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Chapter
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References
12
Clinical Methods for Sclerotherapy of Telangiectasias
334
1. Biegeleisen HI. Telangiectasia associated
with varicose veins: treatment by a
micro-injection technique. JAMA
1934;102:2092.
2. Biegeleisen HI. Varicose veins, related
diseases, and sclerotherapy: a guide for
practitioners. Montreal: Eden Press;
1984.
3. Higgins TT, Kittel PB. Injection
treatment with sodium morrhuate.
Lancet 1930;215:68.
4. Alderman DB. Therapy for essential
cutaneous telangiectasias. Postgrad Med
1977;61:91.
5. Foley WT. The eradication of venous
blemishes. Cutis 1975;15:665.
6. Tretbar LL. Spider angiomata: treatment
with sclerosant injections. J Kans Med
Soc 1978;79:198.
7. Shields JL, Jansen GT. Therapy for
superficial telangiectasias of the lower
extremities. J Dermatol Surg Oncol
1982;8:857.
8. Goldman MP, Weiss RA, Brody HJ,
et al. Treatment of facial telangiectasia
with sclerotherapy, laser surgery, and/
or electrodesiccation: a review. J
Dermatol Surg Oncol 1993;19:899.
9. Prescott R. Treatment of facial
telangiectasias by sclerotherapy. In:
Raymond-Martimbeau P, Prescott R,
Zummo M, editors. Phlébologie ’92.
Paris: John Libbey Eurotext; 1992.
10. Merlen JF. Red telangiectasis, blue
telangiectasis. Soc Fr Phlebol 1970;
22:167.
11. De Faria JL, Moraes IN. Histopathology
of the telangiectasias associated with
varicose veins. Dermatologia 1963;
127:321.
12. Raymond-Martimbeau P, Dupuis JL.
Telangiectasias: incidence, classification,
and relationship with the superficial
and deep venous systems: a doubleblind study. In: Negus D, Jantet G,
Coleridge-Smith PD, editor(s).
Phlebology ’95, Vol. 1 Suppl 1.
London: Springer; 1995:169–171.
13. Sommer A, Van Mierlo PL, Neumann
HA, Kessels AG. Red and blue
telangiectasias. Differences in
oxygenation? Dermatol Surg 1997;
23:55.
14. Tretbar LL. The origin of reflux in
incompetent blue reticular/telangiectasia
veins. In: Davy A, Stemmer R, editors.
Phlébologie ’89. Montrouge, France:
John Libbey Eurotext; 1989.
15. Weiss RA, Weiss MA. Doppler ultrasound
findings in reticular veins of the thigh
subdermic lateral venous system and
implications for sclerotherapy. J
Dermatol Surg Oncol 1993;19:947.
16. Mariani F, Bianchi V, Mancini S,
Mancini S. Telangiectases in venous
insufficiency: point of reflux and
treatment strategy. Phlebology
2000;15:38.
17. Sadick N. Treatment of varicose and
telangiectatic leg veins with hypertonic
saline: a comparative study of heparin
and saline. J Dermatol Surg Oncol
1990;16:24.
18. Scarborough DA, Bisaccia E.
Sclerotherapy: translucidation of the
skin prior to injection. J Dermatol Surg
Oncol 1989;15:498.
19. Marley W. Low dose sotradecol for
small vessel sclerotherapy. Newsl North
Am Soc Phlebol 1989;3:3.
20. Eichenberger H. Results of
phlebosclerosation with hydroxypolyethoxydodecane, Zentralbl Phlebol
1969;8:181.
21. Duffy DM. Small vessel sclerotherapy:
an overview. Adv Dermatol 1988;
3:221.
22. Bodian E. Sclerotherapy. Dialogues
Dermatol 1983;13(3).
23. Green D. Compression sclerotherapy
techniques. Dermatol Clin 1989;7:137.
24. Goldman MP, Bennett RG. Treatment
of telangiectasia: a review. J Am Acad
Dermatol 1987;17:167.
25. Guex JJ. Indications for the sclerosing
agent polidocanol. J Dermatol Surg
Oncol 1993;19:959.
26. Guex JJ, Allaert FA, Gillet JL, Chleir F.
Immediate and midterm complications
of sclerotherapy: report of a prospective
multicenter registry of 12,173
sclerotherapy sessions. Dermatol Surg
2005;31:123.
27. Green AR, Morgan BDG. Sclerotherapy
for venous flare. Br J Plast Surg
1985;38:241.
28. Rao J, Goldman MP. Stability of foam
in sclerotherapy: difference between
sodium tetradecyl sulfate and
polidocanol and the type of connector
used in the double syringe system
(DSS) technique. Dermatol Surg
2005;31:19.
29. Lai SW, Goldman MP. Does the relative
silicone content of different syringes
affect the stability of foam in
sclerotherapy? J Drugs Dermatol
2008;7:399.
30. Cabrera Garrido JR, Cabrera GarciaOlmedo JR, Garcia-Olmedo
Dominguez MA. Elargissement des
limites de la sclérothérapie: noveaux
produits sclérosants. Phlebologie
1997;50:181.
31. Cabrera Garrido J. Los esclerosantes en
microespuma contra la patología
venosa. Noticias Medicas 1997;312.
32. Monfreux A. Traitement sclérosant des
troncs saphènies et leurs collatérales de
gros calibre par la méthode MUS.
Phlebologie 1997;50:351.
33. Benigni JP, Sadoun S, Thirion V, et al.
Télangiectasies et varices réticulaires:
traitement par la mousse
d’Aetoxisclérol a 0.25%. Présentation
d’une étude pilote. Phlebologie
1999;3:283.
34. Mingo-Garcia J. Esclerosis venosa con
espuma: foam medical system. Rev Esp
Med Cir Cosmética 1999;7:29.
35. Tessari L. Metodique extemporaine de
la preparation de la ‘scleromousse’ en
seringue de plastique monousage.
Presented at the Society of French
Phlebology, Paris, December 11,
1999.
36. Frullini A. New technique in producing
sclerosing foam in a disposable syringe.
Dermatol Surg 2000;26:705.
37. Hennet JP. Three years’ experience with
polidocanol foam in treatment of
reticular veins and varicosities.
Phlebologie 1999;52:277.
38. Benigni J, Sadoun S. Telangiectasia:
benefits of a foam sclerosing agent.
J Phlebol 2002;2:35.
39. Weiss RA. Comparison of liquid vs.
foamed 0.1 and 0.2% STS on the
treatment of leg telangiectasia.
Presented at the 16th Annual Congress
of the American College of Phlebology,
Ft. Lauderdale, Fla., 2002.
40. Kern P, Ramelet AA, Wutschert R, et al.
Single-blind, randomized study
comparing chromated glycerin,
polidocanol solution, and polidocanol
foam for treatment of telangiectatic leg
veins. Dermatol Surg 2004;30:367.
41. Guex J-J, Allaert F-A, Gillet J-L, Chleir F.
Immediate and mid-term
complications of sclerotherapy, report
of a prospective multi-center registry of
12,173 sclerotherapy sessions. J
Dermatol Surg 2005;31:123.
42. Breu F, Guggenbichler S, Wollmann JC.
2nd European consensus meeting on
foam sclerotherapy. 28-30 April 2006.
Tegernsee, Germany. Vasa
2008;37(Suppl 71):1.
43. Bohler-Sommeregger K, Karnel F,
Schuller-Petrovic S, Santler R. Do
telangiectases communicate with the
deep venous system? J Dermatol Surg
Oncol 1992;18:403.
44. Lary BG. Varicose veins and
intracutaneous telangiectasia: combined
treatment in 1500 cases. South Med J
1987;80:1105.
45. Ouvry P, Davy A. Le traitement
sclerosant des telangiectasies des
membres inferieurs. Phlebologie
1982;35:349.
46. Bukhari RH, Lohr JM, Paget DS, Hearn
AT. Evaluation of lidocaine as an
analgesic when added to hypertonic
saline for sclerotherapy. J Vasc Surg
1999;29:479.
47. Carlin MC, Ratz JL. Treatment of
telangiectasia: comparison of sclerosing
agents. J Dermatol Surg Oncol
1987;13:1181.
48. Norris MJ, Carlin MC, Ratz JL.
Treatment of essential telangiectasia:
effects of increasing concentrations of
polidocanol. J Am Acad Dermatol
1989;20:643.
49. Sadick N. Sclerotherapy of varicose and
telangiectatic leg veins: minimal
sclerosant concentration of hypertonic
saline and HS relationship to vessel
diameter. J Dermatol Surg Oncol
https://t.me/med1917
1991;17:65.
50. Goldman MP. Treatment of varicose
and telangiectatic leg veins: doubleblind prospective comparative trial
between Aethoxysclerol and Sotradecol.
Dermatol Surg 2002;28:52.
51. Thibault PK. Sclerotherapy of varicose
veins and telangiectasias: a 2-year
experience with sodium tetradecyl
sulfate. Aust N Z J Phlebol 1999;
3:25.
52. Kern P, Ramelet AA, Wutschert R, et al.
Single-blind, randomized study
comparing chromated glycerin,
polidocanol solution, and polidocanol
foam for treatment of telangiectatic leg
veins. Dermatol Surg 2004;30:367;
discussion 372.
53. Leach B, Goldman MP. Comparative
trial between sodium tetradecyl sulfate
and glycerin in the treatment of
telangiectatic leg veins. Dermatol Surg
2003;29:612.
54. Munavalli GS, Weiss MA, Beasley KL,
Weiss RA. Prospective trial of 72%
glycerin vs. foamed 0.1% sodium
tetradecyl sulfate for thigh
telangiectasia. Presented at the 18th
Annual Congress of the American
College of Phlebology. Ft. Myers, Fla.,
2004.
55. Weiss R, Weiss M. Resolution of pain
associated with varicose and
telangiectatic leg veins after
compression sclerotherapy. J Dermatol
Surg Oncol 1990;16:333.
56. Orbach J. A new look at sclerotherapy.
Folia Angiologia 1977;25:181.
57. Marteau J, Marteau J. Contribution de
la cryotherapie en phlebologie.
Phlebologie 1978;31:191.
58. Stamenova PK, Marchetti T, Simeonov
I. Efficacy and safety of topical hirudin
(Hirudex®, Pharmafar, Torino, Italy): a
double-blind, placebo-controlled study.
Eur Rev Med Pharmacol Sci 2001;5:37.
59. Kern P, Ramelet AA, Wütschert R,
Hayoz D. Compression after
sclerotherapy for telangiectasias and
reticular leg veins: a randomized
controlled study. J Vasc Surg
2007;45(6):1212–16.
60. Chrisman BB. Treatment of venous
ectasias with hypertonic saline. Hawaii
Med J 1982;41:406.
61. Guex J-J. Inutilité de la compression
après sclérothérapie des micro-varices
et télangiectasies. Phlebologie
1994;47:371.
62. Fante RG, Goldman MP. Editorial:
removal of periocular veins by
sclerotherapy. Ophthalmology
2001;180:433.
63. Shafir R, Cohen M, Gur E. Blindness as
a complication of subcutaneous nasal
steroid injection. Plast Reconstr Surg
1999;104:1180.
64. Thomas EL, Laborde RP. Retinal and
choroidal vascular occlusion following
intralesional corticosteroid injection of
a chalazion. Ophthalmology
1986;93:405.
65. McGrew RN, Wilson RS, Havener WH.
Sudden blindness secondary to
injections of common drugs in the
head and neck. I. Clinical experiences.
Otolaryngology 1978;86:147.
66. Green D. Removal of periocular veins
by sclerotherapy. Ophthalmology
2001;108:442.
67. Siniluoto TM, Svendsen PA, Wikholm
GM, et al. Percutaneous sclerotherapy
of venous malformations of the head
and neck using sodium tetradecyl
sulphate (Sotradecol). Scand J Plast
Reconstr Surg Hand Surg 1997;31:145.
68. Kersten RC, Kulwin DR. Management
of cosmetically objectionable veins in
the lower eyelids. Arch Ophthalmol
1989;107:278.
69. Weiss RA, Ramelet A-A. Removal of
blue periocular lower eyelid veins by
ambulatory phlebectomy. Dermatol
Surg 2002;28:43.
70. Bowes LE, Goldman MP. Sclerotherapy
of reticular and telangiectatic veins of
the face, hands and chest. Dermatol
Surg 2002;28:46.
71. Lai SW, Goldman MP. Treatment of
facial reticular veins with dynamically
cooled, variable spot-sized 1064 nm
Nd:YAG laser. J Cosmet Dermatol
2007;6:6.
72. Goldman MP, Fitzpatrick RE.
Cutaneous laser surgery: the art and
science of selective photothermolysis,
2nd ed. St Louis: Mosby; 1999.
73. Lim AC, Kossard S. Generalized
essential telangiectasia: treatment with
sodium tetradecyl sulfate sclerotherapy.
Aust N Z J Phlebol 2002;6:26.
74. McCoy S, Evans A, Tiller A, Malouf
GM. A blinded prospective comparative
trial of a topical vitamin K cream for
the treatment of leg telangiectasias.
Aust N Z J Phlebol 2000;4:28.
References
335
13
https://t.me/med1917
C H A P T E R
Treatment of Leg Telangiectasias with Laser and
High-Intensity Pulsed Light
The laser was first conceived in the imagination of H.G. Wells,
who described the use of a light gun in 1896 as an outer-space
weapon. Albert Einstein then transformed this vision into a
theoretical possibility in the early 1900s. Einstein described
the process of stimulated emission as an offshoot in his quest
to show the inherent singular nature of the four basic forces
of the universe. However, it was not until 1960 that the first
laser was actually constructed.
The acronym LASER stands for Light Amplification by the
Stimulated Emission of Radiation. In short, a laser emits a
beam of monochromic, coherent, collimated photons of a
specific wavelength. The emitted wavelength is produced by
exciting an atom or molecule to release photons at a wavelength or wavelengths specific for that type of molecule. This
ability to produce laser light at a specific wavelength is one
key factor in the production of selective damage. By tuning
the laser to the absorption spectrum of a particular target, such
as oxygenated hemoglobin, theoretically only that target will
be affected by the laser energy.
With proper use, lasers are very safe and have not been
associated with long-term side effects. Most of the laser radiation used in medicine is within or near the range of visible
light in the electromagnetic spectrum. Therefore, its radiant
energy level is at a much longer wavelength than that of the
high-energy ionizing radiation associated with X-rays and
radiation therapy; as such, it is not associated with commonly
perceived radiation hazards.
specificity of absorption, each laser’s emitted wavelength also
dictates the depth of its penetration (Fig. 13.1). (A more thorough discussion of laser physics can be found in other
sources.
reasons.
advanced technology, lasers are perceived as ‘state-of-the-art.’
The general public often equates ‘high tech’ with treatment
safety and superiority. Unfortunately, as described later, this
perception by both the general public and the physician has
often resulted in unanticipated adverse sequelae (scarring and
pain) and higher costs; lasers cost considerably more to purchase and maintain than a needle, syringe, and sclerosing
solution.
with sclerotherapy for treating leg telangiectasias. Sclerotherapyinduced pigmentation is caused by hemosiderin deposition
through extravasated red blood cells (RBCs) (see Chapter 8).
Laser coagulation of vessels should not have this effect. In the
rabbit ear model, approximately 50% of vessels treated with
an effective concentration of sclerosing solution demonstrated
extravasated erythrocytes, compared with a 30% incidence
when treated with the flashlamp-pumped pulsed dye laser
(PDL) (Goldman MP, unpublished observations). Furthermore, telangiectatic matting (TM), which occurs in a significant percentage of sclerotherapy-treated patients, has also not
1,2
)
Lasers have been used to treat leg telangiectasias for various
3
First, lasers have a futuristic appeal. By virtue of their
In addition, lasers have theoretical advantages compared
1
In addition to determining the
been seen after laser treatment of vascular lesions. Finally,
specific allergenic effects of sclerosing solutions are not a
concern when treating telangiectasias with a laser.
Both lasers and intense pulsed light (IPL) have been used
to treat leg telangiectasias. Each acts in a different manner to
induce vessel destruction. Effective lasers and IPL are pulsed
so that their effects act within the thermal relaxation times
of blood vessels to produce specific destruction of vessels of
various diameters based on the pulse duration. Lasers of
various wavelengths and the broad-spectrum IPL are used to
selectively treat blood vessels by taking advantage of the difference between the absorption of the components in a blood
vessel (oxygenated and deoxygenated hemoglobin) and the
overlying epidermis and surrounding dermis (as described
below) to selectively thermocoagulate blood vessels. Each
wavelength requires a specific fluence to cause vessel destruction. In addition, leg veins are not composed mostly of
oxygenated hemoglobin, unlike port-wine stains (PWSs) and
hemangiomas, but are filled with predominantly deoxygenated hemoglobin; hence their blue color. Selective wavelengths for deoxyhemoglobin as opposed to oxyhemoglobin
include approximately 545 nm, 580 nm, and a broad peak
between 650 and 800 nm.
Optical properties of blood are mainly determined by the
absorption and scattering coefficients of its various oxyhemoglobin components. Oxyhemoglobin has three major absorption peaks at 418, 542, and 577 nm. A less selective and
broader absorption peak spans from approximately 750 to
1100 nm. Figure 13.2 shows the oxyhemoglobin absorption
and scattering coefficient depth of penetration into blood.
The main feature to note in the curve is the strong absorption
at wavelengths below 600 nm with less absorption at longer
wavelengths. However, a vessel 1 mm in diameter absorbs
more than 67% of light even at wavelengths longer than
600 nm. This absorption is even more significant for blood
vessels 2 mm in diameter. Therefore, use of a light source
above 600 nm would result in deeper penetration of thermal
energy without negating absorption by oxyhemoglobin in
vessels greater than 1 mm in diameter. This is because the
absorption coefficient in blood is higher than that of surrounding tissue for wavelengths between 600 and 1000 nm
(Figs 13.2 and 13.3). Shorter wavelengths heat only the portion
of the vessel wall closest to the skin surface, which can result
in incomplete thrombosis.
lengths greater than 900 nm are less specific and also target
water, making higher fluences required to produce desired
effects on oxyhemoglobin, the desired chromophore.
However, these higher fluences can cause unnecessary damage
to surrounding tissue unless adequate cooling measures are
employed.
Patients seek treatment for a leg vein largely for cosmetic
reasons.
of 500 consecutive patients presenting for laser removal of
7
Bernstein8 has evaluated the clinical characteristics
5
The only caveat is that wave-
4
6
CO
2
Argon
Nd:YAG
Dye
Dye
Ruby
Alex
Nd: YAG
Scattering and absorption 1/cm
Tissue temperature degree (centigrade)
Light
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10,600 nm
514 nm
532 nm
577 nm
585 nm
694 nm
755 nm
1064 nm
Temperature distribution vs depth and
wavelength for a 2-mm-deep vessel
1000
500 nm
580 nm
800 nm
900 nm
1000
Figure 13.1 Diagram representing approximate levels of penetration for
various lasers. (CO2, carbon dioxide; Nd:YAG, neodymium:yttrium–
aluminum–garnet.)
1994, Mosby.)
10000
1000
100
10
1
0
400
Figure 13.2 Coefficient of blood relative to dermis.
lower extremity spider veins. Patients ranged in age from 20
to 70 years and had had noticeable spider veins for an average
(From Goldman MP, Fitzpatrick RE: Cutaneous laser surgery, St Louis,
500 800
Dermis absorption
Oxyhemoglobin absorption
Deoxyhemoglobin absorption
Dermis scattering
Effective attenuation
of 14 years. Twenty-eight percent of patients had leg veins less
than 0.5 mm in diameter; 39% of patients had veins less than
1.5 mm in diameter. Fifty-six percent of patients who had had
sclerotherapy (not stated how this was performed) developed
TM. Any treatment that is effective should be relatively free of
Skin and blood absorption,
scattering and attenuation data
600 1000
700 900
Wavelength (nm)
0 2
Depth (mm)
Epidermal-dermal junction
Epidermis
Figure 13.3 Temperature distribution across skin and blood vessel. A
2-mm deep, 1-mm diameter vessel is assumed. A 10-J/cm2 fluence is
assumed at four different wavelengths. The calculation takes into account
scattering effects in the epidermis and dermis and fluence enhancement
because of scattering. Note the very high temperature on the skin surface
and at the epidermal–dermal junction and the shallow penetration for the
shorter wavelengths.
Inc., Newton, Mass.; from Goldman MP, Fitzpatrick RE: Cutaneous laser surgery, St Louis,
1994, Mosby.)
1 3
Dermis
(Courtesy Shimon Eckhouse, PhD, Energy Systems Corporation,
adverse sequelae. With recent advances, lasers or IPL have
become methods for treating telangiectatic vessels with a
minimum of adverse effects. However, for these advanced
treatments to be effective and safe, they must be used
appropriately.
As detailed in Chapter 8, sclerotherapy has a number of
potential adverse effects. Up to 30% of patients treated with
sclerotherapy develop postsclerosis pigmentation
10
TM.
As discussed above, at least one study determined that
TM developed in 56% of patients who presented for laser
treatment of leg veins.
8
These adverse effects can occur even
9
and/or
with optimal treatment but are more common when an excessive inflammatory reaction occurs. To minimize risks of an
inflammatory response, lasers and IPL act by producing
thermal damage with the ultimate goal being vaporization of
the targeted vessel. When used with appropriate fluences,
pulse durations, and epidermal cooling, the thermal effects of
lasers and IPL present minimal inflammatory response compared with chemical irritation of the vessel wall through
sclerotherapy.
An understanding of the appropriate target vessel for each
laser and/or IPL is important so that treatment is tailored to
the appropriate target. As detailed elsewhere in this book,
most telangiectasias arise from reticular veins. Therefore, the
single most important concept for the treating physician is
Treatment of Leg Telangiectasias with Laser and High-Intensity Pulsed Light
337
Chapter
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13
Treatment of Leg Telangiectasias with Laser and High-Intensity Pulsed Light
338
that feeding reticular veins must be treated completely before
treating the telangiectasia. This minimizes adverse sequelae
and enhances therapeutic results. When no apparent connection exists between deep collecting or reticular vessels, telangiectasia may arise from a terminal arteriole or arteriovenous
anastomosis.
11
In this latter scenario, the telangiectasia may
be treated without consideration of underlying forces of
hydrostatic pressure. Failure to treat ‘feeding’ reticular veins
and short follow-up periods after the use of lasers may give
inflated values to the success of laser treatment.
12
This chapter
reviews and evaluates the use of these nonspecific and specific
laser and light systems in the treatment of leg venules and
telangiectasias (Table 13.1).
Histology of Leg Telangiectasia
The choice of proper wavelength(s), degree of energy fluence,
and pulse duration of light exposure are all related to the type
and size of target vessel treated. Deeper vessels necessitate a
longer wavelength to allow adequate penetration. Large diameter vessels necessitate a longer pulse duration to effectively
thermocoagulate the entire vessel wall, allowing sufficient
time for thermal energy to diffuse evenly throughout the
vessel lumen. The correct choice of treatment parameters is
aided by an understanding of the histology of the target
telangiectasia.
Venules in the upper and middle dermis typically maintain
a horizontal orientation. The diameter of the postcapillary
venule ranges from 12 to 35 µm.13 Collecting venules range
from 40 to 60 µm in the upper and middle dermis and enlarge
to 100 to 400 µm in diameter in the deeper tissues. Histologic
examination of simple telangiectasia demonstrates dilated
blood channels in a normal dermal stroma with a single
endothelial cell lining, limited muscularis, and adventitia.
Most leg telangiectasias measure from 26 to 225 µm in diam-
14
eter.
Electron microscopic examination of ‘sunburst’ varicosities of the leg has demonstrated that these vessels are
widened cutaneous veins.
14
They are found 175 to 382 µm
14,15
below the stratum granulosum. The thickened vessel walls are
composed of endothelial cells covered with collagen and
muscle fibers. Elastic fibers are also present.
Alternatively, arteriovenous anastomoses may be involved
in the pathogenesis of telangiectasia. They have been demonstrated in 1 of 26 biopsy specimens of leg telangiectasias.
Red telangiectasias have been found to have an oxygen saturation of 76%, compared with blue telangiectasias, which have
an oxygen concentration of 69%.
16
Thus each type of telangiectasia may have a slightly different optimal absorption wavelength based on its color in addition to its relative size and
depth.
Unlike leg telangiectasias, the ectatic vessels of PWSs are
arranged in a loose fashion throughout the superficial and
deep dermis. They are more superficial (0.46 mm) and much
smaller than leg telangiectasias, usually measuring 10 to
40 µm in diameter. This may explain the lack of efficacy
reported by many physicians who treat leg telangiectasia with
the same laser and parameters as they do with PWSs.
Laser Treatment of Leg Telangiectasia
Various lasers have been used in an effort to enhance clinical
efficacy and to minimize the adverse sequelae of telangiectasia
treatment. Unfortunately, most have also been associated with
adverse responses far in excess of those associated with sclerotherapy. This is related both to the nonspecificity of the laser
used and the lack of treatment of hydrostatic pressure from
the ‘feeding’ venous system.
The optimal light source would have a wavelength specific
for the vessel treated and would be able to penetrate to the
depth of the vessel through its entire diameter. This wavelength has been proposed to be between 600 and 900 nm.
Ideally, a light source should have a pulse duration that would
allow the light energy to build up in the target vessel so that
its entire diameter is thermocoagulated. Optimal pulse durations have been calculated for various diameter blood vessels
(Table 13.2).
During the process of delivering a sufficient packet of
energy to thermocoagulate the target vessel, the overlying epidermis and perivascular tissue should be unharmed. This
requires some form of epidermal cooling. A number of different laser and IPL systems have been developed toward this
end, as discussed in subsequent sections. In addition to the
information presented in the following sections, the reader is
encouraged to refer to an excellent summary of various laser
treatments for leg veins by Kunishige et al.
6
Carbon dioxide laser
The carbon dioxide (CO2) laser has been used for obliterating
venules and telangiectatic vessels.
described the successful treatment of matted telangiectasias
with fractional photothermolysis.
five successive monthly treatments with the 1550 Fraxel SR
laser (Solta Medical, Hayward, Calif.), at energies ranging
from 10 to 12 mJ, to an area on her medial thigh. At 6 months
after the final treatment session, the target areas showed more
than 75% improvement. However, since the natural history
of matted telangiectasias is usually to spontaneously resolve
over the course of a year, it is uncertain how much of the
improvement seen in the aforementioned case report was
actually due to ‘the tincture of time’ as opposed to the CO
laser treatment.
The rationale for using the CO
telangiectasia is to produce ‘precise’ vaporization without significant damage to tissue structures adjacent to the penetrating
laser beam. Also, since the CO
target melanin, it can be used on those of darker skin types, a
subgroup of the population that cannot be safely treated with
the pulse dye laser. However, with the CO
mis and the dermis overlying the blood vessel are destroyed.
CO
laser disruption of vessels has also been reported to cause
2
occasional brisk bleeding from the vessel, which required
11
pressure bandages for 48 hours.
moderate to severe, but of short duration. Most reported
studies demonstrate unsatisfactory cosmetic results. Treated
areas show multiple hypopigmented punctate scars with
either minimum resolution of the treated vessel or neovascularization adjacent to the treatment site (Fig. 13.4). Because of
this nonselective action, the CO
the electrodesiccation needle and has not been used successfully in treating leg telangiectasia.
17–21
One recent case report
22
The patient underwent
laser in the treatment of
2
laser does not specifically
2
laser, the epider-
2
20
Pain during treatment is
laser is of no advantage over
2
Argon laser
The argon laser with output at 488 nm and 511 nm has wavelengths somewhat preferentially absorbed by hemoglobin and
to a lesser, although significant, extent by water and melanin
(Fig. 13.5). Its relatively short wavelength, combined with a
spot size of 1 mm, prevents its penetration much beyond
0.5 mm. When the patient is pigmented or tanned, epidermal
melanin will selectively absorb the laser energy, preventing
penetration below the epidermis. Thus, the argon laser does
not have ideal parameters for treating leg veins (Fig. 13.6).
Being continuous in nature, argon lasers do not allow for
selective vessel heating, so scarring commonly occurs.
cifically, argon laser treatment of telangiectasia or superficial
varicosities of the lower extremities may cause purple or
23
Spe-
2
Table 13.1 Lasers and light sources for leg veins
https://t.me/med1917
Product
Supplier
American
BioCare
Adept
Medical
Aerolase LightPod Neo XTNd:YAG 1064 Up to 1274 0.65 or 1.5
Alderm Prolite IPL 550–900 10–50
Alma
(formerly
Orion)
AsclepionMeditech
Candela Vbeam Perfecta Pulsed dye 595 Up to 40 0.45–40 Multiple, up to 12 DCD
CoolTouch Varia Nd:YAG 1064 Up to 500 300 continuous 2–10 DCD
Cutera CoolGlide Excel Nd:YAG 1064 5 to 300 1–300 3, 5, 7, 10
Cynosure/
Deka
DDD Elipse IPL 400–950 Up to 21 0.2–50
DermaMed
USA
Name Device Type
OmniLight FPL Fluorescent pulsed
light
Ultrawave II/III Alexandrite 755 5–55 5–50 8, 10, 12 None
Ultrawave Nd:YAG 1064 5–500 5–100 2, 4, 6, 8, 10, 12 None
Harmony Fluorescent pulsed
light
Nd:YAG 1064 30–450 10, 15, 45, 60 2, 6
Pro Yellow CuBr 578 55 300 1.5 None
Vbeam
Platinum
Vbeam
Aestehtica
Cbeam Pulsed dye 585 8–16 0.45 5, 7, 10 DCD
Gentle YAG VR Nd:YAG 1064 Up to 600 Up to 300 1.5–3 DCD
GentleLASE Alexandrite 755 Up to 100 3 6, 8, 10, 12, 15, 18 DCD
GentleMax Alexandrite/Nd:YAG 755/1064 Up to 600 0.25–300 1.5–18
CoolGlide
Vantage
XEO Nd:YAG and Pulsed
Solera Opus Pulsed light 500–635 3–24 Variable 6.35
PhotoGenica V Pulsed dye 585 20 0.45 3, 5, 7, 10 Cold air
PhotoGenica
V-Star
SmartEpil II Nd:YAG 1064 1–200 Up to 100 2, 5, 7, 10 Cold air
Acclaim Nd:YAG 1064 10–600 0.4–300 3, 5 ,7, 10, 12 Cold air
Cynergy Pulsed dye/Nd:YAG 595/1064 2–40/10–600 0.5–40/0.3–300 1.5, 12, 15 Cold air
Cynergy with
XPL
Cynosure PL Pulsed light 560–950 3–10 5–50
PhotoLight Pulsed light 400–1200 3–30 5–50
Elite Alexandrite/Nd:YAG 755/1064 25–50/10–600 0.5–300/0.4–300 1.5, 12, 15 Cold air
Quadra Q4
(Platinum and
Gold Series)
DermaYAG Nd:YAG 1064 15–300 150 1, 2, 3, 4, 6, 8, 10,
Pulsed dye 595 Up to 40 0.45–40 Multiple DCD
Pulsed dye 595 Up to 20 0.45–40 Multiple, up to 10 DCD
Nd:YAG 1064 Up to 300 0.1–300 3, 5, 7, 10 Copper contact
light 1064 and
600–850
Pulsed dye 585–595 40 0.5–40 5, 7, 10, 12 Cold air
Pulsed dye/Nd:YAG/
Pulsed light
595/1064/560–950
Pulsed light 510–1200 10–20 48
Wavelength
(nm) Energy (J)
480, 515, 535,
550, 580–1200
515–950 5–30 10, 12, 15
Up to 300 and
6–40 (Pulsed
light)
2–40/10–600 0.5–40/0.3–
Up to 90 Up to 500 External
0.1 to 300 and
Automatic
(Pulsed light)
300/5–50
Pulse
Duration (ms)
10 × 30
Cold air
Spot Diameter
(mm) Cooling
continuous
10 × 20, 20 × 25
40 × 16
46 × 18, 46 × 10
46 × 18; 46 × 10
10 × 48
33 × 15
12
None
DCD and Cold
air
None
None
None
Laser Treatment of Leg Telangiectasia
339
Chapter
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13
Treatment of Leg Telangiectasias with Laser and High-Intensity Pulsed Light
Table 13.1 Lasers and light sources for leg veins—cont’d
Product
Supplier
Fotana Dualis Nd:YAG 1064 Up to 600 5–200 2–10 None
Iridex Apex-800 Diode 800 5–60 5–100 7, 9, 11 Cooling
LightAge Epicare Alexandrite 755 25–40 3–300 7, 9, 12, 15 None
Lumenis Quantum DL Nd:YAG 1064 90–150 5–38 6
Med-Surge Quantel Viridis Diode 532 Up to 110 15–150
OpusMed F1 Diode 800 10–40 15–40 5,7 None
Palomar MediLux Pulsed light 470–1400 Up to 45 10–100
Quantel Athos Nd:YAG 1064 Up to 80 3.5 4 None
Sciton Profile Nd:YAG 1064 4–400 0.1–200
Name Device Type
XP
DioLite
VariLite KTP/Diode 532/940 250/850 5–100 0.7, 1, 2
Lyra i Nd:YAG 1064 5–900 20–100 1–5 Cont.
Aura i KTP 532 1–240 1–50 1–5 Cont.
Gemini KTP 532 Up to 100 1–100 1–5 Cont.
Quantum SR Pulsed light 560–1200 15–45 6–26
Vasculite Elite Pulsed light 515–1200 3–90 1–75
LightSheer Diode 800 10–100 5–400
Lumenis One Pulsed light 515–1200 10–40 3–100
ProliteII Pulsed light 550–900 10–50 N/A
EsteLux Pulsed light 470–1400 Up to 40 10–100
SLP1000 Diode 810 Up to 575 50–1000 DC
StarLux Pulsed light/Nd:YAG 500–670,
BBL Pulsed light 400–1400 Up to 30 Up to 200
BBL/s N/A 410–1400 Up to 30 Up to 500
Profile HMV Nd:YAG/Pulsed light 1064/410–
KTP 532 250 5–100 0.5, 0.7, 1.0
Nd:YAG 1064 Up to 990 10–100 1–5 Cont.
Nd:YAG 1064 70–150 2–48 6 Cooled
Nd:YAG 1064 10–225 2–20
Diode 800 10–100 5–400
Wavelength
(nm) Energy (J)
Up to 60/Up
870–1400/
1064
1400
to 700
Up to 400 0.1–200/1–15
Pulse
Duration (ms)
0.5–500 1.5, 3, 6, 9
Spot Diameter
(mm) Cooling
Adjustable
Adjustable
Adjustable
Adjustable & 10
34 × 8
35 × 8
9 × 9
15 × 35, 8 ×
2 × 4, 6, 9
9 × 9
10 × 20, 20 × 25
12 × 12+
12 × 12
30 × 30
15 × 45, 15 × 15
15 × 45, 15 × 15
30 × 30, 15
15
× 45
handpiece
Cooling
handpiece
Cooling
handpiece
Cooling
handpiece
Cooling
handpiece
Cooled
sapphire crystal
sapphire crystal
Cooled
sapphire crystal
Cooled
sapphire crystal
Cooled
sapphire crystal
None
None
None
Contact
sapphire
Contact
sapphire
Contact
sapphire
Contact
sapphire
340
∆T (C)
∆T (C)
Table 13.1 Lasers and light sources for leg veins—cont’d
https://t.me/med1917
Product
Supplier
Syneron eLight SR Optical energy/RF 580–980 Up to 45/Up
WaveLight Mydon Nd:YAG 1064 10–450 0.5–90 1.5, 3, 5 Contact or cold
Modified from: Goldman MP: Cosmetic and Cutaneous Laser Surgery, Elsevier, 2006, Philadelphia and THE Aesthetic Guide Primary Care Edition Autumn 2008 (www.miinews.com).
Name Device Type
eLight SRA Optical energy/RF 470–980 Up to 45/Up
eLaser LV Diode/RF 900 Up to 140/Up
eLaser LVA Diode/RF 900 Up to 350/10
Polaris Vascular Diode/RF 900 Up to 50/Up
Galaxy Diode 580–980 Up to 140/Up
Arion Alexandrite 755 5–40 1–50 6, 8, 10, 12, 14 Cold air
Wavelength
(nm) Energy (J)
to 25
to 25
to 100
to 100
to 100 RF
to 100 RF
Pulse
Duration (ms)
N/A
N/A
N/A
N/A
Up to 200 1.5, 3, 5, 7, 10
Spot Diameter
(mm) Cooling
12 × 25
12 × 25
8 × 5
8 × 2
air
Laser Treatment of Leg Telangiectasia
Table 13.2 Thermal relaxation times of blood vessels
Diameter of vessel (mm) Thermal Relaxation Time (sec)
0.1 0.01
0.2 0.04
0.4 0.16
0.8 0.6
2.0 4.0
Presented by R.A. Anderson at the Annual Meeting of the North American Society
of Phlebology, Washington, DC, November, 1996.
Figure 13.4 Hypopigmented scars with skin textural changes 5 years after
treatment of leg telangiectasia with the CO2 laser.
Average temperature increase across a 0.2-mm
800
700
600
500
400
300
200
100
0
400 960
12
10
8
6
4
2
0
400 960
Figure 13.5 Average temperature increase across a cutaneous vessel as a
function of wavelength for two cases: a shallow capillary vessel (similar to
those found in a port-wine vascular malformation), and a deeper (2 mm)
and larger (1 mm) vessel typical of a leg venule. The calculated curves are
generated assuming that the main light-absorbing chromophore in the
blood is either oxygenated or deoxygenated hemoglobin. The calculation is
carried out for a 10-J/cm
by heat conductivity. Note the dramatic shift in the optimal wavelength as a
function of vessel depth and diameter. Also note the difference between
oxygenated and deoxygenated hemoglobin.
Energy Systems Corporation, Inc, Newton, Mass.; from Goldman MP, Fitzpatrick RE:
Cutaneous laser surgery, St Louis, 1994, Mosby.)
deep, 0.05-mm diameter vessel vs wavelength
Oxy
DeOxy
480 560 600 640 680 720 760 800 840 880 920
440 520 1000
Wavelength (nm)
Average temperature increase across a 2-mm
deep, 1-mm diameter vessel vs wavelength
Oxy
DeOxy
440 520 1000
480 560 600 640 680 720 760 800 840 880 920
Wavelength (nm)
2
fluence and does not take into account cooling
(Courtesy Shimon Eckhouse, PhD,
depressed scars. In a report of 38 patients treated by Apfelberg
et al,18 49% had either poor or no results from treatment, and
only 16% had excellent or good results. In addition, almost
half of the patients had hemosiderin bruising. In another
series, Dixon et al24 noted significant improvement in only
49% of patients. They speculated that after initial improvement, incomplete thrombosis, recanalization, or new vein
formation produced reappearance of the vessels after 6 to
12 months.
In an effort to enhance therapeutic success with leg vein
sclerotherapy, the argon laser has been used to interrupt the
telangiectasia every 2 to 3 cm before injection of a sclerosing
agent.25 Eleven of 16 patients completed treatment. Two
patients developed punctate depigmented scars, and three
341
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Treatment of Leg Telangiectasias with Laser and High-Intensity Pulsed Light
342
Figure 13.6 Biopsy of a port-wine vascular malformation on the cheek
of a 40-year-old man immediately after argon laser treatment at 15 J/cm2,
1-mm spot diameter, which produced clinical epidermal whitening. Note
coagulation of ectatic vessels in the middle and deep dermis with
smudging of perivascular collagen. The overlying epidermis shows marked
thermal effects with streaming of the epidermal cells and coagulation
necrosis of the superficial papillary dermis. (Hematoxylin–eosin, ×200.)
(From Goldman MP, Fitzpatrick RE: Cutaneous laser surgery, St Louis, 1994, Mosby.)
patients developed hyperpigmentation. However, 93.7% of
patients were reported to have ‘satisfactory’ results.
Cooling the skin simultaneously with argon or tunable dye
(577 nm, 585 nm) laser treatment has been demonstrated to
produce improvement in 67% of leg telangiectasia 1 mm in
diameter.26 This may be caused by temperature-related vasomotor changes in blood flow.
27
Overall, argon laser therapy appears to be extremely technique dependent and not only relatively ineffective in treating
leg telangiectasia but also associated with an unacceptably
high risk of adverse sequelae.
Contact probe delivery
Directing the laser energy to the target vessel produces another
method for more selective delivery of nonspecific laser energy.
28
Keller
reported on the use of a microcontact argon laser
probe to treat ‘spray telangiectasias’ of the leg. Fifteen patients
were treated with this device using an argon laser energy of 1
to 2 W with a pulse duration of 0.1 second. This treatment
was performed as ‘spot welding’ along the course of the blood
vessel; 100% effectiveness and no notable complications were
reported. We have not achieved the same success rate as
29
Keller,
and further reports of this novel form of therapy have
not occurred. Thus, at present, argon laser therapy apparently
is a satisfactory method for treating selected facial telangiectasia but is much less effective in treating leg telangiectasia.
Box 13.1 summarizes the disadvantages of the argon laser
treatment.
Krypton triphosphate and frequency-doubled
Nd:YAG (532 nm)
Modulated krypton triphosphate (KTP) lasers have been
reported to be effective at removing leg telangiectasia, using
pulse durations between 1 and 50 ms (see Table 13.1). The
532-nm wavelength is one of the hemoglobin absorption
Box 13.1
Disadvantages of argon laser treatment
• Partially selective vascular damage
• Hypopigmentation and hyperpigmentation after treatment
• Atrophic and hypertrophic scarring
• Painful procedure
peaks (see Fig. 13.5). Although this wavelength does not penetrate deeply into the dermis (about 0.75 mm), relatively specific damage (compared with the argon laser) can occur in the
vascular target by selection of an optimal pulse duration,
enlargement of the spot size, and addition of epidermal
cooling.
Effective results have been achieved by tracing vessels with
a 1-mm projected spot. Typically, the laser is moved between
adjacent 1-mm spots with vessels traced at 5 to 10 mm/
second. Immediately after laser exposure, the epidermis is
blanched. Lengthening of the pulse duration to match the
diameter of the vessel is attempted to optimize treatment (see
Table 13.2). With this method, West and Alster
method to treat 12 patients with leg telangiectasia. They used
a 10-ms pulse at 15 J/cm2 with a 1-mm handpiece at a repetition rate of two pulses per second. The average improvement
was 25% to 50% (Fig. 13.7).
Quintana et al31 treated 19 leg veins that were less than
1.5 mm in diameter with the Laserscope KTP Dermastat
(Laserscope, San Jose, Calif.). They used a 2-mm diameter
handpiece at a fluence of 13 to 15 J/cm2 given at a rate of 10
to 15 milliseconds. Patients were treated at 4- to 6-week intervals on four separate visits, with results examined 6 months
after the last visit. Of the 28% of patients evaluated, 15%
percent achieved 100% clearance, 40% had 75% clearance,
35% had 50% clearance, and 10% had 25% clearance. No
scarring was reported, and 25% had transient hyperpigmentation. Therefore, this laser is somewhat effective but requires
multiple treatments.
We and others have found the long-pulse 532-nm laser
(frequency-doubled Nd:YAG) (VersaPulse, Lumenis, Palo
Alto, Calif.) to be effective in treating leg veins less than 1 mm
in diameter that are not directly connected to a feeding reticular vein.
32
When used with a 4°C chilled tip, a fluence of 12
to 15 J/cm2 is delivered as a train of pulses in a 3- to 4-mm
diameter spot size in order to trace the vessel until spasm or
thrombosis occurs. Some overlying epidermal scabbing is
noted with hypopigmentation not uncommonly occurring in
dark-skinned patients. Individual physicians report considerable variation in results. Usually, more than one treatment is
necessary for maximum vessel improvement, with only rare
reports of 100% resolution of the leg vein (Fig. 13.8). A
summary of important clinical evaluations of this technology
follows.
McMeekin
33
treated 18 sites of leg veins ranging from 0.5 to
1.1 mm in diameter in 10 patients, using a VersaPulse with a
3-mm diameter spot, 5.5°C cooling, at 12 and 16 J/cm2 with
one to three passes over each vessel at 2 Hz. He followed the
patients for 1 year after a single treatment. Overall, 44% of
patients had a greater than 50% clearance from a single treatment. Six percent of patients had complete clearance, 88%
had partial clearance, and 6% had no change. Of the partial
clearance group of patients, more cleared at 16 J/cm2 than at
12 J/cm2. At 16 J/cm2, 37% cleared 25% to 50%, 25% cleared
50% to 75%, and 37% cleared 75% to 100%. Ninety-four
percent developed hyperpigmentation that took up to 6
months to resolve. One patient developed blisters and hypopigmented atrophic scars.
Bernstein et al34 achieved similar efficacy in a study of 15
women with leg telangiectasia less than 0.75 mm in diameter
30
utilized this
A
https://t.me/med1917
Figure 13.7 A, before treatment. B, 3 months after treatment there is hyperpigmentation in the telangiectasia treated with the flashlamp-pumped pulsed
dye laser at 15 J/cm2. Of note, the side treated with the KTP (532-nm) laser at 15 J/cm2 and a 10-ms pulse showed no change. (From West TB, Alster TS: Dermatol
Surg 24:221, 1998.)
B
Rights were not granted to include this figure
in electronic media.
Please refer to the printed publication.
Laser Treatment of Leg Telangiectasia
A
Figure 13.8 A, Before treatment. B, After one treatment with the VersaPulse at 15 J/cm2 with a 10-ms pulse through a 3-mm diameter spot with the skin
chilled through a 4°C quartz tip. Notice the residual hypopigmentation at the site of the superiormost reticular vein seen in A.
Goldman MP, Weiss RA, Bergan JJ, editors: Varicose veins and telangiectasia: diagnosis and treatment, St Louis, 1999, Quality Medical Publishers.)
at 27 sites, using a 10-ms pulse duration 532-nm laser at 16 J/
cm2 with a 3-mm diameter spot size at 4 Hz and using a chill
tip with three passes over each vein twice, 6 weeks apart.
Computer-based image analysis demonstrated more than
75% clearing. Ten of the 27 sites (37%) cleared completely
after one treatment. Two of 15 patients (13.3%) reported
blistering with minimal hyperpigmentation noted 6 weeks
after treatment.
A longer pulse duration of 20 to 50 ms, accompanied by
an increase in spot size to 5 mm with a higher total fluence
of 20 J/cm2 became available, with improvement in efficacy
and a reduction in pigment changes. Narukar
35
evaluated
patients with leg veins less than 1.5 mm in diameter, treated
with 2- to 50-ms pulses up to 40 J/cm2 with a 3- to 6-mm
diameter spot size and a 4°C chill tip. He treated patients
at 6- to 8-week intervals two to three times. A 45% clearance
was found. Interestingly, a 68% clearance was found in
patients whose previous sclerotherapy showed a good
response. A 32% clearance occurred in patients whose vessels
responded poorly to sclerotherapy. At 2-month follow-up, 2%
of patients had TM, 4% had hyperpigmentation, and 2% had
hypopigmentation.
Massey and Katz
36
bettered Narukar’s results using a spot
size of 5 mm, a pulse width of 50 ms, fluences of 18 to 20 J/
cm2, and a 1.5-Hz repetition rate. A 75%–100% reduction was
achieved in 68% of vessels less than 1 mm and in 44% of
vessels 1 to 2 mm after two treatments. These results were
obtained with multiple passes to achieve vessel clearance.
Hypopigmentation and mild hyperpigmentation, lasting 6 to
B
(Courtesy Robert Adrian, M.D.; from
8 weeks, were noted in 20% of patients. No scarring was
observed. Krause37 claimed similar results using a 2-mm diameter spot size. A 2-mm diameter spot size is claimed to produce
a narrower band of either hypo- or hyperpigmentation.
A 532-nm KTP laser was also evaluated in a multipulse
mode emission (three stacked pulses of 100 ms, 30 ms,
30 ms, and a delay between pulses of 250 ms), a fluence of
60 J/cm2, and a 0.75-mm collimated spot without cooling
(Virdis Derma, Quantel Medical, France).
38
On average, with
one treatment, 53% of leg veins 0.5 to 1 mm in diameter were
cleared, 78% with two treatments, 85% after three treatments,
and 93% 6 weeks after a fourth treatment, all 6 weeks apart.
It is suggested that the multipulse mode increases intravascular heating in a manner similar to the multipulse mode of IPL
(see below) while allowing cooling of the epidermis. Hypopigmentation lasting ‘a few months’ was observed in 18% of
patients and TM occurred in 7% of patients.
In a study by Woo et al,39 a 532-nm Nd:YAG at 20 J/cm2
delivered as a 50-ms pulse through a contact cooling and
5-mm diameter spot was compared with a 595-nm PDL at
25 J/cm2 with a pulse duration of 40 ms, cryogen spray
cooling, and a 3- × 10-mm elliptical spot. After one treatment
with the 532-nm Nd:YAG there was 50% to 75% improvement in 2 of 10 patients and more than 75% improvement
in 3 of 10 patients. There was better improvement in the
PDL-treated patients, with 6 of 10 having 50% to 75%
improvement.
In another study, a 532-nm diode laser with a 1-mm diameter spot at fluences of 2 to 32 J/cm2 was compared with a
343
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