Objective

The purpose of this study is to describe a simple instrument that can be used in the blunt dissection phase (second step) of the three-step Follicular Unit Extraction technique and to measure its effectiveness in a controlled study.

Materials and Methods

In patients undergoing hair transplantation, the hair in a 2x4 cm patch in the mid-portion of the donor area was clipped to approximately 1-mm in length and anesthetized. Ten follicular units were extracted from one half of the patch using two-step FUE and ten follicular units were extracted from the other half of the patch using the three-step technique. The two step technique was performed using a 1-mm Miltex punch and fine rat-tooth forceps. In the three step technique, a 1-mm Miltex punch was used to score the skin, a thin cylindrical stainless steel tube was used for the blunt dissection and then fine rat-tooth forceps were used for the extraction. The sides were alternated on different patients. After extraction, each graft was examined under a stereo-microscope and the following information was recorded: 1) hair characteristics; color, wave, and thickness, 2) anticipated yield - the number of hairs visible with the stereo-microscope on the surface of the extracted graft, 3) actual yield - the number of intact follicles in the follicular unit visible under the stereo-microscope. Intact hair yields and graft yields were calculated for the two techniques and compared.

Discussion and Results

In the two-step follicular unit extraction technique, proposed by Rassman and Bernstein, there was an attempt to "separate follicular units from the surrounding tissue down to the level of the mid dermis." The rational was that because of the anatomic divergence of individual follicles as the follicular unit entered the fat, a punch that neatly encompassed a follicular unit on the surface would amputate the splayed bulbs as it cut through the deeper tissues and result in unacceptable rates of transection.

To circumvent the problem of "follicular unit splay," they considered Inaba’s technique of removing hair from the donor area with a punch that was used to cut only part of the way down the follicle. The depth of the traditional punch (used in older hair transplant techniques) was difficult to control, however, and transection resulted in many cases. The FOX test was able to screen out the patients who were most likely to be subject to excessive transection and thus improve patient selection, but it did not improve the quality of the grafts.

The three-step FUE technique of Harris overcomes the limitation of the original technique, as the blunt tipped instrument is advanced into the dermis, splayed follicles are gathered together avoiding transection. In effect, Harris’ dull-punch technique allows a full realization of the "extraction concept." One untoward result of the three-step technique is a possible higher incidence of buried grafts. It also adds an additional step to an already tedious hair restoration process.

There are many possible permutations of blunt instrument design. Possibly the most straightforward is to use a cylindrical instrument whose walls are thin enough to dissect though dermal connective tissue with a simple rotating movement, yet thick enough so that the advancing edge avoids follicular transection. The instrument design used in the current study will be presented. The current study confirms the advantage of the three-step procedure over the standard method of follicular unit extraction.

Conclusion

The three-step FUE technique proposed by Harris offers significant improvement over the two-step technique. The main advantage of the three-step technique for hair transplantation is that it minimizes follicular transection. The main disadvantages are the logistics of the extra-step and the increased incidence of buried grafts. A new type of blunt instrumentation is described in this study. The ideal tool design that will minimize both transection and the possibility of buried grafts still needs to be determined.