Donor area harvesting is much more than a
simple excision of tissue from the "permanently" hair-bearing scalp. There are
numerous factors to contemplate, including the location of the donor strip,
whether multiple donor sites will be used or only one, whether one blade will be
used or multiple blades, whether to close the donor region in one or two layers,
whether staples should be used or sutures, and if the latter, which sutures,
whether one wants to create only one donor area scar or is unperturbed by
multiple donor scars. In addition, many physicians, though not all, tumesce the
donor region to different degrees. All of these are discussed below.
DONOR SITE PREPARATION:Most physicians have the patient wash their hair
and scalp with an antiseptic such as Betadine, Hibiclens, Technicare, or a
regular shampoo the night before and morning of surgery. As noted in Chapter 6,
it is helpful to wet the hair to clarify the "safe" donor area and to look for
any signs of future loss such as shorter, finer, or lighter-colored hair. The
hair immediately superior to the area that you will be excising should be combed
superiorly, reducing its obtuse angle to the scalp. This will better expose the
area you wish to excise. Wetting the hair will also often help you to do this.
The hair that is combed superiorly is held in place with hair clips, rubber
bands, or tape. The hair in the proposed donor area is then trimmed to a 21-3 mm
length using small electric clippers such as those used for the beard and
sideburns, large clippers, or curved Metzenbaum scissors. Its width should be 1
or 2 mm wider, both inferiorly and superiorly, than the width of the strip you
want to excise. Bear in mind that the wider the extra width of the trimmed area,
the more difficulty your patient may have in concealing the donor region in the
immediate post-operative phase. Some practitioners leave the hair in the donor
strip slightly longer than 2-3 mm. They feel the longer length aids them in
maintaining the scalpel blade parallel to the angle of hair growth.* Once the
donor region is trimmed the cut hair is combed away. The inferior aspect of the
donor region can be covered with a wrapped gauze, surgical towel, absorbent
sponge, chux, or a feminine hygiene pad. These assist in absorbing blood as it
runs inferiorly from the donor wound.
TUMESCENCE OF THE DONOR AREA:The subject is fully covered in Chapter 9.
Donor tumescence has been used since the days of punch grafting. The amount of
tumescence and the method of infiltration have changed as the means of donor
area extraction have changed. Saline tumescence results in vasoconstriction
through the vascular compression produced by the high volume of infiltrate in
the extra-cellular space. In addition to this tamponade effect, tumescence lifts
the hair follicles off the underlying vascular bed and reduces the risk of
trans-section of deeper and larger arteries and nerves, provided the depth of
incision is controlled. Some practitioners, including Unger and Cole, add
lidocaine and epinephrine to the saline when preparing their tumescent solution.
(See Chapter --). The lidocaine increases anesthesia and the epinephrine helps
to improve hemostasis. Follicle trans-section is also decreased by tumescence as
a result of its spreading the follicles within the donor tissue farther apart,
stabilizing the tissue, and making the angle of hair growth more consistent. The
importance of rigidity of the tissue in preventing trans-section is more
significant with scalpels containing more than one or two blades. The depth of
the incision should be 4 to 7 mm or just below the depth of the hair follicles.
As noted earlier, in general, fine-textured hairs typically do not extend as
deeply into the subcutaneous tissue as coarser hairs. It is possible to make
deeper incisions below the dermal papillae, but the risk of nerve or artery
injury increases.
There are different planes to consider in the donor area: the epidermis, the
dermis, the subcutaneous fat, which contains the follicular bulbs, and the
subcutaneous fat deep to the bulbs, as well as the region between the galea and
the skull. Tumescence in each of these planes has a different effect on the hair
follicles. Tumescence in the sub-galeal plane alone might act to compress and
distort hair follicle exit angles. Infiltration in the subcutaneous plane alone
would increase the distance between the hair follicles and the neurovascular
bundles but would not create the degree of rigidity that is optimal for donor
area excision. Tumescence in the upper dermis alone would create a firm, flat
surface, reduce follicle density, and perhaps decrease follicle trans-section
rates, but would do little to lift the follicles away from the underlying nerves
and vessels. It is therefore beneficial to infiltrate both the subcutaneous
tissue and the dermis to a maximum or near maximum degree, in order to produce
their ideal level of rigidity. There are those who believe that infiltration of
epinephrine into the donor region may decrease hair survival or increase the
risk of necrosis in the donor area. Both Unger and Cole disagree, unless the
wound has been closed with too much tension -- in which case it may play some
role in increasing the chance of necrosis. Cole has injected 5 cc of solutions
containing concentrations of epinephrine as high as 1:30,000 into the donor area
of over 1000 patients with no adverse effects being noted at that site. This
results in excellent hemostasis. However, tumescent infiltration with lower
concentrations of epinephrine is superior in all the other respects including
hemostasis. discussed earlier.
It would seem logical to assume that because the follicles are spread farther
apart by tumescence that the same surface area of skin will contain fewer
follicles and, therefore, the yield of follicles will decrease with tumescence
if the same width of tissue is being excised. Unger uses large amounts of
tumescent fluid immediately before he places "blade to skin" and accepts
the concept of perhaps obtaining slightly fewer follicles in return for
less follicle trans-section. Cole furthermore believes that maximum tumescence
in the average office expands the donor region by only 0.5 mm, and that
this is generally partly compensated for by the point-to-point distance of the
surgical blades. The point-to-point distance of the Arnold knife, for example,
is 0.2 mm greater than the distance between the two blades. (fig. 14). This
relationship partially negates the effect of saline infiltration on reducing the
follicular yield. Infrequently, maximum tumescence can expand the donor area by
up to 5 mm but he feels the dynamic properties of the, which are especially
characteristic of this type of elastic skin, reduce this effect to a very short
duration as the skin rapidly returns to normal. Obviously, how much fluid is
infiltrated by any given practitioner, and how rapidly the strip is thereafter
incised, will affect the degree of any potential lower FU yields. The amount of
tumescence used, has increased significantly over the years. It is common to
employ 75 cc or substantially more to infiltrate the typical donor region.
Arnold has recommended that infiltration should result in a "plateau" in the
donor area rather than merely a raised area like a "hill", * and Unger strongly
agrees with this advice. Blugerman goes further and advises that this "plateau"
should extend to at least 1 cm beyond the proposed area of incision. * (Jul-Aug
1996 Hair Transplant Forum International, page 10.)
Beehner’s technique is to infiltrate 10 to 15 cc into the subcutaneous tissue
using a 10 cc Disposajet syringe (Byron).* He then injects additional fluid into
the more superficial dermal layer every 3 cm, utilizing two 5 cc syringes with
22-gauge needles. On average, he tumesces the donor area with a total of 70 to
80 cc of normal saline containing 1:85,000 epinephrine. After incising the
parallel edges of the strip, he tumesces both extremities of the strip for a
third time and incises its tapered ends.
The optimal amount of fluid infiltration varies from one donor region to
another. Some donor areas require very little, while others accept much larger
volumes. In a large majority of instances, it is possible to achieve a firm
"plateau"-like surface, but in some areas it is impossible to accomplish this.
The elasticity and reabsorbing capacity of the tissue is so great that the
effects of large fluid volumes are lost almost immediately and the benefits are
minimized. It is important to recognize such situations because the risk of
trans-section with a multi-bladed knife increases, and therefore, only single or
double-bladed knives should be utilized in such areas.
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