By Cheryl Guttman
Contributing Editor
Cosmetic Surgery Times (May 1999)
New York — Follicular unit hair transplantation offers many advantages, but hair transplant surgeons continue to debate whether it is worth the effort.
A recent paper that clearly differentiates this hair transplant technique from the older technique of mini-micrografting cut to size is a step toward resolution of this controversy, while a new implanting device minimizes some of the time intensiveness of the hair transplant procedure may further popularize follicular unit transplantation, said Robert M. Bernstein, M.D.
The paper, entitled “Standardizing the Classification and Description of Follicular Unit Transplantation and Mini-micro-grafting Techniques,” was co-authored by Dr. Bernstein and 21 other hair transplant physicians.
“We felt it was necessary to clearly define follicular unit hair transplantation and mini-micrografting cut to size,” explained Dr. Bernstein, assistant clinical professor of dermatology, College of Physicians and Surgeons, Columbia University, New York. “Follicular unit transplantation has many theoretical advantages although there have been no well-controlled studies to confirm its benefits. Having standardized definitions of these hair transplantation techniques will allow us to make valid comparisons of them.”
Dr. Bernstein said the elements defining follicular unit hair transplantation include exclusive transplantation of hair in its naturally occurring individual follicular units, use of single strip harvesting, and division of the donor strip into naturally occurring follicular units with the aid of a dissecting stereomicroscope, a hair transplant technique originally introduced by Bobby Limmer, M.D.
In contrast, a multi-blade knife can be used for donor strip harvesting in mini-micrografting, while subdivision of the strip is achieved using transillumination with magnification.
Grafts Defined by Size
Grafts of specific sizes are created, but they are defined by the number of hairs or amount of tissue they contain and not by follicular unit.
Dr. Bernstein said that all of the differences between the two approaches in terms of harvesting and graft preparation translate into advantages for follicular unit hair transplantation. He explained that donor strip harvesting with a multi-blade knife results in transection of follicles and also breaks up the follicular units that are found randomly in the scalp. A significant number of the fragments produced with this hair transplant technique may not grow, and those that do tend to be finer in quality than intact hairs.
“This is important because hair shaft diameter is as great a contributor to the cosmetic impact of surgery as the actual numbers of hairs,” noted Dr. Bernstein. The differences in technique for dividing the donor strip into individual grafts also favor outcomes with follicular unit hair transplantation.
Follicular unit transplantation preserves the integrity of individual follicular units while dissecting excess skin.
Since larger grafts created for mini and micrografting may contain hairs from adjacent follicular units along with the intervening tissue, they will have a higher ratio of tissue to hair than a follicular unit transplantation graft containing an equal number of hairs. Consequently, mini-micrografting often requires a larger wound for graft placement and can result in surface change along with less hair density.
The potential for growth of both larger and smaller grafts may also be reduced in mini-micrografting since the splitting of follicular units produces trauma that may affect graft viability.
While graft preparation for follicular unit hair transplantation remains time intensive, implantation is being facilitated by a new device, the Rapid Fire Hair Implanter Carousel, designed by William R. Rassman, M.D., Los Angeles. This disposable instrument automates the hair restoration processes of site creation and implant placement and reduces grafting time.
The implanter has a rotating, reloading circular cartridge containing 100 slots for graft insertion. After the cartridge is filled, the grafts are covered with normal saline, and the device is refrigerated. At the time of the hair transplantation surgery, the cartridge is loaded onto the implanting device, which has a sharp point at one end to pierce the scalp and an activation button at the opposite end, explained Dr. Bernstein.
When the hair transplant surgeon presses the activator, the device creates a tiny slit in the scalp and places the graft at the full depth of the recipient hole. The cartridge automatically advances to the next position and is ready for use at the next site.
Dr. Bernstein said this method increases the speed of the hair transplantation process, avoids damage to the grafts that can occur with manual manipulation, and reduces bleeding. Dr. Bernstein has a financial interest in the Rapid Fire Hair Implanter Carousel.
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