Hair transplantation
Hair transplantation involves the surgical removal of a hair-bearing portion of the
scalp and its relocation to an area of absent or thinning hair. In recent years, newer techniques have enabled increasingly smaller "donor" portions to be
transplanted, leading to more cosmetically acceptable results and an increasing number of candidates selecting this solution for
hair loss.
The use of both scalp flaps, in which a band of tissue with its original blood supply is
shifted to the bald area, and free grafts dates back to the 19th century. Modern transplant techniques began in Japan in the
1930s, where surgeons used small grafts, and even "
follicular unit grafts" to replace damaged areas of eyebrows or lashes. They did not attempt to treat baldness per se. Their efforts did not receive worldwide attention at the time, and the traumas of World War II kept their advances isolated for another two decades.
The modern era of hair transplantation in the western world was ushered in in the late
1950s, when New York
dermatologist Orentreich began to experiment with free donor grafts to balding areas in patients with
male pattern baldness. Previously it had been thought that transplanted hair would thrive no more than the original hair at the "recipient" site. Orentreich demonstrated that such grafts were "donor dominant", as the new hairs grew and lasted just as they would have at their original home.
For the next twenty years, surgeons worked on transplanting smaller grafts, but results were only minimally successful, with 2-4 mm "plugs" leading to a doll's head like appearance. Brazilian surgeons led the advances toward "micrografting", "minigrafting" and what is now called "
Follicular Unit Transplantation." [1] With microscopic dissection of donor pieces from a resected portion of scalp, individual follicular units containing but 1-3 hairs could be prepared, and individually relocated into needle punctures in the recipient areas. With current techniques, upwards of 50 grafts per square centimeter should be the standard.
Pre-operative preparation
At an initial consultation, the surgeon analyzes the patient's scalp, discusses his preferences and expectations, and advises him/her on the best approach (e.g.,single vs. multiple sessions) and what results might reasonably be expected.
For several days prior to surgery the patient refrains from using any medicines, or alcohol, which might result in intraoperative bleeding and resultant poor "take" of the grafts. Pre-operative
antibiotics are commonly prescribed to prevent wound or graft
infections.
Surgery
Transplant operations are performed on an outpatient basis, with mild
sedation (optional) and injected topical
anesthesia, and typically last about four hours. The scalp is shampooed and then treated with an antibacterial chemical prior to the donor scalp being harvested.
The surgeon harvests a strip of skin from the posterior scalp, in an area of good hair growth. The excised strip is about 1-1.5 x 15-30 cm in size. While he is closing the resulting wound, assistants begin to dissect individual follicular unit grafts from the strip. Working with binocular
microscopes, they take great care to remove excess fibrous and fatty tissue without damaging the vital follicular cells that will produce the patients' first crop of new hair.
The surgeon then uses a fine needle to puncture the sites for receiving the grafts, placing them in a predetermined density and pattern, and angling the wounds in a consistent fashion to promote a realistic hair pattern. The assistants generally do the final part of the procedure, inserting the individual grafts in place.
The finest surgeons can place more than 50 grafts per square centimeter in order to get a good density and appearance. In a "megasession", they may perform more prolonged surgeries, placing more than 2500-3000 grafts, reportedly even 6000 grafts, in one sitting.
Post-operative care
Advances in wound care allow for semi-permeable dressings, which allow seepage of blood and tissue fluid, to be applied and changed at least daily. The vulnerable recipient area must be shielded from the sun, and is not shampooed for about a week.
During the first ten days, virtually all of the transplanted hairs, inevitably traumatized by their relocation, will fall out ("shock loss"). After two to three months new hair will begin to erupt from the moved follicles. The patient's hair will grow normally, and continue to thicken through the next six to nine months. Any subsequent hair loss is likely to be only from untreated areas. Some patients elect to use medications to retard such loss, while others plan a subsequent transplant procedure to deal with this eventuality.
References
Bernstein RM, Rassman WR, Seager D, Shapiro R, et al. Standardizing the classification and description of follicular unit transplantation and mini-micrografting techniques. Dermatol Surg 1998; 24: 957-63.
External links
*
Emedicine article on hair transplantation
