Hair transplantation aims to restore a more youthful appearance for those distressed by hair loss, particularly androgenetic alopecia. This activity reviews the evaluation and management of patients undergoing hair transplantation and explains the role of the inter professional team in improving care for patients who undergo this procedure.
Hair follicle – composed of a hair shaft, two surrounding sheaths (inner and outer), and a germinative bulb. The follicle divides into three sections: infundibulum (from the skin surface to the sebaceous gland duct), the isthmus (from the sebaceous duct to the arrector pili muscle insertion), and the inferior segment (from the muscle insertion to the base of the matrix)
Bulb – the deepest segment of the hair follicle which contains the hair matrix (creates the hair shaft), dermal papilla (regulates growth), and melanocytes (produce color).
Terminal hair – thick, pigmented hairs at the top of the scalp, beard, axillary, and pubic regions, all of which are androgen-sensitive. The hair elsewhere on the body, including the parietal and occipital scalp, are androgen-independent.
Vellus hair – this is fine, short, non-pigmented hairs (“peach fuzz”) found on the adult that covers much of the body.
Follicular Unit (FU) – a naturally occurring group of hair(s) seen on the scalp consisting of several terminal hairs (usually 1 to 4), a sebaceous gland and duct, and an arrector pili muscle. The collagen band which surrounds the FU is called the perifolliculum.
FUT Donor Site Harvest
The patient placement is in a prone position. If not done already, the donor site hair is trimmed to 2 mm. The calculated strip length is marked, and a local anesthetic is injected superficially into the dermis. A tumescent solution may be injected as well to increase anesthesia, hemostasis, and dermal turgor. A beveled incision is made parallel to the exiting follicles, into but not beyond the subcutaneous tissue (about 4 to 5 mm in depth). With lateral retraction around the periphery using sharp skin hooks, the donor strip gets dissected off the galea aponeurosis and occipital fascia which minimizes bleeding and sensory nerve damage. NOTE: cauterization should be used sparingly to decrease the risk of permanent FU damage.
FUE Donor Site Harvest
The donor site is shaved to 2 mm to visualize the angle of the follicles. The patient placement is in a prone position for ease of harvesting. Local and tumescent anesthesia gets injected into the donor site. If manual FUE is being performed, a sharp punch (diameter 0.8 to 1.2 mm) is oriented within the center of the hair follicle at the same angle and advanced in an oscillating motion to a depth of 4 mm or less to prevent transection. The FU is removed using delicate forceps in an atraumatic fashion and placed either directly into the recipient site (after inspection of FU integrity) or a holding medium of chilled sterile saline.
Recipient Site Creation and Implantation
No matter the harvest technique used (FUE or FUT), the implantation process must also take place in an atraumatic and meticulous fashion. For instance, grafts should only be manipulated using the perifollicular tissue. Furthermore, grafting should be done expeditiously since prolonged exposure of the FU will cause graft desiccation. Attention to the recipient’s hair pattern is important to promote a natural-looking result. For example, hair along the frontal scalp hairline points anteriorly at an angle of 15 to 20 degrees, while hair follicles in the temporal region are oriented inferiorly. Also, the surgeon should strive to recreate a sharp temporal recess in males and a rounded temporal recess in females. Lastly, the angles and spiraled orientation of the crown should be followed to create a natural result.