Dr. Unger's 5th Edition of 'Hair Transplantation'

Serving as the most popular physician reference for practitioners of hair restoration surgery for over 20 years, the 5th edition of Dr. Unger’s multi-author medical textbook was published in 2011

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1) Hair Transplantation depends primarily on the now well-established principle that transplanted hair follicles (roots moved from their original location to another area) will behave as they did in their original site. For example, even in the most advanced cases of common Male Pattern Baldness (MPB), a horseshoe-shaped fringe of hair persists (Figure 1). Hair follicles moved from appropriate areas of this hair-bearing fringe (the donor area) to a bald or balding area on the same patient's scalp (the recipient area), will take root and grow. Continuing hair growth in such transplants has been observed since 1958, and it is believed that the hairs will continue to grow for the individual's lifetime - provided that it would have done so at its original site (see "donor area" below). Many other types of hair loss, in addition to ordinary MPB, can be helped by this procedure. These include Female Pattern Hair Loss (FPHL); scarring from physical injuries or surgery; and a number of diseases that sometimes cause hair loss.

2) For approximately the last 20 years hair transplanting has been increasingly carried out using a surgical technique referred to as Follicular Unit Transplanting (FUT), and since at least 2004-2005 the majority of physicians have been using FUT virtually exclusively. What is FUT?

Although approximately 15-20% of hairs emerge from the scalp as single hairs, the majority of them do that in small groupings of 2 to 5 hairs (Figure 2). These naturally-occurring "follicular groups" or "follicular units" (FU), as well as the single hairs are usually carefully dissected out of a strip of hair-bearing tissue that has been excised from the fringe area of persisting hair. The grafts are created in a tear-drop shape, so that there is minimal skin surface, but a significant amount of protective tissue surrounding their deeper "roots" (Figure 3). The finest textured 1-hair and 2-hair FU can be "cherry-picked" for the front-most hairline zone, and those with three or more coarser hairs, can be utilized behind that to create a gradual natural looking change from finer, sparser hair at the front margin of the hairline to coarser, denser hair farther back (Figures 4-5).

The FUs are placed into tiny incisions, made with an ordinary hypodermic needle or a small blade, at the same angle and direction as the original hair in the area - regardless of whether some of that hair is still present or the area is bald. This results in a natural-looking growth of hair even after only one session in a bald area (or an area destined to become bald). The preceding is referred to as Follicular Unit Transplanting (FUT). FUT is currently used in all of our patients (excepting the occasional patient seen for repair of older and cosmetically unacceptable transplant techniques) (Figures 6-8). If a typical FUT session of 1500 FU to 2500 FU is being carried out, a physician ideally should limit himself/herself to only a single surgery that day - assuming that he/she is personally excising the donor tissue and personally making all the recipient site incisions. Such large procedures begin at 7:30a.m. and usually last until 3:30 to 5:30 p.m.

3) Grafts are held in place by coagulated blood. To keep them secure and properly oriented, a turban-like bandage is usually applied after the operation and left in place overnight. The following day, the bandage is removed and the area is cleansed. However, if you are having the front or midscalp areas of your scalp transplanted, and if there is no more than the average amount of bleeding during surgery, and you are willing to remain in the office for 30 minutes after the procedure is completed, you can go home without a bandage. Most patients seem to prefer the security of an overnight bandage. Perhaps more importantly, every scientific study on wound healing, of which we are aware, has revealed better and faster healing if a wound is covered for the first 12 to 24 hours. Whether you have a bandage or not, you should still return the next day for follow-up cleansing, hair washing, and a check-up.

4) The three most important facts that anybody who is thinking about having a hair transplant for MPB or FPHL should know are:

  a. As noted earlier, transplanted hairs will only last in the new area as long as they would have in the area from which they came. ((Not only do you want the results to be as natural/undetectable as possible - in recipient and donor areas - you also want them to be as permanent as possible)

  b. The areas of hair loss will intermittently enlarge for his/her entire lifetime. The periods of loss and stability vary from person to person so there is no way to know how quickly baldness will progress for any given individual, but it will do that. Finasteride (Propecia) and minoxidil (Rogaine) may temporarily slow this process or even temporarily reverse it in some areas, but there is no evidence that such benefits are permanent even if the medication(s) is/are continued; so surgical planning should never be based on that assumption.

  c. There are only a limited number of hairs in the hairy fringe that are very likely to be permanent in balding men and women. The questions are always, "where are they most likely to be found?" and "how many are there?" In an effort to answer the second question, at least for men, 40 of the world's most experienced and respected hair restoration surgeons (see attached list) answered the following questions in the Spring of 2011:

"Keeping in mind that over the years, more (than elsewhere) or all of the hairs closest to the superior (upper), inferior (lower) and anterior (front) borders of the fringe will be lost, how many follicular units (FU) containing very likely permanent hairs can be harvested from:

        a) A 30-year-old man who you believe is destined to develop Type V MPB (Figure 9) and currently has:

    1) Higher than average donor area hair density?
    2) Average hair density?
    3) Less than average hair density?

        b) Same questions, but for a man who you believe is destined to evolve to Type VI MPB?"

The results are summarized in Table 1. The contents of the Tables represent the mean (average) of the submissions. The sum of the estimates received for each category was divided by the total number of respondents (40).

Table 1

Median: Above Avg = 8000FU/6875FU (Type V/VI); Avg = 6500FU/5000FU (Type V/VI); Below Avg = 5000FU/4000FU (Type V/VI)

Sources of Data: W. Rassman, M. Beehner, R. Shiell, J. Cooley, B. Limmer, C. Puig, J. Wong, M. Mayer, E. Epstein, B. Farjo, B. Nusbaum, W. Reed, P. McAndrews, P. Cotterill, M. Marzola, W. Parsley, T. Mangubat, S. Kabaker, E. Eisenberg, J. Gillespie, R. Unger, P. Rose, V. Elliott, V. Hasson, J. Harris, J. Vogel, N. Farjo, R. Haber, R. Shapiro, J. Martinick, M. Pitchon, D. Pathomvanich, M. Gandelman, F. Jimenez, T. Hwang, A. Tycosinski, S. Keene, R. Knudsen, D. Perez-Meza, and Walter Unger.

It is especially important to recognize that the younger you are when you begin transplanting, the more difficult it is to accurately predict the long-term donor/recipient area ratio, and how many "permanent" hairs will be available in the long run to treat an intermittently enlarging bald area. Thus, the more cautious a young individual should be, before using up large numbers of grafts and choosing "dense packing" of grafts and/or low youthful hairlines like you once had - even though it is understandable that you might want to return to the most youthful appearance possible. But, for example, is it wise to use up 4000 grafts in a hairline zone that is 2 - 4" deep, if that means you may only be leaving 3000 to 4000 permanent hair-bearing FU to treat future areas of hair loss that are likely to be 4 to 8 times larger than that hairline zone (Figures 9-10). What are you going to look like in future years when you could ultimately be left with a dense, low hairline and a very large area behind it with sparse or no hair? Put differently, the more grafts you use today, the fewer you leave "in the bank" to treat the unknown extent of future areas of hair loss. Sadly, it tends to be the youngest patients who most want the lowest hairlines, the densest results and "more now" rather than later, and who often seek out doctors who are advocates of these commonly unwise objectives for young people. (Ironically, older patients, for whom it is more reasonable to want those objectives, often are content to aim for higher hairlines and less hair density).

As for the issue of, "Where are you most likely to find the FU with the most likely life-long hairs?": In 1993-94 Dr. Unger undertook a study of the fringe hair in 328 men 65 years or older, who had MPB, in order to help answer that question. He looked for areas that, despite the patients' ages, maintained a hair density of at least 8 hairs per 4mm diameter circle. Then he tabulated the information and created the outline of an area he called the "safe donor area" (Figure 11). The densest fringe hair ran through the middle of this area and areas that contained less than 8 hairs/4mm diameter circle were above and below it (All aspects of hair transplantation in women are discussed in their own section of this website). He reasoned that although some hairs throughout the fringe are lost as a patient ages, a larger percentage of them would be lost from the latter areas and those zones were therefore less "safe" to use for obtaining donor tissue for long-lasting results of hair transplantation, and therefore should be avoided (At that time, a harvesting technique referred to as Follicular Unit Extraction (FUE) was not known. It is discussed later and allows the harvesting of a limited number of multi-haired FU from carefully selected sites outside of the "safe donor area".

The Procedure

1. At the beginning of each session, the patient is given a mild tranquilizer (Valium or Versed) either orally or intravenously. This minimizes anxiety, reduces discomfort, and helps to prevent or decrease any side effects that might be caused by the local anesthetic.

2. The donor area and the recipient area are anesthetized using a very small gauge needle that is about the size of an acupuncture needle. To reduce any stinging sensation, in addition to using a small gauge needle, we prepare and use an anesthetic solution that is at an almost neutral pH, instead of "stock" anesthetics which are stored in an acidic form. (The acidity is the main cause of the stinging one usually feels with anesthetic injections). Anesthetizing the areas is the only uncomfortable part of the session and although it may be hard to believe, many patients have told us that the above technique usually causes less discomfort than a visit to their dentist.

3. There are two methods of obtaining scalp hair for transplanting: "Strip Harvesting" and "Follicular Unit Extraction" (FUE).

  a. Strip Harvesting:
Hair in the donor area is clipped to a 2-mm length in a single zone that is 12mm to 16mm (1/2" - 5/8") wide, and 10- 25 cm (4 - 10") long. If the hair in the hair-bearing fringe has been left 1 - 2" long, the hair above the donor site completely camouflages it immediately after the procedure. After the anesthetic has taken effect, a scalpel is used to excise a narrow "strip" or "ellipse" of hair-bearing scalp from the densest section of the donor area. (A similar method can also be used to remove scar(s) from preceding scalp surgery or injury.) After the tissue has been removed, the area is stitched or stapled closed - Dr. Unger prefers sutures as this allows for greater precision in approximating the wound edges and is generally much more comfortable for the patients post-operatively than staples. The small linear scar remaining after surgery, using the technique that Dr. Unger employs, is narrow enough in approximately 95% of patients to allow the patient to wear his hair very short (Figures 12, 13). In approximately 5% it is wider - nearly always because of the individuals' inherent healing characteristics - but rarely more than 3mm. Some patients consider the 5% possibility of such a scar the main draw-back to strip harvesting. However, even if the scar is 3mm wide, it can still be easily covered with the surrounding dense hair if it is left 1" to 2" long, and if the patient wants to wear his hair very short, the scar can be substantially improved with trichophytic closure or FUE (see below). Also, if a subsequent strip or strips are excised, the prior scar is included within that strip so no matter how many sessions are carried out, only one scar is ever present and it always runs through the densest hair. This technique is referred to as "Single Scar Strip Harvesting" (SSSH).

In some patients, a "trichophytic closure" is utilized; a very thin slice of superficial skin (epidermis) is removed from one side of the wound prior to closure. When the incision heals, the follicles lying under the scar grow through the middle of it, and increases the ease with which the scar is camouflaged (Figure 14). Thus, trichophytic closure is particularly important to use in the minority of patients who have healed with somewhat wider than typical scars in the past, wear their hair very short, and/or have a strong contrast in the color of their hair and skin. Alternatively, the scar can easily be converted into one that is minimal enough to allow for very short hair styles with FUE (please see below) if the patients wants to do that (Figure 15).

The main advantage of strip harvesting over FUE is that because every FU in a strip can be utilized, excising a total strip width of only approximately 2 inches to 2.5 inches (over the course of 2 to 4 sessions) is usually sufficient to completely transplant an individual who is destined to develop Type V or Type VI MPB (Figure 16). Such a total strip width can commonly be removed from well within the "Safe Donor Area" (Figure 11). As discussed earlier, hair is lost sooner - and in some areas completely - the farther outside the "Safe Donor Area" you harvest and the closer you get to the frontal, upper and lower borders of the fringe hair in a man with evolving MPB. FUE increases the likelihood of this becoming necessary; the reasons for this will be discussed immediately below. Put simply, you can harvest the maximum number of the most likely permanent hairs by using strip harvesting, while staying within the "Safe Donor Area".

b. Follicular Unit Extraction (FUE):
Using this technique, each individual FU is carefully excised directly from the scalp using a small, sharp cylindrical punch (generally 0.8mm to 1.2mm in diameter). The punch can be manually driven or power driven. The skin surface around each FU is superficially incised before it is usually teased out with a combination of forceps traction and pressure on the surrounding skin. Some power punches are equipped with a suction device that removes the grafts without forceps.

The theoretical advantages and disadvantages of this technique are summarized in Table 2. In general, FUE involves no suturing as well as less post-operative discomfort. But it has mostly gained popularity amongst those who want to wear their hair less than 2mm in length because - unlike the classical "strip" technique - it does not leave a linear scar in the donor area of a patient's scalp. To accomplish this, FU removal is ideally performed in a random distribution within "The Safe Donor Area". If done properly, after a single session or even multiple sessions of FUE, hair in the donor area appears slightly less dense than previously, but there is no scar noticeability, even with the hair buzzed very short (Figure 15). However, if done less than ideally, purulent cysts can develop and the donor area hair density can be noticeably sparser and small round scars will be obvious if the hair is too short (Figures 16, 17).

One of the often unmentioned, but major, potential drawbacks of FUE versus SSSH, is that if very large numbers of grafts are likely to be required in a single or multiple sessions over the patient's lifetime, a larger percentage of the transplanted hair is more likely to be lost in the future than would be the case with SSSH. This is because all of the FU in a strip are utilized, whereas only every third to fifth FU can be extracted from a FUE donor area; taking more than that with FUE would result in that area being left with hair that would be too sparse and/or the small round scars being noticeable (Figure 17). Thus, to get the same number of FU as you would from a strip requires a donor area that is 3 to 5 times as large. A consequence of that is a FUE session of 1000 to 1500 FU spaced every 3rd to 5th FU apart, generally can be accomplished within "The Safe Donor Area", a 3000 FU session would require harvesting from twice that scalp area and a 4500 FU session would necessitate FU extraction from over three times that scalp area, etc. The latter two sessions would nearly always exceed the established "Safe Donor Area" boundaries. This would result in non-permanent FU transplantation and potential small round scars becoming visible as that area loses the original hair. As implied from the preceding, the younger the individual is, and therefore the less certain one can be about the ultimate width of the fringe, the more likely that this will occur. The older the patient, the less likely this will happen. A less important, but not unimportant, additional potential drawback of FUE is that the grafts produced via FUE have less protective tissue surrounding the hair bulbs within them and may or may not result in a lower hair survival than that seen with grafts that are microscopically produced from a strip (Figure 3). For example, Michael Beehner, who employs FUE for many of his patients, reported on a 4 patient study of "FUE VS STRIP hair growth" at the 2015 annual meeting of the International Society Of Hair Restoration Surgery. At 12 to 14 months post operatively, hair growth averaged 61.4% for FUE follicles and 86% for strip derived follicles! (Trying to be as fair as possible, when he eliminated the patient with the worst FUE growth from his calculations, the results changed to 70.1% (FUE) and 86% ("Strip"). FUE techniques and equipment remain "works in progress" and no doubt will continue to improve. For example, several hair restoration surgeons are currently working on new punch designs that are producing grafts which look much more like strip grafts, so the above noted difference in hair regrowth will probably be narrowed or perhaps even eliminated.

Despite these limitations, there remain specific populations of patients who can substantially benefit from FUE. For example, patients who as mentioned above, want to have no linear scars at any time and patients with poor scalp laxity who may have excess tension upon closure after a strip harvest (this problem is usually more pronounced after multiple strip harvest excisions). Fortunately, scalp laxity does not significantly impact the cosmetic recovery of the scalp after FUE. Another group benefiting from FUE is the population of patients who have pre-existing scarring. FUE can be employed to obtain FU for transplantation directly into the scar. It is possible to camouflage or eliminate even a fine linear scar resulting from a prior surgery if the patient wants to do that after the last strip harvest is carried out (Figure 15). For this reason, as well as the aforementioned advantage of transplanting the largest percentage of permanent hairs via strip harvest, many surgeons believe that a combination of donor strip harvesting, followed by one (or more) FUE session(s) is optimal to achieve the largest number of safe, long-term FU from the donor area while minimizing or eliminating any resultant scarring (i.e. the best of both worlds). It is important to emphasize that, while the "safe donor area" contains the largest number of FU that are most likely to last a lifetime, some FU outside the "safe donor area" are also quite likely to contain some permanent hairs. Multi-hair FU are widely believed to suffer gradually decreasing numbers of hairs during the worsening of MPB. Three-haired FU become two-haired FU, two-haired FU become one-hair FU, and one-hair FU "disappear". Thus, FU that are generally still relatively close to the "safe donor area" and contain three or two hairs have a reasonable chance of containing at least one lifelong hair. If scalp laxity or hair density adjacent to a scar from prior strip harvesting(s) is substantially reduced, another one or two sessions of FUE might produce more FU than another one or two strip harvests. In addition, as mentioned above, some of the FUE grafts could be used to cosmetically eliminate the linear scar at the same time as the last FUE session is performed.

Body-to-scalp FUE has also been utilized when the patient has insufficient donor hair density in the scalp. The density of results utilizing body hair suggest that the survival is significantly less than scalp hair, however no meaningful set of results have been published and the difference in density may also be related to hair cycles. Anecdotal reports indicate that beard hair has particularly good survival, and may be a good solution for camouflaging donor scars or adding density behind hairlines that are created with finer hairs.

Advantages and Disadvantages of the Current Practice of FUE

Table 2:

Summary
Because transplanted hair will only survive in the new area for as long as it would have from where it was taken, the most important thing all hair transplant patients should remember is that reality. The second most important thing to remember is that there are a limited number of scalp FU that contain permanent hair. The more you use up in one area,for example with low hairlines and "dense packing", the fewer you will have left to treat other areas that are or will become bald as you age. The younger you are, the more important it is to remember both of the preceding.

FUE is particularly advantageous for people who:
    a) heal with wider-than-average scars despite good surgical technique.
    b) prefer to wear their hair less than 2mm long and...
    c) are older or for other reasons can reasonably be expected to maintain a wide fringe area throughout their lifetime.

The main disadvantage of strip harvesting is that a linear scar is always produced; unfortunately, if the excision isn't done properly or a complication occurs it can be quite wide, but it is important to emphasize that such complications are very rare in an experienced hair restoration surgeon's office. Also, as noted earlier, a single scar is all that should ever be present regardless of the number of transplant sessions, because the scar from any prior one(s) is always included in a later one. Most importantly, if a wider than usual scar does occur - secondary to the patient's sub-optimal healing characteristics or other causes - it can be cosmetically corrected with a trichophytic donor wound closure or FUE (Figures 14, 15).

The main advantage of FUE is that there is never a linear scar - just small punctuate ones, that if done properly will be unnoticeable even if the hair is very short - almost shaved. Of course, FUE can also be improperly done, in which case purulent cysts can develop and the scars may be larger and very short hair might not be cosmetically possible (Figures 16, 17).

On the other hand, the main disadvantages of FUE are that hair survival of FU harvested via FUE can be reasonably expected to be lower than in microscopically-prepared FU from strips, and if large numbers of grafts are, or will one day need to be harvested, more of the grafts will only have temporary hair. Not incidentally, the punctuate scars that are present in only temporarily hair-bearing fringe areas today, will become noticeable when that hair is lost in the future. If you are relatively young and contemplating FUE, I urge you to now re-read this paragraph and the bold lettered paragraph above.

All the same, FUE has other advantages that make it useful in certain individuals - for example in some men who have very tight scalps or bad scars from prior hair transplanting and in older men in whom one can more accurately predict a relatively small bald area developing over their lifetime than in young men. As alluded to above, it is also useful for getting hair to transplant into a wider than usual linear scar - cosmetically eliminating it. We are also in the process of perfecting FUE technique and instrumentation to improve hair transection and hair survival rates that, as mentioned earlier, currently are typically not as good as for microscopically prepared strip FU/hairs. (For example, I have been consulting with a company that has been perfecting robotic extraction of FU with lower than common manual FUE transection rates).

In time, FUE will become more useful and in more men especially if it is combined with strip harvesting. For example, often after three or more strip harvests in the same area, the hair density and scalp laxity is sufficiently reduced that another and necessary narrower strip including the prior scar, will yield fewer FU than a FUE session would. However, FUE far from the panacea that some of its Internet proponents suggest it is - especially for young men in whom the ultimate size of the bald and donor areas are far less certain than in older men. (Long-term donor hair density is also less certain in younger men.)

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