The success of hair transplantation depends on the fact that transplanted hair follicles (roots moved from their original location on the body to another area) will behave as they did in their original site. In common male baldness, for example, a horseshoe-shaped fringe of hair persists even in the most advanced cases. 
Hair follicles moved from this hairy fringe to a bald area on the same patient’s scalp will take root and grow. Continuing hair growth in such transplants has been observed since 1958 and it is believed that these grafts will continue to grow over a lifetime. Many less common types of hair loss in addition to ordinary male baldness can be helped by this procedure.
How do hair transplants work?
At the beginning of each session, the patient is given a mild tranquilizer (Valium) either orally or intravenously, which minimizes anxiety, reduces discomfort, and helps to prevent or decrease any side effects that might be caused by large doses of anesthetic.
The hair in the donor area (the area from which the hair follicles will be taken) is clipped to a 2mm length in lines separated by rows of hair which are not cut. The rows of hair which are left intact, together with the hair above the donor area, are then used to completely camouflage the donor sites. This is usually possible even immediately after the operation, providing the hair in this area had not been cut too short before the procedure.
The donor area and the receptor area (the bald area into which the hair will be grafted) are then anesthetized by injecting a local anesthetic with a very small gauge needle in much the same way as a dentist “freezes” teeth before working on them. Anesthetizing the areas takes approximately two minutes at the beginning of the procedure and is the only painful part of the session.
After the anesthetic wears off, about four to six hours later, a vague discomfort is all that is usually felt. Most patients do not use pain killers, but those who do virtually never require anything stronger than Tylenol. In those few patients who need more than this, a stronger pain killer is given–there is no need for any postoperative pain.
After anesthetizing the donor area, a circular punch approximately 4mm to 5 mm in diameter is used to cut hair-bearing plugs in much the same way as cookies are punched out of dough. The small pieces of scalp, or “plugs” each bearing a variable number of hair follicles, are then removed from the scalp, cleaned, and trimmed to the proper length. If single hair grafts are required, individual hairs are then removed from the sides of the plugs. These hairs will be transplanted just in front of the plugs which form the hairline. By transplanting individual hairs at each session, the hairline will eventually have a more natural appearance.
Another slightly smaller punch is then used to cut plugs from the bald scalp of the receptor area into which the grafts will be placed. The sites are placed approximately 3.25 mm to 3.5 mm apart in a “checkerboard” fashion leaving each plug a surrounding source of blood supply.
The prepared hair-bearing plugs are inserted into the punch-out sites on the bald scalp where they are held in place by congealed blood.
The donor and receptor areas are then bandaged appropriately and the patient leaves. The bandage looks much like a sultan’s turban and is left in place overnight. It is removed the next day. The operative area is then cleaned and the surrounding hair is combed over it to provide as much camouflage as is possible. Some physicians glue the plugs in place in order to avoid a bandage. We do not use this technique as the glue also causes crusting to adhere for 2 to 3 weeks longer than if a bandage was employed and therefore makes the surgery more difficult to camouflage. (If any hair is present in the recipient area the glue also tends to mat it together.
III. Number of Session or Transplant Procedures Needed:
Generally, any area to be transplanted can be done totally in five sessions, although a sixth smaller session may be done in which approximately 20-50 plugs of various sizes are used to refine the hairline or thicken any given area.
It is strongly recommended that if one wants to transplant both front and crown areas that an attempt be made to decrease the size of the bald area by one or more “alopecia reduction” operations (or excisions). If this is done there is a better chance of being able to transplant all of the now smaller area before one runs out of available donor plugs. Essentially, a portion of bald or balding scalp is removed and the normal looseness or give of the scalp is used to close the gap left. A narrow long scar is usually all that remains after the procedure.
Within a few weeks, the scalp will become loose again and often additional ARs can be done to further reduce the bald area. While it may sound rather frightening or painful, it is in fact a relatively simple procedure and, in most patients, is no more uncomfortable than a transplant session. Also, some patients have enough donor plugs that they can transplant their whole bald area without the necessity of an alopecia reduction.
Transplant sessions may be spaced as far apart as the patient wishes; however, the intervals in any given area should not be less than six weeks apart for the first two sessions and three to four months apart between the second and third, and third and fourth sessions. If entirely separate areas are being transplanted at the same time, for example the front and the crown, sessions can be much closer together–for example, the crown can be done two days after the front. The sequence can sometimes be speeded up by applying a minoxidil solution to the recipient area twice daily postoperatively. This drug is a vasodilator that increases blood supply and accelerates healing and hair regrowth in most (but not all) patients.
Transplanting sessions into areas that still have a fair amount of hair left in them are done at least 4-6 months apart. The initial effect of transplanting into hair-bearing areas is to thin the area out slightly for approximately 3 months until the hair regrows in the transplanted plugs, and we therefore prefer to wait until preceding sessions have grown an inch or more hair and have thickened the areas before a second session is done. Despite the above-noted temporary thinning, most patients who begin early enough in their hair loss can completely camouflage the surgery postoperatively.
The number of transplant plugs which should be placed at one session and the frequency of transplant sessions depend on the characteristics of each individual case; they can be planned out in advance for each patient.
What to expect after the hair transplant procedure
A crust or scab will form over each graft shortly after the procedure and remain attached to the graft for 7-14 days. When the area is healed, the crusts will then separate from the scalp and fall off, leaving a clean, pinkish circle to indicate the site of the transplant. These crusts, although plainly visible during the one to three week healing period can, by many patients, be easily covered by combing the hair, which is present in an adjacent area, over the transplanted site. If a hairpiece is normally worn, it may be used after the first week to conceal the crusts and should be worn as little as possible for an additional week.
The hair stubs in the transplants do not grow, but are shed between the second and eighth week after the procedure. Sometimes many of these hair stubs fall out attached to the separated crusts; sometimes they persist longer. Rarely, one or two of the transplanted follicles may not shed its hair stub at all, but continue growing immediately after the procedure. With these exceptions, the follicles rest for a period of 10-20 weeks after the operation, during which time the stubs are shed and the grafts are bare. A new generation of hair is seen at the surface, usually during the twelfth week after transplanting, but this may occur slightly earlier or up to eight weeks later in individual patients. These hairs grow at the same rate as they did in their original location.
When a large area is transplanted, swelling of the forehead is a frequent occurrence. While it is usually mild and lasts 2 to 4 days, it occasionally can be severe enough to cause a large amount of puffiness around the eyes and even blackened eyes (in approximately 1 out of 50 patients). The swelling usually begins approximately two to three days after the procedure. Generally this swelling is most noticeable after the first session and usually occurs in a mild form or not at all with subsequent treatments. In view of this, it is advisable, if possible, to schedule a holiday to coincide with the first session. Please be assured that the swelling, though it may appear suddenly, is always temporary and has no harmful effect on the healing transplants.
Contrary to what many patients have been told, the scalp, hairy or bald, has an excellent blood supply. A certain amount of bleeding during the transplant procedure is expected and is controlled by simple pressure. Sutures are used in the donor area. These are removed seven to ten days later. The scalp may be gently shampooed on the third day after transplanting.
Patients from out of town are required to stay over night, after the transplant procedure, so the bandage can be removed and the area properly cleaned the day following surgery.
What are the final results?
It is impossible to predict in advance precisely how many hairs will appear in any given transplant. The average number is between 8 and 15 hairs per graft, but some patients have had as many as 30. Rarely do you encounter a patient who showed no growth whatsoever.
The skin surface of the grafts usually blends in with the surrounding scalp perfectly after a period of four to six months. In some patients, however, the grafts may be a lighter shade until they are “aged” by sun exposure. The grafts are usually level with the surrounding scalp, but are occasionally slightly elevated. Such grafts are flattened down with an electric needle without interfering with hair growth. This is necessary in only approximately 1 out of every 100 patients.
The final appearance is usually that of “early thinning” which is not meant to imply “thin,” but rather to convey the idea that you cannot expect to look like you did when you were a teenager.
The front hairline is not as perfect as a natural hairline, where the hairs are very fine and sparse, because the transplanted hairs are coarser and the growth of the hair is much denser. This is not seen if the hair falls forward or is swept slightly forward and to one side as most men wear their hair.
Transplanting hairs one at a time in front of the first line of plugs has been a major advance in producing more natural looking hairlines. How good the hairline is depends on a number of factors, but most importantly on how fine and light your hair is. The finer and lighter the color of the hair, the better the hairline turns out.