Hair transplantation

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A man before and after a hair transplant.

Hair transplantation is a surgical technique that moves individual hair follicles from a part of the body called the 'donor site' to bald or balding part of the body known as the 'recipient site'. It is primarily used to treat male pattern baldness. In this condition, grafts containing hair follicles that are genetically resistant to balding are transplanted to bald scalp. It is also used to restore eyelashes, eyebrows, beard hair, chest hair, and pubic hair and to fill in scars caused by accidents or surgery such as face-lifts and previous hair transplants. Hair transplantation differs from skin grafting in that grafts contain almost all of the epidermis and dermis surrounding the hair follicle, and many tiny grafts are transplanted rather than a single strip of skin.

Since hair naturally grows in follicles that contain groupings of 1 to 4 hairs, today’s most advanced techniques transplant these naturally occurring 1–4 hair "follicular units" in their natural groupings. Thus modern hair transplantation can achieve a natural appearance by mimicking nature hair for hair. This hair transplant procedure is called Follicular Unit Transplantation (FUT). Donor hair can be harvested two different ways.

Contents

Strip Harvesting

A strip of scalp is removed under local anesthesia, the wound is then sutured back together and this piece of scalp tissue is then cut in to small pieces of tissue called grafts which are then transplanted back in to the thinning area of the patient's head. This method will leave a linear scar in the donor area, which should be covered by a patient's hair (if long). The recovery period is around 2 weeks and will require the stitches to be removed by medical personnel.

Follicular Unit Extraction

Follicular Unit Extraction or FUE Harvesting - individual follicles of hair are removed under local anesthesia; this micro removal uses tiny punches of between 0.6mm and 1.25mm in diameter. Each follicle is then reinserted back in to the scalp in the thinning area using a micro blade. Because individual follicles are removed, only small, punctate scars remain and any post-surgical pain is minimized. As no suture removal is required, recovery from FUE is within 7 days. However, some surgeons note that FUE can lead to a lower ratio of successfully transplanted follicles as compared to strip harvesting. Others also suggest that in case a patient would need more than one transplant, it would be difficult to find a good strip after a FUE.

History

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,[1] where surgeons used small grafts, and even "follicular unit grafts" to replace damaged areas of eyebrows or lashes, but not to treat baldness. 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 the late 1950s, when New York dermatologist Norman 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. Dr. Orentreich demonstrated that such grafts were "donor dominant," as the new hairs grew and lasted just as they would have at their original home.[citation needed]

Advancing the theory of donor dominance, Walter P. Unger, M.D. defined the parameters of the "Safe Donor Zone" from which the most permanent hair follicles could be extracted for hair transplantation.[2] As transplanted hair will only grow in its new site for as long as it would have in its original one, these parameters continue to serve as the fundamental foundation for hair follicle harvesting, whether by strip method or FUE.

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. In the 1980s, Uebel in Brazil popularized using large numbers of small grafts, while in the United States Rassman began using thousands of “micrografts” in a single session.[citation needed]

In the late 1980s, Limmer introduced the use of the stereo-microscope to dissect a single donor strip into small micrografts.

The follicular unit hair transplant procedure has continued to evolve, becoming more refined and minimally invasive as the size of the graft incisions have become smaller. These smaller and less invasive incisions enable surgeons to place a larger number of follicular unit grafts into a given area. With the new "gold standard" of ultra refined follicular unit hair transplantation, over 50 grafts can be placed per square centimeter, when appropriate for the patient.[citation needed]

Surgeons have also devoted more attention to the angle and orientation of the transplanted grafts. The adoption of the “lateral slit” technique in the early 2000s, enabled hair transplant surgeons to orient 2 to 4 hair follicular unit grafts so that they splay out across the scalp's surface. This enabled the transplanted hair to lie better on the scalp and provide better coverage to the bald areas. One disadvantage however, is that lateral incisions also tend to disrupt the scalp's vascularity more than sagitals. Thus sagital incisions transect less hairs and blood vessels assuming the cutting instruments are of the same size. One of the big advantages of sagitals is that they do a much better job of sliding in and around existing hairs to avoid follicle transection. This certainly makes a strong case for physicians who do not require shaving of the recipient area. The lateral incisions bisect existing hairs perpendicular (horizontal) like a T while sagital incisions run parallel (vertical) alongside and in between existing hairs. The use of perpendicular (lateral/coronal) slits versus parallel (sagital) slits, however, has been heavily debated in patient-based hair transplant communities. Many elite hair transplant surgeons typically adopt a combination of both methods based on what is best for the individual patient.[citation needed]

With the latest improvements in surgical technique and especially with the FUE procedure, the recovery time is immediate and the pain negligible. There is no bed rest or hospitalization required after the hair transplant.

The procedure

Example of a graft transplantation to cover the scar of a Hidradenitis suppurativa operation on the back of the head

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 which might result in intraoperative bleeding and resultant poor "take" of the grafts. Alcohol and smoking can contribute to poor graft survival. Post 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 local anesthesia, which typically last about six hours. The scalp is shampooed and then treated with an antibacterial agent prior to the donor scalp being harvested.

In the usual follicular unit procedure, 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 closing the resulting wound, assistants begin to dissect individual follicular unit grafts from the strip. Working with binocular Stereo-microscopes, they carefully remove excess fibrous and fatty tissue while trying to avoid damage to the follicular cells that will be used for grafting. The latest method of closure is called 'Trichophytic closure' which results in much finer scars at the donor area.

FUE harvesting negates the need for large areas of scalp tissue to be harvested and can give very natural results with little or no scarring.

The surgeon then uses very small micro blades or fine needles 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 technicians generally do the final part of the procedure, inserting the individual grafts in place.

Post-operative care

Advances in wound care allow for semi-permeable dressing, 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 shampooing is started two days after the surgery. Some surgeons will have the patient shampoo the day after surgery. Shampooing is important to prevent scabs from occurring around the hair shaft. Scabs adhere to the hair shaft and increase the risk of losing newly transplanted hair follicles during the first 7 to 10 days post-op.

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 grow 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.

Modern techniques

There are several different techniques available for the harvesting of hair follicles, each with their own advantages and disadvantages. Regardless of which donor harvesting technique is employed, proper extraction of the hair follicle is paramount to ensure the viability of the transplanted hair and avoid transection, the cutting of the hair shaft from the hair follicle. Hair follicles grow at a slight angle to the skin's surface, which means that regardless of technique transplant tissue must be removed with a corresponding angle and not perpendicular to the surface.

There are two main ways in which donor grafts are extracted today: strip excision harvesting and follicular unit extraction.

Strip harvesting is the most common technique for removing hair and follicles from a donor site, most commonly the area at the back and sides of the scalp. A single-, double-, or triple-bladed scalpel is used to remove strips of hair-bearing tissue from the donor site. Each incision is planned so that intact hair follicles are removed. Once removed, the strip is dissected into follicular units, which are small, naturally formed groupings of hair follicles.

Follicular Unit Extraction (FUE) takes place in a single long session or multiple small sessions. FUE is considered to be more time consuming, depending on the operator's skill, and there are restrictions on patient candidacy.[3] The advantages of this technique over the conventional strip harvest are that it does not leave a linear scar, and the procedure produces little or no postoperative pain and discomfort. There are some disadvantages such as increased surgical times and higher cost to the patient.[4] Clients are selected for FUE based on a fox test.[5] There is however some debate about the usefulness of this in screening clients for FUE.

Stem cells and dermal papilla cells have been discovered in hair follicles. Research on these follicular cells may lead to successes in treating baldness through hair multiplication (HM), also known as hair cloning. HM is being developed by ARI (Aderans Research Institute, a Japanese owned company in the USA).

Side effects

Hair thinning, known as "shock loss", is a common side effect that is usually temporary. Bald patches are also common, as fifty to a hundred hairs can be lost each day.

Other side effects include swelling of areas such as the scalp and forehead. If this becomes uncomfortable, medication may ease the swelling. Additionally, the patient must be careful if his scalp starts itching, as scratching will make it worse and cause scabs to form. A moisturizer or massage shampoo may be used in order to relieve the itching.

References

  1. ^ Okuda S. The study of clinical experiments of hair transplantation. Jpn J Dermatolurol. 1939;46:135
  2. ^ Unger WP. "Delineating the 'Safe' Donor Area for Hair Transplanting" The American Journal of Cosmetic Surgery, 1994, 11:239-243
  3. ^ Dermatol Surg. 2008 Dec;34(12):1683-8. Epub 2008 Oct 13.
  4. ^ Facial Plast Surg. 2008 Nov;24(4):404-13. Epub 2008 Nov 25
  5. ^ Dermatol Surg. 2002 Aug;28(8):720-8.

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