INTRODUCTIONHair loss due to disease, scarring and in particular,
androgenetic alopecia, has troubled members of the human race since the dawn of
history. A prescription for restoring hair is included in the Ebers papyrus of
ancient Egypt which has been dated at 1800 B.C. (1)
The first attempts at surgical restoration of hair loss was recorded by
Dieffenbach in 1822. In his inaugural thesis at Wurzgurg he described animal
investigations in allo and auto-transplantation of hair, skin and feathers. (2)
Autografts of hair bearing scalp using flaps and large free grafts have been in
use since at least 1893. (3) A Japanese surgeon Sasagawa reported hair follicle
transplantation as early as 1930 (4) and in 1939 Okuda, a Japanese
Dermatologist, described the correction of alopecia of the scalp, eyebrow and
mustache areas using small cylindrical punches to remove the donor tissue and
slightly smaller ones for the recipient area. (5)
Tamura transplanted single hairs to the pubic area in 1943 (6) and Fujita in
1953 reported the use of this technique for a wide variety of defects. (7) No
Japanese author mentioned the use of this technique for the correction of male
pattern baldness and because of war time conditions the work went unrecognised
outside of Japan.
Orentreich, a New York dermatologist studied the donor or recipient dominance
of various alopecia conditions and reported this work in 1959 (8). He noted that
donor dominance was observed in all cases of male pattern alopecia and was able
to refute the prevailing theories that male baldness was a result of poor blood
supply to selected regions of the scalp. His paper captured the attention of the
public and many other dermatologists were trained by him. It can be rightfully
claimed that modern hair restoration techniques date from this time.
Since then there have been a wide variety of surgical procedures described
(9) but for the sake of brevity only those still in frequent usage will be
discussed in this review.
HAIR RESTORATION TECHNIQUESThere are three broad categories of surgical
restoration procedures These may be summarized as follows-
- surgical excision, (alopecia reduction)
- scalp flaps (advancement flaps, rotation flaps and free flaps )
- free autografts of hairy scalp from the well haired to the bald area (these
grafts may be from a diameter of about 5mm down to a single hair follicle.)
All three categories of operation are still performed at the end of the
1990’s but the most generally accepted are the autograft techniques known as
"micrografting", "minigrafting" and "follicular transplantation".
1. ALOPECIA REDUCTION SURGERY
This procedure was introduced in the mid 1970’s in Canada (10) and due to its
simplicity and speed of results, gained rapid acceptance (11, 12). Within 1-2
years the operation was being performed in enormous numbers worldwide
The basic philosophy of removing part of the balding region and undermining
so as to close without undue tension, was very appealing. Many ingenious designs
were introduced (See figure 1) and their various merits argued loud and long at
Hair Restoration meetings.
Unfortunately there are other factors operating which negate the beneficial
effects of this procedure and within a few years the first warnings were being
given (13). The problems were caused by the tendency of the balding area to
stretch again if even the slightest tension was present and more importantly, by
the natural progression of the androgenetic balding process with time. Worse
still, the stresses of the surgical procedure itself were accused of
accelerating the progression of the balding. The mechanism of this can only be
speculated, but the end result was often the rapid recurrence of baldness,
visible scarring and patient disappointment within a few years.
In recent years many procedures and devices have been proposed to lessen the
effects of "stretchback" and other associated problems. These include the
Frechet Extender, the Seery periosteal anchor flap, the Unger Prolonged A.T.E
and the Nordstrom silastic suture, (14, 15, 16, 17 18)
Marzola (19) tackled the problem of the unsightly central scar from a
different approach by electing not to fully close the posterior bald area and by
using an "M" shaped incision.
By the end of the 20th century the use of alopecia reduction had declined
markedly and most surgeons were using these techniques only for highly selected
cases, if at all. This is probably an over-reaction and it is likely that the
technique will be revived in future years. With the benefit of improved
techniques, more caution used in case selection and greater attention to
surgical detail during the operation, more satisfactory results may be
expected.
2. FLAP SURGERY
Scalp flaps for reconstructive surgery of the scalp had been in use since the
1890’s (3).Short hair bearing pedicle flaps to disguise scalp scars were first
described by Passot in 1919 and again by Lamont in 1957 but made very little
impression on the world medical community (20, 21) Scalp flap surgery received
an enormous boost when Argentinean surgeon Jose Juri, who used long
temporo-parieto-occipital flaps, described his twice delayed methods at plastic
surgery meetings in 1972 and 1975 and published his results later that year
(22)
The technique was quickly adopted by courageous but inexperienced surgeons
worldwide with varying results. Tip necrosis, wound breakdown and sloughing of
the entire flap was not uncommon. The technique has a considerable "learning
curve" and was unforgiving if short cuts were taken.
In 1980, Kitaro Ohmori pioneered microsurgically anastomosed free flaps, a
lengthy and technically difficult procedure with a varying degree of success.
(24) Gradually, many surgeons abandoned hair surgery altogether or switched back
to the safer, shorter flaps and a number of inventive variations were introduced
in the following years by Stough, Nataf, Dardour, Bouhanna, Frechet, Nordstrom
and others (25).
The introduction of tissue expanders in the 1980’s made the flap techniques
safer by increasing the area of available donor scalp and enabling tension-free
closure of the wounds. In spite of these advances the residual scars in both
donor and recipient sites often left a cosmetic problem for which no adequate
solution existed and the operation gradually slipped in popularity with both
patients and surgeons. Newer techniques for free grafting were developed and by
the end of the 20th century scalp flap surgery had been abandoned by
all except a few highly experienced surgeons who specialized in this technique
(26).
3. SCALP AUTOGRAFT SURGERY
Free scalp autografts are very reliable providing they are carefully handled
and recipient areas can provide enough oxygen and other nutrients to sustain
life and growth. Once the boundaries are pushed beyond certain parameters
problems begin to occur. The difficulty is that there are as yet, no hard and
fast rules for graft survival. Grafts up to 5 mm in diameter will produce 100%
growth in certain situations while grafts of less than 1 mm will fail if trimmed
improperly or packed too closely together in some scalps.
It is important to get rid of excess dermal components before attempting to
insert grafts close together in large numbers of up to 50 grafts per square
centimeter yet single-hair grafts will fail if trimmed excessively of sebaceous
components and stem cells for future growth.
For 25 years variations on the original Orentreich technique remained in
vogue and sessions of from 40-100 x 4.0 mm grafts were transplanted from the
donor site to slightly smaller recipient sites in the bald area. Smaller 2.0 mm
grafts were used by some surgeons in the 1970’s but received no publicity at the
time. Sessions of up to 240 grafts created by quartering 60 x 4 mm grafts were
being performed by Wayne Bradshaw of Australia in the early 1980’s and extended
to over 400 later. (27, 28)
Dr Carlos Uebel of Brazil (29) appears to have been the first to perform and
speak on larger sessions of up to 1000 small grafts from around 1983 but the
technique did not receive widespread publicity until the Moser Group in Austria
introduced their paper and videotape on the procedure at a meeting in Rio de
Janeiro in 1992. (30)
Dr. William Rassman of California pushed the boundaries of the procedure out
to over 3600 grafts by 1994 (31 ) and started bringing large numbers of
patients, in various stages of completion to Hair Restoration meetings. From
that time onwards the technique became widely accepted and underwent continuous
refinement. ( 32, 33)
The use of microscopes for the dissection of grafts was introduced by Dr Bob
Limmer in 1987 (34) and was slow to gain acceptance because it tripled the time
required for graft preparation Growing disquiet concerning the poor growth which
sometimes resulted from the dense packing of minigrafts (35) led to it’s gradual
acceptance however and, championed by Seager, Bernstein, Norwood and others, the
use of this technique appear to be in the ascendancy as we enter the new
millennium.
FOLLICULAR UNIT TRANSPLANTATION TECHNIQUESIn this increasingly popular
procedure, large numbers of hairs are harvested, with the aid of a 10 power
binocular microscopes, from a strip of excised full thickness scalp. These
naturally occurring follicular clusters each containing 1-4 hairs are then
planted into needle holes in the balding area. This is a refinement of an
earlier technique known as "minigrafting" in which the follicular clusters and
some surrounding skin was planted into slits cut in the scalp with a small
scalpel blade. (fig 2)
Large numbers of hairs can be inserted at a single procedure with either
technique providing certain safeguards are met and quite extraordinary results
may be seen within 4-5 months of operation. (See fig 3) The advantage of
follicular unit grafting is that a greater hair density can be obtained and
figures of up to 61 hairs per square cm. in a single procedure have been
claimed. (36 )
The technique has the disadvantage of being more time consuming, taking
between two and three times the number of work hours to dissect and insert the
same number of hairs. This has considerable economic impact for the patient.
Proponents defend this by claiming that in good hands the number of donor hairs
damaged during the procedure is at least 20 % less than with non-microscopic
methods of dissection. (37) However it has been suggested that follicular
trans-section and bulb amputation are not as important as once thought and
considerable hair regeneration will occur if the follicular stem cells have been
preserved. (38) These points and the future direction of free grafting remain
highly debatable points as we enter the new millennium.
VARIATIONS IN TECHNIQUESThere is a wide variation in technique used by
the various surgeons performing hair transplantation. We need not be concerned
about the finer points of the procedure in this review as many excellent
descriptions are available in print and video format. (38, 39) There are
numerous minor variations such as whether the surface epithelium should be
removed or not, or whether a razor blade or scalpel is used for the dissection.
Whether sutures or staples are employed may be a matter of convenience for the
surgeon or comfort for the patient but have little effect on the cosmetic
result. These are points of individual preference and there are broader issues
which must be addressed.
I have listed these as follows:
- Graft Numbers and Graft Density
- Tumescent Anaesthesia
- Single Blade Vs Multi-blade knife.
- Role of the Stereoscopic Microscope
- The Recipient Site
- Role of the Surgical Laser
1. Graft Numbers and Graft DensityFor an average Type 6 bald scalp of
dimensions say 12 cm. x 20 cm. there is a bald area of about 200 sq. cm.. Even
at a density of only 40 hairs per sq. cm. this will require 8000 hairs. This can
be achieved with the use of 3500 follicular unit grafts or 2000 small minigrafts
if distributed evenly throughout. Most surgeons prefer to place in excess of 60
hairs per cm sq. along the frontal hair zone and this can be achieved in a
single session by some skillful surgical teams with very suitable patients. (36)
One cannot safely place large numbers of bulky minigrafts containing excess
skin elements into slits or holes at a density of much greater than 16 per sq.
cm in a single session although this would yield a result in excess of 60 hairs
per sq. cm if all grew successfully. To achieve density the grafts must be more
carefully prepared to discard redundant tissue and isolate the pilosebaceous
units. If single or double hair groupings are required it is best if these are
selected from naturally occurring groupings rather than artificially creating
small units by cutting down larger ones. (32)
The placing of grafts very close together has been termed "dense packing"
(40)and it is this aspect which has attracting the most criticism.. Cases
presented at meetings have shown how successful the technique can be with ideal
patients, but opponents have described instances where hair growth is much less
than optimal, and even cases where, allegedly, "no growth" has occurred. (41)
Drs. Rassman and Bernstein have agreed that such cases have been seen in their
practice but call them "delayed growth", insisting that significant growth can
occur after 12 months in some cases. (42) This point awaits further
clarification.
2. Tumescent AnaesthesiaFirst introduced as an aid to liposuction, (43)
this technique, in a modified form, has been embraced by hair transplant
surgeons.(44.) The aim is to distribute very dilute solutions of local
anesthetic and vasoconstrictor evenly throughout the donor and recipient sites.
At the donor area this results in a bloodless, firm cutting surface and for the
recipient site, the dermis is thickened so that one is less likely to strike the
larger blood vessels which lie just above the galea.
Operative blood loss may be greatly reduced with this technique with
beneficial effects for patient and surgeon. The operation proceeds much more
smoothly without the operative site obscured by blood and recently inserted
rafts continually "popping". For the patient there is the advantage of less
total blood-loss and decreased postoperative swelling and bruising around the
forehead and eyelids.
Epinephrine (adrenaline) is the most commonly used vasoconstrictor and is
generally added to the anaesthetic agent in a concentration of 1:100,000. In
Australia, New Zealand and some European countries the excellent synthetic drug
8-ornithine vasopressin (P.O.R-8, Sandoz) is available. (45) Unfortunately,
vasoconstriction is not always fully adequate with any currently available
technique or vasoconstrictor. Vigorous and persistent bleeding is frequently
encountered with young men who are very active physically and it is known that
preoperative anti-inflammatory agents can have a profound negative effect on the
speed of coagulation. Alcohol, aspirin and vitamin E are known offenders and it
is possible that other agents such as marihuana may be detrimental to
coagulation. Some surgeons like to infiltrate troublesome regions with small
amounts of anaesthetic containing adrenaline 1: 25,000. (46) Significant changes
in pulse rate or regularity are surprisingly rare in these cases.
3. Single Blade Vs Multi-blade KnifeAt a recent survey 73% of
respondents were using the multi-blade knife. (47) On the other hand it is
interesting that most of those using the stereoscopic microscopes now use a
single blade (48) The argument is that follicular damage is proportional to the
length of unmonitored incision line. For a single 15 cm strip there will be
approximately 30 cm of cut which is all made under visual control. With a multi
blade knife, it is claimed that only the top blade can be closely supervised and
the other 2 - 9 blades cut blindly through the donor tissues.
While there is undoubtedly a measure of truth in this argument, Dr. James
Arnold of San Jose, California, has shown us ways to minimize the potential
damage caused by the multiple parallel scalpel blades. (49,50) This includes
thorough infiltration of the superficial donor tissues with saline and
vasoconstrictor, use of the Persona Plus #10 blade for extreme sharpness, slow
movement of the cutting knife using the fingers and wrist only and frequent
checking of the several strips for change of direction of the emergent hairs.
Using these techniques and a little practice, the strip are almost perfect every
time.
The thin strips are easily dissected on a wooden tongue depressor blade or on
a trans-illuminated plate( 51). The donor skin in some individuals is very soft
and difficult to cut accurately. This has been termed "mushy dermis" and the
multi-blade knife should not be used with these individuals. (52) Dissection of
a single broad strip into thin cross-slices or "slivers", is extremely difficult
as it has no remaining turgor. Unless great care is taken, any advantages
achieved by the single blade strip excision may be lost in the slicing process.
This is where microscopic control is so useful, although frustratingly slow.
Semi-automatic dissection devices constructed from an array of closely spaced
blades have been available for several years. The merits and demerits of these
devices are still being hotly debated. (53, 54)
4. Role of Stereoscopic MicroscopesThe use of stereoscopic dissecting
microscopes was pioneered by Dr Robert Limmer of San Antonio, Texas in 1987 (34)
but has been slow to gain acceptance. Apart from the sheer technical difficulty
of graft preparation at high magnification, there is a considerable disruption
to existing staff work-practices. The number of work-hours per operation is more
than doubled compared with regular mega-session work. This means longer hours of
work or the employment of more assistants. Either way there is considerable
disruption to the equilibrium of any Hair Replacement Clinic making the change
and the possible advantages must be weighed against the disadvantages. (55)
Whether a general change to stereoscopes is justified at this time is still
being debated and many Clinics obtain outstanding results with naked-eye
dissection or with the use of low power binocular loupes. Careful inspection
reveals that there is certainly the potential for less damage to follicular
units with the use of higher power magnification but it is all very much
dependent on the skill of the Assistants. It has been stated that when using the
microscope 20% less donor strip is required to obtain the same number of well
trimmed follicular units. (32) If donor tissue is in short supply, stereoscopic
microscope dissection would certainly appear to be the method of choice.
It is worth remembering that although lip service is paid to the adage that
"every scalp hair is precious" there are in fact an awful lot of them. Surveys
show that only 23 % of men have so much baldness by the age of 70 years that
there is likely to be a severe shortage of donor follicles if they chose to push
the technique to the limit (55) Experience has shown that only a tiny percentage
of men present for transplants or continue to have transplant sessions into
their 7th decade, even if adequate follicles are available. Hair graying and a
general decrease in motivation seems to lessen the obsession for more hair that
so dominated the earlier years of these individuals.
The change to microscopic dissection might be forced by factors in addition
to donor supply. If, for instance, it could be shown that there was faster hair
growth or less hair "crinkle" after microscopic preparation of the follicular
units, this would potentially affect all patients and not just the small
percentage for whom future supply is a critical factor.
5. The Recipient SiteOnce the spacing in megasessions becomes closer
than about 16 per sq. cm. it is no longer advisable to make all the recipient
sites with a No 11 or 15c blade. The slits or holes must be tailored much more
precisely to the size of graft being used and most operators have moved to the
use of 16 and 18 gauge Nokor needles. An alternative system is provided by A-Z
Instrument’s "Lightning Knife". The handle takes SP 91 blades and has a depth
control mechanism. For finer work with density up to 40 follicular units per sq.
cm, a 20 or 21 gauge solid or hollow needle is employed.
6. Role of the Surgical Laser
It is clear that the lasers of 2-3 years ago are generally not satisfactory
for megasession work because of potential thermal damage to the remaining skin
elements. This can be serious enough to cause large areas of scalp necrosis if
grafts are closely spaced.(57, 58) Research is continuing and laser technology
is changing so rapidly it is very likely that the new age Erbium lasers will be
useful aids in future years. (59, 60)
COMPLICATIONS OF FOLLICULAR UNIT TRANSPLANTATIONThere are no
complications specific to the follicular transplantation technique but because
of the large number of units involved, there is, with the mega-session
technique, a higher probability of some inclusion cysts and graft ischemia
occurring. |