Robert M. Bernstein, M.D.
J Am Acad Dermatol. 2013 Dec;69(6): 20-22.
The dermatology residency is unique in that it trains its physicians in the biology of hair follicles, encourages research in both the basic science and clinical aspects of hair, and teaches its residents to perform hair transplantations. Hair transplantation was pioneered by the dermatologist Norman Orentreich. Dermatologists continue to make major contributions to this very specialized branch of medicine.
Dermatologist Bobby Limmer ((Limmer BL. Elliptical donor stereoscopically assisted micrografting as an approach to further refinement in hair transplantation. Dermatol Surg 1994;20:789-93.)) had the novel idea of using a microscope to aid in the dissection of grafts to avoid follicular transection. His method was described in his 1994 article, “Elliptical donor stereoscopically assisted micrografting as an approach to further refinement in hair transplantation.”
The following year, dermatologists Bernstein et al ((Bernstein RM, Rassman WR, Szaniawski W, Halperin A. Follicular transplantation. Int J Aesthetic Rest Surg 1995;3:119-32.)) laid down the conceptual framework for follicular unit transplantation in their 1995 article, “Follicular transplantation.” In 1997, they detailed its clinical application in the paired articles, “Follicular transplantation: patient evaluation and surgical planning” ((Bernstein RM, Rassman WR. Follicular transplantation: patient evaluation and surgical planning. Dermatol Surg 1997;23:771-84.)) and ‘‘The aesthetics of follicular transplantation.” ((Bernstein RM, Rassman WR. The aesthetics of follicular transplantation. Dermatol Surg 1997;23:785-99.))
The 2 advances, the application of the stereomicroscope to follicular dissection and the use of follicular units as the basic element of hair transplantation, arose from a background in dermatology. They moved the field of hair restoration surgery from plugs and mini-micrografting, where this basic anatomical feature of the hair follicle was ignored, to follicular unit transplantation, where the follicular unit became sacrosanct. These 2 ideas, when put to clinical use, allowed the once elusive goal of a completely natural-looking hair transplant to finally be achieved.
Stereomicroscopic dissection is a powerful tool for avoiding follicular unit damage when isolating the units from a donor strip; however, it is unable to prevent transection when the strip is first removed from the scalp. For more than 25 years the donor strip had been excised from the surrounding tissue using a scalpel. It took dermatologist Robert Haber ((Haber RS. Tissue spreader: analysis of transection reduction (abstract). Presented at: International Society of Hair Restoration Surgery Annual Meeting; September 26-30, 2007; Las Vegas, NV.)) to design a spreading device that could remove the strip using blunt manipulation. This innovation helps surgeons reduce follicular transection in the important first step of a follicular unit transplantation procedure.
A number of hair-implanting devices have been devised over the years, but none have been as popular as the Choi hair transplanter. This ingenious hand-held device, created by the dermatologist Yung Choi and his colleague Jung Kim ((Choi YC, Kim JC. Single-hair and bundled-hair transplantation using the Choi hair transplanter. In: Stough DB, Haber RS, editors. Hair replacement: surgical and medical. St Louis (MO): Mosby-Year Book Inc; 1996. pp. 125-7.)) in 1992, simultaneously creates a recipient site and inserts a hair-bearing graft that had been loaded into its chamber. It was equally as useful for the micrografts of 20 years ago as it is for the follicular unit hair transplantations performed today.
Limmer ((Limmer BL. Micrograft survival. In: Stough DB, Haber RS, editors. Hair replacement: surgical and medical. St Louis (MO): Mosby-Year Book Inc; 1996. pp. 147-9.)) suspected that the time grafts were held outside the body was an important variable in graft survival. In a landmark study, he showed a high, but diminishing, survival for micrografts held in chilled saline for the first 8 hours. Dermatologist Jerry Cooley ((Cooley JE. Ischemia-reperfusion injury and graft storage solutions. Hair Transplant Forum Int 2004;14: 121, 127, 130.)) took it a step further, exploring whether the characteristics of the holding solution itself can be modified to enhance the survival of follicular unit grafts. With his work on both ischemia-reperfusion injury and storage injury, Cooley ((Cooley JE. Ischemia-reperfusion injury and graft storage solutions. Hair Transplant Forum Int 2004;14: 121, 127, 130.)) has shown that the use of antioxidants to lower free radical activity can significantly increase graft survival time. This is an important modification of the hair transplantation procedure because, over the years, the number of grafts transplanted per session and the length of time grafts are held outside the body continue to grow.
Dermatologist Dow Stough, ((Stough D. Single hair grafting for advanced male pattern alopecia. Cosmet Dermatol 1993;6:11-5.)) appreciating the inexorable progression of androgenetic alopecia, was one of the first physicians to stress a conservative, long-term approach to hair transplantation. This included: creating an irregular pattern of single-hair grafts at the frontal hairline; using a mature, adult pattern for its position; and focusing on restoring hair to the frontal scalp. Most importantly, he encouraged doctors to delay hair transplantation in younger patients until their hair-loss patterns could be better assessed and their expectations set appropriately.
Stough, with dermatologist O’tar Norwood, founded the International Society for Hair Restoration Surgery, an organization with over 800 physician members that has become the foremost international association of hair restoration surgeons. Norwood also launched the bimonthly journal Hair Transplant Forum International that now serves as the educational hub through which hair restoration surgeons around the globe communicate new ideas and present preliminary scientific data in an informal, but timely, way. Stough, with fellow dermatologist Haber, ((Stough DB, Haber RS. Hair replacement: surgical and medical. St Louis: Mosby-Year Book Inc; 1996.)), ((Stough DB, Haber RS. Hair transplantation. Philadelphia (PA): Elsevier Inc; 2006.)) has published 2 concise, but excellent, texts on hair replacement.
Dermatologist Walter Unger et al ((Unger WP, Shapiro R, Unger R, Unger M. Hair transplantation. 5th ed. London (United Kingdom): Informa HealthCare;2011.)) edited Hair Transplantation, the first comprehensive multiphysician reference textbook dedicated to hair transplantation surgery. Now in its fifth iteration, this encyclopedic series of textbooks has become the standard reference text in the field. Unger et al ((Unger WP, Shapiro R, Unger R, Unger M. Hair transplantation. 5th ed. London (United Kingdom): Informa HealthCare;2011.)) has served as an important cautionary influence on the impetuosity of many newer members of our profession. He astutely warned that ideas, which initially seem to hold promise, warrant further scientific investigation before being adopted.
The office clinician is unable to precisely measure the natural progression of hair loss and its response to treatment. Densitometry can assess the percent of hair affected by miniaturization, but is unable to quantify the wide range of hair diameters seen in androgenetic alopecia. Dermatologist Bernard Cohen ((Cohen BH. The cross-section trichometer: a new device for measuring hair quantity, hair loss and hair growth. Dermatol Surg 2008;34:900-11.)) cleverly solved this problem with an instrument called the cross-section trichometer. This instrument measures hair mass: the cross-sectional area of a bundle of hair present in a premeasured area of scalp. It detects small changes in both hair density and diameter, and is an objective way to measure the effectiveness of various therapies provided by the hair restoration physician.
A method of removing follicular unit grafts directly from the scalp, without the need for a linear incision, had been worked out by an Australian physician in the 1990s. He was, however, secretive with his techniques, and few other doctors attempted to duplicate this new procedure. With the publication of the article, “Follicular unit extraction,” by Rassman et al ((Rassman WR, Bernstein RM, McClellan R, Jones R, Worton E, Uyttendaele H. Follicular unit extraction: minimally invasive surgery for hair transplantation. Dermatol Surg 2002;28:
720-7.)) in 2002, the follicular unit extraction procedure gained popular appeal and was rapidly adopted by doctors worldwide. The authors cautioned on the limitations of this harvesting technique and the risk of follicular damage. Dermatologists Berman, Zering, and Bernstein–along with their colleagues in other specialties–continue to work on the problem of harvesting in follicular unit extraction, with the application of robotic technology showing particular promise. ((Canales MG, Berman DA. The age of surgical robots. Hair Transplant Forum Int 2008;18:95-6.))
Although donor dominance has been the guiding principle for hair transplantation surgeons over the past half century, this did not deter dermatologist Hwang et al ((Hwang S, Kim JC, Ryu HS, Cha YC, Lee SJ, Na YG, et al. Does the recipient site influence the hair growth characteristics in hair transplantation? Dermatol Surg 2002;28:795-8.)) from challenging the very concept. Hwang et al ((Hwang S, Kim JC, Ryu HS, Cha YC, Lee SJ, Na YG, et al. Does the recipient site influence the hair growth characteristics in hair transplantation? Dermatol Surg 2002;28:795-8.)) showed that when hair was transplanted from one part of the body to another, the recipient site can influence such factors as hair growth and survival, hair shaft diameter, and length. His work has profound implications for transplanting hair into a balding scalp from other parts of the body–such as the trunk, legs, and beard–potentially expanding a person’s supply of donor hair.
Going forward, the field of hair transplantation will be shaped by advances in biotechnology that will, in time, enable the cloning of human hair and possibly make a person’s donor supply unlimited. Although it is not clear who will be the first to achieve this elusive goal, important research is currently underway by a number of dermatologist investigators. ((Zheng Y, Hsieh J, Washenik K. The promise of cell therapy. In: Unger W, et al, editor. Hair transplantation. 5th ed (1F: 23e28). New York: Marcel Dekker Inc; 2011.)), ((Morris RJ, Liu Y, Marles L, Yang Z, Trempus C, Li S. Capturing and profiling hair follicle stem cells. Nat Biotechnol 2004;22: 411-7.)), ((McElwee KJ, Kissling S, Wenzel E, Huth A, Hoffmann R. Cultured peribulbar dermal sheath cells can induce hair follicle development and contribute to the dermal sheath and dermal papilla. J Invest Dermatol 2003;121: 1267-75.)), ((Zimber MP, Ziering C, Ziegler F, Hubka M, Mansbridge JN, Baumgartner M, et al. Hair regrowth following a Wnt- and follistatin containing treatment: safety and efficacy in a first-in-man phase 1 clinical trial. J Drugs Dermatol 2011;10: 1308-12.))
This article has surveyed some of the important contributions dermatologists have made to the field of hair restoration surgery over the past 2 decades. Because of space constraints, the contributions of a number of other notable dermatologists have not been mentioned including James Arnold, Marc Avrum, Pierre Bouhanna, Francisco Jimenez, Matt Leavitt, William Parsley, Paul Rose, and Arthur Tykocinski. That this writing is a snippet of contributions, rather than a continuous story, underscores the fact that many of the great strides in hair transplantation are attributable to the hard work of so many physicians who have not been acknowledged in this very brief text.