TYPES OF GRAFTS

In modern hair transplanting, grafts are prepared from a strip of donor area skin
that is sectioned under various types of magnification into whatever kind of graft or grafts that are required.  The donor site is sutured closed and produces a hairless scar that is usually only 0.1 to 0.5 mm wide (Figure 1).  (A small number of patients develop slightly wider scars because of their personal healing characteristics) the donor site can always be easily camouflaged, immediately after surgery, by combing the hair above it.  Any resultant scar can also always be easily camouflaged in the same way.
 

The scar from any previous session is excised as part of the donor strip in any subsequent session so that usually only a single scar is present, regardless of the number of sessions that are carried out.  (Sometimes two donor areas are used in order to obtain hair with different textures and colors.)

Dr. Unger employs five types of grafts.  They are chosen on the basis of:

a) ultimate density objectives of the patient, b) the amount of persisting hair in the recipient area, c) hair characteristics such as color, wave and curl and d) the  estimated long-term donor area/recipient area ratio.  Each of these types of grafts is described below with a summary of their advantages and disadvantages.  They can broadly be categorized as grafts which contain: 
 a) a single “follicular unit” (FU) and b) grafts that contain two, three, or more FUs (multi-FU grafts).  What is a follicular unit?  

Follicular Unit (FU): Dr. Unger uses the terms “follicular unit” “follicular group” and “micrograft” interchangeably.  Most scalp hairs grow in small groups of two or three hairs, separated from adjacent groups by small areas of bald skin (Figure 2).  Usually, 15–20% of hairs exit the scalp as single hair follicles and approximately the same percentage exit as groups of more than three follicles.  Donor tissue can be dissected into grafts that contain only one hair follicle or, alternately, one FU that as noted above, can contain two, three, or more hairs—as they naturally exist in the donor site.  The empty skin between these groups is dissected away from the groups of hair and is discarded.  The FUs are inserted into holes made in the recipient area, with small blades or ordinary hypodermic needles, such as those used to give intra-muscular injections or dental anesthesia.  When FUs are the only type of graft used for hair transplanting, the technique is referred to as Follicular Unit Transplanting (FUT)
.
Fig. 2. Most scalp hairs grow in small groups of two or three hairs separated from adjacent groups by small areas of bald skin. Each group is referred to as a "Follicular Group",
"Follicular Unit" or "Micrograft".The terms are used inter-changeably by Dr. Unger.  (Photo Courtesy of Dr. Ron Shapiro)

The main advantage of transplanting exclusively with FUs is that they produce the most even, natural-looking coverage.  If the recipient area is totally or nearly hairless, the difference between transplanting with FUs, as opposed to grafts containing more than one FU (multi-FU grafts), is virtually always more natural looking when FUs are exclusively utilized (white hair and/or curly hair are sometimes exceptions to this general statement).  Thus, a single session of FUT can “stand on its own” and look natural in an area that is bald or destined to become bald.  As soon as one also employs multi-FU grafts, at least two sessions and sometimes three sessions will ultimately be necessary to produce results that look sufficiently natural to be undetectable except with very close inspection.  As a corollary to the preceding, one can also choose to transplant larger proportions of the bald area with single sessions of FUT— for example, a single session to the frontal area and a single session to the mid-scalp—without having to worry about whether the treated areas will look natural after only one session (Figure 3). 
 

Fig 3a A patient before transplanting.	Fig. 3b The same patient after two sessions of transplanting exclusively with follicular units. One session was carried out frontally and the second was carried in the mid-scalp.
	Fig. 3c. A frontal view photo of the patient taken at the same time as the photo shown in 3b.

 Whether an area ultimately needs to be treated more than once with FUT can be decided upon after full growth of the first session has occurred (approximately one year after the transplant session); additional sessions are done only to create more hair density rather than because they are necessary to produce a more natural appearance.  The decision as to whether one treats any area more than once should take into account the patient’s hair density objectives, the long-term donor/recipient area ratio, the proportion of the existing or evolving bald area the patient wants to treat, and the amount of money, as well as the time, the patient is prepared to expend in the pursuit of his/her goals.  Another advantage of FUT is that small needles or blades are used to make the recipient sites.  These sites can be created between any existing hair in a thinning area, so none of that hair is removed or injured if enough care and skill are employed making them.  (Some temporary hair loss may occur because of temporary decreased blood supply but this usually affects no more than 10% to 20% of the hairs in the area and it is temporary.)

Because of the above noted advantages of FUT, a large number of Hair Restoration Surgeons (HRS) prefer to use only FUT in their practices and some have declared it the “gold standard” of transplanting.  Unfortunately, however, as will be discussed below, there are some disadvantages to FUT that make it a less attractive way to treat some patients.

The disadvantages of FUT are:

1) Less hair density: Multiple sessions of FUT cannot produce the degree of hair density that can be produced by multiple sessions of a combination of FUs and multi-FU grafts (a single session of FUT can match—and even exceed—the hair density produced by a single session of “combination grafting”).  This inability to produce high-hair density is due to two factors: a) individual FUs can never be transplanted as close together as they existed in the original donor area.  Getting them even half as close as in the donor tissue requires two or more sessions in most offices.  Thus, transplanting with FUs has never resulted in hair density comparable to the hair density within a multi-FU graft and, b) the spaces between multi-FU grafts allow for an equal number of grafts and hairs to be transplanted in a second or third session while that is not possible with the usual FU densities that are employed by most FUT practitioners—hence the higher hair density that can be achieved after multiple sessions of “combination” grafting vs. FUT.  In brief, while we may attempt to put hair into the scalp the way nature did it—one FU at a time—we cannot ultimately get them nearly as close together as nature did. 

2) The hair in FUs is more susceptible to potentially lethal damage during graft preparation, storage, and insertion into the recipient area.  This is because there is less “insulating” tissue around the hairs in an FU than hairs in a multi-FU graft.  This results in the need for a large staff of highly trained technicians who must be constantly supervised and too frequently replaced as they move from one doctor’s office to another.  Put differently, the need for staff “perfection” increases as the size of the graft decreases, with FU being the smallest and therefore most unforgiving type of graft.  Nevertheless, although hairs in an FU can more easily be killed than hairs in a multi-FU graft, good quality control of office staff is possible and high-hair survival (90 to 100%) is therefore achievable—it is just more difficult to achieve.

3) The smaller the graft the more of them that are necessary to transplant the same amount of hair—therefore the smaller the graft, the larger the staff and physician time that is required and the more expensive the procedure becomes.  The cost factor of FUT can often be managed because a single session of FUT will look natural so the patient can, if necessary, only do one session or even spread treatments far enough apart to be affordable.

Despite the disadvantages noted above, hairline zones and the “crown” in all patients are treated exclusively with FUs because of the superb naturalness they produce after only one session.  In addition, as noted earlier, because it will produce naturalness in a single pass, it allows the patient the option of either treating the same area again, for more density, or “saving” those grafts for use elsewhere.   Patients with totally bald recipient areas are strongly encouraged to do at least the first session with FUT for the same reasons.  FUT also remains the best option for most (though not all) patients who can afford it.  (See below.)  This is because most patients do not require high hair density to be satisfied.  Furthermore, they should not seek it because most patients do not have good enough long-term donor/recipient area ratios for dense coverage of large areas.  Currently, approximately 30% of Dr. Unger’s patients choose FUT when they are shown photos of what can be expected from this approach (Figures 4-7) and what can be expected from a mixture of FUs and multi-FU grafts.  See also the section of this website on “Confusing Claims”.
 

Fig 4a. A patient before transplanting. The black lines were two options for proposed hairlines that were presented to the patient.	Fig 4b. Six months after a single session consisting of exclusively of follicular units.
	Fig 4c A frontal view photo of the patient taken at the same time as that shown in Fig. 4b.  Note that in Figs. 3 and 4 that the frontal view looks thicker than the view of the top of the head.  When comparing before and after photos, it is generally wise to ask the physician to show you comparable views of that presented in the patient’s before photo.
Fig. 5a.  A patient before transplanting.	Fig. 5b. Nine months after a single session consisting exclusively of follicular units.
Fig. 6a.  A patient before transplanting.	Fig. 6b.  The same patient nine months after his second session of exclusive micrografting.
Fig. 6c. The crown area before transplanting.	Fig. 6d. The crown area six months after a single session consisting exclusively of follicular units.  The patient had returned for a second session of transplanting to his crown.
Fig. 6e.The donor area was clipped short prior to taking the strip for the second session to the crown.  If one looks carefully, a very narrow white scar line can be seen in the middle of the clipped area.  This is the only scar that was present after three sessions.	Fig. 6f. A photo taken just prior to the second session to the crown showing two sessions to the front and one to the crown.
Fig. 7a. A patient before transplanting.	Fig. 7b.Nine months after a single session of exclusive follicular unit transplanting.
Fig. 7c. The same patient before transplanting with the hair parted and prepared with a Betadine solution prior to the surgery.	Fig. 7d. A photo nine months after a single session of exclusively follicular units.

Multi-FU grafts
General comments:
The oft-repeated charge that using anything larger than an FU always results in noticeable plugginess is inaccurate and overly simplistic.  “Plugginess” is not simply a function of graft size.  Other factors play an important role in whether a graft might or might not be noticeable.

a)     The finer the hair texture, the larger the graft can be without looking pluggy.

b)     The less contrast between hair and skin color, the larger the graft can be without looking pluggy.  Patients with white hair, for example, can have grafts with many hairs in them without looking at all pluggy (Figure 8).  Those with salt and pepper, blonde, and light brown or red hair can also frequently use multi-FU grafts without fear of looking “pluggy”.
 

Fig. 8a. An intra-operative photo of a patient before the grafts were placed into the recipient sites that had been made.  Micrografts had been used for the hairline zone, grafts containing two and three follicular units—one behind each other—had been used for slit sites made just behind the micrografts, a zone of slot graft sites had been made behind those and then slit grafts behind the slot grafts.	Fig. 8b. The patient shown in Fig. 8a before transplanting.
Fig. 8c. The same patient shown nine months after his first session.	Fig. 8d.  The transplanted area has been parted down the mid-line for critical evaluation.  Note that despite the use of grafts that were larger than a single follicular unit, there was no cosmetically significant notice ability of those grafts.  The less contrast between hair and skin color, the larger the graft can be without looking “pluggy”.

c)     The more curl or wave to the hair, the larger the graft that can be without looking “pluggy”.

d)     The more persisting hair in the recipient area, the larger the graft can be without looking “pluggy” (Figure 9).  Most of Dr. Unger’s patients come to him well before they are totally bald and therefore do not have to be concerned about the multi-FU grafts being noticeable.
 

What is true, however, is that even in ideal circumstances, very close inspection will always reveal less than the perfectly even coverage that is produced with FUT.  Because of this, a single session of multi-FU grafts is rarely cosmetically acceptable.  As noted earlier, a second and sometimes third session in the same area will ultimately be necessary to produce a satisfactory naturalness.  On the other hand, as was also discussed earlier, more hair density can be created with multi-FU grafts and with greater safety to the hairs and less cost to the patient.  As long as hair characteristics are suitable and additional sessions are carried out in a timely fashion—for example, keeping pace with hair loss in a recipient area that initially was not bald—no plugginess need ever be noticed.  The result is that a majority of Dr. Unger’s patients still choose a combination of FUs and multi-FU grafts over FUT, in order to ultimately achieve more density (or sometimes because it is more cost-effective).

Double Follicular Units (DFU) and Triple Follicular Units (TFU)DFU grafts consist of two FUs lined up one behind each other like soldiers in a row while TFU grafts contain three FUs aligned in a similar fashion.  They are inserted into incisions made with ultra-sharp small blades.  The finer the hair texture, the less skin/hair color contrast, the more hair curl or wave and the more persisting hair present in the recipient area, the more likely these will be used behind the hairline zone without being noticeable.  As noted above, two or more sessions of these types of grafts produce greater hair density than the same number of FUT sessions and do so with more hair follicle safety and less cost (Figures 10-12).  A session consisting of a mixture of FUs and DFUs (with or without TFUs) can also be followed by a second session of FUT or FUs and slot grafts or even small round grafts (see below); the latter two in order to produce even greater hair density, and greater follicle safety.  It is important to repeat, however, that if DFUs, TFUs, or any other type of multi-FU grafts are used in the first session, at least one more session will be necessary at some point to create enough naturalness if the area is bald or destined to eventually become bald.
 

Fig. 10a.  A patient before transplanting in our office.  He had previously had some plugs transplanted in someone else’s office.  These can be seen in the midline of the frontal area.	Fig. 10b.  One year after his second session using a combination of micrografts and slit grafts.  The excellent density is the result of several factors: a) very good donor hair density, color and texture, b) the use of grafts containing more than one follicular unit during our sessions, and c) the round grafts that had been planted by the prior surgeon.
Fig. 11a A patient four months after his first session with a combination of micrografts and slit grafts into what had been a bald area.	Fig. 11b Six months after the third session with the hair parted for critical evaluation.
	Fig. 11c Six months after the third session with the hair combed as normally worn.
Fig. 12a A patient before transplanting.  The black crayon mark denoting the new proposed hairline.	Fig. 12b.  Six months after a single session consisting of a combination of micrografts and slit grafts.  Note that despite the use of slit grafts (containing more than one micrograft), there is no noticeable plugginess in an area that was initially virtually bald.  This is because of the frizziness of the patient’s hair.

Just as with FUs, no existing hair in the recipient area is removed during the preparation of the recipient sites.  These are made between the hairs with small blades.  Because virtually all women with Female Pattern Hair Loss (FPHL) are not destined to lose all of their scalp hair, a mixture of FUs and DFUs/TFUs is usually used in hair transplanting in females (Figures 13-15).  Keep in mind also that whether the patient is a male or female, FUT can be used for the first session and a mixture of FUs and DFUs/TFUs can be used in a second session (or vice versa).  Once a session of FUT has been carried out, however, slot or round grafts cannot be employed without removing some of the previously transplanted hair.

 

Fig. 13a A female patient before transplanting with the proposed hairline marked in with a black crayon.	Fig. 13b  Six months after a single session consisting of a combination of follicular units and slit grafts.
Fig. 14a A female patient with a virtually bald area in the frontal midline.	Fig. 14b The same patient nine months after the second session to the problem area.  A combination of follicular units and slit grafts had been employed.
Fig. 15a. A female patient showing marked thinning of the frontal area before transplanting.	Fig. 15b. Nine months after a single session consisting of follicular units and slit grafts.  This degree of hair density is not typical of what is seen in female patients treated with transplanting, however, it does occur in a small percentage of them.  Additional photographs and more information on transplanting in females can be found in an article published by Dr. W. Unger and Dr. R. Unger in the Journal of the American Academy of Dermatology, vol 49, number 5, pgs. 853-860, November 2003.

Slot Grafts
Slot grafts are three FUs long and approximately two FUs wide.  They typically contain 10 to 12 hairs and are inserted into “slots” created with a special “slot punch” (Figures 8 and 16).  They are particularly suitable for patients who want substantial hair density and who have a sufficiently good long-term donor/recipient area ratio.  Once again, good hair characteristics, for transplanting, such as low hair/skin color contrast, frizz, curl and existing recipient area hair, increase the likelihood that these larger grafts will not be noticeable behind a hairline zone of FUs (and usually a zone of DFUs or TFUs behind the area treated with FUs).
 

Fig. 16a.  An intra-operative photo showing the recipient sites before grafts were inserted into what was a totally bald area.	Fig. 16b.  The same patient six months after a second similar session.
	Fig 16c. A close-up side view photo of the patient taken at the same time as the photo in Fig. 16b demonstrating the different effects of different types of grafts.  The hairline is very natural looking but has a relatively low density because the finest hair that was available in the donor area was used at that site and only follicular units were used in the hairline zone.  Farthest back, the density is a result of the use of the larger slot grafts while slit grafts were used midway back from the hairline zone.  Note that once more the slits grafts did not appear at all pluggy after two sessions into a totally bald area.

The disadvantages of slot grafts are: a) unless hair characteristics are good for transplanting, and the recipient area is suitable, these grafts may be temporarily noticeable, b) when they are used in an area that still retains some of its original hair—as they usually are—some of that hair is removed as the recipient sites are punched out.  Hence, in the slot-grafted zone, there is less hair for the first three months after surgery than there was before the surgery.  (No hair is removed in front of or behind the slot grafted area), c) more hair is also used in the frontal area, and less hair is left in reserve for the treatment of other areas.  Two of these potential drawbacks of slot grafts can obviously be avoided if they are only used in people who do have good hair characteristics and in those men who have and are likely to maintain a good ratio of donor hair to bald area.  (Doing the first two sessions five to six months apart—before the previously transplanted hair gets long and coarse—is also helpful in avoiding temporary noticeably.)  However, such individuals constitute a minority of patients seeking hair transplanting and thus this approach is used in only 10 to 15% of our patients.  It is especially useful for middle aged or older men with salt and pepper or white hair (See Figures 8 and 16).

“Round” grafts
“Round” grafts are actually square grafts placed into holes made by round trephines or “punches” behind a zone of FUs and DFUs, TFUs and slot grafts.  The punches usually have a 2 mm diameter, but occasionally larger punches are employed.

Everything that has been discussed about slot grafts applies to the use of round grafts but even more so.  The potential for hair density and hair follicle survival are increased, as are the problems that can occur and that must be avoided.  Thus, only 10% of Dr. Unger’s patients are currently offered this option.  Nevertheless, in properly selected patients, the results can be spectacular (Figures 17-19).
 

Fig 17a. Before transplanting: frontal view.	Fig 17b. One year after the third session to the frontal area.  Each session included a combination of micrografts, slit grafts and round grafts.
Fig 17c. Before transplanting: side view.	Fig 17d. A side view photo taken at the same time as that shown in Fig. 17c.  Two sessions had also been carried out in the vertex area; however, only micrografts and slit grafts had been used there.
Fig 18a. A patient before transplanting.  This individual wore a hairpiece and wanted maximum density from his transplanting.  He was not concerned about any transitory plugginess as he intended to wear his hairpiece until the transplanting sessions were completed.	Fig 18b. One year after the third transplant to the frontal area.  Note the absence of any noticeable plugginess despite the use of a combination of micrografts, slit grafts and round grafts.
Fig 19a. A patient before transplanting.  He was in his 40s, wanted maximum density, and had abundant donor area hair. Hair dyed black.	Fig 19b. The same patient one-year after his fourth transplant session to the frontal area.
Fig. 19c. A photo taken at the same time as that shown in Fig. 19b but with the hair parted through the middle of the transplanted area for critical evaluation. Note the virtually complete absence of any noticeable plugginess despite the use of round grafts. This degree of density has never, in my experience, been accomplished with the use of anything smaller than round grafts, but is both unnecessary and unwise for most patients whose donor areas are considerably more limited than that of this individual.	Fig 19d. A side view photo taken at the same time as those shown in Figs.19b and 19c.

Repair of Unsatisfactory Prior Transplanting
Most patients seen for repair of unsatisfactory prior transplanting are treated with a combination of: a) excision of part or all of any old large pluggy-looking grafts, b) creation of a new hairline constructed exclusively with FUs, c) the use of FUs and multi-FU grafts behind the new hairline zone.  The type of graft chosen for any given area will depend on a large number of factors but the choice is based on which variety of graft will most rapidly correct noticeable plugginess.  Usually at least two transplant sessions are necessary to create substantial improvement (Figures 20-22). 
 

Fig 20a. A pre-operative photo of a patient seen for correction of unaesthetic prior transplanting.  The black crayon marks denote the limits of the areas that were to be treated.	Fig 20b. Nine months after a single session which consisted of 1270 FUs, 105 DFUs, and 21, 2mm round grafts.
Fig 21a. A pre-operative photo of a patient prior to his first corrective session. The plugginess was the result of round grafts that were employed in his treatment some 15 years earlier.	Fig 21b. Five months after his second repair session.  The first session had consisted of 809 FUs, 266 DFUs, 33 TFUs, and 26, 2mm round grafts.  The second session consisted of 1109 FUs, 220 DFUs, and 20 slot grafts.  The idea that only follicular units or micrografts should be used for corrective procedures is an obviously flawed one.
	Fig 21c. A side view photo taken at the same time as that shown in Fig. 21b.
Fig 22a. A patient before a corrective procedure to the crown area that had been transplanted many years before with only round grafts.  The patient had also had some repair work done frontally but it had not fully grown in at the time this photo was taken.  The hair in the round grafts had been cut short to facilitate removal of a portion of each of the round grafts.	Fig 22b. An intra-operative photo taken at the same time as that shown in Fig. 22a showing round holes where part of each of the round grafts had been excised, as well as smaller sites for micrografts and small slit grafts.  One can also see a very faint outline of a scar peripheral to the treated area.  That scar was produced by a prior Alopecia Reduction (AR) that had been used to remove part of the bald area, in order to save the grafts that would have had to be used to treat the area that was excised, if it had not been removed.
	Fig 22c. One year after the photo shown in Fig. 22b.  The hair has been parted for critical evaluation.  Although the hair density is low, the appearance is virtually completely natural.  One can also see the results of the transplants done farther frontally.  The patient had returned for a second treatment to his crown.

 

Frequently, however, patients will want three or more treatments (if possible) because each session will result in more improvement in both the recipient and donor area.  With regard to the latter, improvement of scarring in the donor area is often as important a goal as is improvement in the recipient area.  As a result of the relatively new technique of strip harvesting, these goals are not incompatible.  One can often excise two rows of wider scars with a zone of hair between them, thereby creating one narrow scar from two wide ones (Figure 23)

 Fig 23

Follicular Unit Extraction (FUE) is sometimes also used to obtain grafts without creating new linear scars.  FUE involves the excision of single FUs from the donor area—one at a time—rather than the excision of a strip that must later be divided into different types of grafts.  In most patients Dr. Unger sees, however, he prefers to remove old scars at the same time as he is obtaining more donor tissue and he likes to have the option of using multi-FU grafts as well as FUs.