Robert M. Bernstein, M.D. New York, NY
Dermatologic Surgery 2:97-98 (1996).
To the Editor:
Regarding the ability to perform hair transplants using grafts in extensive quantities, many “unanswered questions” already have answers. The first issue that “the emphasis in hair restoration has somehow shifted from the eventual outcome or product to the speed and magnitude of the process” is not correct. The outcome is, and always should be, the emphasis in any hair replacement process. The speed and the magnitude of the process, however, directly affect this outcome.
There are a number of reasons; a critical element affecting the final result of the hair transplant is the motivation of the patient to reach a point where the hair restoration is cosmetically useful. Multiple partial procedures produce short term cosmetic problems, unnecessarily extend the duration of the surgical process, interfere with the patient’s daily life, and often leave the patient frustrated and unsatisfied. These patients can be so frustrated that they give up on the process entirely. The ability to perform the restoration in one or two procedures encourages a much greater proportion of patients to complete the process.
Large hair transplant sessions solve other problems intrinsic to multiple small procedures. The first concerns the donor reservoir. Each time grafts are harvested from the donor area there is loss of potential donor hair due to destruction of hair adjacent to the wound edges as a result of the fibrosis associated with primary intention closures. In addition, the hair follicles adjacent to the healed suture line are often distorted and more difficult to harvest on subsequent hair transplant procedures. Minimizing the number of times the donor area is accessed, will minimize the resulting loss and distortion due to the closure.
In the recipient area, the problem with fibrosis also favors fewer hair transplant procedures. In a “virgin scalp,” the blood supply travels unimpeded to the entire recipient area. However, when multiple sessions of large grafts are used, each graft placed in the recipient site induces local scarring that interferes with subsequent blood flow and has the potential to transect or seal off viable blood vessels, even if this effect is subtle. In subsequent procedures, the hair placed between existing grafts is implanted into this scarred tissue and potentially receives diminished blood flow.
In hair restoration using dense packing, the donor site is created with an instrument thinner, and one that produces less trauma, than a traditional punch instrument. A blood vessel that might be pierced would immediately reseal analogous to the way a vessel heals after venipuncture. When the slender graft is then placed into the site, the graft would cause no additional trauma to the vessel. If it were true that “the diminished blood supply fails to support uniform graft take and consequently hair growth” then asymmetry, gaps or areas of variable density, would result from the dense packing technique and this is not observed, in spite of the fact that the dense packing is used predominantly in the frontal hairline, where any problem would be most obvious.
The second issue, that “megasessions cannot duplicate the density of the traditional approach” is really not an issue at all. The density of the traditional approach to hair restoration is NOT one that we should aspire to. The problem with larger grafts in the hair transplant (and I include mini-grafts in this category) is that they don’t parallel the way hair grows in nature. Due to graft contraction they have a higher than normal density with greater than normal spacing in between. In nature, hairs in the frontal hairline (approx. the first 1/2 cm.) grow as single units and behind this region, the natural hair groupings contain two or three hairs. Large grafts contain too many hairs and produce an uneven density that doesn’t mimic nature. This is the cause of the most common complaint that patients have about their hair restoration procedure i.e. that it looks like a hair transplant and doesn’t look natural.
The third issue, that “very small grafts, although natural, cannot be placed close enough together without injury to simulate the density of the larger grafts” has already been answered. The goal in a hair transplant should not be to simulate the density of the grafts, but that of nature. The obsession with density misses the direction we should be headed. The goal of all hair restoration surgery is to produce a fullness that will look natural as the individual ages. An attempt to match or exceed ones original density, even if only at the frontal hairline, will not only be cosmetically unacceptable in the long term, but will tax the donor bank and limit the ability for future hair transplant procedures to be able to cover additional areas as the balding progresses. In judicious planning, the grafts in the frontal hairline should contain only single hairs and be placed close enough to block the eye from looking into the scalp, but not so dense as to be unbalanced as the patient continues to bald.
Finally, the statement “large sessions force distribution of the transplanted hair over the entire extent of the balding scalp” is incorrect. The transplant surgeon using extensive grafting of small follicular units has the total freedom to place these grafts in any distribution that he chooses and, if the hair restoration is planned appropriately, would be most dense in the “crucial frontal zone” that you describe. I agree that the vertex should always be left open in a young extensively balding individual with an average or below average donor density. When the patient has had permanently transplanted hair covering the front and top of his scalp, and the fullness is to his satisfaction, and he still has some reserve of donor hair to address further diminution of the donor fringe, then the crown can be addressed. And this would best be accomplished by extending the hair transplant further back, rather than treating the crown as an isolated area.
Continued experience with the megasession will show that it increases the power and flexibility of the hair transplant procedure rather than limiting it. Future work should be directed at exploring the various ways this safe, but technically demanding, procedure can be of benefit to the balding patient.