Hair restoration surgery, also known as hair transplantation, is a common cosmetic surgical procedure that aims to restore hair growth in areas of the scalp that have experienced thinning. The procedure involves transplanting hair follicles from a donor area, typically the back or sides of the head, to a recipient area, where hair growth is desired. The back and sides of the head are most commonly used for the donor area as they represent the region of dihydrotestosterone (DHT)-resistant follicles.

For both men and women, androgenetic alopecia (AGA), aka male or female pattern hair loss, is caused by a combination of genetic factors and the presence of the metabolite hormone DHT. Genetic factors are believed to modulate the degree of impact DHT has on the DHT-sensitive regions of the scalp. Even though the level of serum DHT present plays a role, individuals with similar DHT levels can have very different degrees of hair thinning due to this variable impact. DHT-sensitive hair follicles experience a process known as miniaturization in which the hair follicle thins in diameter, until eventually there is complete involution of the follicle. This form of hair loss is not characterized by excessive shedding, contrary to popular belief.

Hair restoration, regardless of the technique, is fundamentally a grafting process. Hairs growing in one location are moved to a new location, resulting in a thickening up of one area at the expense of thinning another. The hairs will grow in their new location and be absent from their original location. Patients are often under the false impression that the hairs removed will “grow back” from where they were harvested, which is simply not the case, and a point that should be clarified upon consultation. The typical donor area has enough density to be thinned out without much or any visual significance. The modern hair restoration procedure is vastly improved over older techniques; however, on the most fundamental basis, the procedure remains one of hair redistribution. Although limited to the individual’s donor supply, the advances in hair restoration have led to much more natural results, less downtime, greater graft survivability, and less scarring.

The first successful hair transplants were first described in 1822 in Germany. These procedures involved grafting a patch of tissue with hair to another area that did not have hair. Later in the 19th century these procedures found a use in the treatment of burns and other traumas. Modern hair transplantation procedures can be dated back to Japan in the late 1930s, where a “punch technique” was used to remove small hair-bearing skin grafts and transplant them into areas of hair loss. After the war, this procedure made its way to the United States by way of New York City, where the first hair transplant in the country was performed in 1952. These early hair transplants were often unsightly, with large patches of around 30 hairs being transplanted at once. This led to a “pluggy” or “doll’s hair” appearance that was far from natural. Despite the unnatural results, the procedure gained massive popularity and spread around the world. The plug procedure maintained dominance for nearly 25 years and became synonymous with hair transplantation.

In the early 1980s, “mini-grafting” replaced the plug procedure due to its much more natural appearance. Mini-grafting, as the name implies, used smaller grafts. Instead of punching out grafts, as with the plug procedure, mini-grafts were isolated out of the body from a strip of skin taken from the back of the head. The problem with mini-grafts was that they still did not look perfectly natural and had the look of mini-plugs. This procedure was improved on throughout the 1980s with the advent of “micro-grafts,” which were one or two haired grafts used between mini-grafts and throughout the hairline. While this improved results, it did not fully reproduce the natural anatomy. In addition, these procedures left a linear scar in the back of the head; however, at the time, this was considered more acceptable than the large punch scars from the prior plug days.

Mini- and micro-grafting of the 1980s was replaced by the follicular unit transplant (FUT) procedure in the early 1990s. This procedure, like its predecessors, began with harvesting a strip of tissue from the donor area of hair at the back of the head. The advancement in FUT over the mini-/micro-grafts was that microscopic dissection of the strip tissue was performed to isolate individual follicular units, hence its namesake. Follicular units are the smallest anatomical building blocks that make up hair tissue. On average, there are one to four hair follicles per follicle unit (racial variation is common). Each follicular unit shares a hair pore, a piloerector muscle (responsible moving hairs to trap warm air), a sebaceous gland, and adipose tissue. FUT was the first procedure in the history of hair restoration to be able to produce fully natural results, and it was no surprise that it became the mainstay treatment for the next 20+ years.

With FUT a mainstay, the next advancement was to not only transplant follicular units but also harvest follicular units directly from the scalp, thereby eliminating the linear harvesting scar. The follicular unit extraction (FUE) procedure was first performed in Australia in 1989. Without any specialized FUE instruments, this procedure was tedious and time consuming, resulting in poor adoption for nearly a decade. In the early 2000s many new instruments were being developed to aid in the FUE procedure, which helped it garner much attention. These instruments, which began as small dermatologic biopsy punches, evolved into the modern motorized rotary instruments with a variety of punch shapes and sizes. The main advantage of FUE over FUT was the elimination of scalpels and sutures. This meant much less postoperative pain, no linear scarring in the donor area, and reduced risk of permanent nerve damage to the back of the head.

FUE was always much less invasive than FUT, but its initial long case time relative to FUT, coupled with its increased price tag, made it a less popular option. The 2010s brought much more sophisticated FUE harvesting devices, which sped up the process and increased graft harvesting reliability. Furthermore, the 2010s saw tight, faded haircuts in vogue, which made hiding FUT scars impossible, further favoring FUE. Many hair restoration doctors started performing FUE, and as a result, the price of the procedure came down to where it was competitive with FUT. Around 2015, FUE had surpassed FUT globally ( Fig. 32.1 ). At the time of this writing, FUE accounts for more than 80% of hair restoration procedures, and FUT remains as a lower-cost alternative.

FUE vs. FUT by global volume.

The 2020s, now dominated by FUE as the predominant form of hair restoration surgery, is experiencing a greater adoption of newer and more advanced forms of this procedure. The majority of FUE performed is still being performed fully by hand; however, the use of robots is gaining popularity around the world. While accounting for only a small portion of FUE today, robotic FUE has the potential to replace manual FUE if it can be offered at a competitive price to its manual counterpart.

Patient selection plays a critical role in the success of hair restoration surgery, and the process of selecting the right patient requires careful consideration of various factors that affect both the subjective and objective outcomes of the procedure. The following are some of the important factors that a surgeon should take into account when selecting a patient for hair restoration surgery:

• 1.

  Understanding the patient’s concerns and creating a plan to address them: It is important to understand the patient’s concerns and expectations before undergoing hair restoration surgery. This will help the surgeon create a plan that addresses the patient’s specific needs and creates a roadmap for achieving the desired results. The surgeon should ask questions to better understand the patient’s goals and discuss the different options that are available to meet those goals. It is important to realize that patients with similar hair loss patterns often have very different chief complaints. It is the responsibility of the physician to understand the complaints in order to create a meaningful solution for the patient.

• 2.

  Diagnose the type of hair loss before treating with hair transplant: Diagnosing the type of hair loss prior to hair transplantation is crucial for ensuring the success of the procedure and ensuring the best outcome for the patient. There are several types of hair loss including androgenetic alopecia, alopecia areata, telogen effluvium, and scarring alopecia. It is important for the physician to accurately diagnose the type of hair loss by conducting a thorough medical history and focused physical examination, as well as possibly conducting laboratory tests and scalp biopsy. Knowing the type of hair loss helps guide the treatment plan. Failing to diagnose the type of hair loss can lead to inappropriate treatment and unsatisfactory results.

• 3.

  Evaluate if there is enough donor supply to meet recipient demand: The amount of donor hair will dictate how many grafts the surgeon can transplant without causing a deformity in the donor region. The surgeon should evaluate the donor density and compare it to the amount of recipient hair that would be needed to achieve the patient’s goals. If there is not enough donor hair to meet the recipient demand, the surgeon may need to consider alternative options or propose an alternative plan that may only address only part of a patient’s chief complaint.

• 4.

  Understand and convey how different hair types affect outcomes: Hair characteristics play a large role in predicting outcomes for transplantation. Hairs that are of thicker caliber will take up more volume than very fine hair. Hair that is curly or wavy will similarly take up more volume than straight hair. Hair that has less contrast to the skin (i.e., light hair with light skin, or dark hair with dark skin) will always appear thicker than higher contrast differentials. These are all very important considerations to appreciate when suggesting a treatment plan.

• 5.

  Set and manage patient expectations: Setting and managing the patient’s expectations is critical to the success of the surgery. The surgeon should discuss the expected outcome of the procedure, the time frame for the results, and the potential risks and side effects. It is important to be transparent and honest with the patient and to set realistic expectations that are achievable. The need for a subsequent procedure to achieve desired results should always be discussed.

• 6.

  Rule out body dysmorphia: Body dysmorphia is a mental health condition in which a person has a distorted perception of their body image. If a patient has body dysmorphia, they may have unrealistic expectations about the outcome of the surgery, which can lead to disappointment and dissatisfaction. It is important to rule out body dysmorphia and to manage the patient’s expectations accordingly.

• 7.

  Propose a design that will lead to an age-appropriate look: Hair restoration should create an age-appropriate look that will look natural for their current age and into their future. The surgeon should propose a design that takes into account the patient’s age, hair type, and hair loss pattern. This will help create a plan that will result in an outcome that looks natural and will age gracefully over time.

• 8.

  Create and align on a preliminary plan with the patient: The surgeon should create a preliminary plan with the patient and align on the treatment areas during consultation. This can be done by drawing the proposed treatment plan either directly on the patient or digitally over photos. The preliminary plan should take into account the patient’s goals while holding true to the surgeon’s honest recommendations, even if they are not what the patient wants to hear. Without alignment on a treatment plan, it would be impossible to expect satisfaction.

• 9.

  Educate the patient on the need to prevent future hair loss: Hair restoration surgery does not cure hair loss, and it is important to educate the patient on the need to prevent future hair loss as best as possible. Medical therapies such as finasteride and minoxidil can help preserve the original hairs, which are prone to continued thinning, unlike the transplanted DHT-resistant hairs. The patient should be made aware of the importance of these medical therapies in maintaining the results of the surgery. Should a patient refuse to commit to long-term medical maintenance, it would not be ethical to perform hair restoration surgery. Some patients argue they would rather have multiple surgeries over medical maintenance, but they must understand that there is never enough donor hair to support enough procedures to restore all the hair they are capable of losing.

• 10.

  Ensure the patient understands the risks, benefits, and alternatives: Similar to all forms of surgery, informed consent is necessary. The patient should be fully informed about the risks, benefits, and alternatives of the procedure before undergoing hair restoration surgery. The patient should understand the potential risks and side effects, as well as the benefits and limitations of the procedure. This will help the patient make an informed decision and achieve the best possible outcome. Risks include potential need for subsequent procedures to achieve the desired results, infection, graft failure, and scarring. Alternatives include hair systems (wigs), scalp micropigmentation, or doing nothing.

In summary, patient selection is a critical factor in the success of hair restoration surgery. The surgeon should take into account the patient’s concerns and expectations, ensure their form of hair loss is treatable by transplantation, rule out body dysmorphia, evaluate the amount of donor hair available, set and manage patient expectations, propose a design that will result in an age-appropriate look, create and align on a preliminary plan with the patient, educate the patient on the need to prevent future hair loss, and ensure the patient understands the risks, benefits, and alternatives. By carefully considering these factors, the surgeon can help the patient make an informed decision and achieve the best possible outcome from hair restoration surgery.

Medical indications for hair restoration surgery can include both genetic and acquired forms of hair loss. Genetic hair loss, also known as AGA, is by far the most common cause of hair loss in men and women, and accounts for the vast majority of hair restoration procedures. Male AGA affects up to 50% of men by the age of 50, and female AGA affects 49% of women throughout their lives.

AGA typically presents as a receding hairline and/or thinning crown in men, and diffuse thinning, especially along the central partline, in women. These are also known as male or female pattern baldness as they follow characteristic patterns, notably illustrated in the Norwood-Hamilton and Ludwig-Savin Scales ( Figs. 32.2 and 32.3 ) for men and women, respectively.

Norwood-Hamilton Scale.

Ludwig-Savin Scale.

Acquired hair loss (alopecia), depending on the pathophysiology, may or may not be treatable with hair restoration surgery. Acquired alopecia encompasses a wide range of conditions, including, but not limited to, autoimmune disorders (i.e., thyroid disease, polycystic ovary syndrome, alopecia areata, alopecia universalis), medication induced (i.e., anagen effluvium secondary to chemotherapy), inflammatory (allergic dermatitis), and physical or emotional stress induced (telogen effluvium). Acquired alopecia can also arise from scarring on the scalp (cicatricial or scarring alopecia). Cicatricial alopecia is further classified as either primary (frontal fibrosing alopecia, lichen planopilaris, central centrifugal alopecia) or secondary in the case of trauma or infection. In the case of cicatricial alopecia, hair restoration may not be effective due to a lack of sufficient blood supply. In the case of autoimmune-mediated hair loss, hair restoration should never be considered until the underlying condition is first proven stable for at least 6 to 12 months. In general, it is never a good idea to transplant into an inflamed recipient area.

In order to determine whether hair restoration surgery is an appropriate option, a thorough medical evaluation and scalp examination are performed to ensure a proper diagnosis. The surgeon will take into consideration the individual’s medical history, the pattern and extent of hair loss, and the gross, and potentially the dermatoscopic, appearance of the hair and scalp. It is beyond the scope of this chapter to provide a comprehensive differential diagnosis for acquired hair loss, but it is important to be confident in a diagnosis before treating surgically. Should there ever be suspicion of an autoimmune condition, or a form of cicatricial alopecia, it is prudent to refer the patient for evaluation by an endocrinologist and/or dermatologist, respectively.