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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3786_Библиотеки_им_академика_М_И_Перельмана
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Transcutaneous Laser Vein
https://t.me/med1917
Ablation
Joyce Jackson and Craig F. Feied
1 3
Contents
13.1 Introduction ................................................ 176
13.2 Underlying Pathology ................................ 176
13.3 Treatment of Underlying Causes .............. 176
13.4 Risks Assessment........................................ 176
13.5 Choice of Therapeutic Modality ............... 176
13.6 Biophysics of Vascular Photoablation ...... 177
13.7 Selective Photothermolysis ........................ 177
13.7.1 Laser Light ................................................... 178
13.7.2 Wavelength and Energy Absorption ............ 178
13.7.3 Molecular Targets ........................................ 178
13.7.4 Thermal Relaxation...................................... 179
13.7.5 Pulse Duration/Repetition ............................ 181
13.7.6 Fluence ......................................................... 181
13.7.7 Power Density (PD) ..................................... 181
13.7.8 Epidermal Cooling ....................................... 181
13.7.9 Summary ...................................................... 181
13.8 Lasers Commonly Used in Treatment
of Vascular Lesions .................................... 181
13.8.1 Neodymium: Yttrium Aluminum Garnet
(Nd:YAG) ..................................................... 182
13.8.2 Potassium Titanyl Phosphate
(KTP) Laser ................................................. 183
13.8.3 Intense Pulsed Noncoherent Light (IPL) ..... 183
13.8.4 755 nm Alexandrite Laser ............................ 183
J. Jackson , RN, MSN, ANP, BC (*)
Belmont Aesthetic and Reconstructive Surgery ,
Chevy Chase , MD , USA
Berman Skin Institute , Palo Alto , CA , USA
e-mail: joycejjackson@msn.com
C. F. Feied , MD, FACEP, FAAEM, FACPh
Department of Emergency Medicine,
Georgetown University School of Medicine ,
Washington , DC , USA
e-mail: craig.feied@gmail.com
13.8.5 Flashlamp-Pumped Pulsed Dye Lasers........ 184
13.9 Clinical Considerations ............................. 184
13.9.1 Skin Type ..................................................... 184
13.10 Practical Applications for
Specifi c Lesions .......................................... 185
13.10.1 Facial Telangiectasias .................................. 185
13.10.2 Leg Telangiectasias ...................................... 185
13.10.3 Port-Wine Stains .......................................... 185
13.10.4 Rosacea ........................................................ 186
13.11 Adverse Outcomes ..................................... 186
13.11.1 Ocular Injury ................................................ 186
13.11.2 Hyperpigmentation/Hypopigmentation ....... 186
13.11.3 Blistering ...................................................... 186
13.11.4 Purpura ......................................................... 187
13.11.5 Reactivation of Herpes Simplex .................. 187
13.11.6 Erythema ...................................................... 187
13.11.7 Laser Ineffective .......................................... 187
Conclusions ............................................................... 187
References ................................................................. 187
Abstract
Patients with vascular lesions may benefi t from
a combination of different treatment modalities including sclerotherapy, phlebectomy, and
intravascular thermoablation of larger vessels.
Treatment with lasers and other intense light
sources can be an important adjunct to these
other modalities, and this is especially true in
cases that have proven resistant to sclerotherapy and in patients who have developed telangiectatic matting after sclerotherapy. Surface
vascular lesions can be treated effectively
with a variety of lasers. There continue to be
advances in the treatment of telangiectasias and
other undesired veins. In general, lasers with
E. Mowatt-Larssen et al. (eds.), Phlebology, Vein Surgery and Ultrasonography,
DOI 10.1007/978-3-319-01812-6_13, © Springer International Publishing Switzerland 2014
175
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J. Jackson and C.F. Feied
shorter wavelengths have been more effective
in treating more superfi cial, red telangiectasias versus those with longer wavelengths for
treating deeper blue reticular veins up to 4 mm.
Lower extremity telangiectasias can be resistant to laser treatment particularly when other
high-pressure vessels have not been eradicated.
13.1 Introduction
Patients with vascular lesions may benefi t from a
combination of different treatment modalities
including sclerotherapy, phlebectomy, and intravascular thermoablation of larger vessels. Treatment
with lasers and other intense light sources can be an
important adjunct to these other modalities, and this
is especially true in cases that have proven resistant
to sclerotherapy and in patients who have developed
telangiectatic matting after sclerotherapy.
13.2 Underlying Pathology
Although small superfi cial varicosities and spider
veins may cause symptoms such as itching, burning, and soreness, treatment of small superfi cial
vessels most often is performed for cosmetic reasons. Nonetheless, treatment of small superfi cial
vessels is not always a purely cosmetic procedure.
The approach to treatment must be guided by a
thorough understanding of the underlying pathological venous pathways of the patient being treated.
Small visible superfi cial vessels may be the result of
purely local trauma or infl ammation, or they may be
associated with elevated venous pressures in deeper
venous systems. They may arise from small reticular feeder vessels where deeper venous circuits are
normal, or from longer venous pathways such as the
lateral subdermal plexus, or they may be secondary
to signifi cantly elevated venous pressure in larger
truncal veins with failed proximal venous valves.
recirculation time, therapy directed at the superfi cial veins alone, whether by sclerotherapy or by
laser therapy, will be relatively ineffective. When
superfi cial veins experiencing elevated venous
pressure are treated without fi rst addressing the
deeper problems, the vessels will be resistant to
treatment and prone to early recurrence. In this
situation the patient also has an elevated risk for
complications such as telangiectatic matting.
13.4 Risks Assessment
A decision to treat superfi cial or cosmetic vessels
must also take into account the patient’s overall
health and medical situation. Although the treatment of superfi cial spider veins is often perceived
as a benign intervention with very low risk, each
patient’s situation must be assessed individually.
For example, a patient with a hypercoagulable or
hypofi brinolytic disorder may develop deep vein
thrombosis after treatment of tiny superfi cial veins
by any method because local infl ammation can
result in pathologic propagation of thrombosis into
adjacent vessels, while circulating prothrombotic
factors may trigger spontaneous remote thrombosis. There have been many recognized cases of
deep vein thrombosis associated with intercurrent
treatment of superfi cial spider veins, and although
there is no prospective evidence to prove causality,
procoagulant factors are a known component of the
physiological response to injury of superfi cial
vessels.
For all these reasons, even when a patient has
apparently isolated superfi cial spider veins, it is
important that a careful history and physical
examination should be performed and that venous
ultrasound should be used to identify and map any
associated refl ux pathways. Any identifi ed source
of elevated venous pressure feeding superfi cial
veins should be ablated before treatment of the
more superfi cial vessels is undertaken.
13.3 Treatment of Underlying
Causes
When superfi cial spider veins are actually terminal branches of a deeper reservoir of venous
blood with high venous pressures and prolonged
13.5 Choice of Therapeutic
Modality
Once the decision has been made that the
patient has superfi cial small vessel disease
with cosmetic implications, the choice of
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therapeutic modality becomes important. The
standard treatment for many years has been
chemical ablation of even the smallest vessels,
and it is true that a skilled practitioner can successfully introduce sclerosant into vessels
much smaller than the diameter of the 30 gauge
needles commonly used in treatment. However,
the appeal of transcutaneous treatment
approaches for small vein ablation is undeniable. Some patients are extremely needle phobic, while others may be allergic to components
of sclerosants. Some vessels are highly resistant to chemical sclerosis, and some patients
have an aggressive telangiectatic response to
sclerosant injection. From the viewpoint of the
practitioner, a bloodless fi eld with no sharps is
a tremendous convenience in the treatment
room. For all these reasons, a wide variety of
techniques have been used in attempts to ablate
superfi cial vessels through the delivery of
energy in the form of heat, electrical fi elds, or
light. Of these approaches, lasers and noncoherent intense light sources have proven most
useful to date.
13.6 Biophysics of Vascular
Photoablation
As laser light interacts with the skin, it is either
refl ected, transmitted, scattered, or absorbed.
Absorbed energy causes heating of the intended
target and also of surrounding tissues. Although
laser light has many interesting characteristics, it
is this tissue heating that is responsible for important biological effects: thermal injury is the fundamental mechanism by which phototherapy
effects venous ablation.
13.7 Selective Photothermolysis
For many years after their initial introduction
into the clinical arena, medical lasers could
only be used for nonselective tissue vaporization and nonselective photocoagulation. The
modern fi eld of laser medicine has its roots in
the work of Anderson and Parrish, who in 1983
described the principles of selective photother-
molysis, in which light sources of specifi c
wavelengths are used in selective targeting of
specifi c chromophores (e.g., water, melanin,
and hemoglobin) to achieve differential heating in adjacent tissues [ 1 ]. To destroy unwanted
vessels without excessive injury to surrounding or overlying tissues, selective photothermolysis attempts to exploit differences in
energy absorption in different tissue types to
cause selective heating of the vessel or its contents. In general terms, the frequency (or its
inverse: the wavelength) of the energy source
is tuned to the absorption spectrum of the tissues into which the energy is delivered. In a
perfect system, the abnormal vessel would
absorb 100 % of the energy delivered and all
other tissues would absorb no energy. In reality, all tissues absorb some energy across a
wide range of wavelengths, and thermal energy
rapidly diffuses from the site of absorption into
nearby tissues. In practical terms, it is suffi cient if the temperature in the abnormal veins
can be elevated enough to destroy the vessel
endothelium while the temperature of surrounding tissues remains low enough that no
clinical signs of thermal injury are
recognized.
Over the past several decades, advances in the
design of medical lasers and intense pulsed light
(IPL) sources have made it possible to vary many
different parameters in order to improve tissue
targeting and reduce collateral injury, and the
advent of relatively inexpensive systems for
delivering energy via laser and other intense light
sources has greatly expanded the practical
options for treatment of undesirable superfi cial
vascular lesions. Through manipulation of wavelength, fl uence, pulse duration, extrinsic cooling,
and other parameters, it is now possible to use
phototherapy successfully in the treatment of red
spider veins, blue reticular veins, port-wine
stains, and many other vascular lesions.
A large number of different devices are
available in the marketplace, each offering a
slightly different range of parameters and different methods for controlling them. A practitioner using such devices must have a thorough
understanding of basic laser biophysics, principles of laser safety, and the concepts underlying a choice of wavelengths and treatment
parameters.
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13.7.1 Laser Light
An ideal laser emits energy in the form of light
that is monochromic (single wavelength), perfectly coherent (having temporally and spatially
constant interference), and collimated (nondivergent) [ 2 ]. Real-world medical lasers emit
light that typically contains some mixture of
wavelengths with a fairly high degree of temporal coherence and collimation. Although coherence and collimation are important attributes of
lasers for many nonmedical purposes, the attribute of primary importance for medical therapy
is the wavelength, since this is what allows a
laser to deliver energy selectively to one type of
biological structure versus another. An equally
important feature of medical lasers is the ability
to deliver precise amounts of energy over very
short periods of time. Noncoherent IPL sources
have also proven useful in delivering energy
selectively to different tissue structures. A variety
of methods are used to create light pulses of
proper wavelength, energy, and pulse duration.
13.7.2 Wavelength and Energy
Absorption
The energy absorption of a laser, or other intense
light source, depends on the wavelengths of light
emitted and the characteristics of the tissues through
which it passes. The probability that a photon will
be absorbed by chromophores in a particular type of
tissue per unit path length is referred to as the
absorption coeffi cient (μa). The absorption coeffi cient depends upon both the particular wavelength
of light and the type of light- absorbing molecules
(target molecules) that are present in the tissue [ 3 ].
A good target molecule absorbs a high proportion
of the energy delivered by light at a wavelength
where surrounding tissues absorb very little.
Wavelength also determines how deeply light
can penetrate into tissues before being absorbed;
near-infrared wavelengths of 755 and 810 nm (e.g.,
alexandrite and diode lasers) may penetrate deeply
enough to target the chromophores of vessels up
to 2 mm, among the largest that may be treated
primarily with transcutaneous phototherapy.
Near-infrared wavelengths of 940 nm and above
allow for even deeper penetration and potentially
for larger vein treatment, but the longer wavelengths also lead to some loss of selectivity, with
increased absorption in tissue water and fat.
Wavelength is the most important determinant of
differential light energy absorption in different tissues, but wavelength is not the only parameter to
consider when evaluating the suitability of a particular laser device for a specifi c task. Other important
factors include heat diffusion and thermal relaxation
time, pulse duration, fl uence, power density, epidermal cooling, and selective photothermolysis.
13.7.3 Molecular Targets
The degree of absorption and its thermal effects
on the skin vary with the relative number and
type of chromophores present in the skin, the
vessel to be treated, and surrounding tissues.
Each type of vessel absorbs a different fraction of
the total tissue energy, based on its color, size,
and depth [ 17 ]. It is therefore important when
choosing a laser to identify a wavelength that will
target the lesion to be treated while minimizing
the energy delivered to surrounding tissues. The
primary molecular targets for the treatment of
superfi cial vascular structures are oxygenated
and deoxygenated hemoglobin within the red
blood cell, and the primary competitors for
energy absorption include skin melanin, water,
and tissue fat. The absorption curves for hemoglobin, melanin, water, and fat are shown in
Figs. 13.1 , 13.2 , 13.3 , and 13.4 .
In the arterial system, hemoglobin saturation is
generally above 93 %, whereas in the venous system, it may be 60–80 % in ordinary circulation
(mixed venous blood) and lower in the setting of
venous stasis with prolonged local recirculation
times. Both oxyhemoglobin and deoxyhemoglobin molecules absorb laser energy over a broad
range of wavelengths with differential peaks in
the visible (blue/green/yellow) portion of the
electromagnetic spectrum between 418 and
577 nm [ 3 ]. Examples of devices that produce
wavelengths in this range include pulsed dye
lasers (PDL), potassium titanyl phosphate lasers
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Fig. 13.1 Absorption
spectrum of hemoglobin
and deoxyhemoglobin
27 ] )
(Prahl [
Fig. 13.2 Absorption
spectrum of melanin
(Jacques [
28 ] )
6
10
)
−1
5
10
M
−1
4
10
3
10
Molar extinction coefficient (cm
2
10
300
5
10
)
−1
M
4
−1
10
400 500 600
Wavelength (nm)
Hb02
Hb
700 800 900 1,000
Eumelanin
Pheomelanin
(KTP), and IPL sources used with the appropriate
fi lters [ 19 ]. There is also a broad hemoglobin
absorption peak from 800 to 1,000 nm, which is
of special interest because longer wavelengths
can penetrate more deeply into the dermis and
thus offer the potential to reach deeper vessels.
3
10
2
10
Molecular extinction coefficient (cm
1
10
200
300 400 500
13.7.4 Thermal Relaxation
Thermal relaxation time is defi ned as the time
required for a given chromophore to lose 50 %
of its heat through diffusion. If a laser pulse
is longer than the thermal relaxation time, the
600 700 800 900
Wavelength (nm)
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J. Jackson and C.F. Feied
Fig. 13.3 Absorption
spectrum of water (Hale
and Querry [
Fig. 13.4 Absorption
29 ] )
spectrum of fat (van
Veen et al. [
30 ] )
0
10
−4
10
)
−1
−3
10
Absorption (cm
−2
10
−1
10
2
10
300 400 500
600 700 800 900 1,000
Wavelength (nm)
)
1
−1
10
0
10
Absorption coefficient (m
−1
10
700
750 800
chromophore will have absorbed all the energy it
can for that pulse, and the remaining energy will
be delivered to other tissues, reducing the tissue
selectivity of the treatment. In contrast, if the
desired energy can be delivered using a pulse of
850 900 950 1,000
Wavelength
shorter duration than the thermal relaxation time
of the target, the largest possible proportion
of the light energy can be delivered directly to
the desired target, with minimal heating of
surrounding tissues.
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13.7.5 Pulse Duration/Repetition
Pulse duration, often referred to as pulse width, is the
time at which the laser power remains above half its
maximum value. Pulse repetition is the number of
pulses delivered per second, reported as Hz . In gen-
eral, pulse duration should not exceed the practical
thermal relaxation time. The size of the target is also
a factor when considering thermal relaxation times:
the larger the vessel the greater the amount of total
thermal energy that must be delivered to raise its
temperature, the greater the amount of energy available to injure adjacent tissues, and the longer it takes
to cool down by thermal diffusion.
Delivering the same amount of energy over
longer pulse durations (or delivering energy with
repetition using multiple pulses) may exploit differential thermal relaxation times in different tissue
types, potentially allowing delivery of greater
amounts of energy to deeper tissues. Reducing the
energy per unit time can also help to reduce epidermal heating. However, when vessels are small and
superfi cial, the more selective thermal targeting of
shorter pulse durations offers many advantages.
13.7.6 Fluence
Fluence, sometimes referred to as “radiant exposure,” is a measure of the number of photons
delivered per unit area. For a fi xed set of wavelengths, this is also a measure of the total energy
delivered per unit area (usually measured in joules
per square centimeter [J/cm 2 ]). At a fi xed power
output and pulse width, the fl uence will decrease
if the spot size increases (the same energy is delivered over a larger area). Given the same laser
power and the same spot size, a shorter pulse will
deliver a lower fl uence than a longer pulse.
13.7.7 Power Density (PD)
The power density or intensity of the laser beam is
defi ned as the beam power per unit of crosssectional area. If the same amount of energy is
delivered over the same amount of time in a smaller
spot size, the power density will be increased.
13.7.8 Epidermal Cooling
Absorption of laser light by epidermal melanin
causes epidermal heating. In general, the shorter
the wavelength, the greater the superfi cial absorption of energy and the greater the likelihood of epidermal injury. Surface cooling may help to protect
the dermis, allowing the delivery of higher fl uences to the targeted vessels. Epidermal cooling
can also help with analgesia [ 12 ]. Epidermal cool-
ing may be particularly useful when longer pulse
durations are needed, because heat accumulates in
the epidermis more quickly than it accumulates in
the blood vessels being treated, increasing the risk
of epidermal injury [ 13 ]. Commonly used meth-
ods for extrinsic cooling of the epidermis include
cryogen spray, air cooling, and contact cooling
with ice, cold gel, or sapphire or quartz crystals.
13.7.9 Summary
Selective photothermolysis leverages differences
in laser power density, pulse width, and wavelength, along with differences in tissue chromophores, thermal relaxation time, and other
ambient factors to produce targeted, selective
damage to specifi c tissues while minimizing the
effects on surrounding tissue. Selective treatment
of a targeted chromophore occurs when a laser
system is chosen with a wavelength matching the
absorption spectrum of the target, using an appropriate energy level to suffi ciently heat the tissue
through energy absorption by the targeted chromophore, with a pulse duration shorter than the
thermal relaxation time of the target.
13.8 Lasers Commonly Used
in Treatment of Vascular
Lesions
Lasers can produce light energy in several different modes, including continuous wave (CW),
pulsed wave, and Q-switched. Continuous wave
lasers deliver energy continuously, which makes
them unable to exploit differential thermal relaxation times and reduces the selectivity of energy
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Table 13.1 Summary of some laser applications
1,064 nm Nd:YAG 125–150 J/cm 2 6 mm spot 25 ms pulse duration
75–100 ms pulse duration (reticular veins)
120–170 J/cm
PDL 6.5–7.5 J/cm
5–8 J/cm
532 nm KTP 16–22.5 J/cm
17 J/cm
Long-pulsed 532 nm Nd:YAG 12–14 J/cm
IPL 35–20 J/cm
2
2
2 mm spot
2
2
2
3 mm spot 5–40 ms pulses
2
3–5–7–10 mm spot Pulse duration 20–40 ms
2
500–700 μm spot Pulse duration 10–30 ms
10 ms delay through a 550 nm cutoff fi lter
J. Jackson and C.F. Feied
delivery, thus increasing the likelihood of thermal
damage to surrounding tissue [ 2 ]. Pulsed lasers
durations measured in milliseconds. The term
“Q-switching” refers to a process whereby the
laser is fi rst placed in a mode where it is unable to
emit light yet is pre-saturated with energetic photons and then is suddenly allowed to emit light,
resulting in a very fast emission of all the prestored energy in a very short pulse in the range of
10–250 ns. Lasers commonly used in the treatment of cutaneous vascular lesions are mostly
pulsed or Q-switched lasers. A variety of suggested treatment parameters have been published
for each class of laser. However, in practice, each
patient is unique and each device performs differently, thus suggested parameters can be taken only
as a rough guide to clinical therapy (Table 13.1 ).
13.8.1 Neodymium: Yttrium
Aluminum Garnet (Nd:YAG)
The long-pulsed 1,064 nm Nd:YAG laser is most
effective when treating facial telangiectasias and
blue reticular vessels on the face. It has also been
used to treat leg veins up to 4 mm in diameter,
spider angioma, and cherry angiomas. The principal advantage of the 1,064 nm Nd:YAG is the
fact that the longer wavelength allows for deeper
penetration and weaker melanin absorption. The
longer pulse duration at lower fl uences translates
into slower heating of the vessels. It has been
claimed that this can cause photocoagulation
without vessel rupture, minimizing the risk of
purpura. This wavelength is well absorbed by
both methemoglobin and deoxyhemoglobin and
thus can deliver energy to darker blue veins [ 4 ].
Published recommendations include: for superfi cial vessels less than 1 mm in diameter, small
spot size (2 mm), short pulse durations (15–30 ms),
and high fl uences (350–600 J/cm 2 ) and for reticular veins of 1–4 mm in diameter, increased spot
size (2–8 mm), longer pulse durations (25–60 ms),
and fl uences (90–370 J/cm 2 ) [ 3 ].
In a study of 20 patients with size-matched
superfi cial telangiectasias of the lower extremities, Lupton et al. compared sclerotherapy treatments to vein irradiation with the 1,064 nm
Nd:YAG laser [ 5 ]. The telangiectasias responded
best to the sclerotherapy, with fewer treatment
sessions required, and similar adverse sequelae
occurred in both groups. The conclusions were
that lower extremity telangiectasias can be effectively treated with both modalities and that laser
treatment may be more effective for patients with
contraindications to sclerotherapy, including
those with needle phobias, telangiectatic matting,
or allergies to sclerosant solutions.
Sadick demonstrated longer term
(12 months) successful photosclerosis of blue
venulectasias and reticular feeder veins in 25
patients treated with the 1,064 nm Nd:YAG
laser using a spot size of 6 mm [ 6 ]. Treatment
parameters for vessels 0.2–2.0 mm: double
pulse of 7 ms at 120 J/cm 2 ; vessels 2.0–4.0 mm
were treated with a single pulse of 14 ms and
fl uences of 130 J/cm 2 .
When using the 1,064 nm Nd:YAG laser with
the proper settings, effective treatment of many
cutaneous vascular lesions can be obtained, especially if epidermal cooling is available. However,
complications are not uncommon and can include
crusting, hyperpigmentation, hypopigmentation,
scarring, transient erythema, bruising, edema,
and telangiectatic matting.
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13.8.2 Potassium Titanyl Phosphate
(KTP) Laser
The potassium titanyl phosphate (KTP) laser,
a quasi-CW system, uses an Nd:YAG source passed
through a KTP crystal to double the frequency
(halve the wavelength), producing a laser with
532 nm wavelength. The system has been further
modifi ed to produce millisecond (ms) pulse durations [ 7 ]. The resulting KTP laser system delivers
high-energy pulses in spot sizes ranging from 0.25
to 4.0 mm and pulse durations of 1–50 ms.
The wavelength of 532 nm allows for some
selective absorption by the hemoglobin chromophore, but epidermal melanin is also a target.
Compared to the Nd:YAG laser, the shorter wavelength decreases the potential for deep tissue penetration, but this can be offset by extending the
pulse duration up to 50 ms [ 4 ]. The KTP laser has
been used in the treatment of telangiectasias on
the face and legs, rosacea, spider angioma, and
cherry angiomas. Weiss and Goldman [ 8 ] suggest
the KTP laser system as one of the useful nearinfrared pulsed lasers for the treatment of bright
red vessels. Their most encouraging results were
achieved with using a spot size of 3–5 mm, longer
pulse durations of 10–50 ms, and fl uences of
14–20 J/cm 2 , with a train of pulses delivered over
the vessel until spasm occurs.
To evaluate the effi cacy of the 532 nm KTP
laser in the treatment of superfi cial leg telangiectasias, Fournier et al. [ 9 ] treated 14 patients with
leg vessels, 0.5–1.0 mm in size. Using a nonuniform stacked pulse sequence, veins were treated
with a total fl uence of 60 J/cm 2 , 0.75 mm collimated spot size, with a pulse delay of 250 ms
between pulses. The stacked pulses were 100, 30,
and 30 ms delivering 38, 11, and 11 J/cm 2 ,
respectively. They demonstrated safe and effective treatment with minimum adverse effects.
Side effects seen were transient and included erythema, edema, scabbing, hypopigmentation, and
telangiectatic matting.
In addition, Woo et al. [ 13 ] compared treat-
ment of telangiectatic leg veins in ten patients
using a 532 nm Nd:YAG and a 595 nm PDL
using ultra long pulse durations. Leg veins treated
measured up to 1.0 mm in diameter. Both lasers
showed improvement and some vessel clearance
after one treatment with minimum side effects.
Treatment parameters used with the Nd:YAG
were a fl uence of 20 J/cm 2 and a pulse duration of
50 ms using a contact cooling device. The PDL
laser used a fl uence of 25 J/cm 2 , a pulse duration
of 40 ms, and cryogen spray precooling.
13.8.3 Intense Pulsed Noncoherent
Light (IPL)
The IPL is a noncoherent light source emitting
light as a continuous spectrum within the 500–
1,200 nm portion of the electromagnetic spectrum. It is used primarily in the treatment of facial
telangiectasias and rosacea but is also indicated
in the treatment of a variety of vascular lesions,
including larger diameter vessels, spider angioma, and cherry angiomas. Light is delivered in a
train of pulses, single, double, or triple, with
varying time intervals between pulses. The IPL
system uses a fi ltered fl ashlamp with fi lters used
to remove lower wavelengths of visible light,
while pulse durations can be adjusted to match
desired thermal relaxation times [ 8 , 19 ]. Using a
light source longer than 600 nm potentiates
deeper penetration of thermal energy, targeting
the chromophore of deoxyhemoglobin.
Schroeter et al. [ 10 ] demonstrated successful
treatment of rosacea using IPL. In a study of 60
patients treated with an IPL spectrum ranging from
515 to 1,200 nm with different pulse durations
between 4.3 and 6.5 ms and energy densities of
25–35 J/cm 2 , there was a reported 77.8 % clearance
of lesions. Published treatment parameters include
[ 3 ]: for smaller vessels, single pulse, 2.5–5 ms, fl u-
ence 25–45 J/cm 2 , and fi lters 515–550 nm, and for
larger vessels, double or triple pulses, with longer
wavelength fi lters for deeper tissue penetration,
higher energy densities of 50–75 J/cm 2 , and longer
pulse delays between pulses of 40–60 ms.
13.8.4 755 nm Alexandrite Laser
The long-pulsed alexandrite laser operates in the
infrared spectrum of the electromagnetic scale.
It has been used for the treatment of telangiectasias, but recent studies also show that it may be
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J. Jackson and C.F. Feied
effective for treatment of larger vessels and for
congenital vascular malformations (e.g., portwine stains) that are resistant to treatment with
the pulsed dye laser [ 18 ]. Recent device modifi -
cations include longer pulse durations of up to
20 ms or longer. The long-pulsed alexandrite
laser penetrates to a depth of 2–3 mm, allowing
energy delivery to larger and deeper vascular
lesions. Published treatment parameters were
20 J/cm 2 , double pulsed at a repetition rate of
1 Hz [ 11 ].
13.8.5 Flashlamp-Pumped Pulsed
Dye Lasers
Pulsed dye lasers (PDL) are used to treat a variety
of vascular lesions including port-wine stains,
spider angioma, facial telangiectasias, and the
superfi cial components of hemangiomas and
rosacea. The original PDL with a wavelength of
585 nm was well suited to the treatment of vascular lesions targeting hemoglobin. However a high
fl uence with a short pulse duration of 450 μs
often resulted in visible bruising that is cosmetically unappealing to patients. The very short
pulse duration also resulted in poor results with
vessels larger than 0.1 mm.
The PDL has since been modifi ed to deliver a
longer wavelength of 595 nm while adding variable pulse width, longer pulse durations, and epidermal cooling. These modifi cations allow higher
fl uences over longer pulse durations, thus
increasing the size and depth of potential targets
while decreasing the likelihood of posttreatment
purpura. Alam et al. [ 14 ] treated 11 patients with
facial telangiectasias to determine whether treatment parameters that did not produce purpura
would be as effective as treatment parameters
that did produce purpura. Although the longer
pulse durations did produce improvement in telangiectasias, larger and darker telangiectasias
benefi ted more from shorter pulse widths that
caused purpura.
Ivey and Fitzpatrick [ 15 ] showed that making
multiple passes, with lower fl uencies in each
pass, produced cumulative thermal ablation with
less postoperative purpura. However, their con-
clusions were also that this approach was effective for smaller vessels but that larger caliber
vessels benefi ted more from treatment with short
pulse widths that did produce purpura.
13.9 Clinical Considerations
13.9.1 Skin Type
Because of differences in skin type, tissue density, pigmentation, and hemoglobin, each patient
has a slightly different absorption spectrum for
the skin and other tissues surrounding small
superfi cial vessels. Some patients may be safely
treated with a wide range of light wavelengths,
intensities, and energy fl uxes, while others may
tolerate only a narrow range of wavelengths
with carefully selected intensities and delivery
times. Patients with fair skin may pass a larger
Table 13.2 Fitzpatrick skin type classifi cation
Skin
type Skin color
I White, very fair, red or
blond hair, blue eyes,
freckles
II White, fair, red or blond
hair, blue, hazel or green
eyes
III Cream white, fair with any
eye or hair color
IV Brown, typical
Mediterranean Caucasian
skin
V Dark brown, Middle
Eastern skin types
VI Very dark brown/black Never burns, tans
Table 13.3 Different fl uence and pulse duration settings
for different skin types
Skin type Fluence (J/cm 2 ) Pulse duration (ms)
I 40 20
II 30–40 15–30
III 25–35 30
IV 20–30 30
V 15–25 30
Response to sun
exposure
Always burns,
never tans
Usually burns,
tans with diffi culty
Sometimes mild
burn, gradually
tans
Rarely burns, tans
with ease
Very rarely burns,
tans very easily
very easily
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