May 102012
 
hair_transplant_diagram

The basic concept of hair transplantation is straightforward and easily understood. The hair growing on the sides and lower part of the back of the head is permanent in most people. It persists even in advanced degrees of male pattern baldness because follicles in these locations are not subject to the deleterious affects of the hormone DHT, a byproduct of testosterone. The characteristics of the individual follicles move with them when they are transplanted. Therefore, permanent hair will remain permanent regardless of where it is transplanted, a phenomena termed “donor dominance.” This is the basis of hair transplantation.

In the process of hair restoration surgery, permanent hair is redistributed to cover the areas of the head where the hair has thinned or has been lost. No new hair is actually created; existing hair is just moved around. Therefore, there is never a “net” increase in total hair volume. In spite of this, a skillfully performed hair transplant procedure can make a person “look” as though he or she has more hair, often considerably more.

The process of hair restoration is an aesthetic exercise as well as a technical feat. Re-distributing hair on a person’s head is like painting a portrait. The physician should attempt to create a natural looking result that is consistent with the hair supply, the specific hair characteristics of the patient, and most important, the patient’s goals.

As with other forms of cosmetic surgery, the art is at least as important as the surgical technique. The hair transplant surgeon must have a thorough understanding of human facial anatomy; good basic surgical skills and a thorough knowledge of different hair transplant techniques. The physician must know the physiology of hair in depth, and understand basic medical conditions that affect the scalp. He must be aware of, and be able to critically evaluate, new developments in the field. Finally, the specialist must study each patient carefully and tailor each procedure to the patient’s unique attributes and needs.

History
Transplantation of portions of hair-bearing skin from either animals or humans has been done with varying degrees of success since the early 1800′s. However, significant modern developments in hair transplantation did not occur until the next century. In 1939, a Japanese dermatologist named Okuda first described the punch technique of hair transplantation. Dr. Okuda, working on severe burn patients, transplanted round grafts of skin containing hair follicles from the permanent hair-bearing areas into slightly smaller round openings in scarred areas of scalp. The grafts continued to produce hair in their new locations. In 1943, another Japanese dermatologist, Dr. Tamura, used 1-3 hair micrografts to restore female pubic hair. These very small micro-grafts were obtained from a single elliptical incision taken from the donor area. Interestingly, his techniques were very similar to those we are using today. The work of both of these physicians were published in Japanese medical journals, but their pioneering procedures remained unknown to the Western World because of World War II.

Hair transplantation was rediscovered by Dr. Norman Orentreich in New York City in 1952, where he performed the first hair transplant for male pattern alopecia. In 1959, Dr. Orentreich published his work in the Annals of the New York Academy of Science (after several years of rejection by a disbelieving medical community). In this publication he put forth his theory of “donor dominance” and this began the “modern” era of hair transplantation. Unfortunately, his work paralleled the “punch” technique of Okuda, rather than the “micrograft” technique of Tamura and so, by the 1960′s, hair restoration surgery in the United States was off and running, but in the wrong direction.

 

What is a Hair Graft?
During hair transplant surgery, small grafts of skin containing hair follicles are removed from the areas of permanent hair in the back and on the sides of the head, and moved to the areas where balding or thinning occurs. The grafts are placed into openings created in the bald area where hair is desired. The openings can be slits (incisions where tissue is not removed), a punch hole, or laser hole (where recipient tissue is actually removed or destroyed). Both the size of the grafts and the size of the wounds where they are placed have become smaller over the past 40 years. This decrease in size has made the transplants dramatically more natural in appearance.
The way the transplanted hair follicle behaves differs from most other “organ” transplants. When kidney, heart or liver transplants are performed, the person receiving the transplant must remain on powerful immune suppressing medications to prevent rejection, as the organs are generally transplanted from one person to another. Since a hair transplant is an “autograft,” (a transplant from one part of the body to another) there is no rejection and no medications are required.

Different Graft Sizes
Hair grafts are divided into four general categories: traditional standard grafts, minigrafts, micrografts, and follicular unit grafts. Traditional standard grafts are 3-4 mm in diameter and have 12-30 hairs per graft. Minigrafts are smaller, 1.2-2.5 mm in diameter, and have 4-12 hairs per graft. Micrografts are even smaller measuring 1.5-1.0 mm or less in diameter, with 1-3 hairs per graft. Follicular units are the naturally growing groups of hair follicles. Each follicular unit graft contains 1-4 hair follicles.

Although minigrafts and micrografts are a significant improvement over the larger grafts, they are not ideal. The idea was reasonable: to keep the number of hairs in each graft low. However, mini-micrografts were moved in unnatural arrangements and the naturally growing groups of hair were ignored. This is because in minigrafting and micrografting, the donor hair is harvested with a multi-bladed knife. This instrument that breaks up naturally occurring follicular units and causes unavoidable damage to follicles. Focusing on the number of hairs, rather than the naturally growing groups, minigrafting and micrografting damage the follicles, causing a significant transplant failure rate. Micrografts tend to produce a thin look when used exclusively over the entire head, and often produce inconsistent graft growth.
Follicular unit grafts are based upon the observation that hair emerges from the scalp in naturally occurring clusters called follicular units. Each follicular unit is comprised of one to four terminal hairs. By using the follicular unit as the base unit of the transplant, the surgeon can create hair patterns that mimic the way hair grows naturally. The art of the follicular unit approach is that the characteristics of the patient’s hair dictate the size of the implant (rather than the doctor). The surgeon determines distribution and balance. By preserving both the natural physiologic and aesthetic elements of human hair, the best cosmetic results can be achieved.

There are many advantages of Follicular Unit Transplantation over micrografting. A fuller look is achieved, as the grafts can be of the same size (or even smaller) than micrografts yet contain more hair. Graft growth is more consistent than when the follicular units are split up. Recipient wounds heal more quickly because sites in the recipient area are smaller, and the results look more natural. Follicular unit transplantation allows the doctor to distribute grafts to mimic the way hair grows naturally in the patient’s own scalp.

Follicular Unit Transplantation enables the surgeon to restore more hair using a smaller amount of donor tissue, as the technique is more efficient than minigrafting and micrografting. The tissue between the follicular groups is dissected away, while the vital support structures around the unit are preserved. Cobblestoning (irregularities in the surface of the scalp) and depigmentation (the appearance of whitish blemishes of the transplanted skin) can be avoided because excess skin in the grafts has been removed, making the grafts significantly smaller. The follicular units produce very small physiologic implants, that can, in turn, be inserted into very small sites. In addition, larger amounts of hair may be safely moved in one session reducing the necessity for multiple procedures. The patient benefits significantly with less time devoted to restoration, fewer procedures and, often, a lower cost per graft.

The large plugs used in the past, transplanted far too much bald skin in each graft. Minigrafts and micrografts also consist of multiple (partial or complete) follicular units along with the intervening skin. Even micrografts containing as few as two or three hairs may contain unnecessary skin if the hair was taken from two or more separate follicular units. Hair moved in these types of grafts results in transplanted tissue that has the same ratio of follicles to skin as the donor area. As healing occurs, the scar around the graft contracts, pushing the hairs in the graft together, and the density of the hair within the graft increases. The hair density within these larger grafts often exceeds the hair density in the donor area. This higher hair density within grafts is intrinsic to the principles of scar contraction, and produces the pluggy appearance of traditional grafts.

There are other problems associated with the use of the larger grafts. It takes four to six days for the buds of new capillary blood vessels to grow into the grafts from the surrounding tissue. Until these new blood vessels grow into the grafts, the graft’s cells depend upon the surrounding tissue fluid seeping into them to bring them oxygen and nutrients. Hair follicle cells have a very high metabolic rate, and they require more oxygen and other nutrients than other cells. If the graft is too large, the cells of the follicles in the center of the graft may die before sufficient oxygen and nutrients can reach the center of the graft. The follicles at the periphery of the graft survive because they receive sufficient oxygen. When hair finally grows from these larger grafts, it has a doughnut configuration, with hair at the edges and a bald central area. This is one of the numerous reasons why many doctors have changed to the use of smaller grafts.

Small Grafts vs. Large Grafts
To meet the demand for natural-looking hairlines, doctors began decreasing the size of grafts in the 1980s. Smaller grafts had the advantage of being less visible during the transition period after transplantation and before the hair had grown in. Large grafts placed in a frontal hairline look pluggy and unnatural when the hair was combed back or to the side. The patient in this situation was forced to comb his hair forward and down to hide his hairline. When large grafts are placed behind the hairline or in the crown, they tend to look like intermittent clumps of hair and are very difficult to disguise.

The amount of time and work needed to place a large number of tiny grafts is much greater than the time and work needed to place a smaller number of larger grafts. Smaller grafts also produce a thinner (but more natural) appearance. If the restoration process is stopped before completion, the patient will still look natural. Larger grafts tend to obligate the patient to complete multiple sessions in the quest for natural-looking results and the patient’s appearance can be strikingly unnatural before the work is completed. Even with additional work, the large graft transplants often fail to appear natural because they are intrinsically clumpy. On close inspection, it is literally impossible for large graft transplants to look and feel natural, even after the best work.

Patients should discuss the size of the grafts and the planned distribution of the grafts in detail with their surgeons. Some surgeons use larger grafts for the bulk of the work and then use smaller grafts in an attempt to hide the larger grafts. Others only transplant small grafts. Some hair transplant surgeons invent unusual terms for grafts in an attempt to make it appear that they have some special, unique knowledge or technique. These terms are intended to imply special variations in graft sizes or an invisible appearance of the grafts. Do not be confused by arcane terminology. The potential patient should be wary when a doctor claims to have a unique technology or technique that no other doctor knows about or uses, unless it is documented and published in a peer-reviewed medical journal.

Hybrid Grafting Technique
The use of larger grafts for the top and non-central portion of the crown and smaller grafts for the frontal hairline and perimeter of the transplant has a variety of names including the Hybrid Technique, Blend Grafting and Variagrafting. Although this hybrid approach is detectable on close inspection, it may not be noticeable in a social setting unless the hair is wet or the patient is in bright sunlight. The results are best in patients who have curly, white or very blonde hair. Although the look from a distance of two to three feet in soft lighting may be relatively undetectable, on closer inspection it always is; and it will never fool the barber.
In individuals with curly or wavy hair, the hybrid approach may be a reasonable way to reduce the costs of the process. For individuals with straight hair, such an approach can be disastrous, particularly if the color of the hair stands out against distinctly contrasting skin tones. The hybrid procedure generally costs less, and can be performed without the intense labor required for larger sessions of small grafts. The larger grafts may range from 1.5 mm in size to more than 2 mm in size. Another disadvantage for those who will accept the hybrid compromise is that the larger grafts may become more evident when further balding occurs, particularly when recession allows them to be viewed from a different angle. The hybrid approach is more a short-term economic solution than a long-term one and is not recommended by NHI physicians.

Appearance of Hair Transplants
What makes a hair transplant bad is that everyone can tell it is a transplant. The uneven, patchy effect of the large pluggy grafts occurs when large grafts are used and the spaces between the grafts are wide. This causes a contrast between the bald skin and the islands or clumps of hair and creates a “dolls-head” appearance. Traditional hair transplants also produce small subtle deformities in the skin. Skin abnormalities with larger grafts occur for two reasons. First, the surface of the transplanted skin may not be aligned with the surface of the surrounding scalp (this is seen in larger hair grafts where the transplanted skin has enough mass to produce the problem). Second, scar contraction and/or skin dimpling occurs at the recipient site from the healing process. As the grafts increase in size, these abnormalities occur with increasing frequency. When the grafts are smaller than the critical size, these problems rarely exist.

The natural hair mass is composed of hair groupings of one to four hairs that are close together (follicular units). In nature, only single-hair follicular units appear at the leading edge of the hairline. To appear natural, a hair transplant should simulate that look as closely as possible. An ideal hair transplant consists of follicular units placed closely together with naturally occurring single units placed at the frontal edge of the hairline. When follicular grafts are placed into small sites, skin deformities are rare, or nonexistent.

Method of Harvesting Grafts
There are four common methods of harvesting donor grafts. The original method, devised by Dr. Orentreich, used a hand punch to cut single grafts 4-mm in size that could contain up to 30 or more hairs. Each punch hole was separated by small islands of skin. Besides producing very large grafts, there was hair wastage around the periphery, due to transection and improper angling of the punch. This method is now rarely used. A second method utilizes a mechanical punch held in a small hand engine to core out a number of round grafts of known size. The punch turns at very high speeds; the torque and heat energy generated by this method will damage the donor grafts. The donor grafts obtained by the punch methods can be made into minigrafts by halving or quartering them. The donor area can then be closed by suturing or can be left open. If the donor sites are not closed, they develop significant scars. Most doctors have abandoned these techniques.

The third method uses multiple, parallel scalpels attached together on a handle, called a multi-bladed knife. Multiple thin strips of hair-bearing donor skin are removed simultaneously and then grafts of the desired size are cut from the thin strips of tissue produced by the multi-bladed knife. Using a scalpel does not produce any torque or heat energy; therefore, no heat or torque damage to the grafts can occur. This method is quick and simple and still quite popular. Unfortunately, this method can cause extensive damage to the donor tissue, as it is impossible to line up the multiple blades parallel to the hair follicles. Because of this there is unacceptable cutting of individual follicles (transection) and breaking up of naturally occurring follicular units.

In a fourth method, called single strip harvesting, the donor tissue is removed as a single strip. The great advantage of this method is that the tissue is removed from the scalp with the minimal amount of “blind” cutting. The only blind cutting is the single incision around the periphery of the donor strip as it is removed. All further dissection can be then performed by direct visualization using a dissecting stereomicroscope. This keeps potential damage to follicles at an absolute minimum and allows preservation of intact naturally occurring follicular units. In order to perform Follicular Unit Transplantation, single strip harvesting and stereo-microscopic dissectAppearance of the Donor Area

Unless the back and side hair is extremely short, the donor area will be covered by hair and will be unnoticeable after surgery. All donor “harvests” result in a scar, but if done properly, the scars may become, for all practical purposes, virtually invisible. Not only is it important for the scar to be closed meticulously, but also the scar must be placed in the proper position, in the mid-portion of the donor area. Scars that are place too low have an increased risk of stretching from the movement of the neck muscles. Scars that are placed very high run the risk of being visible if there is extensive balding. In addition, the hair that is obtained from these high incisions may not be permanent.

Re-harvesting the same area is important to keep visible scaring to a minimum and to keep the donor scar in the mid-portion of the permanent zone. Some doctors harvest a new area for each surgery. When many surgeries are done, these patients have a stepladder appearance of the back of the scalp from the multiple scars. Each scar distorts the hair shafts in either side of the adjacent skin. This distortion occurs because scars tend to contract. When contraction occurs, the microscopic structures around the scar are pulled. If different donor sites are chosen for each hair transplant procedure, the total area for distortion of the hair follicles becomes quite extensive. Such distortions can affect the surgeon’s ability to maximize the donor hair supply for more extensive hair transplant restorations and often limit the surgeon’s ability to keep the donor site undetectable. The following photographs demonstrate the contrast between extensive scarring associated with multiple procedures, when donor hair is taken from different areas for each procedure and a properly placed scar repeated from the same location.

Scar Improvement
Hair transplant specialists are often confronted with patients whose donor areas have been severely scarred by an older harvesting method, improper harvesting techniques, too many surgeries, or, in the rare patient, a large scar due to the patient’s individual healing tendencies. Frequently when scars occur, they can be surgically improved. The modification of obvious scarring may be attempted at the same time as a transplant procedure.

Hairlines
Proper selection of donor sites and graft sizes are extremely important aspects of the surgery. Design of the hairline and placement of the recipient sites are also crucial to an aesthetically successful outcome. Some doctors create the same standard hairline on every patient. This practice is less than ideal. Natural hairlines vary from one individual to another as much as facial features do. The hair transplant specialist must be aware of the spectrum of variations that normally occur. Few natural hairlines are symmetrical; therefore, one should not attempt to create a perfectly balanced hairline, as it is distinctly unnatural looking. Men of European descent with naturally full heads of hair often have receded corners at the temple or a slightly pointed hairline. Men from the Middle East and Asia often have wide, flat hairlines with a gentler curve. Men of African descent tend to have a very straight, flat hairline.

Errors can occur when over-demanding patients or over-aggressive doctors place the hairline too low on the forehead, or restore the juvenile hairline. The patient must have an active voice in all decisions concerning the placement and design of the hairline, but it is up to the physician to educate the patient so that his decisions will be appropriate in the future as well as the present. Faulty decisions, once acted upon, will be permanent. The only remedy for a hairline that has been placed too low is to remove the grafts surgically; a situation that is better avoided than treated after the error has been made.

Hair and Its Variations
Certain hair types may be more common in certain human groups. Understanding these characteristics may be critical in anticipating the results one can expect. African hair is very curly. This single characteristic makes African hair produce some of the best results in hair transplantation, but the dissection must be performed with extreme care to avoid damage to the curved follicles.

Most Asian hair is black, coarse and straight, making this hair type the most difficult when striving for good reconstruction results with traditional hair transplant techniques, especially when the skin is fair. Korean hair, for example, requires very small grafts (usually one to two hairs per graft) to produce a natural look. In fair-haired Caucasians with a low contrast between hair and skin tones, hair transplant results can be spectacular, as the fair skin and blonde hair color match closely. Using only naturally occurring individual follicular units will produce natural results with all hair and skin types.

In addition to the variation of size and character of the terminal hairs in different areas of the head, hair grows in different directions in different parts of the scalp. Hair in back of the head grows backward and downward; hair in the front and top grows forward; hair on the sides of the head grows away from the middle of the head. The place where they meet in the crown is reflected in the “cowlick.” The art of your surgeon should reflect knowledge of your natural growth patterns, your hairstyle preferences, and how you want your hair to look when groomed or un-groomed. To create a natural looking head of hair, the grafts that go into the recipient area should produce hair that is as close as possible in consistency and direction to the original hair and should reflect the various characteristics of both your hair and heritage.

A working knowledge of the nuances of different hair characteristics is essential in producing an ideal result. Fine techniques are necessary to make perfect donor grafts that are exactly parallel to the direction of the hair shafts of the original hair in the transplanted area. Artistry is required to design a hairline that is appropriate to the size and shape of the patient’s head. Precision must be employed for the proper placement of the many small grafts.

The Fast Track Method
The technique of performing a large number of grafts in a single session was introduced in Brazil at the clinic of Dr. Carlos Uebel in the mid-1980′s. Work of a similar nature was performed a little later in Austria, Germany, and Japan. Dr. Uebel’s focus was on moving one- to two-hair grafts in quantities of up to 1,500 grafts in a single session.

In 1992, New Hair Institute expanded upon the earlier micrograft procedures to perform large megasessions of 2,000-3,000 very small 1-3 hair grafts in a single session and called this the Fast Track¨ method. The procedure was popularized worldwide when, in 1994 and 1995, NHI brought several dozen live patients with their work completed to two conventions of the ISHRS (International Society of Hair Restoration Surgeons) in the United States and Canada and showed the results of these megasessions.

The results were so impressive that they put to rest the challenges to NHI’s Fast Track¨ method and put the “Megasession” permanently on the map. In 1995, NHI began using only follicular units in these large sessions and called the procedure Follicular Transplantation. The name was formally changed to Follicular Unit Transplantation in 1998.

Although Dr. Uebel’s balding patients did not necessarily have the appearance of full heads of hair, they were able to achieve thin natural heads of hair in single sessions to frame their faces. They also had the opportunity to stop after just one session without worrying about an unfinished appearance. The Fast Track¨ approach takes these advances a step further and makes the transplant reconstruction fit into a socially acceptable time period. The most distinct difference between the Fast Track¨ and other similar transplantation procedures is the high number of hair follicles that are moved in naturally growing follicular units. This dramatically reduces the number of procedures required.

The Fast Track¨ method may condense the entire hair transplantation process into one or two surgical procedures. With this approach, each procedure may stand on its own, and subsequent procedures are simply the decision of the patient to add additional density or refinement. If more than one procedure is desired, another can be performed in as little as 8 months, if appropriate. A second procedure should await the results of the earlier procedure before reassessing goals and determining the cosmetic effects of the first procedure. This means that density may be added incrementally, and that the patient may stop with just one procedure if he chooses to do so and still achieve an attractive and natural outcome. With the Fast Track¨ method, the number of surgeries is minimized, as is the disruption of the patient’s life.

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