Donor region management in hair restoration
Hair transplantation in the recent years has the following
basic protocol – use of anesthesia, harvesting donor hair, suturing
the donor area wound, dissecting the donor hair, preparing the
recipient area and inserting the grafts. The most common site
that is selected for donor hair harvesting is the back of the
head (the occipital region). Donor hair can be harvested from
the neck region or from the scalp region above the ears, but the
hairs from the neck region grow poorly and donor skin taken from
above the ears can give rise to ugly scars that become visible
when the hair loss expands. The most cosmetic disadvantage in
hair transplantation is the scarring and how the donor region
has to be managed in such a way that the scarring is minimal depends
on the patient’s hair loss pattern and the skill of the
surgeon.
Donor hair harvesting is performed by following certain basic
parameters since there is no specific site(s) demarcated for harvest.
The occipital hairs are best suited because of the number of hairs
available for grafting and as a result completing the entire grafting
procedure in a single mega session.
Donor hair harvesting – While harvesting the hair strip,
the lines of incision should be parallel to the hair follicles
to avoid minimum damage to the peripheral follicles and also care
should be taken to incise the region parallel to the area with
respect to scalp tension. By incising parallel to the minimum
tension region, scarring due to collagen transection can be best
avoided. This shows the inherent difficulties a surgeon faces
during donor hair harvesting. Usually the donor hair incisions,
after the strip is removed, look like a crescent moon in shape
and this is referred to as the horizontal ellipse cut. The tapering
of the ends facilitates better suturing but some of the follicles
also get damaged in the process. To avoid damage, strips are harvested
in the shape of a trapezoid by Dr Seery who claims this is a superior
approach.
Anesthesia – is used to minimize pain for both donor hair
harvesting and recipient site graft insertion. 1% xylocaine with
1:100,000 epinephrine, is the most frequently used local anesthesia.
However, the patient has to bear the pain of needles when the
anesthetist is administering it initially. Pain is usually minimized
by using fine needles, slow administration of anesthesia so that
the tissue distension is lowered and buffering of anesthesia using
sodium bicarbonate to increase its pH.
Tumescence – When a surgeon follows a single blade procedure
for donor strip removal, local anesthesia would suffice. When
a multi blade system is followed, tumescent anesthesia is required.
In this procedure apart from the local anesthesia administered,
an isotonic anesthesia solution using a vasoconstrictor is infused
to increase the pressure of the tissues. Since the method loses
effect if done at a time in a large area, the anesthetist follows
a sequential procedure and does so for every 2 cm and continues
it until the surgeon excises the strip completely. It is sometimes
argued that the pressure developed due to tumescence may damage
hair follicles but concrete evidence of this claim is awaited.
Use of blades in harvesting – There is a lot of debate
regarding the use of blades for donor hair harvesting. Type 10
blades are used for single blade harvesting while a series of
blades numbers are used for multi blade harvesting. Single blade
harvesting is generally followed by highly skilled and experienced
surgeons because they opine that multi blade harvesting damages
many of the hair follicles. However, the use of blades is largely
according to the preference of the surgeons and the scalp characteristics
of the patient.
The technique of harvesting – While harvesting the follicles,
the incision must be made at optimum depths so as to avoid follicular
damage. With the help of a microscope a surgeon can incise to
an appropriate depth and tease the fat layer from the base of
the follicular layer so that the strip can be removed from the
scalp. The use of a scalpel for this excision is preferred over
scissors as it is less traumatic to the surrounding tissues. Some
fat is however retained so that the strip does not undergo desiccation.
Controlling bleeding during harvest – It is natural that
when the skin is cut that some bleeding occurs. But bleeding during
the harvesting is stopped using hemostats which clamp the blood
vessels when required and these are later removed during suturing.
Suturing the donor area – Closing of the donor area after
harvesting is done in a systematic way. After the donor strip
is removed and preserved in chilled saline, the surgeon removes
the hemostats and starts the suturing. He may use staples as a
guiding factor during wound closure. While he is suturing, he
also uses a scalpel to remove a few millimeters of excess skin
under the sutures by following sweeping movements of the scalpel
[a procedure called undermining] to minimize the rising of scars.
He sutures the skin in a criss - cross fashion using moderate
tension so that the wound is closed completely and no cavity is
formed under the sutured area. The suturing, and especially undermining,
varies when the patient requires multiple sessions. The suturing
process is critical for limiting scarring after the wounds have
healed. When the patient undergoes multiple sessions in quick
succession, he usually experiences a ladder rung-like scar formation
which he has to mask by growing his hair long. Hence a single
mega session of hair transplants is always preferred to multiple,
smaller grafting sessions.
Sometimes the closure of the donor area becomes problematic if the surgeon
has not conducted thorough scalp characteristic studies. If the scalp tension
is high, the two layers of skin need to be pulled and clamped using clips
after which suturing is done. The surgeon may use large needles, heavy suturing
material and may close the wound with difficulty. But the healing of such
closures is rather slow and can be painful for the patient. To prevent such
poor quality closures, the surgeon must carefully evaluate his patient before
the surgery.
The scalp is made up of various components such as collagen,
blood vessels, nerve fibers and lymphatic tissues. When the skin
is undermined extensively or stretched to close the wound, all
these components are directly affected and the skin looses its
original elasticity and can never be regained. When such a situation
arises, the stretched skin can no longer withstand further donor
harvests and the underlying blood and nerve supply is highly reduced.
This condition is seen to occur not only in closure of donor hair
site during follicular unit transplants but also during scalp
reduction procedures. So undermining should be minimal to help
the scalp skin remain its normal self post surgery.
Donor region management in hair restoration
references
- Seery GE.
Hair transplantation: management of donor area.
Dermatol Surg. 2002 Feb;28(2):136-42.
PMID: 11860424
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