Guten Tag,
leider muss ich Sie enttäuschen. Eine Vervielfältigung von Haaren funktioniert leider nicht. Zumindest konnte ein derartiger Effekt bisher nicht wissenschatlich nachgewiesen werden.
Eine dazu durchgeführte Studie ergab im Empfängerbereich niedrige Anwuchsraten von 20-41% und die Haare waren auch feiner und qualitativ minderwertiger als gewünscht.
Es heisst also weiter, mit den zur Verfügung stehenden Haaren geschickt und genau geplant einen Effekt zu erreichen.
Ausserdem sollten die Transplantate schonend entnommen, vereinzelt und zügig eingesetzt werden.
Bei diesen Arbeitsschritten ergibt sich in der Regel für die Streifenentnahme und Stereomikroskopie mit follicular unit transplantation eine höhere Ausbeute und ein Überlebensvorteil für die Transplantate.
Mittels trichophytic closure kann die Hinterkopfnarbe minimiert werden, ggf. können zudem später Einzelhaare hineintransplanitert werden.
Wobei die Einzelhaarentnahme FUE (ggf. ergänzend) bei einigen geeigneten Patienten durchaus ihre sinnvolle Berechtigung haben kann.
Mit freundlichen Grüßen,
Dr. Finner
Literatur:
Hair Transplant Forum, November/December 2005 Volume 15, Number 6
Follicular Unit Multiplication:
Is It Possible to Harvest an Unlimited Donor Supply?
Ergin Er, MD, Melike Kulahci, MD, Emirali Hamiloglu, MD
Discussion:
The hair follicle is a complex structure. It contains stem cells that govern the rate of cell loss and the regeneration of the hair during its life cycle.4 These stem cells are not only located at the bulb but also at the outer sheath close to the erector pili muscle in the "bulge" area located near the mid portion of the follicle.5,6 Therefore, theoretically, each half of the follicle should contain a stem cell reservoir allowing for new shaft production and hair growth, and therefore follicle duplication. Recently, Rochat and Kobayashi confirmed the bulge hypothesis by isolating keratinocyte colony-forming cells from human hair follicles.7 They transected hair follicles at the level immediately below the bulge area. The lower half of the follicle had the same growth rate as the intact follicle but the upper half exhibited a reduced shaft production capacity, suggesting that it still contained some follicular stem cells. This study showed that the upper half of the follicle could regenerate independent from the bulb. In our study we observed similar results with a growth rate of 29.3% in the upper half of the follicles after 1 year. But the regrowth rate was 68% at the donor site during this period, which is low when compared to transplanting an intact follicle. This result emphasizes the importance of the outer sheath cells for regeneration of the hair follicle.
Oliver et al. showed that rat vibrissae could still regenerate after removing the lowest one-third of the follicle.8 Similarly, Inaba et al., Kim, and Choi proved that grafted hair follicles could regenerate after removal from the bulb.2,9 In our study, we observed 20% of the upper one-third and 41.3% of the upper two-thirds of a hair follicle could regenerate as a new follicle after transplantation. These results demonstrate that as the transection level goes lower and the number of outer root sheath cells included in the graft increases, the survival rate will also increase. This data also supports the bulge hypothesis, which indicates that stem cell migration begins in the upper outer root sheath and moves downward through the bulb area. Therefore, it is logical to include both stem cell locations and as much outer sheath as possible to increase the graft yield after the transplantation.
The most important problem in FUE procedures is the unacceptable levels of transection in some patients. Our study showed that these transected follicles can still grow at the recipient site. However, the degree of recipient growth depends on the level of transection. In addition, even if the upper two-thirds of the follicle is transplanted, emerging follicles at the recipient site are thinner than the original ones and therefore cannot cover the recipient site sufficiently. Although bulge area stem cells can regenerate a new follicle, without the bulb the new follicle will not have the original caliber. Placing these transected
Grafts may therefore not be in the patient's best interest. If transected grafts must be placed, selecting those grafts containing at least the upper half of the follicle and placing at a high density should be considered by the surgeon.
Extracting intact grafts from the same donor site after regrowth also proved very difficult, as the weakened skin at these sites caused the punch to suddenly penetrate into the skin.
In summary, our study did not support the concept of unlimited or repetitive donor harvesting using FUE. Follicular unit extraction is a minimally invasive surgical procedure that has some advantages to classical strip harvesting, but the high rate of transection remains an important drawback. To our knowledge, our clinical study is the first study that compares bisected hair follicle growth and donor regrowth for individual follicles obtained by FUE. The survival and growth rate of transversely sectioned human hair follicles directly depends on the level of transection. However, we don't recommend routine transplantation of the sectioned parts due to low growth rates and diminished hair shaft caliber.
