are no stitches generally. Another plus: The donor field may be extended and enlarged slightly, but the future ramifications of this enlarged donor field need to be considered. If a large number of grafts are needed then it is best to use the FUT method because the FUE method is more costly and takes twice as long to do the same number of grafts.
FUE’s biggest handicap is that it is less efficient than FUT in harvesting hair from the central part of the permanent hair donor region of the scalp. In FUT, the strip is taken, utilizing all the hairs in this region. Only every other follicular unit is utilized in FUE, so that enough hair is left to cover the remaining scalp. Therefore there is approximately half the total donor hair available when doing FUE as opposed to FUT. This inefficient harvesting of FUE causes the donor supply to shrink and then in many cases only part of the patient’s hair transplant goals can be met (ex. only front work, no crown work). To make up for this donor supply shrinkage the surgeon may be tempted to harvest hair beyond the upper and lower margins of the permanent hair- safe zone, thus taking a chance with implanting hair that is non-permanent and may die soon. As stated above FUE causes numerous remaining circular scars. These scars distort the nearby skin and follicular hair units, making any future FUE procedure harder to do, and thus again limits the available donor supply. With the above in mind, a surgeon should use FUE as a harvesting technique only when a small number of grafts are needed to accomplish the transplant goals of the patient.
Some other negative aspects of FUE are: The FUE grafts are cut finer and with less precision in general without the aid of a microscope; there is less surrounding nourishing, protective tissue and therefore the graft is more prone to trauma, and death. Thus the yield is likely to be less. If too many extraction procedures are performed on the back of one’s head, a general thinning appearance of the donor area or a moth eaten appearance can be unintentionally created. In some patients as large numbers of grafts are harvested a casual observer can detect the areas harvested and the areas left alone. With FUE the patient must be willing to have the entire donor region shaved (military cut) to get ready for the procedure. Another major negative point about FUE should be considered: operating the motorized punch is very difficult in terms of hand-eye coordination, therefore it is probable that 10-15% of the grafts will be damaged (transected) and wasted. And with that same thought in mind: Patients that have curly or very wavy hair maybe technically difficult with FUE and make the process even slower or cause more transections.
The tightness with which follicular units are held in the dermis differs from one person to the next, thus some grafts can be extracted easily with little to no transection or damage to the cut hair follicles. In other cases it is hard to extract the grafts and transections occur at an unacceptable rate. Sometimes a test (Fox test)is done on some FUE candidates, extracting 100 follicular units, prior to the procedure. These harvested grafts are then examined under the microscope to make sure that the grafts are intact and are not transected. The follicle’s length, the surrounding fibrous connective tissue, or the angle of the follicle to the surface of the skin may hamper and make it too difficult to extract the whole intact follicular unit.
FUE is a good choice when doing body hair harvesting. It is ideal for scar repair. Possibly another good time to use FUE on a small case is when a hair loss patient who had a previous strip harvesting but has no donor area left for a repeat session of strip harvesting.
Some surgeons and ads that prefer FUE say that there is less pain and shorter patient recovery time, but there is no evidence to support this view according to the International Society of Hair Restoration and Surgery (ISHRS).
In summary both FUE and FUT (strip) methods have positive aspects and negative aspects. The decision on whether to use the FUE or the FUT method needs to be made by the doctor depending on the patient’s hair status and needs.