Hair Transplantation Treatment & Management

Nearly all men and most women who have androgenic or inherited pattern baldness can be treated with hair transplantation. As in all other elective cosmetic surgeries, the most important patient selection criterion in hair transplantation is the individual's motivation. Results of hair transplantation are usually most dramatic when the procedure is performed on individuals with advanced degrees of hair loss. In general, the greater degree of hair loss, the larger number of grafts transplanted.

Hair transplantation may not be the most effective therapy for some medical causes of hair loss; in some instances, it exacerbates the condition. Therefore, workup to rule out other treatable causes of hair loss is important, especially in women, in whom nongenetic etiologies for the hair loss are more common than in men.

In addition to male pattern baldness and female pattern baldness, a variety of conditions can be successfully treated with hair transplantation. Scarring of the scalp due to trauma or surgery and hair loss due to traction (seen with extended wearing of hair pieces or trichotillomania) can be repaired with hair transplantation. Finally, hair transplantation can be successfully used to restore hair to the eyebrows; eyelashes; beard, mustache, or goatee area; and even to areas of the body, such as the pubis or chest.

Individuals must be motivated to undergo hair transplantation. Some surgeons conduct a formal psychological evaluation by means of lengthy questionnaires and examinations. The consultation helps ensure the patient is mature enough to decide to undergo the planned procedure. A prospective patient who has realistic motivations and expectations before the procedure is likely to be happy after the procedure. Honest and thorough preprocedural consultation is an extremely important part of the process.

Poor medical health is a potential contraindication for elective surgery of any kind. Individuals cannot be taking anticoagulants (eg, warfarin, aspirin) before the procedure. Good surgical judgment must be exercised when one considers surgery in individuals with potentially complicating medical conditions. Age is not a medical contraindication, as these procedures have been performed on men in their late 70s. However, ensure that such patients provide medical clearance from their internist.

Perhaps no single hair-loss condition calls for more conservatism in judgment than premature male pattern baldness. Teenagers and men in their early 20s are particularly self-conscious about hair loss because most of their peers still have full heads of hair. These young men often hold unrealistic expectations, desiring a youthful hairline that will not be appropriate as they age. Worse, early surgical correction uses a large number of donor hairs, which will be sparse in the future, potentially resulting in an unnatural look and a disappointed patient.

In a study of 52 patients presenting with androgenetic alopecia who underwent hair transplantation by follicular unit extraction at 2 medical centers, 49 patients reported satisfaction with the final results. Researchers found that patients younger than 33 years and with Norwood classification 4a or better experienced the best results. ^[22]

In general, attempt to delay the procedure in individuals in their 20s or younger. When counseling young men about hair loss, it is advised to use a conservative approach to give patients time to consider hair transplantation. If the patient and surgeon agree on transplantation, restore a relatively high hairline and encourage the patient to use minoxidil or finasteride for the crown region. Perhaps in the future, as effective medical therapies that end or substantially slow male pattern baldness progression become available, a less conservative approach can be taken.

For a number of medical conditions that are associated with or that can cause hair loss, treatment with hair transplantation is not appropriate. Examples are the active phases of alopecia areata, lupus, and infections. Scalp conditions, such as vitiligo and psoriasis, must be evaluated because hair transplantation can aggravate them.

The scarring alopecias are nondominant, and, while active, do not respond to hair transplantation. These include discoid lupus erythematosus, lichen planopilaris, and other cicatricial alopecia. ^[23]

Both men and women may be deemed candidates for hair restoration surgery as long as their donor area (both current and projected) is able to yield a sufficient number of hair follicles to adequately address the projected recipient area (a calculation termed “donor to recipient area ratio”). A family history of hair loss in both the maternal and paternal branches should be investigated and compared with standardized scales of hair loss in women and men (eg, Norwood Pattern, Ludwig Pattern). Young patients (in their 20s) with a limited hair density in their donor area coupled with a projected Norwood Type VII or greater hair loss, for example, will almost certainly not have an adequate number of permanent “fringe” hair follicle reserve to address the future recipient area and often cannot be considered candidates for the procedure.

Helpful screening technology that enables quantitative microscopic donor area measurements (eg, folliscope) aids physicians in patient candidacy evaluation by helping to discern between terminal and vellus (or miniaturized) hairs. ^[24] Young patients who possess more than 20% miniaturized hairs within their safe donor area may not ultimately benefit from the procedure because, over time, the transplanted hairs may not persist.

Only 2 medications, minoxidil and finasteride, have received approval from the US Food and Drug Administration (FDA) for treating hair loss. Active clinical research is continually conducted to search for medications that are more effective than these, with pharmaceutical companies eager to market a product that more than 50 million Americans may desire. ^[25]

Minoxidil (Rogaine) is a liquid applied directly to areas of the scalp undergoing hair loss. Originally indicated for the treatment of severe hypertension, minoxidil slows the progression of hair loss and causes fine hair regrowth in the back half of the scalp in 25-40% of men. Both the 2% (available in generic form) and 5% concentrations (ie, Extra-Strength Rogaine) are available over the counter. Both medications elicit few reported adverse effects; the most common are heart palpitations and headache. In women, the 2% concentration has a response rate similar to that seen in men, helping 20-40% of women retain their hair and, occasionally, achieve hair regrowth.

Minoxidil should be applied twice daily. Like finasteride, minoxidil must be used continuously to maintain hair regrowth. Otherwise, on cessation of the drug, most of the strengthened hairs fall out. The exact mechanism of action of minoxidil is unknown, but it may work by means of local vascular dilation, prolongation of the anagen (growth) phase of the hair follicle, or nonspecific occupation of dihydrotestosterone (DHT)–binding sites in the hair bulb.

Some physicians recommend the use of minoxidil after transplantation. Application to the grafted areas once per day can shorten the interval between the procedure and the growth of transplanted hair from 4 months to fewer than 3 months.

Finasteride (Propecia) is more effective than minoxidil in treating male-pattern hair loss. This 5-alpha reductase inhibitor blocks conversion of testosterone to DHT, the hormone thought most responsible for the miniaturization and eventual involution of scalp hairs in male pattern baldness. Finasteride 1 mg taken orally once per day is effective in approximately two thirds of men. The major benefits of finasteride are the slowing and occasional cessation of hair loss and even the potential regrowth of hairs, primarily in the back half of the head.

Several benefits accrue from the addition of finasteride in individuals undergoing hair transplantation procedures. First, finasteride potentially reduces the need for further procedures, increasing hair allocation to the anterior and middle scalp, areas that do not respond to medication. Second, by potentially minimizing and even reversing the miniaturization process of hairs in the back half of the scalp (including hairs in the donor strip along the back of the head), finasteride can increase the density of those transplanted hairs, thus improving surgical results. Although uncommon, adverse effects can occur and include a less than 2% published incidence of reduced libido and decreased sexual function.

A new treatment modality to receive FDA approval is low-level laser light therapy. This poorly understood treatment involves the several-time weekly application of a laser-emitting device to "stimulate" hair growth of existing miniaturized hairs. It is not clear whether this technique has the equivalent benefits of medical treatments minoxidil or finasteride, but it does appear to be tremendously valuable, in particular slowing down shedding of hair. While the use of low-level light therapy can increase hair caliber in both men and women, any aesthetic improvement is more appreciable in women than in men. ^[26]

Surgical hair restoration is the procedure of choice for restoring hair. The concept behind all forms of hair restoration is redistribution of hair rather than addition of new hair. Three hair-restoration procedures have traditionally been available: hair grafting, bald scalp reductions, and scalp-flap surgery. Today, hair grafting accounts for more than 99% of procedures performed. Hair grafting has a high success rate with a low incidence of complications, it is performed in the outpatient setting with little surgical preparation or specialized setup, and (most important) patient acceptance is high.

Bald scalp reduction is of historic interest only. It involves the excision of alopecic scalp. The excised area typically consists of the crown and occasionally extends anterior to the middle scalp. Relatively popular during the 1980s through the mid 1990s, scalp reduction is performed infrequently today. Reducing substantial areas of bald scalp without causing abnormal hair growth, scarring, and marked patient discomfort is difficult, and most surgeons recommend options other than bald scalp reduction for treating hair loss on the middle and posterior scalp.

Few surgeons perform scalp-flap surgery because of the need for specialized surgical training in the technique. In addition, most patients are not ideal candidates for the procedure unless they are motivated, unless they are in their mid 40s or older, and unless they seek a dense hairline with relatively limited hair loss restricted to the anterior scalp. A single scalp flap can contain as many as 10,000 hairs, resulting in the creation of a dense hairline in just 2-3 procedures performed in an interval of several weeks. Complications of scalp-flap surgery (including flap necrosis) can be devastating, although they are rare when an experienced surgeon performs the procedure.

Hair grafting, the most common hair-restoration procedure, can be performed by using different techniques. From the early 1990s until recently, transplanting with micrografts (1-2 hairs), often combined with minigrafts (3-5 hairs), was considered state of the art. Today, most surgeons consider follicular-unit grafting the definitive procedure.

As discussed in Anatomy in Overview, transplanting only follicular units and dissecting away all non–hair-bearing tissue can offer several advantages. These follicular-unit grafts can be placed into tiny recipient sites, allowing for dense packing and reducing postprocedure crusting. The requirement for careful dissection reduces the accidental transection rate and therefore minimizes depletion of good hair follicles, a benefit that potentially maximizes hair yield from a particular strip of donor hairs. Finally, because hairs are transplanted in accordance with their natural growth in these tiny follicular units, the results are virtually undetectable.

The follicular units can be obtained by either the strip technique (follicular unit grafting of follicular unit strip surgery) or individual extraction (follicular unit extraction). Follicular unit extraction is preferred for younger men and those who wish to shave their head, because it avoids making a linear donor site scar.

The technique used in women differs from that used in men. ^[27] To prevent telogenic effluvium of the existing hairs, the use of minoxidil 2% for 2 weeks preoperatively and resuming 5-7 days postoperatively is increasing in popularity. Larger grafts behind the hairline are necessary to create increased density. Some authorities prefer the 0.5 X 2.5-mm slot graft, which contains 5-7 hairs and routine use of 3.5X loupe magnification to avoid injury to existing hairs. The grafts are cut using stereo microscopes.

To perform hair transplantations in the eyebrow, a pattern must first be made by the patient, surgeon, or esthetician. Eyebrow and eyelash transplantation require a great deal of maintenance. Brow hairs must be trained with gels or waxes, and eyelashes must be curled. Both must be trimmed and shaped. Use of donor trichophytic closure techniques can decrease visibility of donor scars. ^[28]

For patients with extensive alopecia or those with thin black hair and pale white scalp skin, major grafts still produce a tufted or artificial appearance. In response to these patients, in 1986, Dr Wayne Bradshaw introduced micrografting techniques that involved the use of single hairs as an alternative method of hair replacement. The demonstration of his own scalp covered with thousands of single hair grafts at a major hair transplant meeting opened up the field to procedures other than major grafts and introduced size as a major variable in hair transplant surgery.

Minigrafts and micrografts

Micrografts, which consist of 1-2 hairs per graft, and minigrafts, which contain 3-8 hairs per graft, became part of the new tools available to the hair transplant surgeon. These smaller grafts, when properly placed, provide a more natural, less abrupt appearing hairline in contrast to the standard graft of 4 mm. Nordstrom demonstrated that the smaller minigrafts and micrografts are best placed into incision sites termed "slits" placed in horizontal rows along the frontal hairline. ^[29] His techniques changed the mechanics, appearance, and character of the procedure.

Slit techniques supported a simpler method for placing hair grafts. Large numbers of 1- to 3-hair micrografts are placed in slit incisions without using recipient punches to remove bald scalp. The technique can be used for younger patients with thinning hair without sacrificing existing hair follicles in the recipient area. Patients with female alopecia, cicatricial alopecia, and extensive alopecia were now candidates for slit graft hair transplantation. The older concept of removing bald scalp and replacing it with hair-bearing scalp thus had changed with the addition of slit minigrafting techniques. Many transplant surgeons converted to solely minigrafting and micrografting, and the old problems with the frontal hairline and its natural refinement were solved with these techniques. Fine micrograft hairs are placed in the front line and are backed up by larger micrografts and minigrafts.

The average hair transplant patient can have the procedure completed in 2 or 3 sessions rather than 4, typical with standard grafts. Using these techniques, even poor candidates with thin dark hair can have natural, blended hairlines. Innovators such as Alfonso Barrerra have demonstrated that the "mega-session" approach allows the transplantation of thousands of micrografts and minigrafts during a single operative procedure. ^[30] In most cases, an additional follow-up procedure, if necessary, is usually minor and brief.

Slits and holes

The traditional harvesting technique for obtaining minigrafts and micrografts still used standard hair transplant punches. Minigrafts and micrografts were harvested from 4.5-mm standard grafts by quadrisecting them to smaller grafts. Slits or recipient holes were made with 1.5-mm and 2.0-mm trephines, placing the slits or smaller holes near the frontal hairline and the larger ones farther back. The grafts then were placed into the recipient holes where bald scalp was removed and thus treated as a standard hair transplant procedure. A major debate ensued as hair transplant surgeons arguing over which technique was better, slits or holes, for minigrafts and micrografts. ^{[31, 32]}

It was noted that the slit grafts compressed with healing to a single stalk from which 2-5 hairs would grow. This gave an artificial or tufted look when only slit minigrafts were used. The grafts did not have the natural density of holes for minigrafts. Similar minigrafts placed in holes seemed to remain spread out and did not have this compressed, artificial appearance. The advocates for holes emphasized that using the small holes to remove bald scalp was advantageous because density was greater than that obtained with slit grafting techniques alone. Others versed in both procedures have found that mixing slits with holes and varying graft size are major factors in obtaining a natural hair transplant.

Harvesting technique

There currently exist 2 methods of hair follicle harvesting: follicular unit strip surgery (or strip harvesting) and follicular unit extraction. Both possess unique advantages and disadvantages. Regardless of which method is used, the importance of extracting hair follicles from within the safe donor area remains paramount.

Extracting intact follicles from the safe donor area for subsequent transplantation ensures not only that they are the most likely to remain in their new location for the longest period of time, but also that any scar remaining in the area from which they were extracted will be concealed by neighboring hairs for the longest period of time. Maximum follicle survivability is also aided by transplanting only intact hair follicles that are not transected by traumatic extraction. To this end, with either follicular unit strip surgery or follicular unit extraction methods, the skin incisions are angled parallel to the hair follicle (rather than simply perpendicular to the scalp itself) to minimize transection.

Follicular unit strip surgery

Within the safe donor area, a strip is excised as an elongated fusiform ellipse of full-thickness scalp using either a single No. 10 or No. 15 blade or a double-bladed scalpel with blades mounted in parallel.

Prior to strip excision, the desired donor region may be infiltrated at a depth of 4-5 mm with sterile saline tumescence in order to minimize follicle transection by aligning them more perpendicularly to the skin surface and to provide separation between the follicular bed base located within the superficial subcutaneous tissue and the larger nerve plexuses and vessels that abound within the deep subcutaneous tissue.

The width of the elliptical strip (generally ranging from 10-15 mm) is determined by the laxity of the patient’s scalp in order to yield the maximum number of grafts while still limiting tension upon closing the edges of the resultant wound with either sutures or skin staples. The advantages of follicular unit strip surgery include, but are not limited to, a larger number of grafts harvested in a shorter period, lower hair follicle transection rates (2-5%), and the ability for inclusion of more protective tissue surrounding the stem cell–containing portion of the transplanted hair follicles owing to the manual dissection under microscopic visualization. ^[33]

Regardless of the number of sessions a patient may undergo throughout his or her lifetime, only a single scar should remain. The scar from any prior session should always be included within the subsequent strip excision.

Follicular unit extraction

Individual hair follicles or small, naturally occurring groupings of 2-4 follicles (follicular units) may be extracted either manually or with a motorized rotating punch device using follicular unit extraction. Akin to a cylindrical cookie cutter, the punch incises a 0.7- to 1.2-mm diameter circular scalp area. The punched-out follicles are then manually extracted with forceps.

Follicular unit extraction has the advantage of not creating a linear scar (resulting in a shorter, more comfortable recovery time) and allowing patients to wear their hair shorter in the donor area after the procedure. ^[34] However, this method may result in numerous hypopigmented punctate scars within the donor area. It may also result in increased follicle transection rates (which reduce graft hair survivability). Since follicular unit extraction is more time consuming for the patient and the physician, robotic devices also perform this method of follicle harvest.

Furthermore, as each individual follicle extracted must be separated by three or more intact neighboring follicles so as not to create a uniformly alopecic donor area, the risk of needing to harvest follicles from a larger surface area that extends beyond the limits of the safe donor area is heightened.

Over time, as the fringe hair beyond the safe donor area is lost, the punctate scars may be exposed and transplanted follicles harvested from this fringe area may disappear.

Creating and dissecting grafts (follicular unit transplantation)

After either method of harvesting (although to a much lesser extent with follicular unit extraction), the follicular units obtained must be trimmed under microscopic visualization using a razor blade.

In follicular unit transplantation, only hair follicles separated into their naturally occurring clusters of 1-4 (or more) hairs are transplanted, rather than large grafts containing multiple (3 or more) follicular units. The average naturally occurring follicular unit contains approximately 2.3 hairs.

Resultant grafts should retain a pear shape in which the epidermis has been maximally trimmed while the dermal and subcutaneous tissue surrounding the follicle isthmus and inferior portion remains.

This optimal micrograft shape is frequently achieved after follicular unit strip surgery, but rarely from follicular unit extraction. The cushioning provided by the intact surrounding tissue has been found to maximize graft viability by minimizing desiccation during preinsertion storage and mechanical trauma to the follicle from handling. ^[35]

Graft storage

Selection of proper storage solution has grown increasingly more important as larger surgeries involving smaller grafts have become more common and out-of-body time has lengthened. Survival of transplanted grafts has been shown to decrease about 1% per hour out of the body. ^[36] Factors of negative influence during this extended out-of-body time between harvest and implantation include ischemia-induced hypoxemia and subsequent adenosine triphosphate depletion, as well as ischemia-reperfusion injury. Three categories of storage media (ie, intravenous fluids, culture media, hypothermic tissue–holding solutions) help minimize out-of-body variations in pH, osmotic balance, antioxidant capabilities, and nutrient support to follicles.

Creating recipient sites

Various techniques are used to create and prepare recipient sites for subsequent transplantation of follicular units. With each method, the critical element of following the angle and direction at which the hair follicle exits the scalp results in the least damage to existing hairs and the most natural-appearing transplanted hair.

The most widely accepted density of recipient site creation distributes 30 follicular units per square centimeter. Some practitioners advocate for dense packing of more than 40 follicular units per square centimeter. However, the viability of grafts may be compromised as competition for a limited blood supply increases.

Various techniques exist for recipient site creation and graft insertion. Blades may be cut to match the size of the follicular units to be inserted. Hypodermic needles (18-21 gauge) may be used to make incisions for subsequent graft placement. Recipient site size increases as the surgeon moves posteriorly away from the hairline and the priority shifts from single, fine-caliber hairs to multiple and higher-caliber follicular units.

A stick-and-place technique can be used to virtually eliminate the time between which the recipient site is made and the graft is placed within it.

A spread-and-place technique minimizes mechanical trauma from graft handling as the graft is placed into a smaller recipient site.

Graft insertion

Jeweler forceps or similar nontoothed forceps are generally used to gently place the graphs into recipient sites. Transplanted hair follicle viability is maximized by minimizing mechanical trauma to the follicle. This is accomplished by handling the subcutaneous tissue along the base of the graft rather than the graft itself. Furthermore, some implantation devices exist that allow for near-simultaneous recipient site creation and hair follicle insertion. ^[37]

 

On the day of the procedure, a relaxing atmosphere should be created, enhanced by the usual administration of the chosen oral sedation. Diazepam (Valium) 10 mg and zolpidem (Ambien) 10 mg are effective and safe options.

A valuable opportunity to further discuss expectations and goals with the patient and his or her significant others is presented when marking the planned transplant areas on the patient.

An aesthetic hairline design is crucial in providing a natural-appearing result appropriate for the individual at present and in the future. Aesthetic hairline design usually requires a hairline irregular and wavy appearing, with slight-to-substantial frontotemporal recessions. In basic hairline design, the central-most aspect of the hairline is placed 8-10 cm above the nasion (root of the nose). Then, the hairline is carried laterally in an up-sloped direction when the patient is viewed on the Frankfort horizontal plane. This design results in the central aspect of the hairline being the lowest (most caudal). In many patients, the creation of a slight widow's peak improves the natural appearance.

In patients with substantial caudal recession of the superior aspect of the temporal tuft, transplanting this area to build it superiorly is sometimes helpful. Fine grafts containing 1-2 hairs are typically used to create a thin but natural-appearing result. The resulting temporal horns, which often occur naturally, allow the lateral hairline to join with the superior temporal hairline, even if the transplanted hairline is high and thus prevents an isolated frontal tuft.

Note that all lines drawn to mark the hairline serve as a rough template, from which an irregular saw-tooth pattern can be transplanted to mimic natural hairlines. The goal of hairline creation is to create a hairline that is not discernible as a line.

A conservative approach is important when transplants are placed into the crown region because of the likelihood of progressive enlargement of the crown. If this occurs, additional grafting is required in the future to avoid the appearance of a donut-shaped area of bald scalp surrounding a central circle of transplanted hairs. Frequently, only the anterior one half to two thirds of the crown is transplanted densely, whereas the remaining crown area is transplanted less densely by scattering 1- or 2-hair micrografts to provide some minimal coverage to prevent the appearance of a shiny area.

The final step before the patient is transferred into the procedure room is to determine the necessary size of the donor area and then to trim the hairs to be transplanted. The donor site is usually in the middle-to-superior aspect of the back of the head, accounting for and avoiding any potential recession in the crown area. A number of techniques have been described to determine the size of donor area necessary to provide the required number of grafts. Typical procedures consist of 1400-2800 follicular-unit grafts, but procedures as large as 3200 grafts are not uncommon. Use of a densitometer, which measures the number of hairs per square centimeter, is the most accurate way to determine donor-site size. Approximately 75 follicular units are obtained from each square centimeter of area; therefore, a planned 2000-graft procedure requires a donor strip 24 X 1 cm.

See the images below.

The patient should be free of all medications that may influence bleeding tendency such as aspirin, nonsteroidal anti-inflammatory medications, blood thinners, and herbs or nutrients that create bleeding problems such as garlic, St Johns wort, and Ginkgo biloba. The patient may have a light meal prior to surgery and be given oral fluids as needed

Patients are advised to wash their hair with shampoo on the evening prior or morning of the surgery. Once the region within the safe donor area (the region within the inferior parietal and inferoposterior scalp in which hair follicles are most likely to remain throughout a patient’s lifetime ^[38] ) has been determined, the hair within that region should be clipped to approximately 1-2 mm in length with either scissors or an electric trimmer.

The donor area and recipient area into which the grafts will be placed should be prepped with a povidone-iodine antiseptic solution. However, scrubbing the recipient and donor areas with 4% chlorhexidine gluconate may be preferable in patients with white or grey hair as the povidone-iodine may temporarily stain light-colored follicles.

The use of perioperative antibiotics remains controversial in hair restoration surgery. The decreased risk of wound infection must be weighed against the increased threat of hypersensitivity reaction and the possible emergence of resistant organisms. Prophylactic antibiotic use is most effective when administered 1 hour preoperatively and is not questioned in instances of endocarditis prophylaxis or other precautionary uses. First-generation cephalosporins are most commonly used preoperatively. When hypersensitivity exists, erythromycin is an effective alternative. These prophylactic oral regimens coupled with topical antibiotic use along the donor wound postoperatively help reduce the already slim risk of infection. Some practices advise patients to continue use of oral and topical antibiotics for 3-5 days postoperatively.

Anesthesia

Preoperative analgesic and antianxiolytic medications are often given to patients in oral form prior to the surgery and intravenously throughout the procedure. In addition, local anesthesia is administered slowly and using a fine 30-gauge needle in order to minimize discomfort. Local administration of 1-2% lidocaine with 1:100,000 epinephrine along the inferior edge of the clipped donor area provides ample anesthesia while minimizing intraoperative donor wound bleeding. Local infiltration to create a ring block of anesthesia anterior to the anticipated recipient area remains the most commonly used technique for achieving recipient region anesthesia. Care should be taken in both the donor and recipient areas to limit the lidocaine dose to 7 mg/kg with epinephrine (maximum 500 mg) or 4.5 mg/kg without epinephrine (maximum 300 mg). After 2 hours, the local anesthetic should be reinforced with 0.25%-0.5% bupivacaine with 1:100,000 epinephrine (maximum 200 mg). This lasts approximately 4 hours.

Positioning

The patient should be placed either in a prone position or (less often) a seated position for donor hair follicle removal.

The patient is seated in a semirecumbent position, and local anesthetic is injected. A computerized injection device called the Wand, which allows for the slow and controlled injection of agent, can be used. First, the donor area is injected superficially, followed by a slightly deep injection along the entire hairline to create a field anesthesia. Most patients receive oral sedation, whereas local anesthetic is sufficient for the rest. The rare patient chooses to have intravenous sedation provided by a nurse anesthetist. With the patient sitting, the scalp is prepared in sterile fashion. Approximately 25 mL of 1:50,000 epinephrine is injected into the donor region for tumescence. The single fusiform donor strip is most easily excised in a superficial subcutaneous plane, which helps in avoiding the occipital neurovascular bundle structures and other smaller vessels. If necessary, electrocautery is used, and the donor-site incision is reapproximated with a simple running 3-0 Prolene suture by staying superficial to the hair follicles to minimize compression injury and resultant alopecia along the donor-site scar.

At this point, the surgical personnel split into two teams. Good results in hair transplantation require a highly trained team of assistants to dissect grafts and to help plant them. One team consists of those who perform the slivering; this team sections the donor strip into many narrow strips that are 1 follicular unit wide. These narrow strips then can be divided into individual grafts consisting of a single follicular unit. These follicular units most commonly contain 2-3 hairs, but they can contain 1-4 hairs. Excess tissue not containing hair is excised to allow for the transplantation of just these follicular units.

Assistants perform graft cutting with the aide of binocular microscopes for most accurate dissection. This process is demanding and time consuming but critical for the success of the procedure. The typical assistant can cut 100 grafts per hour; hence, a team of 6 assistants can cut 1800 grafts in 3 hours. The grafts are cut on a Teflon cutting block by using Personna size-11 scalpel blades or double-sided razor blades. While awaiting transplantation, the grafts are stored in chilled preservative-free solution of isotonic or some other storage solution. If the follicular unit extraction technique is to be used, the patient is usually placed in a face-down fashion and the back of the head prepared by shaving it then anesthetizing. Using a variety of extraction tools, including individual manual punches 0.9-1 mm in size, a hand-held specially designed drill, or more recently one of several automated devices, the individual follicular units are harvested. From several hundred to 1800 or more grafts can be obtained. These grafts are placed into a storage solution where they await transplantation.

As grafts undergo dissection, the surgeon creates recipient sites. The author's preferred instruments are tiny blades custom cut from single-edge Personna razor blades. These blades measure 0.5-0.9 mm, but blades of 0.6, 0.7, and 0.8 mm are most commonly used for grafts containing 1, 2, and 3 hairs, respectively. The 0.6-mm blade is typically used along the frontal hairline, where 1-hair grafts are placed most anteriorly, with the 2-hair grafts placed immediately behind into incisions made with a 0.6- or 0.7-mm blade. Finally, depending on the size of the 3- and occasional 4-hair grafts, the 0.8- or 0.9-mm blade is used to create the remainder of recipient sites.

Several concepts are important in the making of recipient sites, as the direction and location of these sites determine the direction and location of growth of the transplanted hairs. Usually, the more anterior along the hairline, the more oblique the angle of penetration of the recipient site. By working posteriorly, a continued anterior but less oblique direction of growth is maintained. When hairs are transplanted into thinning areas that still have original hairs, the direction of the recipient sites must mirror the direction of growth of these existing hairs to prevent transecting and damaging the hair follicles and to ensure an even and equivalently patterned growth of all scalp hairs. These recipient sites must be made between existing hairs to avoid transection of existing hair follicles. Although this process is a time-consuming challenge, such attention to detail reduces telogen effluvium (ie, rapid hair loss), which is observed when a substantial number of hairs are damaged.

In the crown area, the radial direction of growth of hairs is maintained. In the anterior portion of the crown, the hairs tend to grow anteriorly, while more posteriorly, the hairs indeed grow posteriorly. Somewhere between the anterior and posterior areas usually lies a circular whirl. On occasion, recreation of this whirl is necessary, especially when the entire crown is filled.

After the recipient sites have been created, the grafts are then inserted. This is an extremely challenging and delicate process because atraumatic placement of individual grafts is crucial to prevent lack of growth of the hairs and to minimize scalp edema. For graft insertion, the preferred tool is the curved and straight ultrafine jewelers' forceps. These forceps allow grafts to be handled and placed by grasping them only along the subcutaneous fat just deep to the follicle.

Graft placement constitutes the final step in the time-consuming hair-transplant procedure. A 2200–follicular-unit graft procedure typically requires 5 hours to perform when done by a surgeon and 8 assistants). Afterward, patients can leave the office bandage free. To prevent any periorbital swelling that sometimes results from edema along the frontal hairline from migrating inferiorly, a strip of elastic tape is placed across the patient's forehead. This tape is worn for the next 3 days and is easily concealed by wearing a baseball hat.

On postoperative day 1, patients usually return to the office for a hair wash and checkup. The occasional "popped" graft can be returned to the recipient site at this time. On postoperative day 3, patients can wash the hair themselves by gently applying shampoo and rinsing with water. Sutures are usually removed on days 10-12. By this time, all crusting (typically minimal with the follicular unit grafting procedure) should be gone, and the scalp typically appears entirely normal except for possible slight erythema along the recipient site region. To speed the resolution of crusting and to promote rapid healing, patients can use a copper-containing moisturizing spray called GraftCyte. Postprocedural medications include cephalexin 500 mg for 3 days, prednisone 50 mg for 3 days, and ibuprofen or acetaminophen with codeine #3 as necessary. For most patients, discomfort is mild, and ibuprofen is adequate.

Many practices use a postoperative compression surgical dressing to minimize local edema and to reduce the risk of graft dislodgement. Prior to positioning this dressing, surgeons should apply a topical antibiotic ointment, nonstick gauze, Kerlix gauze, and wrapped gauze to establish a turban-like pressure dressing. This dressing is removed on postoperative day 1 when the patient is given instructions related to scalp care.

Corticosteroids may be administered orally (up to 60 mg) followed by a tapered dose in order to reduce postoperative facial edema as well as donor area discomfort. If an intravenous line is established, dexamethasone may be given in doses totaling 12 mg during the procedure. Some surgeons also recommend local administration of triamcinolone acetonide 2.5 mg/mL in 0.5% bupivacaine along the inferior donor wound edge or anterior to recipient site created along the hairline to minimize postoperative edema. ^[39]

Patients may experience postoperative discomfort along the donor wound edge. Typically, this is minimal and lasts only overnight. However, as this discomfort may correspond with edema along the suture line, some patients may require oral narcotics, especially if the pain persists for more than a day or two (rare). Generally, acetaminophen with codeine, hydrocodone bitartrate 5 mg/acetaminophen 500 mg (Vicodin), or oxycodone 5 mg/acetaminophen 325 mg (Percocet) are more than sufficient to alleviate postoperative discomfort.

After the procedure, advise patients to avoid exertion for the first 48 hours. After this, light exercise, such as running and golf, can be resumed. By postoperative day 5 when the transplanted follicles have established their own capillary network, no further restrictions are placed on the patient with the exception of swimming with the head submerged, which should be delayed until postoperative day 7.

Advise patients that more than 80% of transplanted hairs fall out between postoperative days 14 and 21. With follicular-unit grafting, as many as 20% of hairs may continue to grow. The transplanted hairs reappear 3-4 months later and continue to grow for the patient's lifetime at a rate of approximately 0.5 in/month. To shorten this interval of hair regrowth to 10 weeks, patients are instructed to apply minoxidil daily for the first 3 months.

Approximately 50% of patients choose to undergo a second hair-transplant procedure at some point. This procedure can be performed as soon as 5 months after the first procedure. The most common reasons for patients wanting a second procedure are to increase hair density and to cover more areas than could be covered in the initial procedure. Patients sometimes return several years later to have an additional procedure or to fill in areas that have undergone hair loss. With additional procedures, the donor site almost always encompasses the first procedure's donor site, resulting in a continued single incision line and minimal scarring.