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Size
of donor area and tissue to be collected
This page refers to the procedure generally used for patients
with androgenetic alopecia. The procedure will vary somewhat depending
on the personal preference of the surgeon, and will vary even more
if you have a form of alopecia other than androgenetic alopecia
that is being surgically restored.
Planning the donor site is just as important is planning the hair
implant recipient site in hair restoration. The donor area has
to be preserved as much as possible, you don’t want an irregular
shaped occipital scalp hair growth or a large scar from the removal
of the donor hair follicles. The primary issue for the hair transplant
surgeon in planning the donor site is how big it is and how much
skin should be taken to provide enough hair follicles for the transplant
session. Not all donor sites are the same size in hair transplant
patients. Some men and women have quite large areas of occipital
scalp where the hair follicles remain unaffected by androgenetic
alopecia. In other patients, the androgenetic alopecia has spread
far back on the scalp and the occipital scalp hair growth area
is relatively small. In addition, there are some people in whom
their androgenetic alopecia is so extensive that the hair follicles
on the occipital scalp are also affected to some extent and the
hairs are finer and thinner than would be expected. If the donor
area is too small or the area is affected by androgenetic alopecia
then the individual may not be a suitable candidate for hair restoration.
Some experience is required on the part of the hair transplant
surgeon to correctly define the area of donor hair on the occipital
area that is unaffected by androgenetic alopecia. It is important
to get it right as transplanting hair follicles that are androgen
responsive will lead to transplanted hair follicles miniaturizing
in response to the androgen hormones. Also, the surgeon must leave
enough hair behind after removing the donor hair follicles to ensure
a natural look to the occipital hair line. It is generally believed
that the “safe” area of potential donor hair follicles
resistant to androgenetic alopecia is in the area from the lower
hairline at the back of the neck, up to an imaginary line running
around the back of the head about 2cm above the openings of the
ears. This defines the maximum extent of the potential donor area
for all but a few individuals. However, when actually removing
the donor skin, the surgeon must leave margins above and below
the removed hair follicles. The surgeon also has to take into account
the possibility that the patient may need more hair restoration
procedures in the future. Bearing these limitations in mind the
surgeon will identify an area of skin to remove.
Preparing
the occipital scalp for donor skin removal
At the start of the procedure, you, as a patient, will be dressed
in a surgical gown, or at least you will be asked to cover your
upper body and around your neck in a disposable apron. You will
be positioned face down on an operating table with your head on
a prone pillow – it has a hole in the middle for your face
to go into so you can breathe! The area of skin at the back of
your head will be sterilized with one or more solutions swabbed
over the skin and hair. The long hair that you have hopefully been
growing to use later to cover over the sutures, will be combed
out of the way and held in place with hair clips. The area of skin
from which the donor hair follicles will be cut, will be shaved
with clippers or cut with scissors so that the long hair doesn’t
get in the way of cutting the skin and later when the skin is microdissected
to obtain the hair follicles. The hair is not completely removed
down to the skin surface, about 2mm of hair is left above the skin
surface so that the surgeon can see where the hair follicles are
when he cuts the donor skin. The skin is swabbed again to get rid
of the loose, cut hair and to repeat the sterilization. Usually
the solution is iodine (Betadine) or chlorhexidine (especially
if you are allergic to iodine).
To prepare the skin ready for cutting, your skin will be injected
with a saline solution and then a local anaesthetic or alternatively
you may receive both saline and anaesthetic as a mixed solution.
The intention of the saline is to increase tumescence in the skin
that is, to make the skin relatively hard. This makes it easier
to cut with a scalpel and ensures nice clean edges to the cut skin
which makes healing of the wound quicker. It also spreads the hair
follicles apart so they are easier to see and to cut between with
the scalpel blade. The local injections can be painful, although
the pain should be brief until the local anaesthetic takes effect.
To overcome the brief pain during injection of the saline and local
anaesthetic, some surgeons offer the option of a partial systemic
anaesthetic like nitrous oxide. You usually administer this to
yourself, by breathing it through a mask you apply to your mouth
as and when you feel you need it, during the injection of saline
and local anaesthetic. You should remain awake throughout the procedure.
The breathable anaesthetic is only used until the local injected
anaesthetic takes hold.
Method
of donor tissue collection
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Donor
skin sample just cut from the scalp of an individual undergoing
a hair transplant. The top is the outer skin surface. The
hair follicles penetrate deep into the fatty tissue at
the bottom. This strip of skin is ready for microdissection
under the microscope.
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The next step is for the surgeon to actually cut the donor skin
area. Most hair transplant surgeons currently (as of 2004) use
a multi bladed knife to remove a strip of skin from the occipital
scalp. The distance between the blades and the length of cut determines
the size of the skin area that is removed. The multi bladed knife
can be resized to change the distance between the blades. The surgeon
will determine how much skin is needed and position the blades
of the knife appropriately. The scalpel blades are inserted into
the skin at one side of the head at an angle such that the blades
are parallel to the hair follicles in the skin. The surgeon can
predict how angled the hair follicles are in the skin by observing
the angle of hair growth coming from the hair follicles. The cut
is relatively quick in the hands of an experienced surgeon. It
can take less than 30 seconds. However, it can take longer if you
are one of the few individuals in whom the angle of the hair follicles
changes across the scalp. Then the surgeon has to go more slowly
and carefully to ensure he/she does not cut into the hair follicles.
The surgeon will then cut across the skin to make the strip of
donor hair follicles. If you have already had one or more procedures
done, the surgeon will cut the strip of skin just next to where
the previous strip of skin was cut. The surgeon will cut the new
strip of donor skin such that it also just cuts out the scar left
from the previous operation. In this way, the surgeon can ensure
that, regardless of how many implant procedures you have, you only
ever have one scar on the occipital scalp. Just how much skin is
removed depends on the size of the recipient area that needs to
be implanted and the density of your hair follicles. Roughly speaking,
the density of hairs in the donor region of the scalp typically
ranges from 70 to 120 follicular units per square centimeter, with
a median of 80. Therefore, in the typical patient, a 20-cm2 donor
strip (20 cm in length by 1 cm in width) would be required for
a 1600-graft procedure.
The strips are then cut away from the scalp. Usually, the surgeon
or nurse will pull gently on one end of the donor strip with forceps
and as the skin is lifted up above the remaining scalp skin, a
pair of surgical scissors will be used to cut underneath the hair
follicles to release the skin strip from the scalp. This is then
put into a saline solution in a plastic dish in an ice bucket.
This is taken away for further processing to make the grafts ready
for implanting. What is left is a usually a narrow elliptical hole
in the occipital scalp skin. If there is bleeding from some of
the larger blood vessels, they may be cauterized. The wound is
then sutured (sewed) together, often with a single running stitch.
Some hair transplant surgeons use biodegradeable sutures that eventually
fall out. Most however, use normal sutures that need to be taken
out by a doctor at a later date. It will take a while until the
grafts have been dissected ready for implantation. During this
time you will probably be free to sit up and read or watch a video.
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