Planning Principles: Good Short- and Long-term Planning in Hair Transplantation

20 Planning Principles: Good Short- and Long-term Planning in Hair Transplantation

Walter P. Unger and Mark Unger

Summary

The goal of this chapter is to remind and emphasize to practitioners the most important element of planning in hair transplantation: namely, consideration of the probable eventual size of the area of alopecia and the probable eventual size of the donor area, hair density, and hair caliber. Such an approach maximizes the likelihood of producing the best possible results while avoiding potential long-term pitfalls in the recipient and donor areas. Included is advice from other experts, a review of the author’s “Safest Donor Area” (SDA), and a critical assessment of the long-term problems that can be predicted to occur more frequently with follicular unit excision (FUE) than with single scar strip harvesting, especially in patients who are relatively young, who undergo “mega-sessions” of greater than 3,000 FU that are harvested using FUE, or who are likely to require higher-than-average numbers of FU over a lifetime. In such individuals, the advantages of using lower-than-usual recipient area graft densities should also be weighed. Finally, the author advises practitioners to consider future hair loss when planning the recipient area, and to transplant into evolving areas of hair loss by making recipient area incisions at the same angle and direction of existing recipient area hair.

Keywords: male pattern baldness dense packing lower graft densities female pattern hair loss transected follicular units high graft density

Key Points

•The coverage and density achievable in hair transplant surgery is determined by the relationship between the severity of alopecia in the recipient area and the amount of hair available for grafting in the donor area, otherwise expressed as the donor-to-recipient ratio.

•For the majority of individuals, the donor-to-recipient area decreases over the lifetime of a patient, as areas of alopecia expand over time and donor hair resources shrink.

•Successful planning in hair transplantation must take into consideration both the current and expected donor-to-recipient ratio. In other words, effective planning weighs current and future recipient area needs, and current and expected donor area supply.

•It is unwise to use high recipient area graft densities except in carefully selected patients or in small strategic areas, as a limited donor supply is one of the greatest obstacles to successful hair transplantation. Moreover, high recipient densities are unnecessary, as average scalp hair density is likely much lower than the previous estimate of 100 FU/cm², and since the illusion of fullness can be achieved at approximately 50% of normal density.

•Using follicular unit excision (FUE) for donor harvesting can have significant long-term repercussions. In most patients, in order to obtain the same number of grafts from FUE as from strip harvesting, the harvesting must take place over a donor area that is at least three times as large. This ratio takes into consideration both acceptable near-term and long-term donor area appearances.

•A key component of planning is anticipating future hair loss and transplanting into areas of evolving hair loss. This can be successfully performed provided that recipient area incisions are made at the same angle and direction as existing hairs. Such an approach also avoids adding unnecessarily transected hairs to the amount of true postoperative anagen hair loss that may occur.

20.1 Introduction

The goal of this chapter is to remind and emphasize the importance of planning that is based on the likely eventual size of the area of alopecia as well as the likely eventual donor area size, hair density, and hair caliber. Such an approach optimizes the ability to create permanent, cosmetically exceptional results in both areas. Important principles related to this topic are presented below.

20.1.1 Hair Loss Is a Progressive Process

Male pattern baldness (MPB) and female pattern hair loss (FPHL) are progressive processes, a fact that practitioners know, but can “forget” when planning. While the progression of hair loss is intermittent, it is inevitable for as long as a person lives. Intervals of hair stability are periodically punctuated by periods of hair loss, during which areas of partial and complete alopecia enlarge. Hence, except in rare cases, the size of the recipient area grows over time.

20.1.2 Donor Supply Decreases Over Time

As the size of the recipient area grows, the opposite process occurs in the donor zone, for example, it shrinks. Patients with a family history of severe hair loss should be especially cautious about using large amounts of donor hair to treat finite, early areas of alopecia. This guidance assumes particular importance in younger patients, in their third and fourth decades, as the extent of long-term hair loss is less predictable, and thus there is a risk that they will develop large alopecic areas for which there is an insufficient supply of donor hairs. This means, for example, that while spectacularly dense and youthfully low hairlines can be created by using “dense packing” of 40, 50, 60, or more “follicular unit” (FU) grafts/cm², such choices are extraordinarily unwise for the majority of young individuals. Conversely, however, there are some benefits to being older: the older the patient is, the more aggressive the physician can dare to be, because there is a better chance of accurately prognosticating the trajectory of hair loss.

The patient shown in Fig. 20.1 had a family history of type VI and VII MPB. He originally requested transplanting to the inferior hairline that I outlined Fig. 20.1a. He visited websites in which that sort of objective was presented as reasonable. The more superior hairline was the one that I advised him to accept (see Video 20.1 that demonstrates how frontal hairline outlines are created by the author). The area between the more frontal drawn hairline and the higher one that I had recommended would have required “dense packing” of approximately 4,000 FU according to the owners of a few websites that this patient consulted. After examining him, there was little doubt in my mind that he would eventually evolve to a type VI or worse MPB. Yet Fig. 20.2 suggests that he may ultimately, on average, have only approximately 5,393 FU grafts containing permanent hair available to use over his lifetime.¹ If he had gone to one of the physicians whose sites offered him the “dense packing” and a lower hairline, he would have ended up with a very dense and low frontal hairline zone. While initially he would have been happy with the results, eventually he would have developed an extraordinarily large area of alopecia posterior to that and a grossly unnatural appearance. Unfortunately, some doctors with very active Internet sites (sadly, more than one of whom I have trained) promote the more inferior hairline or one similar to it, as well as very high hair density goals because this is what too many patients want rather than what they should want. (With cosmetic surgery, doing what canbe done is less important than doing what should be done!). Fortunately, this patient was wise enough to choose the more superior than usual hairline and the lower than usual FU density that I recommended, given his predicted poor long-term donor-to-recipient area ratio and the hair loss progression that would make his original choice unnatural over time.

Fig. 20.1 (a) The more aggressive frontal hairline outline is the one suggested by several other physicians for this 29-year-old patient. (b) The more superior one was the one I recommended. (c) An intraoperative photo. (d) 17 months after his first frontal session (2,611 FU) transplanted at 30 grafts/cm² of primarily one and two hair grafts in the hairline zone and 20 grafts/cm² of a mixture of primarily two and three or more hair grafts elsewhere.

Fig. 20.2 Average usable FU estimates in 30-year-old Caucasians.

20.1.3 What Is the Available Donor Supply over the Life of a Patient?

This is one of the most important questions in hair transplantation, as it sets a ceiling for what is possible, and hence realistic in terms of outcomes. For every patient, we know that there are a limited number of permanent donor hairs. While we can estimate that number based on the size and density of the donor zone at the time of consultation, family history, and other variables, this number remains just an estimate. In order to obtain an approximate idea of the answer to this all-important question, I asked the following questions to members of an “invitation only” email group of world experts in hair restoration surgery (see Chapter 20.3 Addendum for their names).

Keeping in mind that, over the years, the hairs closest to the superior, inferior, and frontal borders of the fringe will be lost, how many FUs containing very likely permanent hairs can be harvested from:

1.A 30-year-old patient who you believe is destined to develop type V MPB and has the following:

•Higher than average hair density.

•Average hair density.

•Less than average hair density.

•The same question but for a patient you believe is destined to evolve to type VI MPB.

The answers of this panel of 39 experts are presented in Fig. 20.2. In general, the number ranged from as low as 4,000 grafts in patients with poor density to as high as 8,000 grafts in patients with exceptional density. These numbers, while not dogmatically applicable, are far from meaningless, given that the estimate is from a group of practitioners who have over 900 years of cumulative experience.

20.1.4 The Significance of the “Relatively” Safe Donor Area

A priority in hair transplanting is selecting donor hairs that are likely to be “permanent” (the quotation marks are because nobody can be absolutely certain what is the permanent donor area). Failing to recognize that the fringe of hair narrows over time can lead to poor long-term recipient and donor area results. It is equally important to recognize that even hairs in the “permanent” donor fringe become shorter and finer-textured, more so at the periphery of the fringe.

In the early days of transplanting, we failed to recognize how severely and quickly the fringe hair might narrow, and even less how the caliber of donor hair would decrease. This latter point is as relevant as the former, as finer caliber hairs produce considerably less coverage and apparent density when compared with larger ones. For example, Cole noted that increasing the diameter of an average hair by just 0.01 mm increases hair coverage by 36%!²

Over time, a failure to accurately estimate the SDA can result in a loss of recipient hairs and exposure of donor scars from harvested fringe areas, first when hair is wet and later even when hair is dry (Fig. 20.3). To an extreme, in areas where there is total donor area alopecia, there may be no camouflage at all! The preceding phenomenon is responsible for the worst long-term complications in hair transplantation and can haunt practitioners and patients alike.

Fig. 20.3 (a) Twenty-nine years after starting transplanting, the fringe hair of this patient had become sparse enough that obvious scar noticeability existed in all the prior donor areas. The patient had unsuccessfully tried to improve the appearance in these areas with inexpert tattooing. (b) This photo was taken at the same time as a but with the hair dry and combed down. At this point, he was only 53 years old and could reasonably anticipate many years of a worsening cosmetic problem.

When I started seeing those complications, I decided to carry out a study to try to establish the most likely boundaries of the fringe area that might contain the largest number of hairs that were the most likely to be permanent. In concert with a resident physician, we carefully examined the fringe hair of 328 men 65 years old or more, looking for areas where there were at least 8 hairs/4-mm diameter circle.³ Using the data that we collected, we outlined the margins of a SDA, which later, and more accurately, was referred to as the “safest donor area.” We published this information and it remains a widely accepted guide to ethical practitioners, as to where they should ideally, or “most safely,” obtain grafts for transplanting; the word “guide” is in bold letters to designate that it is only a guide or warning, rather than a dogmatic necessity to stay within the SDA. The densest hair runs through the horizontal midline of the SDA. (SDAs suggested by other investigators have, to this point, been based on far fewer men who were also, for the most part, substantially younger, and are therefore less reliable as a guide to long-term prognoses.) Clinicians should also use clinical examination, the patient’s age, family history, etc., to decide if the boundaries can be reasonably enlarged or reduced for any given individual. Inherent in the preceding, it would seem to be safest, from the perspective of hair longevity, to harvest grafts from within the densest fringe hair, while avoiding the frontal, superior, and inferior fringe borders from which MPB and FPHL hair loss progresses. This is best accomplished by first excising a strip of hair-bearing donor tissue from the densest fringe hair, and in subsequent sessions including the scar from the prior one(s) in the new strip. The physician, with each harvest, thereby obtains not only the next most likely permanent hairs but also leaves behind only one scar running through the densest fringe hair, regardless of the number of sessions the patient has undergone (Fig. 20.4).

Fig. 20.4 (a) A typical strip scar 6 months after the procedure. (b) The same patient as in (a) but after the fourth donor strip. Donor scars need not get progressively wider after each subsequent harvest as some have suggested, if the wound closing tension does not increase with each harvest because of inappropriate strip widths. (c) The strip scar in a different patient that is a little wider than that shown in the first figures (a and b). (d) The same patient as in c but the hair has been combed as normally worn and it was still barely visible. 90–95% of our patients have scars similar to that shown in (a and b) and can wear their hair as seen above without the scar being noticeable.