Phẫu Thuật Tạo Hình Grabb & Smith’s (Bản Cập Nhật – Kevin C. Chung)

Aging Skin
Common age-related skin changes include skin laxity, pigment changes, keratoses, and wrinkles.
Identification and diagnosis of the target skin malady guide treatment toward options aimed at reversing
these changes.
Solar damage causes actinic irregularities that are characterized histologically by epidermal hyperplasia
and keratinocyte proliferation forming seborrheic and actinic keratoses. These may be individually
treated with curettage and cryotherapy if they are isolated or more broadly targeted with full facial
resurfacing in the form of a chemical peel, mechanical dermabrasion, or ablative technologies when
appropriate. 4
Age and photodamage cause asynchronous melanin distribution and basilar hyperpigmentation or
dyschromias. Melanocytes along the basement membrane, which normally produce and distribute
melanin to 15 to 18 keratinocytes, are disrupted leading to collections of excess pigment (lentigines). Both
an increased number of basal melanocytes and increased deposition of melanin in keratinocytes are
observed. Elimination of these pigmented lesions requires targeted destruction of melanocytes in the
basal layer of the epidermis. Treatment options include trichloroacetic acid (TCA) peels, lasers that are
absorbed by melanin, or intense pulsed light (IPL). 5,6
Melasma is a condition characterized by symmetric hyperpigmented patches with an irregular outline,
commonly occurring on the face that is important to differentiate from other pigmented lesion. It is most
prevalent in young females and is exacerbated by sun exposure, pregnancy, and use of oral
contraceptives. The condition is unpredictable, usually recalcitrant to treatment and prone to recurrence.
A Wood lamp can help distinguish melasma from other more superficial skin pigmented lesions. The
Wood lamp enhances superficial pigment and leaves deeper dermal pigment, as seen in melasma,
unchanged. The treatment of melasma is targeted at blocking melanin production with topical tretinoin,
hydroquinone (HQ) 2% to 4%, and topical corticosteroids. Additionally, dermal chemical peels, IPL, and
nonablative and ablative laser treatments may improve but not fully eliminate melasma.
The etiology of static and dynamic rhytids is multifactorial. Atrophy of all layers of the skin progresses
over time resulting in thinning and deflation. The protective stratum corneum of the epidermis becomes
loose and disorganized. Loss of elastic fibers in the superficial dermis and elastotic thickening of the
remaining elastic fibers gives the skin a thickened and fissured appearance. Degeneration of collagen
fibers and reduction in glycosaminoglycans in the reticular dermis contributes to dermal thinning. A loss
of oxytalan fibers at the DEJ that normally form vertical attachments between the two layers of skin leads
to laxity and also contributes to cutaneous lines. 7-9 Telangiectasias form from weakened and dilated
blood vessels. Finally, underlying bony resorption, soft tissue volume loss, and weakened
osseocutaneous connections result in deflation and, thus, the more prominent appearance of wrinkles.
Although many factors have yet to be elucidated, what remains clear is that the treatment of skin
wrinkles requires ablative therapy of the DEJ into the papillary dermis. 8,9
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Patient Selection
Patient evaluation including a thorough history and clinical examination is required for patients seeking
skin rejuvenation. The aim should be to establish patient goals and set clear expectations of outcomes.
Photographic documentation is critical to assess treatment response.
Arguably the most important factor to consider in patients seeking skin rejuvenation is Fitzpatrick skin
type (Table 45.1). It is prognostic of developing signs of photoaging. Alternatively, the Glogau skin scale
separates patients into four categories based on cumulative sun exposure (Table 45.2). Although both of
these classification systems are useful, they do not provide the physician with all the information needed
to select the ideal patient-specific treatment. They precede the advent of nonablative and fractional
ablative technologies and fall short in addressing patients with thicker and darker skin types.
TABLE 45.1
Fitzpatrick Skin Type
Type I
Always burns, never tans, extremely fair complexion
Type II
Always burns, sometimes tans, fair complexion
Type III
Sometimes burns, always tans, medium complexion
Type IV
Rarely burns, always tans, olive complexion
Type V
Never, burns, always tans, medium brown complexion
Type VI
Never burns, always tans, markedly dark brown/black complexion
TABLE 45.2
Glogau Scale
Mild
No wrinkles
No keratosis
Wears little to no makeup
Moderate
Wrinkles in motion
Early keratosis, sallow complexion
Usually needs makeup
Advanced
Wrinkles at rest
Many actinic keratosis, telangiectasia
Always wears makeup
Severe
All wrinkles
Severe keratosis, severe photoaging
Wears makeup with poor coverage
Other factors to consider and discuss with the patient before treatment include
Skin tone, pore size, pore density, amount of sebaceous secretions
Degree of actinic damage
Depth, location and severity of wrinkles (static versus dynamic rhytids)
History of pathologic scarring
Isotretinoin, HQ, SPF use within the past 6 months
Previous surgeries, dry eyes
Color of dyschromia (brown versus red lesions)
Patient’s lifestyle, expectations, and acceptable downtime
Special attention should be taken while treating patients with freckles, melasma, or postinflammatory
hyperpigmentation (PIH). Regardless of ethnic background or skin type, a history of these signs heralds
the risk of PIH.
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Biology of Wound Healing Following Resurfacing Procedures
Resurfacing treatments rely on controlled destruction of targeted layers of the skin past the level of the
abnormality, followed by healing and replacement with healthy tissue. The goal is to optimize healing
and minimize scarring. The limits of the body’s normal healing capacity are unknown. Deeper injuries
carry higher risk of scarring. However, the mechanism and depth of insult after which permanent
scarring occurs remain unclear and vary by modality.
If the injury is isolated to the epidermal layer, an intact basal layer is capable of re-epithelialization
without involvement of the underlying dermis. Insults extending into the superficial layer of the dermis
repopulate the epidermis in two mechanisms—vertical migration of epithelial cells within dermal
appendages (hair follicles and sweat glands) and lateral migration of keratinocyte from adjacent
epidermal edges. Deeper injuries within the dermal layer stimulate fibroblast production of new collagen
via the classic inflammation, proliferation, and remodeling phases of wound healing. Appropriate
remodeling and reorganization of the collagen deposited can result in skin tightening and the decreased
appearance of fine lines. 10,11
Areas prone to scar include the neck and mandibular border that have thinner underlying dermis and
fewer adnexal skin structures for efficient re-epithelialization.
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Chemical Peels
Epidermal Targets
The targets of epidermal treatments are excess accumulation of keratinocytes, pigmented lesions, and
actinic keratoses. Complete treatment of an area is safe and effective, as the epidermal basement
membrane remains intact for rapid re-epithelialization.
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Skin Preconditioning
Skin conditioning should begin at least 6 weeks (or 8–12 weeks in darker individuals) prior to chemical
resurfacing. 8 Topical tretinoin 0.05% to 0.1% is used in conjunction with HQ 4% cream to restore even
epidermal thickness and improve solar elastosis.
Vitamin A and its derivatives (tretinoin) are effective for reversing actinic sun damage, reducing fine
lines, improving skin texture, and increasing collagen synthesis. 12 On a cellular level, there is increased
epithelial cell turn over, decreased thickness of stratum corneum keratinized cells, and decreased
adherence of epithelial cells within dermal appendages. Additionally, tretinoin suppresses melanocyte
activity. 12-14 It is often used as pretreatment for chemical peels to ensure even depth of treatment
penetration and faster postprocedure healing. 15
Many retinoids are photolabile. It is suggested that they be applied at night and to the entire face
(avoiding the corners of their mouth and eyelids). Treatment begins with either 0.025% or 0.05% tretinoin
cream every other night and can be increased to nightly application if tolerated. Side effects include dry
skin, peeling, and erythema similar to a sun burn and hypersensitivity to the UV rays—collectively
referred to as retinoid dermatitis. It is the only therapy proven to repair photodamage with benefits
persisting even after discontinuation of use (Figure 45.2).
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FIGURE 45.2 Patient with sun-damaged skin before (A) and 7 months after (B) beginning topical skin conditioning with 0.05%
tretinoin and 4% hydroquinone.
A topical 4% HQ may be added for darker skin patients twice daily to decrease melanin production. A 6-
to 12-week pretreatment with tretinoin and HQ can help prevent pigmentation irregularities following a
chemical resurfacing procedure.
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Superficial Peels
α-Hydroxy Acids
α-Hydroxy acids (i.e., glycolic, lactic, malic, tartaric, and citric acids) occur naturally in milk products and
fruit. Treatment end point for α-hydroxy acids is an indistinct frosting followed by water rinse. Glycolic is
the most widely used acid of the group because it penetrates the epidermis most easily owing to the fact
that it is a small molecule (two carbon chain). The Food and Drug Administration suggests a limit of 30%
concentration, but it has been used off label as high as 50%, and the recommended lower limit of the pH
is 3. Both the concentration and pH affect penetration depth. α-Hydroxy acids are usually applied in a gel
base for more even epidermal penetration to avoid patchy peeling. 16
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β-Hydroxy Acids
β-Hydroxy acids differ from the α-hydroxy acid group on a molecular level owing to two carbons
separating the hydroxyl groups instead of one. Salicylic acid is the most commonly used acid in this
group and usually dosed up to a concentration of 30%. There is a risk of tinnitus at higher concentrations.
The treatment end point for salicylic acid is a much more distinct white frost, and it has demonstrated
particular effectiveness in acne patients. The white frost is a byproduct of coagulation of keratinocyte
proteins. 16
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Jessner Solution
Jessner solution (formerly Coombs; resorcinol 14 g, salicylic acid 14 g, lactic acid 14 mL and OS ethanol
100 mL) is the most commonly used superficial peeling agent. 17 It combines both α-hydroxy and β-
hydroxy acids in low concentrations to take advantage of the benefits of each while limiting side effects.
There is a clear light frost end point, and it does not require neutralization owing to its rapid volatility.
The depth of treatment is controlled by number of layers applied. Jessner solution can be used in isolation
as a superficial chemical peel or as a prelude to a deeper peel, such as TCA. Preemptive Jessner
dekeratinization of the cutaneous surface promotes a more even and more intense depth of penetration
with a TCA peel.
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Medium-Depth Peels
Trichloroacetic Acid
Trichloroacetic acid (TCA) is a derivative of acetic acid that has been used since the 1960s for resurfacing
of aging skin. As it penetrates the skin, TCA causes protein coagulation and denaturation and can be used
to reach a variety of depths. It is self-neutralizing and will keep penetrating until the acid has been used
up by a certain amount of protein. Therefore, regardless of concentration, the acid can drive deeper into
the skin with repeated application. For this reason, it is important to monitor clinical depth signs during
the peeling process to achieve safe and reproducible depths of peel. TCA peel depth and clinical end
points are as follows 18 :
Partial-depth epithelial: light white frost with stable epidermis
Full-thickness epithelial: light white frost with epidermal sliding
Papillary dermis: white frost with pink beneath
Reticular dermis: opaque white frost
The TCA solution is applied with sweeping brush strokes to regional facial units and allowed to sit for
one to 2 minutes until the characteristic white frost develops. Pretreatment with a keratolytic agent like
Jessner solution will degrease the skin just before the peel for more uniform treatment with increased
depth of TCA penetration. The progression of the frosting color from pink to uniform white signifies
entry into the papillary dermis, and the subsequent gray hued frost denotes the reticular dermis. Once the
desired depth of peel is reached, the acid is diluted with water, which helps to dissipate the heat
generated. A fan may be helpful for patient comfort to further diffuse the heat. 17,19
Special care must be taken with thin, dry, crepey skin. Ultimately, practitioner experience is the best
judge of safety. Experience, technique and attention to subtle differences in the desired end points help
optimize maximum treatment efficacy while minimizing the risk of scarring.
After 24 hours, the skin will feel tight and darken. The patient should cleanse daily with water and apply
ointment to help promote re-epithelialization. Once desquamation is completed after 5 to 7 days, the
patient may begin to use moisturizer and even makeup. Erythema may persist for several months while
collagen remodeling proceeds (Figure 45.3).
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FIGURE 45.3 Patient with sun-damaged skin before (A) and 1 year after (B) face and neck lift with 30% trichloroacetic acid
(TCA) peel.
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Deep Peels
Phenol, or carbolic acid, causes rapid coagulation and destruction of surface keratin. It predictably
penetrates the upper reticular dermis for a relatively deep chemical peel to treat fine lines, wrinkles, and
dyschromias. In the 1960s, Baker-Gordon popularized a formula mixing phenol with croton oil for
severely sun-damaged and thickened skin. 20 Further investigation by Hetter demonstrated that croton oil
was the active ingredient for deep peeling in the Baker-Gordon formula, and he suggested concentrations
for different depths 21,22 (Table 45.3).
TABLE 45.3
Phenol Peel Formulas22
Hetter Formulas
Heavy Peel
Medium-Light
(most common)
Very Light (for eyelids and neck)
33% phenol
4 mL phenol 88%
6 mL water
16 drops septisol
1.1% croton oil
3 drops croton oil
33% phenol
4 mL phenol 88%
6 mL water
16 drops septisol
0.35% croton oil
1 drop croton oil
27.5% phenol
2 mL phenol 88%
5 mL water
Follow-up studies by Stone suggest that friction during application is the major factor in treatment depth
and efficacy. 23 The end point for phenol/croton oil is similar to the TCA frosting, but it appears more
gray-white. Of note, the croton oil elicits an erythematous response, which can skew the appearance of
the frost. The phenol/croton oil peel is the most aggressive and most efficacious peel for deep set and
perioral rhytids. Owing to its depth of penetration, it also carries the highest risk of scarring and
hypopigmentation. It should be performed with extreme care and caution not to exceed the slightly gray-
white frost end point. Completely gray could indicate full thickness skin destruction. Additionally, care
must be taken to make sure the solution does not inadvertently drip onto the patient, as this can lead to
uneven peels.
Posttreatment care is much like that of the TCA peel. Patients should use wet dressings for several hours
until hemostasis sets in, followed by ointment until re-epithelialization in 10 to 14 days. Erythema persists
for several months while collagen is remodeled.
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Complications of Peels
A common complication from TCA peels is PIH especially in darker skinned patients. This is thought to
be due to over production of melanin from newly regenerated melanocytes. Patients with a history of
herpes are at risk for outbreak during the peeling process and should be prophylactically treated with
antivirals. Pretreatment with isotretinoin (Accutane) may increase the risk of hypertrophic scarring
because it interferes with the re-epithelialization process and keratinocyte adherence along dermal
adnexal structures (hair follicles and sweat glands).
Complications of phenol/croton peels include hypopigmentation due to decreased melanocytes.
Following treatment, PIH may occur while neomelanocytes are especially sensitive to sunlight
stimulation. Sunscreen must be used regularly. Rarely wound infections with yeast or staphylococcus and
streptococcus can occur and must be treated immediately. Cardiac monitoring and easily accessible
resuscitation equipment are recommended in case of arrhythmia for phenol peels.
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Dermabrasion
Mechanical injury from surgical sanding or dermabrasion is thought to be one of the first resurfacing
techniques, which was developed as early as the 1940s. The treatment involves mechanical abrasion and
complete obliteration of the epidermis with varying depth of dermal penetration depending on the
desired effect. Depth of treatment is determined through reliable end points:
DEJ: uniform pink
Superficial papillary dermis: punctate bleeding, transudate
Midpapillary dermis: confluent bleeding
Deep papillary dermis: scattered bleeding
Dermabrasion is most commonly used to reduce raised scars, especially acne scars, to bring them to the
same level as the surrounding skin. Baker described the current technique for microdermabrasion in 1998,
which uses course crystals, diamond fraise, or a wire brush in lieu of sand paper to exfoliate the
epidermis. 24 Histological studies have demonstrated permanent reduction in dermal thickness following
dermabrasion, which is distinct from the compensatory dermal thickening that occurs following chemical
peels and coagulative lasers. 24-27
Dermabrasion patients receive pretreatment nerve blocks, intravenous sedation, and/or general
anesthesia for comfort. Rhytids are marked prior to treatment. The hand-held power dermabrading
instrument spins at 12,000 to 15,000 rpm. Gentle pressure is applied to the tissue until the proper depth is
achieved. Treatment end points for dermabrasion depend on the desired depth of treatment based on the
predetermined depth of the wrinkle. There is a notable color transition from white in the epidermal layer
to the pink DEJ. The papillary dermis layer demonstrates a progression from punctate to an almost
confluent bleeding pattern with a fine lattice. Deeper reticular dermal bleeding becomes sparser with the
points spread out wider.
The challenge with dermabrasion is the technical demands of uniform treatment. It is excellent for
isolated scars or the lip borders, but it is difficult to stabilize the tissue for even sanding with the power
rotary device. This can be problematic particularly around the eyes. Temporary freezing techniques may
increase tissue stiffness to facilitate ease of treatment. 26
Following treatment, a wet dressing is applied until the bleeding stops a few hours later. Once the wound
bed is hemostatic, a thin layer of ointment is applied and either covered with a semiocclusive xeroform
gauze or left uncovered until re-epithelialization is complete.
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Laser Resurfacing
Laser technology began to develop in the 1960s. The devices use light energy and are classified by
wavelength on the electromagnetic spectrum (Figure 45.4). Discovery of selective photothermolysis, or the
specific affinity of certain wavelengths for different biologic targets or chromophores, ultimately made way
for the advent of cutaneous laser resurfacing in the 1980s. 22 The chromophore or target in the treatment
of skin resurfacing for fine lines and rhytids is water. Other chromophores that are popular targets
include melanin and dermal hemoglobin. Selective photothermolysis uses a wavelength that reaches and
is preferentially absorbed by the desired chromophore (Figure 45.5). The tissue is then exposed to the
energy for a duration equal or less than the time it takes for the target structures to cool, which is called
the thermal relaxation time. Sufficient energy must be delivered to damage the target. Laser treatments
targeting water produce histological changes similar to those of phenol peels, although the permanence
of skin changes following laser treatment remains controversial. 23 Complete photorejuvenation requires
targeting water, hemoglobin, and melanin. No one laser or wavelength meets all of those objectives on its
own.
FIGURE 45.4 Electromagnetic spectrum of light wavelengths.
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FIGURE 45.5 Chromophore absorption spectrum, illustrating which wavelengths are preferentially absorbed by specific
components of the skin.
All lasers have four basic components: an active medium, an energy source, a rear reflective mirror, and a
partially reflective mirror/output coupler (Figure 45.6). Laser light differs from ordinary light in that it is
more organized. Laser light is monochromatic (all photons in the laser beam exhibit the same color
wavelength), collimated (all photons travel in parallel), and coherent (all photons are in phase and travel
in the same direction). 28
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FIGURE 45.6 Components of a laser. The external power source excites the medium, which stimulates photon emission.
These photons collide with surrounding atoms that release more photons all of which are reflected between the mirrors at either
end of the optical chamber. Opening the output coupler allows emission of the laser beam.
There are several basic parameters that should be considered when performing a procedure using light. 29
Light interaction with tissue is based on absorption and scattering. A beam of light weakens as it moves
through scattering surfaces. The dermis is white making it a strongly scattering surface. In general,
shorter wavelengths have a higher absorption coefficient and penetrate more superficially compared with
longer wavelengths (Figure 45.7). Wavelengths in the near-infrared spectrum (740–1300 nm) are absorbed
by the darkest shade of gray present in tissue and far infrared spectrum (1300 nm+) wavelengths are
absorbed by water as opposed to pigment.
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FIGURE 45.7 Illustration demonstrating the inverse relationship between wavelength and depth of penetration.
(From Farkas, JP, Hoopman, JE, Kenkel, JM. Five parameters you must understand to master control of your laser/light based devices. Aesthet Surg J.
2013;33(7):1059-1064. Reproduced by permission of The American Society for Aesthetic Plastic Surgery, Inc.)
For continuous wave lasers, important factors include power, time, and spot size, while for pulsed lasers,
parameters include energy per pulse, pulse duration, spot size, fluence, and repetition rate. Energy is
measured in joules (J). Power is the rate of energy delivered and is measured in Watts (W = J/s). Spot size
(cm2) is the area over which the laser energy is delivered. Power density (power/spot size or W/cm2) can
be controlled in a manner similar to a magnifying glass by concentrating a given number of photons over
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a smaller area to increase thermal effect on a target tissue. Thus, decreasing the spot size will increase the
power density. However, decreasing spot size also decreases depth of penetration and increases scatter.
To maintain the depth of thermal energy delivered, one must increase the power (rate of energy
delivered) as one decreases the spot size (Figure 45.8). For example, a 6 mm spot size and 90 J/cm2 may be
needed to close a vessel; if you increase the power density and use a 3 mm spot size instead, the energy
needed would increase to 190 J/cm2 to have a similar effect.
FIGURE 45.8 A. Power density equals power multiplied by spot size. A given number of photons are concentrated into an
area or spot size. As the spot size decreases, the power density increases. B. Effective treatment zones versus spot size.
Depth of penetration is proportionally related to spot size: larger spot sizes allow for deeper absorption of a given wavelength.
(From Farkas, JP, Hoopman, JE, Kenkel, JM. Five parameters you must understand to master control of your laser/light based devices. Aesthet Surg J.
2013;33(7):1059-1064. Reproduced by permission of The American Society for Aesthetic Plastic Surgery, Inc.)
Finally, pulse width is the time over which the energy is delivered and represents the duration of laser
exposure. The energy must be deposited in the target before the target has time to cool. Thermal
relaxation time is how long it takes for a target chromophore to release over half of the temperature rise
after laser exposure. Larger targets take longer to cool. For example, a 200 to 300 µm hair follicle has a
thermal relaxation time of 10 to 100 ms, whereas a 100 µm blood vessel has a thermal relaxation time of
5 ms. Assuming equal power densities are applied, longer pulse durations cause greater collateral
damage. 30
The degree of thermal injury and thus tissue response are related to the duration and temperature of
exposure. Cell death is more sensitive to temperature than time, as seen when protein denaturation
increases linearly with time and exponentially with temperature. 31 Most resurfacing devices convert light
or electrical energy to heat. Under 43°C, the skin remains unharmed for as long as 20 minutes. Molecular
structural changes occur at temperatures from 43 to 50°C. High temperatures at shorter times (>100°C for
1 ms) can induce cell death as well. 22
Effective laser therapy aims to maximize thermal effect on specific targets while minimizing collateral
damage. Selective photothermolysis aims to deliver thermal energy to targets with a higher absorption
coefficient than the surrounding tissue to minimize damage to innocent bystanders. 31 When the ratio of
light absorption between the chromophore and surrounding tissue is large (>10), there is a desirable
advantage. However, when the target is water, which constitutes 65% of the dermis, differential light
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absorption cannot be manipulated to protect neighboring structures. Other ways to localize temperature
elevation to specific targets is to cool surrounding areas or deliver very small beams (fractional methods).
32
Surface cooling methods have helped deliver higher energy to targets with less risk of collateral damage
and at a deeper depth. Epidermal damage is most likely with visible light (green-yellow, IPL) treatments
targeting dermal hair follicles and blood vessels. Cooling is also important in infrared laser technology to
prevent bulk heating of deep tissues. When water is the chromophore, even at low power density, the
ubiquitous nature of the target creates the risk of catastrophic tissue damage. Cooling or fractionated
techniques must be used to avoid laser-induced top to bottom skin injury.
Generally speaking, lasers used in skin resurfacing are either ablative or nonablative and can be full field
or fractionated. Ablation refers to the uniform destruction of tissue within the epidermis and/or papillary
dermis. Nonablative resurfacing spares epidermal destruction, targeting deeper structures within the
dermis. This triggers collagen remodeling during the process of healing. Fractional photothermolysis
delivers treatment in core sections or microthermal zones, leaving untreated areas in the skin to promote
more rapid healing.
A word about safety: Appropriate laser safety precautions include wavelength-appropriate eyewear,
appropriate signage, and smoke evacuation.
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Types of Lasers
Ablative Lasers
There are two ablative lasers with the highest affinity for water, and those are erbium:YAG and carbon
dioxide (CO2). Both of these have wavelengths in the infrared portion of the electromagnetic spectrum.
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CO2 Laser
The earliest CO2 (10,600 nm) lasers used continuous wave to heat water in the skin to ablate fine lines.
The primary chromophore is water, and the depth of penetration can be controlled by altering power,
density, or duration of exposure. 33 The threshold for tissue ablation has been calculated to be 5 J/cm2.
Below this, the tissue is not vaporized but rather coagulated which is also useful to trigger skin
remodeling. At high powers and short exposures, the CO2 laser can be used for tissue cutting (depth of
100–150 microns). 34 Significant variability in depth of injury exists among different CO2 lasers and carries
with energy and pulse duration.
Continuous CO2 laser resurfacing remains the most effective method of wrinkle removal. It is effective
against deep coarse fixed perioral and periorbital rhytids. 35 Redundant skin is tightened by thermal
coagulation, wound healing, and collagen contraction. These dramatic results come at the expense of slow
healing, painful recovery, prolonged erythema (6+ months), and permanent hypopigmentation which has
decreased the CO2 modality’s popularity. 36
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Erbium-Yttrium-Aluminum-Garnet Laser
The next major advancement was the development of the erbium-yttrium-aluminum-garnet (Er:YAG)
2940-nm wavelength laser. The 2940 nm wavelength has an affinity for water that is nearly 12 to 15 times
higher than that of the CO2 laser. This affinity allows Er:YAG to deliver energy to specific depths in the
skin without heating the surrounding tissue, thus causing less collateral damage. However, the limited
photothermal effects of this laser also lead to significantly reduced collagen contraction. Newer Erbium
devices have lengthened the laser pulse duration to induce better tissue contraction. 37 The Er:YAG laser
can be used to deliver either coagulation or cool ablation. This is a solid-state laser with a solid rod
through which the light is passed. This is different from the CO2 laser that is only a heat-coagulative
ablative technology. The cool ablation mode produces a result similar to dermabrasion. In the cool
ablative mode, the resulting skin may have thinner dermis, as with dermabrasion. Erbium and CO2 lasers
have similar resurfacing results with settings of 50% overlap, 25 to 100 microns of ablation, and 50 to
100 microns of coagulation. 38
The clinical end point of using the CO2 laser is a chamois color seen with ablation of the papillary dermis
and waterlogged cotton thread appearance upon penetration into the reticular dermis. 39 With each
additional pass of the CO2 laser, there is a diminishing or plateaued response because the residual
carbonized tissue acts as a heat sink. 40 Erbium lasers create less coagulated tissue to absorb heat and
make it is easier to drill deeper wounds into the skin with each pass. Following CO2 laser treatment, the
desiccated tissue should be wiped off; however, after erbium laser treatment, the barrier is left in place for
faster healing and decreased posttreatment pigmentary changes. A split-face study of CO2 and Er:YAG
laser resurfacing study demonstrated a 63% improvement on the CO2 laser side with 7.7 days of crusting
compared with 48% improvement on the Er:YAG side with 3.4 days of crusting, although these results
are highly dependent on depth of treatment and energy used. 41,42
Ablative lasers are also commonly used to treat acne scarring. Specifically, elevated acne scars are more
amenable to ablative resurfacing than ice-pick or nondistensible surface irregularities. Benign
hyperplasias such as rhinophyma and other epidermal proliferations (seborrheic keratosis, actinic
keratosis, xanthomas) can be treated with ablative laser therapy. Of note, ablative laser therapy carries the
risk of infection (bacterial, viral, and fungal) due to the absence of the protective epidermal barrier. All
patients should be treated prophylactically with antiviral medications to prevent herpetic infection of the
denuded skin. This treatment should begin 1 or 2 days before laser treatment and continue for 2 weeks
following (Figures 45.9 and 45.10).
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FIGURE 45.10 Patient with deep perioral static rhytids before (A) and 9 months after (B) erbium laser ablative resurfacing.
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FIGURE 45.9 Patient with sun-damaged skin before (A) and 7 days (B) and 1 year (C) after erbium laser ablative resurfacing.
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Fractionated Photothermolysis Lasers
Fractionated lasers first became available in 2003 to preserve dermal appendages for more efficient
healing. They are designed to keep the stratum corneum largely intact, delivering thousands of
microscopic ablative injuries surrounded by healthy tissue. Fractionated lasers ablate a variable amount
of dermis depending on the physician’s preferred density. 43 The laser creates an array of microthermal
treatment zones. These columns of thermally denatured collagen that vary in size and density are
scattered between islands of untreated skin to maintain the skin’s barrier function and act as a reservoir
for healing to speed re-epithelialization. 44 The advent of fractionated photothermolysis, in theory, allows
a more aggressive depth of treatment with a better safety profile to the predecessor ablative lasers. These
devices can safely be used on darker skinned patients. The skin surface usually heals within 7 days;
however, the recovery and downtime for patients remains significant with prolonged erythema and
swelling for several months post treatment. The best parameters for optimal outcomes remain the subject
of ongoing debate.
There are multiple ablative and nonablative fractional lasers available commercially. They differ based on
spot sizes, depth of treatment, energy delivered, and mode of delivery. One of the first clinical
applications of fractionated laser therapy was treatment of facial melasma. Initial results suggested
resolution of the deep pigment; however, lengthy follow-up demonstrated a tendency of the melasma to
recur. Fractionated treatments have led to less dramatic results than the nonfractionated ablative devices,
with noticeable improvement of periorbital rhytids in only 30% of patients in one study, which improved
to 54% improvement after four treatments. 45 These results are highly dependent on depth of treatment,
density of microthermal treatment zones, and energy used. Fractionated ablative treatments have also
proven to be relatively safe in notoriously difficult to rejuvenate areas such as the neck and décolletage
because the areas of undamaged skin left behind aide in efficient healing.
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Hybrid Fractionated Lasers
Dual wavelength hybrid fractional lasers use both fractionated Er:YAG 2840 nm to deliver epidermal
ablation up to 100 µm and diode laser 1470 nm to cause dermal coagulation from 100 to 700 µm. 46 In
doing so, there is simultaneous treatment of the epidermis and dermis, but the fractional component
allows more efficient healing over an intact dermis. The epidermis is able to regenerate in 24 hours
following ablation to 100 µm. The underlying coagulated dermis heals more slowly over 1 week. This
dual technology takes advantage of ablative and nonablative technology to obtain more dramatic ablative
type results with shorter nonablative type healing times. Early studies suggest improvement in skin
texture, pigment, pore size, and number; additional studies are ongoing. 47
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Nonablative Lasers
Nonablative facial skin rejuvenation refers to interventions that preserve the epidermis and generate
selective dermal heating for wrinkle reduction. These so called subsurface remodeling include electrical,
light, and ultrasound modalities to induce selective dermal injury and remodeling. 48 Nonablative devices
include neodymium-doped yttrium aluminum garnet (Nd:YAG), pulsed dye laser (PDL), IPL, and
potassium-titanyl-phosphate (KTP). Their applications are wide, including acne scars, dyschromias, and
vascular lesions.
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Laser Treatment of Vascular Lesions
Blood vessels can be heated by three different techniques:
Visible light: 520 to 600 nm
Near-infrared I: 755, 700 nm
Near-infrared II: 940, 980, 1064 nm
The chromophore target oxyhemoglobin has absorption peaks at 418, 542, and 577 nm. Using any of these
wavelengths when treating lesions with high hemoglobin concentration (telangiectasias) relative to their
surrounding tissue induces intravascular thrombosis and subsequent fibrosis of the target vessel. This
leads to an immediate purpuric reaction, which can be avoided by delivering longer pulse widths (>6 ms)
to gently heat the vessel and avoid bruising.
Visible light (520–600 nm) has a very strong affinity for hemoglobin and melanin, whereas infrared
technology has progressively weaker affinity. Specifically, infrared II has the weakest affinity for melanin
rendering it safer to use in patients with higher Fitzpatrick types.
Treatment considerations when selecting a device include blood vessel depth and thickness and patient
skin type. Equally important considerations include hair follicles, melanin content of skin, and other
structures that may unintentionally absorb light energy. It is important not to compress the target vessel,
as compression of the vessels can exclude blood and decrease the laser target. Conversely, vasodilatory
anesthetics should be avoided in the treatment of vascular lesions.
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Pulsed Dye
The pulsed dye laser (PDL) emits a wavelength of 577 nm or 585 and 595 nm for deeper tissue
penetration up to 1.2 mm. These wavelengths target hemoglobin as the chromophore and make the PDL
an effective laser choice for treating vascular lesions (telangiectasias, capillary malformations, rosacea).
Short pulse durations (0.45–3 ms) have been shown to cause a bruised appearance related to intravascular
coagulation and vessel leakage. Longer pulse durations (6–10 ms) are less effective, but when multiples
passes are employed (pulse stacked) purpura-free results can be achieved.
The 577 to 595 nm wavelengths are also absorbed by melanin to a lesser degree than hemoglobin. This
device should be used with caution in patients with darker skin, as they may be prone to burns and
depigmentation. The treatment has been described as a hot rubber band snapping on the skin and is
generally well tolerated by adults.
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Potassium-Titanyl-Phosphate
Potassium-titanyl-phosphate (KTP) lasers have a wavelength of 532 nm and are popular for treatment of
fine facial capillaries, small leg veins, capillary malformations, and rosacea. The wavelength closely
corresponds to hemoglobin absorption peak at 542 nm. This device is safest in patients with skin
phototypes I-III as the wavelength is also absorbed by melanin. Patients usually require 6 to 12 serial
treatments under general anesthetic with this laser to adequately treat their vascular lesions. The KTP
laser is associated with a fleeting stinging sensation and is generally well tolerated by adults. 49
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Nd:YAG
The Nd:YAG (1064 nm) penetrates deeper than the 532 nm wavelength. The darkest target in the field
absorbs this wavelength; it is not attracted to a specific chromophore. The 1064 nm wavelength has much
less affinity for hemoglobin than the KTP and PDL lasers, but its absorption by melanin is also limited,
making it relatively safer to use in darker skinned patients. With a longer wavelength, this laser can be
used to treat deeper vascular lesions. Higher energy and longer pulse widths are required when using
this wavelength because of its relatively low absorption coefficient by hemoglobin, making it potentially
painful and with a narrow window of safety. 50
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Intense Pulsed Light
Intense pulsed light (IPL) is a filtered flash lamp that emits noncoherent, noncollimated, polychromatic
light at a range of 420 to 1300 nm. These devices are not lasers, much like a laser an IPL device can be
fitted with filters to eliminate unwanted wavelengths and target more specific chromophores. A 550 nm
filter will block all wavelengths from 420 to 550 nm, delivering only wavelengths of 551 to 1200 nm to the
tissue. Similar to penetration of laser light, longer IPL wavelengths penetrate deeper into the tissue for
treatment of deeper targets. Different filters serve different purposes (i.e., vascular lesions, pigmented
lesions, and hair removal).
Two to three passes of this device to the particular treatment area are performed in different orientations
help produce uniform treatment without zebra-like pigmentary irregularities and skipped areas. Clinical
end points vary with target chromophore. They may include darkening of the pigmented lesions and
disappearance or dark blue appearance of the telangiectasias. IPL is safest to use in patients with skin
phototypes I-III. Care must be taken to avoid photoepilation of eyebrows or bearded skin. 51
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Melanin-Containing Lesions
Melanin has a broad spectrum of absorption. Many different lasers and wavelengths can treat melanin-
containing lesions. The depth of the pigment is important in selecting the appropriate treatment
modality. The KTP laser can effectively target epidermal and papillary dermal pigment in most skin types
with limited recurrence. 52 PDL at 595 nm has affinity for both hemoglobin and melanin. By manually
compressing the skin with the laser hand piece, the vasculature blanches removing the hemoglobin
chromophore, and melanin-containing lesions absorb the light. Q-switched Nd:YAG laser with a
wavelength of 1064 nm is much less well absorbed by melanin than the aforementioned devices, but it
reaches deeper tissue and can treat dermal pigmented lesions.
Melasma is difficult to predictably treat with laser resurfacing. Er:YAG and Q-switched lasers can lead to
temporary improvement followed by problematic PIH. 53 The aforementioned topical modalities remain
the mainstay treatment.
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Postprocedural Care
Meticulous postprocedural care is paramount for optimal results. Open or closed dressings may be used
to dress the patient. Potential advantages to open dressings include fewer wound infections, ability to
survey the resurfacing process, and decreased maceration. Pain is a frequent patient complaint when
open dressings are used in ablative therapy. Immediately after ablative therapy, serous drainage is
expected. Keratinaceous crust forms over 24 to 48 hours. If the open wound care regimen is selected, the
patient must frequently wash with normal saline or 0.25% acetic acid (dilute vinegar) soaks followed by
gentle blotting for exfoliation. Moisturizer is applied during re-epithelialization.
Numerous studies have shown that occlusive dressings may speed re-epithelialization and decrease
discomfort, erythema, and edema. These occlusive dressings (e.g., Biobrane, Flexzan) can be used for 1 to
3 days and then left open to air.
Edema and erythema of treated skin is common following both ablative and nonablative therapies,
although they are more pronounced and longer lasting in ablative procedures. 54 Nonablative edema and
erythema can resolve in 24 to 48 hours following treatment. Most patients are able to return to normal
activities and apply makeup in 7 to 10 days. Delayed hypopigmentation or PIH are feared complications
of laser resurfacing. 55 Lines or demarcation of treated areas can be avoided by feathering and
crosshatching during nonablative laser treatment. Caution must be taken when overlapping treatments
during ablative therapy. Decreasing the density and/or energy may allow for this without focused areas
of deeper injury.
Infection must be recognized and treated early. Staphylococcal, viral, or fungal infections are all possible
following ablative treatments. The use of prophylactic antivirals is recommended from the day before the
procedure to up to 2 weeks after. Antibiotics and antifungal treatment can be utilized on a case by case
basis, although they are not routinely administered.
Scarring following laser therapy is a risk that is especially pronounced in the neck and chest. It is
important to make sure the patient has not had any sun exposure in the 2 weeks leading up to light
energy treatment, increasing risk of burns and dyspigmentation. PIH can occur in the months following
treatment when new repopulating melanocytes are extrasensitive to sunlight. It can be seen can be seen in
any patient who has had an energy-based treatment. Use of 4% HQ cream and sun avoidance help
decrease the risk of PIH.
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Conclusion
A wide range of resurfacing techniques from peels to mechanical dermabrasion to selective
photothermolysis can all be employed to achieve predictable and safe results. Careful patient selection
and meticulous tailoring of resurfacing modalities based on individual needs is of the utmost importance
to achieve predictable, safe, and appreciable results. These noninvasive techniques are never a
replacement for surgical intervention but can be extremely powerful adjuncts to help ensure the most
satisfied patients.
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Questions
1. What is the clinical end point for full-field CO2 ablative facial resurfacing?
a. Punctate bleeding
b. Subcutaneous fat
c. Pale yellow coloration of the skin
d. No clinical end point, settings determine therapy
2. What is the clinical end point for full-field erbium:YAG ablative facial resurfacing?
a. Punctate bleeding
b. Subcutaneous fat
c. Pale yellow coloration of the skin
d. No clinical end point, settings determine therapy
3. Two days after full-face erbium laser resurfacing, a 54-year-old otherwise healthy woman with
Fitzpatrick type II skin experiences facial pain and pruritus. She has been treated with occlusive
dressing immediately post procedure. On examination, there is diffuse erythema and edema. Which
of the following is the most likely diagnosis?
a. Allergic reaction
b. Bacterial infection
c. Fungal Infection
d. Herpes simplex virus
e. Normal healing
4. Which of the following is the beneficial effect of pretreatment with tretinoin prior to facial chemical
peel?
a. Decreased epidermal proliferation
b. Decreased fibroblast deposition of glycosaminoglycans
c. Increased epidermal melanin
d. Increased transit rate of keratinocytes through the epidermis
5. A patient returns to the office 2 weeks after full-face carbon dioxide ablative laser resurfacing with
persistent erythema and edema. Which of the following topical treatments will decrease the patient’s
postoperative erythema?
a. Amoxicillin
b. Ascorbic acid
c. HQ
d. Prednisone
e. Valacyclovir
6. A patient presents to your office with pigmented lesions of the face and desires fractional laser
resurfacing. The patient is followed by a dermatologist and completed an oral course of isotretinoin
2 months ago. What is your next step?
a. Schedule fractionated laser treatment at next available appointment
b. Contact the dermatologist and request his opinion on proceeding
c. Wait 10 months and then schedule the procedure
d. Begin a course of oral antivirals in preparation for procedure
7. A patient with Fitzpatrick type III skin type undergoes CO2 laser resurfacing for facial rhytides and
acne scars. What is the patient most at risk for after the procedure?
a. Treatment failure
b. PIH
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c. Infection
d. Scarring
e. Hypopigmentation
1. Answer: c. Color indicators help define clinical end points for CO2 ablative laser. Vaporization
limited to the epidermis results in an opalescent hue with a cracking sound. Entering the superficial
papillary dermis is characterized by a flat smooth pink color with punctate bleeding that progresses
to confluent bleeding. Further vaporization into the deeper papillary dermis has a characteristic
yellow chamois skin color, which is the common end point for treatment. Finally, the reticular dermis
has a waterlogged cotton thread appearance.
2. Answer: a. Erbium ablative therapy is optimal for fine and superficial skin resurfacing. The goal of
treatment is a depth just past the DEJ. This depth is characterized by pinpoint bleeding, which
usually is the clinical sign to stop treatment.
3. Answer: e. Erythema and edema are expected for routine healing at 48 hours following an ablative
laser resurfacing. Desquamation can last anywhere from 5 to 7 days, after which the skin should re-
epithelialize. Abnormal postoperative infections would be marked by increased pain, increased
drainage, and possible blisters or vesicles if herpes simplex is suspected.
4. Answer: d. Tretinoin is one of the most studied resurfacing agents on the market. At a histological
level it has been shown to improve the appearance of fine lines by increased glycosaminoglycan
content of the skin, decrease melanocyte activity, and increase epidermal proliferation. Epidermal
cells have a faster turn over rate as they travel from the basement membrane to the surface.
5. Answer: b. Vitamin C, L-ascorbic acid, is powerful antioxidant normally found in the skin. It is
rapidly depleted during the inflammatory state. It is readily absorbed transcutaneously and has been
shown to decrease both the degree and duration of post–CO2 laser erythema. It is essential for
collagen synthesis and also has photoprotective qualities.
6. Answer: c. Isotretinoin, 13-cis-retinoic acid, use has been shown to cause delayed wound healing
and potentially abnormal scarring. The mechanism is thought to be related to disruption of
keratinocyte adherence along dermal adnexal structures interfering with the skin’s ability to re-
epithelialize. It is recommended that treatment with isotretinoin be stopped 6 to 12 months prior to
any elective cosmetic laser resurfacing procedure to avoid potential complications.
7. Answer: b. PIH tends to affect darker skinned patients with greater frequency. It is an acquired
hypermelanosis following cutaneous inflammation or injury. Patients with higher Fitzpatrick skin
type do not have an increased risk of treatment failure or infection with ablative procedures. They
are more likely to develop hyperpigmentation than hypopigmentation.
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References
American Society of Aesthetic Plastic Surgeons. Cosmetic Surgery National Data Bank Statistics; 2017. Available at

Ha, RY, Nojima, K, Adams, WP Jr, Brown, SA. Analysis of facial skin thickness: defining the relative thickness index. Plast Reconstr Surg.
2005;15(6):1769-1773.
Iyengar, S, Makin, IR, Sadhwani, D, et al. Utility of a high-resolution superficial diagnostic ultrasound system for assessing skin thickness: a
cross-sectional study. Dermatol Surg. 2018;44:855-864.
Ortonne, JP, Pandya, AG, Lui, H, Hexsel, D. Treatment of solar lentigines. J Am Acad Dermatol. 2006;54:S262.
Weiss, RA, Weiss, MA, Beasley, KL. Rejuvenation of photoaged skin: 5 years results with intense pulse light of the face, neck and chest.
Dermatol Surg. 2002;28:1115.
Kilgman, DE, Zhen, Y. Intense pulsed light treatment of photoaged skin. Dermatol Surg. 2004;30:1085.
Bosset, S, Barré, P, Chalon, A, et al. Skin aging: clinical and histopathologic study of permanent and reducible wrinkles. Eur J Dermatol.
2002;12:247.
Smith, L. Histopathologic characteristics and ultrastructure of aging skin. Cutis. 1989;43:414.
Lee, JY, Kim, YK, Seo, JY, et al. Loss of elastic fibers causes skin wrinkles in sun-damaged human skin. J Dermatol Sci. 2008;50:99.
Janis, JE, Harrison, B. Wound healing: part 1. Basic science. Plast Reconstr Surg. 2014;133(2):199e-207e.
Janis, JE, Harrison, B. Wound healing: part 2. Clinical applications. Plast Reconstr Surg. 2013;133(3):383e-392e.
Kligman, AM, Grove, GL, Hirose, R, Leyden, JJ. Topical tretinoin for photoaged skin. J Am Acad Dermatol. 1986;15:836-859.
Giguere, V, Ong, ES, Segui, P, Evans, RM. Identification of a receptor for the morphogen retinoic acid. Nature. 1987;330:624-629.
Petkovich, M, Brand, NJ, Krust, A, Chambon, P. A human retinoic acid receptor which belongs to the family of nuclear receptors. Nature.
1987;330:444-450.
Hevia, O, Nemeth, AK, Taylor, JR. Tretinoin accelerates healing after trichloroacetic acid chemical peel. Arch Dermatol. 1991;127:678-682.
Stagnone, JJ. Superficial peeling. J Dermatol Surg Oncol. 2003;42:829.
Obagi, ZE, Ichinose, H, Obagi, ZE, Laub, DR. TCA-based blue peel: a standardized procedure with depth control. Dermatol Surg. 1999;10:773-
780.
Obagi, ZE. Obagi Skin Health Restoration and Rejuvenation. New York, NY: Springer; 2000.
Johnson, JB, Ichinose, H, Obagi, ZE, Laub, DR. Obagi’s modified trichloroacetic acid (TCA)-controlled variable-depth peel: a study of clinical
signs correlating with histological findings. Ann Plast Surg. 1996;3:225-237.
Baker, TJ, Gordon, HL. The ablation of rhytids by chemical means: a preliminary report. J Fla Med Assoc. 1961;48:451.The art and science behind
chemical peeling is discussed. This landmark article came at the beginning of the development of chemical resurfacing techniques. Description of the
technique for peeling is included.
Hetter, GP. An examination of the phenol-croton oil peel. Part I: dissecting the formula. Plast Reconstr Surg. 2000;105:227.
Hetter, GP. An examination of phenol-croton oil peel: face peel results with different concentrations of phenol and croton oil. Plast Reconstr
Surg. 2000;105:1061.
Stone, PA. Chemical peeling. In: Rubin, MG , ed. Chemical Peels. Philadelphia, PA: Elsevier; 2007:87.
Baker, TJ, Gordon, HL. Chemical face peeling and dermabrasion. Surg Clin North Am. 1971;51:387.
Karimipour, DJ, Karimipour, G, Orringer, JS. Microdermabrasion: an evidence-based review. Plast Reconstr Surg. 2010;125:372.
Poilos, E, Taylor, C, Solish, N. Effectiveness of dermasanding (manual dermabrasion) on the appearance of surgical scars: a prospective,
randomized blinded study. J Am Acad Dermatol. 2003;48:897.
Gold, MH. Dermabrasion in dermatology. Am J Clin Dermatol. 2003;4(7):467.
Alster, TS, Lupton, JR: Lasers in dermatology: an overview of types and indications. Am J Clin Dermatol. 2001;2:291.
Farkas, JP, Hoopman, JE, Kenkel, JM. Five parameters you must understand to master control of your laser/light based devices. Aesthet Surg
J. 2013;33:1059-1064.A review of the basic science behind laser- and light-assisted selective photothermolysis. This article reviews energy, power,
fluence, spot size, and pulse width, as they relate to choosing appropriate settings for patients. Comprehensive explanations of the guiding principles of
light energy.
Herd, RM, Dover, JS, Arndt, KA. Basic laser principles. Dermatol Clin. 1997;5:355.
Anderson, RR, Parish, JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science. 1983;22:535.
Achauer, BM. Lasers in plastic surgery: current practice. Plast Reconstr Surg. 1996;99:1442.
Walsh, JT, Flotte, TJ, Anderson, RR, et al. Pulsed CO2 laser tissue ablation: effect of tissue type and pulse duration on thermal damage. Lasers
Surg Med. 1988;8:108-118.
Newman, JB, Lord, JL, Ash, K, et al. Variable pulse erbium:YAG laser skin resurfacing of perioral rhytides and side-by-side comparison with
carbon dioxide laser. Lasers Surg Med. 2000;26:208-214.
Fitzpatrick, RE, Goldman, MP, Satur, NM, et al. Pulsed carbon dioxide laser resurfacing of photo-aged facial skin. Arch Dermatol.
1996;132(4):395-402.This is a blinded assessment of CO 2 laser efficacy for periorbital and perioral rhytids. It was a landmark paper for selective
photothermolysis and the clinical application of ablative facial resurfacing.
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Hunzeker, CM, Weiss, ET, Geronemus, RG. Fractionated CO2 laser resurfacing: our experience with more than 2000 treatments. Aesthet Surg
J. 2009;29:317-322.
Fitzpatrick, RE, Rostan, EF, Marchell, N. Collagen tightening induced by carbon dioxide laser versus erbium:YAG laser. Lasers Surg Med.
2000;27:395.
Conn, H, Nanda, VS. Prophylactic fluconazole promotes reepithelialization in full-face carbon dioxide laser skin resurfacing. Lasers Surg Med.
2000;26:201-207.
Zachary, CB. Modulating the Er:YAG laserModulating the Er:YAG laserModulating the Er:YAG laser. Lasers Surg Med. 2000;26:223-226.
Alster, TS, Garg, S. Treatment of facial rhytides with a high-energy pulsed carbon dioxide laser. Plast Reconstr Surg. 1996;98:791-794.
Manstein, D, Herron, GS, Sink, RK, et al. Fractional photothermolysis: a new concept for cutaneous remodeling using microscopic patterns of
thermal injury. Lasers Surg Med. 2004;34:426-438.The first description of fractional laser treatment and microthermal zones are described. This was a
landmark article for the introduction of fractional therapy. The first clinical applications of fractional photothermolysis followed.
Karsai, S, Czarnecka, A, Jünger, M, Raulin, V. Ablative fractional lasers (CO2 and Er:YAG): a randomized controlled double-blind split-face
trial of the treatment of peri-orbital rhytides. Lasers Surg Med. 2010;42(2):160-167.Well-designed study comparing fractional CO 2 and Er:YAG
outcomes in the treatment of periorbital rhytids. The study supports efficacy of both techniques. There is increased recovery and erythema as well as
increased efficacy seen with CO 2 .
Manaloto, RM, Alster, T. Erbium:YAG laser resurfacing for refractory melasma. Dermatol Surg. 1999;25:121-123.
Laubach, HJ, Tannous, Z, Anderson, RR, et al. Skin responses to fractional photothermolysis. Lasers Surg Med. 2006;38:142-149.
Pozner, J, DiBernardo, B. Laser resurfacing. Clin Plast Surg. 2016;43(3):515-525.
Bass, LS, DelGuzzo, M, Doherty, S, et al. Combined ablative and non-ablative fractional treatment for facial skin rejuvenation. Lasers Surg
Med. 2009;15(suppl):29.
Tanzi, EL, Alster, TS. Single-pass carbon dioxide versus multiple-pass Er: YAG laser skin resurfacing: a comparison of postoperative wound
healing and side-effect rates. Dermatol Surg. 2003;29:80-84.
Ross, EV, Sajben, FP, Hsia, J, et al. Nonablative skin remodeling:selective dermal heating with a mid-infrared laser and contact cooling
combination. Lasers Surg Med. 2000;26(2):186-195.
Rashid, T, Hussain, I, Haider, M, et al. Laser therapy of freckles and lentigines with quasi-continuous, frequency-doubled, Nd: YAG (532 nm)
laser in Fitzpatrick skin type IV: a 24-month follow-up. J Cosmet Laser Ther. 2002;4:81-85.
Ozturk, S, Hoopman, J, Brown, SA, et al. A useful algorithm for determining fluence and pulse width for vascular targets using 1064 nm
Nd:YAG laser in an animal model. Lasers Surg Med. 2004;34(5):420-425.
Sadick, NS. Update on non-ablative light therapy for rejuvenation: a review. Lasers Surg Med. 2003;32(2):120-128.A review of nonablative skin
resurfacing modalities is presented. A thorough look at the various modalities available and their indications.
Nanni, CA, Alster, TS. Complications of carbon dioxide laser resurfacing: an evaluation of 500 patients. Dermatol Surg. 1998;24:315-320.
Zenzie, HH, Altshuler, GB, Smirnov, MZ, Anderson, RR. Evaluation of cooling methods for laser dermatology. Lasers Surg Med. 2000;26:130-
144.
Wanner, M, Sakamoto, FH, Avram, MM, Anderson, RR. Immediate skin responses to laser and light treatments warning endpoints: how to
avoid side effects. J Am Acad Dermatol. 2016;74:807-819.
Grimes, PE, Bhawan, J, Kim, J, et al. Laser resurfacing–induced hypopigmentation: histologic alterations and repigmentation with topical
photochemotherapy. Dermatol Surg. 2001;27:515.
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C H A P T E R 4 6
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Dermal and Soft-Tissue Fillers: Principles,
Materials, and Techniques
Ivo A. Pestana and Malcolm W. Marks
Key Points
The use of injectable fillers for tissue augmentation is increasing.
The most common indication for the use of injectable fillers is minimizing the stigmata of aging.
Each injectable filler has its own biophysical properties and risk/benefit profile, making an
understanding of these characteristics, as well as injection techniques for their application, critical to
the safe use of these products.
Soft-tissue augmentation with injectable fillers is one of the most common minimally invasive
interventions employed for cosmetic facial and body rejuvenation. According to the American Society of
Plastic Surgeons (ASPS) National Plastic Surgery Statistics, 2.7 million soft-tissue filler procedures were
performed in 2017. This is over a 300% increase compared with the year 2000. 1
The dramatic increase in the number of filler procedures performed over the years is multifactorial and
includes improved access to physicians and physician extenders who perform filler procedures, increased
understanding of soft tissue and bone volume alterations associated with the aging process, and
improved product quality and marketing. As injectable products and their use rapidly expand, a
comprehensive knowledge of indications for filler use, of available filler products and their biologic
properties, and of filler complications and their management is essential for the safe execution of soft-
tissue filler procedures.
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Historical Perspective
Similar to other reconstructive and cosmetic procedures, injectable filler use has its origin in Europe. The
first soft-tissue filler employed was autologous free fat. The German surgeon Gustav Adolf Neuber in
1893 harvested several small fat grafts from the arms to fill a soft-tissue depression of the face in a 20-
year-old man. 2 Vaseline and paraffin injections for cosmetic purposes were described in 1899 by the
Austrian surgeon Robert Gersuny who injected these materials into the scrotum of a man to improve the
appearance of the genitals after castration for tuberculous epididymitis. 3 Vaseline, paraffin, and mineral
oil remained popular in both Europe and the United States until the early 1900s. Liquid silicone use was
popularized for cosmetic purposes in the 1940s and used through the 1970s. Liquid silicone use was
associated with multiple complications such as migration of the material, hepatic granulomas and
hepatitis, and even death. 4,5
Because of the problems associated with silicone and other nonautologous fillers, use of autologous fat
was revitalized and improved by the invention of the liposuction technique by Fischer in 1974. Later in
1978, French physicians, Illouz and Fournier, further developed the liposuction procedure and
introduced it to clinical practice such that by 1980 liposuction was becoming extremely popular in the
United States. Subsequently, in 1986, Illouz described the reinjection of fat from liposuction to fill soft-
tissue defects. 6
Nonautologous fillers also advanced in the 1980s with introduction of bovine collagen for the treatment
of wrinkles, perioral lines, and certain scar types in 1981. Human-derived collagen and hyaluronic acid
(HA) fillers were introduced in the early 2000s. Since that time, modification of HAs fillers and
introduction of other filler materials—including poly-l-lactic acid (PLLA) in 2004, calcium
hydroxylapatite (CaHA) in 2006, polymethylmethacrylate (PMMA) in 2006, and porcine collagen in 2008
—have come to characterized the injectable filler market.
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Indications for Filler Use
Amelioration of the stigmata of aging is the most common indication for the use of injectable fillers. This
indication extends to the most visible portions of the human body including the head and neck and, most
recently, the hands. 7,8
The effects of gravity on the skin and muscle in conjunction with extrinsic factors, such as smoking and
sun exposure, has been the leading theory that accounts for the aged appearance. Thinning of the skin
because of dermal collagen reduction, elastosis, and lipoatrophy has been demonstrated in aging skin and
results in characteristic appearance changes (Figure 46.1). Common appearance complaints associated
with aging are static rhytids of the midface and lower face, drooping of the malar soft tissues, increased
prominence of the nasolabial folds, jowl development, and atrophy and actinic changes of the lips
including the vermillion border resulting in downturning of the oral commissures.
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FIGURE 46.1 A 60-year-old woman demonstrating characteristic age-related facial changes. Arrows indicate static rhytids of
the midface and lower face. Asterisks mark the drooping of the malar soft tissues. Hashtags indicate atrophy and actinic
changes of the lips including the vermillion border resulting in downturning of the oral commissures. The patient also
demonstrates visible tear trough deformity at the lower eyelid-cheek junction and increased prominence of the nasolabial folds
with associated jowl development.
Recently, vertical descent of the skin and subcutaneous tissue as the main component of aging has been
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challenged. 9,10 Using computed tomography (CT), Pessa et al. demonstrated a posterior and inferior
rotation of the facial skeleton and bony remodeling contributing to the loss of midface projection seen
with aging. Alteration in ligamentous support or ligament-resting vectors may also contribute to the
characteristic changes seen in the aged individual. 11 Based on the above, it appears that composite tissue
(skin, subcutaneous tissue, ligamentous structures of the midface, and bone) changes over time may
explain the aged appearance as well as support the benefits of volume restoration provided by filler
procedures. 12
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Patient Selection
Cosmetic filler use is an elective procedure asked for by the patient and therefore careful consideration
must be employed prior to the procedure to maximize patient satisfaction and minimize procedure-
related complications. In addition to physical examination, a comprehensive medical history, including
previous cosmetic procedures (injectables, implants), allergic reactions and sensitivities, acne, keloids,
viral infections or dental infections, and immunocompromised states should be obtained to prevent
treatment of patients with preexisting conditions that are contraindications to the use of soft-tissue
augmentation with injectable fillers.
A critical element of the preprocedural interview must include a discussion of the patient’s procedural
expectations. These expectations must be thoroughly understood and managed to prevent the expectation
of an unrealistic outcome. Each patient must be made aware of the limitations and risks associated with
the planned filler as well as the financial commitment associated with injectables because of their finite
duration in some cases. Caution should be exercised when caring for an individual who demonstrates
signs of underlying mental health disturbances.
Patients should be advised that, if medically appropriate, they should stop anti-inflammatory and
antiplatelet agents a week prior to treatment to minimize bruising. If this is not possible, the American
College of Chest Physicians recommends continuation of anticoagulation for minor skin procedures with
low risk of bleeding. Today, there are more than 20,000 herbal supplements/medicines on the market and
their use has dramatically increased in the past 2 decades. Common supplements like arnica, bromelain,
dong quai, feverfew, garlic, ginger, ginseng, and saw palmetto may increase bleeding; therefore, patients
utilizing these products should stop their use 1 to 2 weeks prior to the procedure. 13 As the number of
supplements available is vast and difficult to cover completely in a clinic visit, patients may benefit from
a list of foods, herbal supplements, and over-the-counter medications to avoid to minimize
postprocedural problems or complaints. 14
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Peri-Injection Practices and Injection Techniques
Preinjection
As for all procedures involving the implantation or injection of foreign materials, avoidance of
contamination is critical. Practices such as hand cleansing, makeup removal and delay of its reapplication
for several hours, skin preparation prior to injection, sterile technique for product reconstitution and
dilution, and glove changes after contact with contaminated surfaces or cavities should be employed by
all practitioners performing soft-tissue augmentation with fillers. Injection of foreign materials during
active skin infections of the planned injection area, or infection in the close vicinity, should be avoided.
Patient with infections such as periodontal disease, ear-nose-throat (ENT) infections, or dental abscesses
should not be treated until the process has resolved. 15
Practices to reduce pain associated with filler procedures abound to maximize patient satisfaction with
the entire process of filler injection. Ice anesthesia, topical anesthetic mixtures, nerve blocks, and local
anesthetic administration to the planned injection area followed by filler injection can be employed.
Because of the increased time associated with the above anesthetic practices, concomitant injection of
local anesthetic and filler has been described, 16 and filler companies have released products that contain a
mixture of the filler and a local anesthetic. Similarly, smaller needles may be associated with reduced pain
by minimizing injection site trauma, adjacent soft-tissue trauma, and risk of infection. In general, the
smallest needle that allows safe passage of the filler material and affords accurate injection should be
utilized. Fillers with low viscosity may be safely injected with 30-gauge needles whereas more viscous
fillers should be injected with larger bore needles such as a 27-gauge needle (e.g., CaHA) or 25-gauge
needle (e.g., PLLA) to avoid clumping of the material or clogging of the needle itself.
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Injection
Commonly described injection techniques include: serial puncture and droplet technique, linear threading,
and fanning and/or cross-hatching. The serial puncture and droplet technique requires multiple injections
along an area of tissue deficit and deposition of small aliquots of filler material. The injection sites are
located in close proximity to allow the material to meld into a continuous line filling and lifting the
deficient area. In contradistinction, linear threading deposits filler material in a continuous line.
Anterograde and retrograde linear threading have been described, each with their own benefits and
drawbacks. Anterograde technique, due to hydrodissection of the planned filler trajectory, may be
associated with less bruising as vascular structures in the area may be displaced out of the way of the
needle. Retrograde injection of filler as the needle is withdrawn may minimize the risk of intravascular
injection and diminish accessory dissected regions, as hydrodissection is not an important component of
this technique. Fanning and cross-hatching employ multiple distinct passes of the needle with an
administration of filler in different patterns (fan pattern versus grid pattern, respectively) in multiple
planes allowing for three-dimensional filling.
Although different products are recommended to be injected at different soft-tissue depths, the majority
of product injected is found in the subcutaneous tissues despite use of general visual cues guiding needle
depth and use of the various injection techniques. 17 Moreover, certain technique may be associated with
the occurrence of local adverse events. Techniques that produce higher levels of subepidermal injury and
dissection (fanning, rapid injections, high-injection flow rates, and larger volume filler injections) are
associated with higher incidence of local adverse events. On the other hand, techniques that produce
more epidermal injury (multiple punctures as in serial puncture or cross-hatching techniques) do not
seem to increase the occurrence of adverse events. 18
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