eventual hair loss. It is helpful to know that most patients have at least the ability to have two to three strips of scalp, 8–10 mm wide, removed from the permanent hair-bearing scalp. In these strips, the average balding male has from 5,000 to 7,000 FUs that can be safely used for transplantation.

In general, the first strip should be removed from the occipital scalp at or above the level of the occipital protuberance. Unger’s studies on the size of the safe donor area [30] indicate that an area, for 80% of men under 80, exists that is from 70 mm wide at the midline occipital region extending laterally to 80 mm at its widest point and then narrowing to 50 mm wide in the temporal scalp above the ears.

13.9.5 Estimating Size of Donor Strip

This step takes much experience to be comfortable knowing the size of strip and number of grafts required to transplant the size of area to be treated. Some physicians will choose to transplant all small oneto threehaired FUs, while others will choose a combination of FUs and MFUs. This can alter the size of strip required. The following is an example to illustrate how one might go about determining strip length for a commonly treated area:

1.If one is to transplant the hairline to mid-scalp, the average area to be covered is approximately 60 cm squared. (To more accurately determine the area to be covered a 1 cm2 transparent grid can be used and the area to be transplanted traced on top of the grid to give the recipient area size.)

2.Assume the density of the average permanent safe donor zone is 100 FU/cm2. The range is from 60 to 140 FU/cm2. (To accurately determine the density a trichscope, densitometer, or video microscope can be used to assess donor density.)

3.A decision is made as to what density the surgeon wants to plant the FUs. In an initial session, for the novice surgeon, it is good to know that densities of 25–30 FU/cm2 will yield a satisfactory appearance and is suggested. In some practices, densities of 50 FU/cm2 and greater are achieved, but should be reserved for those with adequate staff and expertise.

4.Once the number of follicular units required to transplant the area to be treated is determined then

the length of a 1 cm wide donor strip, based on the number of FUs needed, can be estimated.

An example calculation shows that if a frontal hairline and scalp are to be transplanted in a 60 cm2 area, placing the grafts at a density of 25 FUs/cm2 then: (60 × 25) = 1,500 FUs will be required.

If 1,500 FUs are required from a strip that is 1 cm wide, taken from a donor site with a density of 100 FUs/cm2: (1,500/100) then the strip needs to be 15 cm long.

Tip

For a novice surgeon or surgeon that does transplantation infrequently the average size of a frontal area from hairline to mid-scalp is approximately 60 cm2. To transplant at densities of 25–30 FU/cm2, approximately 1,800–2,000 FU grafts (one to four hairs each) are required, taken from an average density donor zone. A 1 cm wide strip should then be removed at approximately 20–22 cm long.

13.10 Anesthesia

For the vast majority of cases, local anesthesia, with or without oral sedation, is the most commonly used form of anesthesia for hair transplantation. Procedures can be performed without any oral sedation or with a mild sedative such as 10 mg of oral valium and/or 2 mg of sublingual lorazepam given 30 min before the start of surgery. Some physicians will use intravenous twilight sedation using midazolam, propofol, or fentanyl. The author has found the need for twilight sedation to be used only in those circumstances when the patient has a strong desire to be totally unaware of what is happening. In those rare circumstances, or when the author feels the patient with a preexisting medical condition could put the patient at risk, an anesthetist will be present for the entire procedure. An automatic blood pressure cuff and pulse oximeter should be used for each surgery and to have available oxygen, a defibrillator, a fully equipped crash cart with emergency medications, and an emergency action plan with staff trained in basic cardiopulmonary life support is essential.

Techniques used to aid in the delivery of local anesthesia to the scalp include topical lidocaine cream, needleless injectors, supraorbital, supratrochlear, occipital nerve blocks, and field blocks. The maximum dose of lidocaine with epinephrine, (7 mg/kg), and bupivacaine (3 mg/kg), must be kept in mind. Epinephrine is commonly used in scalp anesthesia to act as an effective vasoconstrictor and as such can prolong the affect of the local anesthetic. The use of tumescent anesthesia will allow for large volumes of a dilute anesthetic to be administered with minimal chance of toxicity.

Once the donor area has been identified, clipped, and prepared (Fig. 13.12), an initial field block in the occipital donor area is administered using a 10 ml syringe filled with 1% lidocaine with 1:100,000 epinephrine and a 30 gauge, half inch needle. Six to eight small wheels are slowly injected to raise small blebs of solution, about 1 in. apart just at the inferior edge of the clipped hair. To mask the sting of the initial injections, some physicians advocate the use of ice in the area, local vibration, or buffered anesthetics. Once the initial wheels are raised, the operator goes back to each wheel and continues the field block aiming the needle left and right from each already numbed site to fill in the gaps, using a total of 8–10 ml. In this manner, the patient should only feel a mild sting of the initial injections. A tumescent solution is prepared using a 100 ml bag of normal saline adding 5 ml of 2%

lidocaine without epinephrine and 0.4 ml of 1:1,000 epinephrine to give a 100 ml tumescent solution of

.1% lidocaine with 1:250,000 epinephrine. Using 10 ml syringes with 21 gauge 1.5 in. needles, inject just superior to the block as much tumescent solution as the tissue will take. The intent is to cause maximum tissue turgor in order to lift subcutaneous fat away from underlying arteries and nerves and to keep the tissue firm to minimize transection of follicles during removal of the strip. The high volumes of dilute anesthetics also help to minimize bleeding. The patient is then left for 10–15 min to allow proper anesthesia and vasoconstriction to take place. The patient is then placed in a prone pillow, if a mid-occipital area is to be harvested (Fig. 13.13). Just before the initial strip is removed, an additional 8–10 ml of tumescent solution is injected to allow for further turgor and to test that the area is fully numbed.

The recipient site is anesthetized while the donor strip is being dissected. With the patient in a semi-supine position, a ring block is administered, similar to the initial donor area block, just inferior to the anterior hairline. Up to 10 ml of a 2% lidocaine with 1:100,000 epinephrine mixture is used. One 10 ml syringe is then filled with a mixture made up using 0.6 ml of 1:1,000 epinephrine to 30 ml injectable saline to yield a 1:50,000 epinephrine mixture. The entire recipient area is then plumped up using 10 ml of the 1:50,000 epinephrine

mixture (and 5–10 ml of further 1% lidocaine where required), to allow for complete anesthesia and hemostasis. If further plumping of tissue is required, injectable normal saline can be used. Some surgeons may also employ additional tumescent anesthesia to minimize damage to the supragaleal vascular plexus during surgery, to improve hemostasis and to expand the recipient sites during surgery allowing for contraction of sites, and minimizing distances between sites, once the tumescent fluid has dissipated. Some physicians will also mix marcaine with lidocaine solutions to give prolonged anesthesia.

13.11 Removal of Donor Strip

With the patient seated the donor site is marked and clipped with curved Metzenbaum scissors to 2–4 mm in length. This minimum hair length is required so that hair direction can be continually assessed while removing the donor strip. The shorter hair length also helps to avoid hairs being inadvertently trapped while planting the graft. Once the donor site has been clipped it is then cleaned with alcohol and with a povidoneiodine solution. The area is then anesthetized and allowed to sit for 10–15 min to enable the adrenalin to take effect. (The recipient area anesthetic is administered later in the procedure.) The patient is then placed in a prone pillow. At this stage the donor site is further tumesced. This allows for maximum tissue turgor just before the strip is cut and additionally checks are made for adequate anesthesia. The author prefers to use a single bladed scalpel with a #15 blade to remove a single ellipse that is tapered at the ends. Some surgeons may use double-bladed (Fig. 13.14) or multiblade scalpels with spacers to allow multiple strips to be excised simultaneously with the aim of reducing the time for dissection. However, studies have shown that there can be more transection of follicles with a multi-blade knife as there is less visualization of the follicles. The strip is cut to 1–2 mm below the level of the hair follicle leaving some subcutaneous tissue to protect the root bulb. Going much deeper will disturb the subcutaneous blood supply and incur more bleeding. The operator must continually assess the angle of the hair follicles and adjust the blade accordingly. The assistant provides counter traction with a tissue clamp to allow easier strip removal.

Fig. 13.14 Double-bladed scalpel with four spacers that could accommodate further blades

Once the strip is removed it is immediately placed in chilled saline and handed to the technician for dissection. Figure 13.15 shows the author’s technique for strip removal. Any electrocautery, if necessary, is used at this point and any stray hairs or hair spicules are very diligently cleaned from the wound. Undermining is performed when excessive tension on closure is a concern. The author rarely needs to perform undermining as the wound width is generally kept to less than 1.2 cm to allow for easy closure. With minimal tension the scar should heal to being pencil line thin. Some physicians, the author included, will perform trichophytic closure. A 1 × 1 mm wide triangular strip, cut at a 45° angle, is trimmed from the inferior wound edge (Fig. 13.16). This will de-epithelialize one to two hair follicles and when the wound is sutured closed, the superior border will cover the trimmed inferior border allowing the inferior hairs to grow through the scar to allow more enhanced camouflage. The author will perform this in most circumstances where there is minimal tension. If there has been multiple procedures performed in the same area or there is above average tension demonstrated at the time of strip excision, then a standard closure is performed. Physician preference dictates what type of suture is used and if staples are favored. The author uses a running single-layer closure with a 3–0 non-dissolving thread. Sutures are to be removed in 7–10 days.

When subsequent sessions are performed, it is common to re-excise the previous linear scar with the new strip excision to minimize scaring of the donor zone. It should be kept in mind that with subsequent re-exci- sions, overall tension in the donor zone increases, such that the width of the donor strip should be adjusted