Hair Transplant With FUT Method
What are Follicular Units (FUs)?
Hair transplantation with the FUT method has been thought for years that scalp hair grows in individual strands, but scalp hair actually grows in small groups of 1-4 hairs each. These groups are called “follicular units”. Surprisingly, even after the doctors found out about the existence of these groups, they did not consider using it in hair transplantation. However, if a person cuts the hair short (up to about 1mm) and then looks at the scalp at 30X magnification using a tool called a densitometer, the groups become easily visible. Since FUs are full anatomical and physiological structures, keeping them intact during hair transplantation will ensure their maximum survival and growth. FUs are very small structures, but only careful stereo-microscopic dissection by a skilled and experienced surgical team can ensure that it remains as a whole and is not damaged at various stages of the hair restoration process.
What is the advantage of FUs in hair transplantation?
The biggest advantage of using follicular units in hair transplant surgery with the FUT method is to keep the recipient areas as small as possible.
The smaller the recipient sites, the safer they can be placed on the scalp. Small recipient areas allow for the safe transplantation of larger numbers of grafts in a single hair restoration session without damaging the scalp or compromising blood flow. Therefore, the use of these small units maximizes the density of grafts that can be transplanted in a single session and the number that can be used safely at any time.
Hair fullness
The appearance of fullness in a hair transplant depends not only on the number of grafts, but also on the number of hair contained in each graft. Since the hairs in the follicular unit are very close to each other, transplanting provides maximum fullness by placing most of the hair in the smallest possible recipient areas. Since the follicular units represent the way hair grows in nature, this ensures that the grafts will not appear blocked. Although the use of FUs prevents a blocked appearance, they should be placed in the right direction and distribution to provide a completely natural appearance to the hair restoration. Using grafts larger than follicular units will always compromise naturalness, while using grafts smaller than follicular units will always result in sparseness.
Stereo-Microscopic Graft Dissection
One of the most important aspects of hair transplantation with the FUT method is stereo-microscopic dissection. Successful dissection allows follicular units to be removed from the donor strip without breaking or being damaged. During dissection, it is very important to keep the entire FU intact as it will maximize its growth. Robust units will also give the most fullness as they contain the complete, natural complement of 1-4 strands. The average donor strip is approximately 1 cm wide and variable in length depending on the number of grafts required for hair restoration.
The average person’s scalp has about 90-100 follicular units per square cm of donor tissue, so 2,000 graft transplant sessions require a 1cm wide strip that is just over 20cm in length. The stereo-microscope series required for follicular unit dissection is available in the operating room to allow simultaneous graft dissection and transplantation to save time.
Receiving area
In all of our hair transplant procedures, recipient areas are made using lateral slits (also called coronal or horizontal slits). The lateral slits have the advantage of guiding the hair within the follicular unit to conform to the way it grows in nature. They give the surgeon the greatest degree of control over the direction and angle in which the transplanted hair will eventually grow. Controlling the depth of the incision is also critical in making recipient areas, as it minimizes injury to deeper blood vessels in the scalp, allows grafts to be placed closer together, reduces tissue swelling after hair transplantation surgery, and facilitates healing. We use thin hypodermic needles or a series of custom made, ultra-thin blades to create hair transplant recipient areas. The sizes of chisel blades vary in increments of tenths of a millimeter and range from 0.6 mm for single hair grafts to 1.2 mm for 4 hair FUs.
Donor area
Minimizing scarring from the donor incision is a critical part of a successful hair transplant procedure. A thin donor scar allows the person to keep his hair relatively short after surgery (if he wants to do this) and increases the amount of grafts that can be removed (removed) in subsequent procedures.
Techniques to minimize donor injury
A number of techniques have been developed to minimize donor scar while using strip excision during FUT Hair Transplantation. These include the use of intumescent anesthesia, weakening, absorbable stitches, buried stitches, staples, and trichophytic closures. The FUE technique, in which the grafts are removed directly from the scalp without a linear incision, is discussed in another section. Although the length of the donor incision is predominantly determined by the number of grafts required, the width (height) of the donor incision depends on the patient’s scalp looseness. This is a genetic feature of the patient’s scalp that must be carefully measured by the surgeon during the initial evaluation. With good scalp laxity, a wider strip can be removed from the donor area without the risk of scarring (however, patients with very loose scalp may have a higher risk of a large scar. If the scalp is too tight, a normal sized strip can be removed.
When the strip width is too narrow, the cut will need to be unnecessarily long to get enough donor hair. If the strip width is too wide, the risk of having an enlarged scar will increase significantly. Expert clinical judgment from years of experience is needed for the surgeon to consistently adjust the appropriate length and width of the donor strip and achieve the minimum scarring possible.
Obtaining donor strip-inflating anesthesia
A major improvement in donor strip removal is the use of intumescent anesthesia. Swelling means expanding simply by injecting the fluid into the tissues. In this technique, very dilute concentrations of anesthetic fluid are injected into the fat layer of the donor area of the scalp.
What is the significance of this?
This serves a number of purposes, the first is to reduce the bleeding caused by the pressure of the fluid on the small blood vessels (capillaries), the second is to tighten the skin so the incision can be more easily controlled, and the third is to increase the distance between the follicles and the deeper tissues of the scalp.
How to help the surgeon?
This helps the surgeon keep the incision superficial so that the larger nerves and blood vessels in the scalp are not damaged and the fascia is not cut. Fascia is a layer of fibrous tissue just below the fat layer that supports the scalp. If this layer is cut, the risk of developing a taut scar increases significantly.
What is Trichophytic “Tricho” closure?
In trichophytic closure, the surgeon makes the first incision parallel to the hair follicles and then cuts the upper or lower edge of the wound edge, so that 1-2 mm of the top of the hair follicles at that wound edge is removed. During the “knitwear” closure, the cut wound edge is pulled towards the opposite edge so that the lower parts of the cut hair point slightly towards the cut (not directly to the skin surface). The aim is that these hairs eventually grow through the incision, thus reducing the visibility of the scar.
