R. H. Unger, MD1 and W. P. Unger, MD2
1Private Practice, New York, NY, USA
2Private Practice, Toronto, ON, Canada
As hair transplant surgery has evolved, combinations of micrografting and minigrafting have enabled physicians to produce ever more natural combinations of both. A wide range of men and women can now receive significant aesthetic benefits from hair transplants. In recent years, practitioners have further refined hair-transplant techniques to ensure that the hairs available for transplantation are used most efficiently. Specifically, methods of harvesting hair, preparing grafts, creating recipient sites, and placing grafts are designed to permit the maximum percentage of hairs to survive and thrive after transplantation. Careful planning, close cooperation with the patient, and a staged surgical approach can also result in hair conservation and optimal cosmesis.
Key Words: hair transplant, micrografting, minigrafting
This paper is not intended to describe surgical techniques in general; we refer readers to other publications for that.1,2 Rather, it will address new concepts and techniques in hair transplantation, which have evolved over the last approximately 10 years.
Rather fortunately, the definition of an “acceptable candidate” for hair transplantation has broadened substantially in the last 10 years. New donor area removal techniques, as well as micrografting and minigrafting, have revolutionized the procedure. Moreover, patients who have poor donor areas, secondary to genetics or previous “old” transplanting techniques, may still achieve an acceptable aesthetic improvement because of these advances.
We now think of the recipient area in men as being composed of three segments: the frontal, midscalp, and “crown” areas.3 Generally, only one of these is treated in any single session, although later sessions may include thickening of portions of the two previously transplanted areas. Most patients can ultimately treat at least the anterior two areas because of the innovations that will be described here. If this is done, a patient will look like he has hair from the frontal view, as well as the side view. Because micrografting and minigrafting can produce natural-looking results with the use of less donor tissue than was necessary with larger grafts, one can now choose to treat larger portions of the area of male pattern baldness (MPB) with lighter coverage, or alternatively to concentrate the available donor tissue in regions where high density is preferred. Some individuals can even treat their entire eventual area of MPB, especially if they are willing to have portions of the alopecic areas excised.4 Also many more female patients are acceptable candidates for the procedure now that hair-transplanting techniques do not involve the removal of any hair in the recipient area hair. Especially in females, however, a careful history to rule other medical and/or dermatologic conditions is necessary.5
Whether the patient is male or female, the physician should also try to determine the future donor/recipient area ratio. It is always preferable to err on the side of conservative estimates if there is any doubt. In addition, the physician and patient need to come to an agreement as to how much of the area can be treated and with what kind of grafts and hair density objectives. The better the donor/recipient area ratio, the more options are available. A wide, dense donor rim allows the patient the choice to aim for high density in the recipient area. Higher density is achieved with the use of minigrafts, slot grafts and small round grafts.6 These are always situated behind a hairline zone that is approximately 2.5cm in width and is composed entirely of follicular units (FUs). The treatment plan should include areas of future loss, so that the donor area can be apportioned appropriately. For example, if a patient is destined to be a Norwood Class VI or VII, and wants to cover his whole head with hair, then Follicular Unit Transplanting (FUT) is the best option. If, on the other hand, the patient has good hair characteristics, and the physician predicts that he will be a Norwood Class IV, many other treatment plans can be considered.
The physician excises an ellipse or uses a multi-bladed handle to excise contiguous narrow strips from the donor area. A tumescent solution and/or normal saline is injected into the donor area to help reduce transection of follicles during this stage. In our office, we do not aim for a specific number of grafts, rather our goal is to take a donor strip as long and as wide as we believe is prudent. Its size is limited by scalp laxity, by scar tissue, which may or may not be present, and (of course) by the blood supply. Overzealous donor harvesting can leave patients with wide scars, poor wound healing and other problems. The authors use two donor areas in many patients, one inferiorly in the occipital region and one superiorly on the contralateral, occipital, parietal, and temporal areas. This allows us to obtain hair of different textures and colors for use in the recipient area. During the second session, contralateral donor sites that end at the scars from the first session are employed.7 After the first two sessions, there will be two fine linear scars and these are excised as part of any subsequent sessions. A single donor area from ear to ear is used if hair density or scalp laxity is lower than average, if very large numbers of grafts are required, or if we believe that the patient is destined to develop types VI or VII MPB with a correspondingly narrow permanent rim of hair.
The excised donor strip is placed into a petri dish with cold saline. Graft preparation generally begins with division of the strip into “slivers” that are one FU wide, much as one would slice a loaf of bread. FUs consist of two to five closely bound follicles. These slices are then sectioned into smaller pieces of tissue, containing the desired number of FUs. The dissection is usually carried out with the aid of an 8x-10x microscope and a backlighting box, to minimize follicle injury. Larger grafts are created by producing slices, which are wider; slots, for example, are two FUs wide and three FUs long while 2mm grafts are usually three FUs x three FUs.
Every effort is made to minimize physical injury to the follicles and to keep them moist and cool. Given the central role of technicians in the preparation, storing, and handling of grafts, it becomes much more important, than in the past, to ensure that they are highly trained and that quality control is rigorously checked.
In most offices, all of the recipient sites are created prior to graft insertion. Sites for FUs are made with 16 to 21-g needles, those for “slit” grafts with various types of small blades, and for slot grafts or round grafts with special “slot punches” or round trephines, respectively.6,7
As implied, the recipient area can be treated in several different ways:
1) exclusively with FU (FUT) (Fig. 1).
2) with a combination of FUs and “slit grafts” that are one FU wide and two to three FUs long (Fig. 2).
3) with a combination of FUs, “slit grafts” and larger grafts (“slot” or “round” grafts) (Fig. 3).
FUT is ideal in several situations, including patients who begin treatment when they are already completely alopecic, those who have very limited available donor hair, and those who are seeking only light-to-moderate hair density. FUT can produce very natural looking results after only one session in any given area. Some physicians attempt to produce denser coverage in a single session by employing “megasessions” of 3000 or more FU/sessions and “dense packing” FUs at 35 to 40 FU/cm2. We believe that the level of follicle death with this approach is unacceptable in a large majority of offices;8 survival is far more reliable with smaller sessions and when the density is 20-25 FU/cm2. A combination of FUs and larger grafts is often the “best of all worlds” for most patients, because one can ultimately produce more density with such combinations.6 As patients age, hair density in both donor and recipient areas can be expected to decrease. Thus, starting with denser transplanted hair may prove to be advantageous.
A wide hairline zone (usually at least 2.5cm) is always created with FUs: single hair FUs are utilized most anteriorly, and larger FUs are usually placed more posteriorly and/or in a central “egg-shaped” region in the midline of the anterior frontal area (Fig. 4). Posterior to this zone, one may continue using only FUs or various combinations of multi-FU, “slit”, “slot”, or “round” grafts.
The treatment of hair loss in women is somewhat different.5 The hairline zone is treated in a similar manner, but the rest of the surgical plan is carefully tailored to the needs of the patient. Some women are most concerned about filling the temporal triangles, others want greater hair density in their part-line, and still other patients want general thickening in the center of the frontal region. Depending on donor area hair density, some (or all) of these strategic areas can be treated. Each session is usually done with a combination of FUs and small slit grafts and will nearly always create a significant aesthetic improvement (Fig. 2).
The final step in the procedure is graft placement. This is performed by technicians in most offices, but some physicians take an active role in this stage. Communication and training are of vital importance. Specifically, grafts must always be kept well hydrated, handled minimally, carefully placed, and the physician’s instructions should be clear with regard to the appropriate hair caliber and number of hairs in given locations. There are many possible errors that can occur during the filling of recipient sites and for these reasons all staff should have extensive training and regular quality checks. It is important that all sites are filled with the appropriate graft, that none are “buried” beneath the level of the skin, and that each site is filled only once (no “piggybacking”).
Hair transplant surgery is continually evolving and many of the new techniques have improved patient results. They also introduce some new problems. For example, FUT and micro-minigrafting rely heavily on a group of very well trained technicians. Physicians who are unable to create or maintain such a team are unlikely to consistently produce good results. Another potential problem is that although the density achieved with smaller grafts may be acceptable to many patients in the short term, they will likely require future periodic hair transplant procedures. If too large an area is covered initially and donor area is limited, there may not be enough hair “left in the bank” to finish the regions that were started. It is our opinion, therefore, that conservative estimates must guide treatment plans, the “transplant team” needs to be highly trained and supervised, and that patients should be offered a variety of reasonable treatment options.