Author: Robert M. Bernstein, M.D.
INTRODUCTION -
Although follicular unit transplant eliminates many of the shortcomings of older surgical hair restoration techniques, such as a 'pluggy' look, a 'moth-eaten' donor area or midline scalp reduction scars, poor aesthetic judgment and techniques that compromise graft growth can still lead to problems. Perhaps because follicular unit transplant requires large numbers of grafts (using a significant portion of the donor area at one time), because so many staff members are involved in the process, and because some of the problems of small graft procedures are very difficult to correct, improperly performed follicular unit hair transplantation can pose a greater risk to patients than traditional grafting. The risk is compounded by the fact that many physicians perceive follicular unit transplant as a safe, risk-free procedure and describe it to patients as such.
The remainder of this section will focus on some of the most common mistakes made by follicular unit transplant practitioners, particularly in the areas of planning, hair transplant design and handling large numbers of small grafts. These problems and how they may be avoided are summarized below.
1. Operating on patients that are too young or prior to medical therapy
2. Failing to identify low donor density prior to surgery
3. Failing to identify a tight scalp
4. Harvesting a donor strip that is too wide
5. Placing the donor incision too low or too high
6. Using a multi-bladed knife
7. Crushing grafts during insertion
8. Allowing grafts to dry
9. Placing the frontal hairline too far forward
10. Creating a hairline that is too broad
11. Angling hair in the wrong direction
12. Attempting to cover an area that is too large
Operating on Patients That Are Too Young or Before Medical Therapy -
Patents in their early twenties have their flat adolescent hairline and original density fresh in their memory. A hair restoration designed with enough frontal and temporal recession to look good ones entire life will rarely satisfy a younger patient. Creating a density that is ideal for a younger person will not leave enough hair in reserve if there is further loss. In addition, at this age the extent of future balding is difficult to even reasonably anticipate. For these reasons, a hair transplant should rarely be considered in patients with androgenetic alopecia younger than 25 years old.
Often a hair restoration doctor begins medical therapy and schedules surgery at the same time. However, if there is a possibility that using a medication, such as finasteride (Rogaine), can make hair transplantation unnecessary, then the medication should be used for at least a year before any decision on surgery is reached. Medication should be the first line of therapy for all younger patients with androgenetic alopecia, regardless of the degree of their hair loss.
Failing to Identify Low Donor Density Prior to Hair Transplant Surgery -
Assessing a potential patients\' donor supply with densitometry is of vital importance and cannot be stressed enough. A low donor density, generally less than 1.5 hairs per mm2, usually indicates that donor supply is insufficient to create adequate density or coverage, rendering the surgical hair restoration procedure inadvisable. An exception might be an older person with very conservative goals. High miniaturization in the donor area, particularly in a person under the age of 30, suggests Diffuse Unpatterned Hair Loss (DUPA) and is a contraindication to surgery.
Transplanting patients with low donor density will also risk a visible scar if the hair is worn short. Follicular unit extraction is not appropriate in such cases, since it further limits the total available hair. In fact, since the contrast between bald and non-balding scalp in patients with low donor density is naturally low, their best option tends to be wearing their hair short, to decrease the contrast even more (rather than having hair transplant surgery).
Failing to Identify a Tight Scalp (Scalp Laxity) -
Assessing scalp laxity is an underappreciated aspect of the patient evaluation, probably because it is difficult to quantify. However, a tight scalp severely limits the total amount of harvestable donor hair and can constitute a contraindication to surgery, except when hair transplantation patients have extremely conservative goals or are expected to experience only limited balding. The constraints that low scalp laxity impose generally manifest themselves after the first transplant session. Though laxity should be judged in the pre-op evaluation, the intra-operative assessment, made while suturing, is most accurate in predicting future difficulties. Therefore, every operative report should include a record of the ease of closure and intra-operative suture tension.
Harvesting a Donor Strip That Is Too Wide -
In large sessions, it can be tempting to take a slightly wider donor strip in order to conserve on length. A strip that is 25 cm by 1 cm, for instance, can be shortened by 6 cm if widened by just 3 mm--and yield the same amount of hair. However, a wide strip puts unnecessary tension on the donor closure and is probably the most common cause of widened scars. If larger sessions are appropriate, and the scalp lacks adequate mobility, the hair restoration doctor should consider a longer incision rather than a wider one.
If a wide donor strip has been identified as the likely cause of a stretched scar, it is advisable to wait at least eight months, to give the scar a chance to mature and regain some of its original laxity. When the next excision is made, the strip should measure at least 3-6 mm narrower than the previous one. Attempts to remove the entire width of the old scar invariably lead to a reoccurrence, or worsening, of the old scar. To facilitate healing, the new excision should extend to the hair transplant patient\'s hair-bearing edge.
Unfortunately, attempts to re-excise scars commonly result in either no improvement or an even wider defect. For this reason, many doctors use follicular unit extraction to place hair directly into the scar as a primary method of treatment.
Placing the Donor Incision Too Low -
The location of the donor incision greatly affects scalp mobility. The ideal position for it is in the mid-portion of the permanent zone that lies, in most people, at the level of the external occipital protuberance and the superior nuchal line. The muscles of the neck insert into the inferior portion of this ridge, so an incision below this anatomic landmark will be impacted by the muscle movement directly beneath it. A stretched scar in this location is extremely difficult to repair since re-excision, even with undermining and layered closure tends to heal with a wider scar. To compound the problem, one is more likely to cut through fascia with a low donor incision; and once the fascia has been violated, the risk of widening the scar rises considerably.
In addition to the slightly greater risk of a widened scar, the main problems of harvesting hair too high are lack of permanence of the transplanted hair (since it may be subject to androgenic alopecia) and future visibility of the scar were the donor fringe to narrow further. Incisions made too high are best left untreated, unless the scar is wide and poor surgical technique has been identified as the cause. The temptation to transplant permanent donor hair into a high scar should be resisted, as progressive balding would isolate the hair-bearing scar, presenting new cosmetic problems.
Interestingly, in the case of young hair transplant patients with traumatic scars and hair-loss patterns that are still unclear, Follicular Unit Extraction can function as a hedge against this risk. If the hair is harvested from the immediate vicinity of the scar, any future balding will affect the transplanted hair in the scar at the same rate as the hair surrounding it.
Using a Multi-Bladed Knife -
In order to save time, a hair restoration doctor performing large transplants may use a multi-bladed knife (one with three or more blades) for harvesting donor tissue. The resulting pre-sliced multiple thin strips are much easier to work with than a single intact strip. Unfortunately, harvesting this way causes unacceptable levels of follicular transection while destroying the naturally occurring follicular unit and is therefore incompatible with follicular unit transplant.
Crushing Grafts During Insertion -
Proper placing technique necessitates the use of forceps to grasp the graft by the fat below the bulb or by the dermis alongside the hair shaft in order to avoid damaging the germinative components of the follicle. Though placers often exercise enormous care while initially grasping the graft, there is a tendency to become rougher when repositioning the forceps for further inserting, replacing a popped graft or transferring grafts from the holding solution to the fingers. Since follicular units and other small grafts are particularly susceptible to crush injury after a hair transplant, improper handling can more than negate the benefits of careful stereo-microscopic dissection.
Allowing Grafts to Dry -
An elegant study using electron microscopy has shown that desiccation is by far the most significant form of injury to grafts and makes them much more susceptible to other forms of injury, such a mechanical trauma and warming. Grafts should therefore be kept well-hydrated with chilled isotonic solution (such as Ringer\'s lactate) from the moment the tissue is harvested until the time they are reinserted into the scalp.
Placing the Frontal Hairline Too Far Forward (Too Low) -
Despite the fact that individual follicular units at the hairline in themselves look natural, their proper placement is no less important than in traditional grafting. The frontal hairline should be placed no lower than 1.5 cm above the upper brow crease. Particularly if the underlying skin is normal, follicular units placed too low can be removed with an alexandrite (755 nm) or diode (800, 810 nm) laser. Electrolysis is more difficult and time-consuming with transplanted follicles, but should also be considered. Punch excision is too imprecise for very small grafts and risks scarring.
Creating a Hairline that is Too Broad -
Since significant temporal recession is characteristic of the normal adult male hairline, a broad, flat transplanted hairline will not age well and can cause cosmetic problems if baldness becomes extensive. The treatment is the same as with low hairlines, but it should be noted that if grafts larger than follicular units were used, and/or if there is scarring of the recipient skin, punch excision with reutilization of the hair may be indicated.
Angling Hair in the Wrong Direction -
As noted earlier, in the front and top part of the scalp, hair grows in a distinctly forward direction, changing to a radial pattern as it approaches the crown. It emerges from the scalp at an acute angle, with the hair lying practically flush to the skin at the temples.
There has been a tendency among some hair restoration doctors to transplant grafts perpendicular to the skin -- probably due to the fact that the mechanics of the old plug procedures made sharp angling technically difficult. The cosmetic consequence of this is most apparent at the frontal hairline. When the hair is perpendicular, the viewer\'s eye is guided to the base of the hair shaft where it inserts into the skin; conversely, when hair is transplanted in its natural, forward-pointing position, it is bowed by grooming and the eye settles on the body of the hair shaft.
When grafts at the frontal hairline are transplanted in a radial direction, combing the hair in any style becomes problematic and invariably results in an unhappy patient. As with low or broad hairlines, hair that is angled in the wrong direction, particularly in the frontal hairline, should be removed.
Attempting to Cover an Area That Is Too Large -
Attempting to cover an area greater than the donor supply can adequately fill may leave cosmetically important areas thin or un-transplanted. In general, the first region to bald is the area where you should be most hesitant to transplant. Recession at the temples and thinning in the crown are usually the earliest manifestations of baldness, but they are acceptable, especially as patients age, so these areas may be left un-transplanted. The central forelock region, however, is generally late to bald, but when balding occurs, the patient loses the frame to his face and its restoration becomes essential.
Whether or not these areas need coverage at the time of the initial transplant, an adequate amount of hair must always be reserved for critical areas, such as the forelock and top of the scalp. If donor reserves are limited, the transplantation of less critical areas should be postponed or avoided all together.
SUMMARY -
Developed within the past decade, Follicular Unit Transplantation has emerged as both the standard and the cutting edge in hair transplant surgery. In conserving donor hair, achieving optimal coverage and creating a natural look, follicular unit transplant represents a considerable advance over earlier methods of hair restoration. Appropriately, it also demands considerably more from its practitioners. Surgical hair restoration teams must develop the skill and stamina for the delicate handling of large numbers of follicular unit grafts, while surgeons must cultivate a keen aesthetic sensibility with regard to transplant design and graft placement.
In view of the psychological aspects of hair loss, Follicular Unit Transplantation requires a thorough preoperative assessment to understand the patient\'s expectations, a careful examination to determine if surgery is appropriate and, most importantly, the establishment of realistic goals. If the surgical route is chosen, meticulous attention to detail is required in every aspect of the procedure so that these goals may be realized. It is a daunting task for the hair restoration doctor and surgical team to develop the necessary expertise for perfecting Follicular Unit Transplantation; but when they do, their work can benefit patients for their lifetime.
REFERENCES -
{for a complete list of references, please visit http://www.bernsteinmedical.com/resources/FUHT2005-5.php}
About the Author
Dr. Bernstein is Clinical Professor of Dermatology and is recognized worldwide for pioneering Follicular Unit Hair Transplantation. Dr. Bernstein\'s hair restoration center in Manhattan performs Follicular Unit Transplants and other hair restoration procedures. To read more publications on hair loss, visit http://www.bernsteinmedical.com/.