Definition of Process, and Distinction from FUE Using Head Hair Donor Sources

FUE traditionally involves restoring balding areas of the head by extracting grafts in vivo from the SDA one follicular unit at a time. It is a minimally invasive process involving little pain and is performed with patients receiving local anesthesia and a mild sedative. Depending on the number of grafts to be transplanted, most procedures can be scheduled over the course of several back-to-back work days with additional work for extensive cases scheduled months later. Microsurgical techniques allow patients to usually return to most normal activities the day after surgery is completed with healing ranging from 3 weeks to 4 months.

The use of nonhead donor hair in FUE requires several considerations related to follicles. Hair follicles renew themselves through a cycle consisting of three distinct phases: (1) anagen, (2) catagen, and (3) telogen. Research into a fourth phase, commonly called the exogen phase, is ongoing. Although 85% to 90% of scalp hair is anagen hair, between 40% and 85% of body hair can be in the telogen phase, and the anagen phase of body hair is much shorter, a few months compared with several years for head hair. Consequently, it is not only desirable to change these proportions before harvesting grafts but also develop a method where late-phase anagen hair can be identified, because early phase anagen and telogen hair are unsuitable for transplantation (being much more fragile and susceptible to transection during the extraction processes). The characteristics of the recipient hair have to be matched to the donor hair, taking into account hair diameter, color, curliness, typical rate of growth, and shaft angle. However, the slight modifications of these parameters by the recipient area may occur but are generally of minimal cosmetic significance.

Indications for Use of Nonhead Hair Donor Sources in General

In hirsute individuals, the use of nonhead donor hair is considered in situations of a relative or absolute lack of head donor hair supply. Head donor supply may be rendered inadequate because of a severe bald state. An example of this scenario is a Norwood 6 to 7 patient requiring global coverage with only a total head donor hair supply of 6000 to 7000 follicular units. Another situation is a patient who has undergone prior hair transplants that have resulted in a depletion of head donor supply but who still has a significant amount of bald areas that require restoration. Nonhead donor hair can also be used to provide coverage for baldness in conjunction with scalp hair from the occipital region where the level of baldness is not too severe.

Special Indications for the Use of Specific Nonhead Donor Sources

Some hair restoration scenarios can take advantage of the innate characteristics of certain types of nonhead hair to especially produce more natural and realistic results. The following are examples.

• 1.
  

  Because hairs from the extremities, such as legs, are innately finer and shorter compared with hair from the SDA, they are a natural fit for eyebrow restoration. This is also the case for vanguard hair in hairlines and temple areas where leg hair nascent characteristics make for a softer, more natural look. Such an approach could also be especially beneficial for the repair of previously transplanted harsh hairlines. Other individuals who may benefit in this situation include Asians who have thicker hair at the back of the scalp and persons with dark hair and contrasting lighter skin.

  
  
• 2.
  

  Patients requiring restoration of upper facial hair, such as mustaches or side burns, could find a more natural fit in using beard hairs from the neck areas of the beard.

  
  
• 3.
  

  Beard hair, which is coarser, is a viable alternative for camouflaging a donor scar from a previous procedure.

Patient Selection

In general, patients regardless of gender must be hirsute. The quantity, quality (thicker caliber hair preferred), and hair distribution at the donor area are all important considerations in deciding on preferred candidates. Vellus hair has less chance of growth, and is cosmetically inconsequential if it does grow. As in any indication for hair transplantation, all other nonsurgical options must have been explored and found to be nonviable in relation to the patient’s goals (although they can still be used in conjunction with hair transplantation).

For potential patients who are African American, it is generally observed that those with tight curls have a higher transection rate that may not produce acceptable outcomes. Anecdotally, I have observed that, apart from the tightness of the curls, another significant factor causing a higher transection rate in this demographic population is the skin texture and graft relationship with surrounding tissue: tougher skin texture and a tighter connection of the follicle to the dermal tissue results in a higher transection rate. Consequently, any at-risk patient seeking head and nonhead FUE should be first tested by extracting 25 to 50 grafts and observing for transections before a large-scale surgery is planned.

Managing Expectations

It is important for patients to understand that the quality of transplanted nonhead hair is not as high as that of scalp hair and that survival rates are not as high for transplanted body hair compared with transplanted head hair. Although the recipient site does seem to influence the characteristics of the donor hair minimally, with the exception of beard hair, transplanted body hair may not grow as long or fast as head hair. Consequently, patients are advised, at least initially, to keep their hair cut short. Body hair could also initially be a different color than head hair, although over time sunlight and other factors can bleach exposed transplanted hair in the scalp. As a result, the body donor hair usually assumes the lighter look of the surrounding recipient site hair. Nevertheless, transplanted gray hair almost always stays gray.

In the case of eyebrow transplants, despite best matching efforts, donor hair taken from different areas of the body can often present characteristics, appearance, and growth rates that are dissimilar compared with existing eyebrow hairs. Thus, patients should be advised accordingly to expect a need for more frequent trimming of the transplanted eyebrow. However, leg and arm hair, which are innately finer and shorter, require less frequent trimming on transfer to the eyebrows compared with eyebrows that have been transplanted using hair from the SDA.