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Follicular unit transplant
Follicular unit transplant
First introduced in 1998, FUT capitalizes on the use of undifferentiated stem cells associated with hair follicles to replenish melanocytes in areas of leukotrichia. A melanocyte reservoir consisting of inactive melanocytes (Dopa-negative) exists in the outer root sheath (ORS) of hair follicles.37 In vitiligo, the active melanocytes (Dopapositive) in the dermis are destroyed, whereas inactive melanocytes are unaffected.38 If induced by ultraviolet light therapy or by removal of the associated epidermis, the inactive melanocytes can convert to active melanocytes, as described by Starrico in 1959.39 Once activated, these melanocytes can migrate toward the epidermis and induce perifollicular pigmentation, while the hair matrix migrates downward to make melanin,
as outlined by Cui et al. in 1991.37,38
In follicular grafting, the donor graft is typically selected from the occipital or posterior-auricular aspect of the scalp. Here, the donor graft is obtained by using the strip method (known as the FUT method), where a strip of follicles is harvested from the scalp and then dissected into follicular units.38 The extracted hair follicles are then placed in a Petri dish filled with cold NS. Meanwhile, the RS is prepared by making slits using either a hair transplantation machine, a curved cutting needle, or an 18-guage needle, to allow for insertion of the hair follicle graft via jewelerโs forceps. After 10 days, adjuvant therapy can be initiated.38
This technique is advantageous for hair-bearing areas, as leukotrichia can be reversed. A greater number of melanocytes are found in a single hair follicle, which corresponds to a larger melanocyte and stem cell reservoir compared to normal nonglabrous skin. This procedure is useful for smaller, more difficult to treat areas such as the eyelashes. Benefits include excellent color matching and a lack of textural abnormalities such as cobblestoning. Additionally, this is a low cost procedure that does not require specialized equipment or a laboratory.40 There is, however, a longer time required to see repigmentation compared to FUE. FUT is generally not appropriate for nonโhair-bearing regions.